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Navvabi A, Homaei A, Pletschke BI, Navvabi N, Kim SK. Marine Cellulases and their Biotechnological Significance from Industrial Perspectives. Curr Pharm Des 2022; 28:3325-3336. [PMID: 35388747 DOI: 10.2174/1381612828666220406125132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 11/03/2021] [Accepted: 01/18/2022] [Indexed: 01/28/2023]
Abstract
Marine microorganisms represent virtually unlimited sources of novel biological compounds and can survive extreme conditions. Cellulases, a group of enzymes that are able to degrade cellulosic materials, are in high demand in various industrial and biotechnological applications, such as in the medical and pharmaceutical industries, food, fuel, agriculture, and single-cell protein, and as probiotics in aquaculture. The cellulosic biopolymer is a renewable resource and is a linearly arranged polysaccharide of glucose, with repeating units of disaccharide connected via β-1,4-glycosidic bonds, which are broken down by cellulase. A great deal of biodiversity resides in the ocean, and marine systems produce a wide range of distinct, new bioactive compounds that remain available but dormant for many years. The marine environment is filled with biomass from known and unknown vertebrates and invertebrate microorganisms, with much potential for use in medicine and biotechnology. Hence, complex polysaccharides derived from marine sources are a rich resource of microorganisms equipped with enzymes for polysaccharides degradation. Marine cellulases' extracts from the isolates are tested for their functional role in degrading seaweed and modifying wastes to low molecular fragments. They purify and renew environments by eliminating possible feedstocks of pollution. This review aims to examine the various types of marine cellulase producers and assess the ability of these microorganisms to produce these enzymes and their subsequent biotechnological applications.
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Affiliation(s)
- Azita Navvabi
- Department of Marine Biology, Faculty of Marine Science and Technology, University of Hormozgan, Bandar Abbas, Iran
| | - Ahmad Homaei
- Department of Marine Biology, Faculty of Marine Science and Technology, University of Hormozgan, Bandar Abbas, Iran
| | - Brett I Pletschke
- Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, 6140, South Africa
| | - Nazila Navvabi
- Department of Tumor Biology and Immunotherapy, Molecular Biology of Cancer, Institute of Experimental Medicine, Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Prague, Czech Republic
| | - Se-Kwon Kim
- Department of Marine Sciences and Convergent Technology, Hanyang University, Ansan, Seoul 426-791, Republic of Korea
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2
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Vesala R, Rikkinen A, Pellikka P, Rikkinen J, Arppe L. You eat what you find – Local patterns in vegetation structure control diets of African fungus‐growing termites. Ecol Evol 2022; 12:e8566. [PMID: 35342606 PMCID: PMC8928904 DOI: 10.1002/ece3.8566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 11/26/2021] [Accepted: 12/22/2021] [Indexed: 11/12/2022] Open
Abstract
Fungus‐growing termites and their symbiotic Termitomyces fungi are critically important carbon and nutrient recyclers in arid and semiarid environments of sub‐Saharan Africa. A major proportion of plant litter produced in these ecosystems is decomposed within nest chambers of termite mounds, where temperature and humidity are kept optimal for the fungal symbionts. While fungus‐growing termites are generally believed to exploit a wide range of different plant substrates, the actual diets of most species remain elusive. We studied dietary niches of two Macrotermes species across the semiarid savanna landscape in the Tsavo Ecosystem, southern Kenya, based on carbon (C) and nitrogen (N) stable isotopes in Termitomyces fungus combs. We applied Bayesian mixing models to determine the proportion of grass and woody plant matter in the combs, these being the two major food sources available for Macrotermes species in the region. Our results showed that both termite species, and colonies cultivating different Termitomyces fungi, occupied broad and largely overlapping isotopic niches, indicating no dietary specialization. Including laser scanning derived vegetation cover estimates to the dietary mixing model revealed that the proportion of woody plant matter in fungus combs increased with increasing woody plant cover in the nest surroundings. Nitrogen content of fungus combs was positively correlated with woody plant cover around the mounds and negatively correlated with the proportion of grass matter in the comb. Considering the high N demand of large Macrotermes colonies, woody plant matter seems to thus represent a more profitable food source than grass. As grass is also utilized by grazing mammals, and the availability of grass matter typically fluctuates over the year, mixed woodland‐grasslands and bushlands seem to represent more favorable habitats for large Macrotermes colonies than open grasslands.
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Affiliation(s)
- Risto Vesala
- Finnish Museum of Natural History University of Helsinki Helsinki Finland
| | - Aleksi Rikkinen
- Department of Geosciences and Geography University of Helsinki Helsinki Finland
| | - Petri Pellikka
- Department of Geosciences and Geography University of Helsinki Helsinki Finland
- State Key Laboratory for Information Engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan China
| | - Jouko Rikkinen
- Finnish Museum of Natural History University of Helsinki Helsinki Finland
| | - Laura Arppe
- Finnish Museum of Natural History University of Helsinki Helsinki Finland
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3
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Chen Y, Zhao C, Zhang D, Zhang S, Zeng W, Li Z. The effect of amending soils with biochar on the microhabitat preferences of Coptotermes formosanus (Blattodea: Rhinotermitidae). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 232:113240. [PMID: 35091298 DOI: 10.1016/j.ecoenv.2022.113240] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/05/2022] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
Biochar has attracted worldwide attention owing to its potential for mitigating greenhouse gas emissions, improving soil properties, increasing plant growth and so on. While, the assessment of a substantial amount of security is required to determine before biochar is more extensively applied. Our goal was to evaluate the security of biochar by determining the effect of biochar on the preference of soil arthropods for microhabitats. In this study, we examined the effect of varying amounts of biochar on the preference of the Formosan subterranean termite (Coptotermes formosanus) to microhabitats. In addition, we analyzed key soil characteristics to explore their relevance to the termite preferences. Our results found that when compared with 0% (control soil), there was no preference when 2.5% and 5% of biochar were applied. The application of >5% biochar repelled the termites, which then left these soils. Their fresh weight and rates of survival also decreased. The soil pH increased, but the humidity decreased when >5% of biochar was applied. Soil bacteria composition when biochar was amended at 20% also differed from 0% and 2.5% applications. The relative abundance of Cellvibrio and Flavisolibacter in 20% were significantly higher than 0% and 2.5%, while the relative abundance of Burkholderia, Candidatus_Solibacter, Dyella, Edaphobacter, Fulvimonas and Occallatibacter were significantly lower than them. And the functional results predicted by Bugbase suggested that biochar application can cause an increase in the soil potentially pathogen phenotype. In conclusion, our research indicated that biochar can affect the preference of termites for microhabitats and changes in the characteristics of soil might cause changes in these preferences. In addition, our results suggest that soil that has been amended with >10% biochar has the potential to control termites.
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Affiliation(s)
- Yong Chen
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Sciences, Guangzhou, China
| | - Chongwen Zhao
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Sciences, Guangzhou, China; School of Ecology, Sun Yat-sen University, Guangzhou, China
| | - Dandan Zhang
- School of Ecology, Sun Yat-sen University, Guangzhou, China
| | - Shijun Zhang
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Sciences, Guangzhou, China
| | - Wenhui Zeng
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Sciences, Guangzhou, China.
| | - Zhiqiang Li
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Sciences, Guangzhou, China.
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4
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Zhang MX, Li J, Zhang XN, Li HH, Xu XF. Comparative transcriptome profiling of Termitomyces sp. between monocultures in vitro and link-stipe of fungus-combs in situ. Lett Appl Microbiol 2021; 74:429-443. [PMID: 34890484 DOI: 10.1111/lam.13628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 11/18/2021] [Accepted: 12/02/2021] [Indexed: 11/29/2022]
Abstract
The edible mushroom Termitomyces is an agaric-type basidiomycete fungus that has a symbiotic relationship with fungus-growing termites. An understanding of the detailed development mechanisms underlying the adaptive responses of Termitomyces sp. to their growing environment is lacking. Here, we compared the transcriptome sequences of different Termitomyces sp. samples and link-stipe grown on fungus combs in situ and monocultured in vitro. The assembled reads generated 8052 unigenes. The expression profiles were highly different for 2556 differentially expressed genes (DEGs) of the treated samples, where the expression of 1312 and 1244 DEGs was upregulated in the Mycelium and link-stipe groups respectively. Functional classification of the DEGs based on both Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed an expected shift in fungal gene expression, where stress response genes whose expression was upregulated in link-stipe may adaptively be involved in cell wall hydrolysis and fusion, pathogenesis, oxidation-reduction, transporter efflux, transposon efflux and self/non-self-recognition. Urease has implications in the expression of genes involved in the nitrogen metabolism pathway, and its expression could be controlled by low-level nitrogen fixation of fungus combs. In addition, the expression patterns of eleven select genes on the basis of qRT-PCR were consistent with their changes in transcript abundance, as revealed by RNA sequencing. Taken together, these findings may be useful for enriching the knowledge concerning the Termitomyces adaptive response to in situ fungus combs compared with the response of monocultures in vitro.
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Affiliation(s)
- M-X Zhang
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - J Li
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - X-N Zhang
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - H-H Li
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - X-F Xu
- College of Food Science, South China Agricultural University, Guangzhou, China
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5
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Ahmad F, Yang GY, Liang SY, Zhou QH, Gaal HA, Mo JC. Multipartite symbioses in fungus-growing termites (Blattodea: Termitidae, Macrotermitinae) for the degradation of lignocellulose. INSECT SCIENCE 2021; 28:1512-1529. [PMID: 33236502 DOI: 10.1111/1744-7917.12890] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 10/06/2020] [Accepted: 10/19/2020] [Indexed: 06/11/2023]
Abstract
Fungus-growing termites are among the most successful herbivorous animals and improve crop productivity and soil fertility. A range of symbiotic organisms can be found inside their nests. However, interactions of termites with these symbionts are poorly understood. This review provides detailed information on the role of multipartite symbioses (between termitophiles, termites, fungi, and bacteria) in fungus-growing termites for lignocellulose degradation. The specific functions of each component in the symbiotic system are also discussed. Based on previous studies, we argue that the enzymatic contribution from the host, fungus, and bacteria greatly facilitates the decomposition of complex polysaccharide plant materials. The host-termitophile interaction protects the termite nest from natural enemies and maintains the stability of the microenvironment inside the colony.
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Affiliation(s)
- Farhan Ahmad
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, College of Agricultural and Biotechnology, Zhejiang University, Hangzhou, China
- Entomology Section, Central Cotton Research Institute, Sakrand, Shaheed Benazirabad, Sindh, Pakistan
| | - Gui-Ying Yang
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, College of Agricultural and Biotechnology, Zhejiang University, Hangzhou, China
| | - Shi-You Liang
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, College of Agricultural and Biotechnology, Zhejiang University, Hangzhou, China
| | - Qi-Huan Zhou
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, College of Agricultural and Biotechnology, Zhejiang University, Hangzhou, China
| | - Hassan Ahmed Gaal
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, College of Agricultural and Biotechnology, Zhejiang University, Hangzhou, China
- Department of Entomology, Faculty of Veterinary and Animal Husbandry, Somali National University, Mogadishu, Somalia
| | - Jian-Chu Mo
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, College of Agricultural and Biotechnology, Zhejiang University, Hangzhou, China
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6
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Bayen S, Roy S, Chakraborti D, Mukhopadhyay A, Hazarika LK, Pramanik P, Borchetia S, Mukherjee S. Mutualistic relation of termites with associated microbes for their harmonious survival. Symbiosis 2021. [DOI: 10.1007/s13199-021-00809-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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7
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Wildermuth B, Oldeland J, Juergens N. A beneficial relationship: associated trees facilitate termite colonies (
Macrotermes michaelseni
) in Namibia. Ecosphere 2021. [DOI: 10.1002/ecs2.3671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- B. Wildermuth
- Institute of Plant Sciences and Microbiology University of Hamburg Hamburg Germany
| | - J. Oldeland
- Institute of Plant Sciences and Microbiology University of Hamburg Hamburg Germany
| | - N. Juergens
- Institute of Plant Sciences and Microbiology University of Hamburg Hamburg Germany
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8
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High diversity and low host-specificity of Termitomyces symbionts cultivated by Microtermes spp. indicate frequent symbiont exchange. FUNGAL ECOL 2020. [DOI: 10.1016/j.funeco.2020.100917] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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9
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Abstract
The evolution of a mutualism requires reciprocal interactions whereby one species provides a service that the other species cannot perform or performs less efficiently. Services exchanged in insect-fungus mutualisms include nutrition, protection, and dispersal. In ectosymbioses, which are the focus of this review, fungi can be consumed by insects or can degrade plant polymers or defensive compounds, thereby making a substrate available to insects. They can also protect against environmental factors and produce compounds antagonistic to microbial competitors. Insects disperse fungi and can also provide fungal growth substrates and protection. Insect-fungus mutualisms can transition from facultative to obligate, whereby each partner is no longer viable on its own. Obligate dependency has (a) resulted in the evolution of morphological adaptations in insects and fungi, (b) driven the evolution of social behaviors in some groups of insects, and (c) led to the loss of sexuality in some fungal mutualists.
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Affiliation(s)
- Peter H W Biedermann
- Research Group Insect-Fungus Symbiosis, Department of Animal Ecology and Tropical Biology, University of Würzburg, 97074 Würzburg, Germany;
| | - Fernando E Vega
- Sustainable Perennial Crops Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, Maryland 20705, USA;
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10
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Caste-specific nutritional differences define carbon and nitrogen fluxes within symbiotic food webs in African termite mounds. Sci Rep 2019; 9:16698. [PMID: 31723187 PMCID: PMC6853943 DOI: 10.1038/s41598-019-53153-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 10/28/2019] [Indexed: 11/30/2022] Open
Abstract
Fungus-growing termites of the genus Macrotermes cultivate symbiotic fungi (Termitomyces) in their underground nest chambers to degrade plant matter collected from the environment. Although the general mechanism of food processing is relatively well-known, it has remained unclear whether the termites get their nutrition primarily from the fungal mycelium or from plant tissues partly decomposed by the fungus. To elucidate the flows of carbon and nitrogen in the complicated food-chains within the nests of fungus-growing termites, we determined the stable isotope signatures of different materials sampled from four Macrotermes colonies in southern Kenya. Stable isotopes of carbon revealed that the termite queen and the young larvae are largely sustained by the fungal mycelium. Conversely, all adult workers and soldiers seem to feed predominantly on plant and/or fungus comb material, demonstrating that the fungal symbiont plays a different nutritional role for different termite castes. Nitrogen stable isotopes indicated additional differences between castes and revealed intriguing patterns in colony nitrogen cycling. Nitrogen is effectively recycled within the colonies, but also a presently unspecified nitrogen source, most likely symbiotic nitrogen-fixing bacteria, seems to contribute to nitrogen supply. Our results indicate that the gut microbiota of the termite queen might be largely responsible for the proposed nitrogen fixation.
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11
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12
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Zoberi MH, Grace JK. Fungi Associated with the Subterranean TermiteReticulitermes Flavipesin Ontario. Mycologia 2018. [DOI: 10.1080/00275514.1990.12025883] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Mujeeb H. Zoberi
- Faculty of Forestry, University of Toronto, Toronto, Ontario M5S 1A1, Canada
| | - J. Kenneth Grace
- Faculty of Forestry, University of Toronto, Toronto, Ontario M5S 1A1, Canada
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13
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Zhou N, Sun YT, Chen DW, Du W, Yang H, Liu SJ. Harnessing microfluidic streak plate technique to investigate the gut microbiome of Reticulitermes chinensis. Microbiologyopen 2018; 8:e00654. [PMID: 29897677 PMCID: PMC6436436 DOI: 10.1002/mbo3.654] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Revised: 04/04/2018] [Accepted: 04/23/2018] [Indexed: 02/01/2023] Open
Abstract
The termite gut microbiome is a model system to investigate microbial interactions and their associations with host. For decades, extensive research with molecular tools and conventional cultivation method has been carried out to define the microbial diversity in termite gut. Yet, many bacterial groups of the termite gut microbiome have not been successfully cultivated in laboratory. In this study, we adapted the recently developed microfluidic streak plate (MSP) technique for cultivation of termite gut microbial communities at both aerobic and anaerobic conditions. We found that 99 operational taxonomic units (OTUs) were cultivable by MSP approach and 18 OTUs were documented first time for termite gut microbiota. Further analysis of the bacterial diversities derived by culture‐dependent MSP approach and culture‐independent 16S rRNA gene typing revealed that both methods have bias in recovery of gut microbiota. In total 396 strains were isolated with MSP technique, and potential new taxa at species and/or genus levels were obtained that were phylogenetically related to Burkholderia, Micrococcus, and Dysgonomonas. Results from this study indicate that MSP technique is applicable for cultivating previously unknown and new microbial groups of termite gut microbiota.
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Affiliation(s)
- Nan Zhou
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center at, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yu-Tong Sun
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center at, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Science, at Hebei University, Baoding, China
| | - Dong-Wei Chen
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center at, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Wenbin Du
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center at, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Hong Yang
- School of Life Sciences at Central, China Normal University, Wuhan, China
| | - Shuang-Jiang Liu
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center at, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China.,College of Life Science, at Hebei University, Baoding, China
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15
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Yoshioka Y, Tanabe T, Iguchi A. The presence of genes encoding enzymes that digest carbohydrates in coral genomes and analysis of their activities. PeerJ 2017; 5:e4087. [PMID: 29201566 PMCID: PMC5710165 DOI: 10.7717/peerj.4087] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 11/02/2017] [Indexed: 11/20/2022] Open
Abstract
Numerous enzymes that digest carbohydrates, such as cellulases and chitinases, are present in various organisms (e.g., termites, nematodes, and so on). Recently, the presence of cellulases and chitinases has been reported in marine organisms such as urchin and bivalves, and their several roles in marine ecosystems have been proposed. In this study, we reported the presence of genes predicted to encode proteins similar to cellulases and chitinases in the genome of the coral Acropora digitifera, their gene expression patterns at various life stages, and cellulose- and chitin-degrading enzyme activities in several coral species (A. digitifera, Galaxea fascicularis, Goniastrea aspera, Montipora digitata, Pavona divaricata, Pocillopora damicornis, and Porites australiensis). Our gene expression analysis demonstrated the expressions of these cellulase- and chitinase-like genes during various life stages, including unfertilized eggs, fertilized eggs, zygotes, planula larvae, primary polyps and adults of A. digitifera. Agar plate assays confirmed cellulase and chitinase activities in the tissues extracted from adult branches of several coral species. These results suggested that corals are able to utilize cellulases and chitinases in their life histories.
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Affiliation(s)
- Yuki Yoshioka
- Department of Bioresources Engineering, National Institute of Technology, Okinawa College, Nago-City, Okinawa, Japan
| | - Toshiaki Tanabe
- Department of Bioresources Engineering, National Institute of Technology, Okinawa College, Nago-City, Okinawa, Japan
| | - Akira Iguchi
- Department of Bioresources Engineering, National Institute of Technology, Okinawa College, Nago-City, Okinawa, Japan
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Vesala R, Niskanen T, Liimatainen K, Boga H, Pellikka P, Rikkinen J. Diversity of fungus-growing termites (Macrotermes) and their fungal symbionts (Termitomyces) in the semiarid Tsavo Ecosystem, Kenya. Biotropica 2017. [DOI: 10.1111/btp.12422] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Risto Vesala
- Department of Biosciences; University of Helsinki; P.O. Box 65 FIN-00014 Helsinki Finland
| | - Tuula Niskanen
- Department of Biosciences; University of Helsinki; P.O. Box 65 FIN-00014 Helsinki Finland
- Royal Botanic Gardens; Kew Richmond Surrey TW9 3AB UK
| | - Kare Liimatainen
- Department of Biosciences; University of Helsinki; P.O. Box 65 FIN-00014 Helsinki Finland
| | - Hamadi Boga
- Taita Taveta University; P.O. Box 635-80300 Voi Kenya
| | - Petri Pellikka
- Department of Geosciences and Geography; University of Helsinki; P.O. Box 68 FIN-00014 Helsinki Finland
| | - Jouko Rikkinen
- Department of Biosciences; University of Helsinki; P.O. Box 65 FIN-00014 Helsinki Finland
- Finnish Museum of Natural History; Botany Unit; University of Helsinki; P.O. Box 7 Helsinki FIN-00014 Finland
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17
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Poulsen M. Towards an integrated understanding of the consequences of fungus domestication on the fungus-growing termite gut microbiota. Environ Microbiol 2015; 17:2562-72. [PMID: 25581852 DOI: 10.1111/1462-2920.12765] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Revised: 12/13/2014] [Accepted: 12/26/2014] [Indexed: 01/08/2023]
Abstract
Approximately 30 million years ago (MYA), the subfamily of higher termites Macrotermitinae domesticated a fungus, Termitomyces, as the main plant decomposer and food source for the termite host. The origin of fungiculture shifted the composition of the termite gut microbiota, and some of the functional implications of this shift have recently been established. I review reports on the composition of the Macrotermitinae gut microbiota, evidence for a subfamily core gut microbiota, and the first insight into functional complementarity between fungal and gut symbionts. In addition, I argue that we need to explore the capacities of all members of the symbiotic communities, including better solidifying Termitomyces role(s) in order to understand putative complementary gut bacterial contributions. Approaches that integrate natural history and sequencing data to elucidate symbiont functions will be powerful, particularly if executed in comparative analyses across the well-established congruent termite-fungus phylogenies. This will allow for testing if gut communities have evolved in parallel with their hosts, with implications for our general understanding of the evolution of gut symbiont communities with hosts.
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Affiliation(s)
- Michael Poulsen
- Centre for Social Evolution, Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, Copenhagen Ø, DK-2100, Denmark
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18
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Rahman MM, Inoue A, Ojima T. Characterization of a GHF45 cellulase, AkEG21, from the common sea hare Aplysia kurodai. Front Chem 2014; 2:60. [PMID: 25147784 PMCID: PMC4123733 DOI: 10.3389/fchem.2014.00060] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 07/15/2014] [Indexed: 11/18/2022] Open
Abstract
The common sea hare Aplysia kurodai is known to be a good source for the enzymes degrading seaweed polysaccharides. Recently four cellulases, i.e., 95, 66, 45, and 21 kDa enzymes, were isolated from A. kurodai (Tsuji et al., 2013). The former three cellulases were regarded as glycosyl-hydrolase-family 9 (GHF9) enzymes, while the 21 kDa cellulase was suggested to be a GHF45 enzyme. The 21 kDa cellulase was significantly heat stable, and appeared to be advantageous in performing heterogeneous expression and protein-engineering study. In the present study, we determined some enzymatic properties of the 21 kDa cellulase and cloned its cDNA to provide the basis for the protein engineering study of this cellulase. The purified 21 kDa enzyme, termed AkEG21 in the present study, hydrolyzed carboxymethyl cellulose with an optimal pH and temperature at 4.5 and 40°C, respectively. AkEG21 was considerably heat-stable, i.e., it was not inactivated by the incubation at 55°C for 30 min. AkEG21 degraded phosphoric-acid-swollen cellulose producing cellotriose and cellobiose as major end products but hardly degraded oligosaccharides smaller than tetrasaccharide. This indicated that AkEG21 is an endolytic β-1,4-glucanase (EC 3.2.1.4). A cDNA of 1013 bp encoding AkEG21 was amplified by PCR and the amino-acid sequence of 197 residues was deduced. The sequence comprised the initiation Met, the putative signal peptide of 16 residues for secretion and the catalytic domain of 180 residues, which lined from the N-terminus in this order. The sequence of the catalytic domain showed 47–62% amino-acid identities to those of GHF45 cellulases reported in other mollusks. Both the catalytic residues and the N-glycosylation residues known in other GHF45 cellulases were conserved in AkEG21. Phylogenetic analysis for the amino-acid sequences suggested the close relation between AkEG21 and fungal GHF45 cellulases.
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Affiliation(s)
- Mohammad M Rahman
- Laboratory of Marine Biotechnology and Microbiology, Division of Applied Marine Life Science, Graduate School of Fisheries Sciences, Hokkaido University Hakodate, Japan ; Department of Fisheries Biology and Genetics, Bangladesh Agricultural University Mymensingh, Bangladesh
| | - Akira Inoue
- Laboratory of Marine Biotechnology and Microbiology, Division of Applied Marine Life Science, Graduate School of Fisheries Sciences, Hokkaido University Hakodate, Japan
| | - Takao Ojima
- Laboratory of Marine Biotechnology and Microbiology, Division of Applied Marine Life Science, Graduate School of Fisheries Sciences, Hokkaido University Hakodate, Japan
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Zhang M, Liu N, Qian C, Wang Q, Wang Q, Long Y, Huang Y, Zhou Z, Yan X. Phylogenetic and functional analysis of gut microbiota of a fungus-growing higher termite: Bacteroidetes from higher termites are a rich source of β-glucosidase genes. MICROBIAL ECOLOGY 2014; 68:416-425. [PMID: 24584416 DOI: 10.1007/s00248-014-0388-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Accepted: 02/04/2014] [Indexed: 06/03/2023]
Abstract
Fungus-growing termites, their symbiotic fungi, and microbiota inhibiting their intestinal tract comprise a highly efficient cellulose-hydrolyzing system; however, little is known about the role of gut microbiota in this system. Twelve fosmid clones with β-glucosidase activity were previously obtained by functionally screening a metagenomic library of a fungus-growing termite, Macrotermes annandalei. Ten contigs containing putative β-glucosidase genes (bgl1-10) were assembled by sequencing data of these fosmid clones. All these contigs were binned to Bacteroidetes, and all these β-glucosidase genes were phylogenetically closed to those from Bacteroides or Dysgonomonas. Six out of 10 β-glucosidase genes had predicted signal peptides, indicating a transmembrane capability of these enzymes to mediate cellulose hydrolysis within the gut of the termites. To confirm the activities of these β-glucosidase genes, three genes (bgl5, bgl7, and bgl9) were successfully expressed and purified. The optimal temperature and pH of these enzymes largely resembled the environment of the host's gut. The gut microbiota composition of the fungus-growing termite was also determined by 454 pyrosequencing, showing that Bacteroidetes was the most dominant phylum. The diversity and the enzyme properties of β-glucosidases revealed in this study suggested that Bacteroidetes as the major member in fungus-growing termites contributed to cello-oligomer degradation in cellulose-hydrolyzing process and represented a rich source for β-glucosidase genes.
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Affiliation(s)
- Meiling Zhang
- School of Life Sciences, East China Normal University, Shanghai, China
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Ni J, Wu Y, Yun C, Yu M, Shen Y. cDNA cloning and heterologous expression of an endo-β-1,4-glucanase from the fungus-growing termite Macrotermes barneyi. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2014; 86:151-164. [PMID: 24719302 DOI: 10.1002/arch.21158] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Major β-glucosidase (BG) and endo-β-1,4-glucanase (EG) activities were localized to the midgut of the fungus-growing termite Macrotermes barneyi. Previously, we obtained the endogenous BG gene (MbmgBG1) from the midgut of M. barneyi. Here, we report the cDNA cloning of another endogenous cellulase, the EG protein MbEG1. This cellulase was partially purified from crude extract of the midgut of worker termites using zymogram analysis. Based on the N-terminal amino acid sequence and using rapid amplification of cDNA ends (RACE), a full-length cDNA of 1,843 base pairs was obtained. This encoded 448 amino acids and the sequence was similar to that of the members of glycoside hydrolase family 9. The MbEG1 transcript was detected primarily in the midgut using quantitative real-time polymerase chain reaction (PCR). To confirm functional activity of MbEG1, heterologous expression was conducted in both Escherichia coli and Pichia pastoris expression systems. Results indicated that MbEG1 could be functionally expressed in P. pastoris. This study provides the information that may facilitate understanding of cellulolytic systems in fungus-growing termites.
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Affiliation(s)
- Jinfeng Ni
- State Key Laboratory of Microbial Technology, Shandong University, Shandong, China
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Nobre T, Koopmanschap B, Baars JJP, Sonnenberg ASM, Aanen DK. The scope for nuclear selection within Termitomyces fungi associated with fungus-growing termites is limited. BMC Evol Biol 2014; 14:121. [PMID: 24902958 PMCID: PMC4085734 DOI: 10.1186/1471-2148-14-121] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 05/29/2014] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND We investigate the scope for selection at the level of nuclei within fungal individuals (mycelia) of the mutualistic Termitomyces cultivated by fungus-growing termites. Whereas in most basidiomycete fungi the number and kind of nuclei is strictly regulated to be two per cell, in Termitomyces mycelia the number of nuclei per cell is highly variable. We hypothesised that natural selection on these fungi not only occurs between mycelia, but also at the level of nuclei within the mycelium. We test this hypothesis using in vitro tests with five nuclear haplotypes of a Termitomyces species. RESULTS First, we studied the transition from a mixture of five homokaryons (mycelia with identical nuclei) each with a different nuclear haplotype to heterokaryons (mycelia with genetically different nuclei). In vitro cultivation of this mixture for multiple asexual transfers led to the formation of multiple heterokaryotic mycelia, and a reduction of mycelial diversity over time. All heterokaryotic mycelia contained exactly two types of nucleus. The success of a heterokaryon during in vitro cultivation was mainly determined by spore production and to a lesser extent by mycelial growth rate. Second, heterokaryons invariably produced more spores than homokaryons implying that homokaryons will be outcompeted. Third, no homokaryotic 'escapes' from a heterokaryon via the formation of homokaryotic spores were found, despite extensive spore genotyping. Fourth, in contrast to most studied basidiomycete fungi, in Termitomyces sp. no nuclear migration occurs during mating, limiting the scope for nuclear competition within the mycelium. CONCLUSIONS Our experiments demonstrate that in this species of Termitomyces the scope for selection at the level of the nucleus within an established mycelium is limited. Although 'mate choice' of a particular nuclear haplotype is possible during mating, we infer that selection primarily occurs between mycelia with two types of nucleus (heterokaryons).
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Affiliation(s)
- Tania Nobre
- Laboratory of Genetics, Wageningen University and Research Center, Droevendaalsesteeg 1, Radix West, Building 107, 6708 PB Wageningen, The Netherlands
- Currently: ICAAM, University of Évora, Pólo da Mitra Apartado 94, 7002-554 Évora, Portugal
| | - Bertha Koopmanschap
- Laboratory of Genetics, Wageningen University and Research Center, Droevendaalsesteeg 1, Radix West, Building 107, 6708 PB Wageningen, The Netherlands
| | - Johan JP Baars
- Plant Research International – Mushrooms, Wageningen University and Research Centre, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Anton SM Sonnenberg
- Plant Research International – Mushrooms, Wageningen University and Research Centre, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Duur K Aanen
- Laboratory of Genetics, Wageningen University and Research Center, Droevendaalsesteeg 1, Radix West, Building 107, 6708 PB Wageningen, The Netherlands
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Microbial brokers of insect-plant interactions revisited. J Chem Ecol 2013; 39:952-61. [PMID: 23793897 DOI: 10.1007/s10886-013-0308-x] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 06/01/2013] [Accepted: 06/06/2013] [Indexed: 12/22/2022]
Abstract
Recent advances in sequencing methods have transformed the field of microbial ecology, making it possible to determine the composition and functional capabilities of uncultured microorganisms. These technologies have been instrumental in the recognition that resident microorganisms can have profound effects on the phenotype and fitness of their animal hosts by modulating the animal signaling networks that regulate growth, development, behavior, etc. Against this backdrop, this review assesses the impact of microorganisms on insect-plant interactions, in the context of the hypothesis that microorganisms are biochemical brokers of plant utilization by insects. There is now overwhelming evidence for a microbial role in insect utilization of certain plant diets with an extremely low or unbalanced nutrient content. Specifically, microorganisms enable insect utilization of plant sap by synthesizing essential amino acids. They also can broker insect utilization of plant products of extremely high lignocellulose content, by enzymatic breakdown of complex plant polysaccharides, nitrogen fixation, and sterol synthesis. However, the experimental evidence for microbial-mediated detoxification of plant allelochemicals is limited. The significance of microorganisms as brokers of plant utilization by insects is predicted to vary, possibly widely, as a result of potentially complex interactions between the composition of the microbiota and the diet and insect developmental age or genotype. For every insect species feeding on plant material, the role of resident microbiota as biochemical brokers of plant utilization is a testable hypothesis.
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Abstract
The main challenge in second generation bioethanol production is the efficient breakdown of cellulose to sugar monomers (hydrolysis). Due to the recalcitrant character of cellulose, feedstock pretreatment and adapted hydrolysis steps are needed to obtain fermentable sugar monomers. The conventional industrial production process of second-generation bioethanol from biomass comprises several steps: thermochemical pretreatment, enzymatic hydrolysis and sugar fermentation. This process is undergoing continuous optimization in order to increase the bioethanol yield and reduce the economic cost. Therefore, the discovery of new enzymes with high lignocellulytic activity or new strategies is extremely important. In nature, wood-feeding termites have developed a sophisticated and efficient cellulose degrading system in terms of the rate and extent of cellulose hydrolysis and exploitation. This system, which represents a model for digestive symbiosis has attracted the attention of biofuel researchers. This review describes the termite digestive system, gut symbionts, termite enzyme resources, in vitro studies of isolated enzymes and lignin degradation in termites.
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De Fine Licht HH, Biedermann PHW. Patterns of functional enzyme activity in fungus farming ambrosia beetles. Front Zool 2012; 9:13. [PMID: 22672512 PMCID: PMC3502098 DOI: 10.1186/1742-9994-9-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 06/06/2012] [Indexed: 11/10/2022] Open
Abstract
Introduction In wood-dwelling fungus-farming weevils, the so-called ambrosia beetles (Curculionidae: Scolytinae and Platypodinae), wood in the excavated tunnels is used as a medium for cultivating fungi by the combined action of digging larvae (which create more space for the fungi to grow) and of adults sowing and pruning the fungus. The beetles are obligately dependent on the fungus that provides essential vitamins, amino acids and sterols. However, to what extent microbial enzymes support fungus farming in ambrosia beetles is unknown. Here we measure (i) 13 plant cell-wall degrading enzymes in the fungus garden microbial consortium of the ambrosia beetle Xyleborinus saxesenii, including its primary fungal symbionts, in three compartments of laboratory maintained nests, at different time points after gallery foundation and (ii) four specific enzymes that may be either insect or microbially derived in X. saxesenii adult and larval individuals. Results We discovered that the activity of cellulases in ambrosia fungus gardens is relatively small compared to the activities of other cellulolytic enzymes. Enzyme activity in all compartments of the garden was mainly directed towards hemicellulose carbohydrates such as xylan, glucomannan and callose. Hemicellulolytic enzyme activity within the brood chamber increased with gallery age, whereas irrespective of the age of the gallery, the highest overall enzyme activity were detected in the gallery dump material expelled by the beetles. Interestingly endo-β-1,3(4)-glucanase activity capable of callose degradation was identified in whole-body extracts of both larvae and adult X. saxesenii, whereas endo-β-1,4-xylanase activity was exclusively detected in larvae. Conclusion Similar to closely related fungi associated with bark beetles in phloem, the microbial symbionts of ambrosia beetles hardly degrade cellulose. Instead, their enzyme activity is directed mainly towards comparatively more easily accessible hemicellulose components of the ray-parenchyma cells in the wood xylem. Furthermore, the detection of xylanolytic enzymes exclusively in larvae (which feed on fungus colonized wood) and not in adults (which feed only on fungi) indicates that only larvae (pre-) digest plant cell wall structures. This implies that in X. saxesenii and likely also in many other ambrosia beetles, adults and larvae do not compete for the same food within their nests - in contrast, larvae increase colony fitness by facilitating enzymatic wood degradation and fungus cultivation.
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Affiliation(s)
- Henrik H De Fine Licht
- Microbial Ecology Group, Department of Biology, Lund University, Ecology Building, Solvegatan 37, SE-22362, Lund, Sweden.
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Li X, Guo W, Ding J. Mycangial fungus benefits the development of a leaf-rolling weevil, Euops chinesis. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:867-873. [PMID: 22465740 DOI: 10.1016/j.jinsphys.2012.03.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 03/21/2012] [Accepted: 03/21/2012] [Indexed: 05/31/2023]
Abstract
While a wide array of insects form symbiotic relationships with microbes, the underlying mechanisms of these relationships are various and complex. In this study, we investigated the role that the mycangial fungus Penicillium herquei plays in the development of the leaf-rolling weevil Euops chinesis, which feeds on the knotweed Fallopia japonica. The weevil inoculates the fungus during oviposition into a leaf-roll that it creates for its larvae. We found that removal of P. herquei inocula from leaf-rolls significantly decreased the weevil's survival rate especially in the larval stage. Although inoculation with P. herquei had no effect on the plant's lignin content, it significantly decreased the cellulose content of the knotweed leaves. P. herquei also showed antibiotic properties against two fungi (Rhizopus sp.) that attack the weevil's leaf-rolls. Our results suggest that the mycangial fungus may help alter leaf chemical components and protect against pathogens thus improve leaf-rolls for the development of E. chinesis.
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Affiliation(s)
- Xiaoqiong Li
- Key Laboratory of Aquatic Plant and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, Hubei, China
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Uddin MM, Chowdhury MMH, Mojumder S, Dwaipayan S. Multiple endo-beta-1,4-glucanases present in the gut fluid of a defoliating beetle, Podontia quatuordecimpunctata (Coleoptera: Chrysomelidae). Pak J Biol Sci 2012; 15:333-340. [PMID: 24163959 DOI: 10.3923/pjbs.2012.333.340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Endo-beta-1, 4-glucanase (EC 3.2.1.4) activity was measured in the gut fluid of phytophagous insect Podontia quatuordecimpunctata Linnaeus (Coleoptera: Chrysomelidae) in different days of development. The eight day-old larva showed maximum activity with 1.73 U mg(-1) of protein, which was confirmed by gel zymography. In zymogram, using Carboxymethyl Cellulose (CMC) as substrate, four distinct cellulolytic protein bands were detected in leaf borer gut fluids through out of its development. The optimum temperature and pH were 60 degrees C and 5.0, respectively. This endo-beta-1,4-glucanase showed maximum stability at 20-45 degrees C with approximately 20% remaining activity. Zymography also showed complete loss of endo-beta-1,4 glucanase activity at 55 degrees C. This is the first report that the cellulolytic enzyme is produced in the gut of P. quatuordecimpunctata through the whole developmental stages, from the 1st instar to the adult, except for pupae.
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Affiliation(s)
- Mohammad Mosleh Uddin
- Department of Biochemistry and Molecular Biology, University of Chittagong, Bangladesh
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Fungal partnerships stimulate growth of Termitomyces clypeatus stalk mycelium in vitro. World J Microbiol Biotechnol 2012; 28:2311-8. [PMID: 22806105 DOI: 10.1007/s11274-012-1038-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 03/05/2012] [Indexed: 10/28/2022]
Abstract
The symbiotic relationship between termites and Termitomyces fungi, which allows the termite to digest cellulose-rich food sources, is poorly understood. In this study, in vitro mixed symbiotic relationships between Termitomyces clypeatus and fungi isolated from individual fungus-comb communities using a culture-dependent method were analyzed. Twenty-day-old stalk cultures of three T. clypeatus isolates were co-cultured with cellulase-producing fungi on potato dextrose agar. The high cellulase-producing fungal isolate no. 18, which showed 99 % ITS sequence identity to Sordariomycetes endophyte isolate 2171 (EU687039), increased growth of T. clypeatus 18/50 by 85.7 %. The high xylanase-producing isolate no. 13, which showed 88 % ITS sequence identity to Arthrinium sacchari isolate L06 (HQ115662), stimulated T. clypeatus 18/50 growth by 58.6 %. The high cellulase- and xylanase-producing isolate no. 50, which showed 90 % ITS sequence identity to the fungal endophyte isolate 2196 (EU687056), improved T. clypeatus 18/50 growth by 45.7 %. A Gigantropanus sp. promoted the growth of T. clypeatus 18/50 and 20/50 by 45.7 and 44.1 %, respectively, and that of T. clypeatus 19/50 by 10.6 %. These results indicated the most beneficial potential partnership of T. clypeatus might involve cellulase-producing fungi isolated from the same ecological niche. The Gigantropanus sp. is a potential partner of T. clypeatus but is likely to be less common than cellulase-producing fungi isolated from fungus combs owing to the lower host specificity of the Gigantropanus sp. This study provides an interesting method to culture Termitomyces using an in vitro mixed culture method for production of Termitomyces fruiting bodies in the future.
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Fungiculture or Termite Husbandry? The Ruminant Hypothesis. INSECTS 2012; 3:307-23. [PMID: 26467962 PMCID: PMC4553630 DOI: 10.3390/insects3010307] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 03/03/2012] [Accepted: 03/07/2012] [Indexed: 11/16/2022]
Abstract
We present a new perspective for the role of Termitomyces fungi in the mutualism with fungus-growing termites. According to the predominant view, this mutualism is as an example of agriculture with termites as farmers of a domesticated fungus crop, which is used for degradation of plant-material and production of fungal biomass. However, a detailed study of the literature indicates that the termites might as well be envisioned as domesticates of the fungus. According to the “ruminant hypothesis” proposed here, termite workers, by consuming asexual fruiting bodies not only harvest asexual spores, but also lignocellulolytic enzymes, which they mix with foraged plant material and enzymes of termite and possibly bacterial origin. This mixture is the building material of the fungus garden and facilitates efficient degradation of plant material. The fungus garden thus functions as an external rumen for termites and primarily the fungi themselves benefit from their own, and gut-derived, lignocellulolytic enzymes, using the termites to efficiently mix these with their growth substrate. Only secondarily the termites benefit, when they consume the degraded, nitrogen-enriched plant-fungus mixture a second time. We propose that the details of substrate use, and the degree of complementarity and redundancy among enzymes in food processing, determine selection of horizontally transmitted fungal symbionts at the start of a colony: by testing spores on a specific, mechanically and enzymatically pre-treated growth substrate, the termite host has the opportunity to select specific fungal symbionts. Potentially, the gut-microbiota thus influence host-fungus specificity, and the selection of specific fungal strains at the start of a new colony. We argue that we need to expand the current bipartite insect-biased view of the mutualism of fungus-growing termites and include the possible role of bacteria and the benefit for the fungi to fully understand the division of labor among partners in substrate degradation.
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Nobre T, Koné NA, Konaté S, Linsenmair KE, Aanen DK. Dating the fungus-growing termites' mutualism shows a mixture between ancient codiversification and recent symbiont dispersal across divergent hosts. Mol Ecol 2011; 20:2619-27. [PMID: 21481052 DOI: 10.1111/j.1365-294x.2011.05090.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The mutualistic symbiosis between fungus-growing termites and Termitomyces fungi originated in Africa and shows a moderate degree of interaction specificity. Here we estimate the age of the mutualism and test the hypothesis that the major splits have occurred simultaneously in the host and in the symbiont. We present a scenario where fungus-growing termites originated in the African rainforest just before the expansion of the savanna, about 31 Ma (19-49 Ma). Whereas rough age correspondence is observed for the four main clades of host and symbiont, the analysis reveals several recent events of host switching followed by dispersal of the symbiont throughout large areas and throughout different host genera. The most spectacular of these is a group of closely related fungi (the maximum age of which is estimated to be 2.4 Ma), shared between the divergent genera Microtermes, Ancistrotermes, Acanthotermes and Synacanthotermes (which diverged at least 16.7 Ma), and found throughout the African continent and on Madagascar. The lack of geographical differentiation of fungal symbionts shows that continuous exchange has occurred between regions and across host species.
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Affiliation(s)
- T Nobre
- Laboratory of Genetics, Wageningen University, Droevendaalsesteeg 1, Radix West, Building 107, 6708 PB Wageningen, The Netherlands.
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Bignell DE, Anderson JM, Crosse R. Isolation of facultatively aerobic actinomycetes from the gut, parent soil and mound materials of the termites Procubitermes aburiensis and Cubitermes severus. FEMS Microbiol Ecol 2011. [DOI: 10.1111/j.1574-6941.1991.tb01719.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Microbiome of fungus-growing termites: a new reservoir for lignocellulase genes. Appl Environ Microbiol 2010; 77:48-56. [PMID: 21057022 DOI: 10.1128/aem.01521-10] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fungus-growing termites play an important role in lignocellulose degradation and carbon mineralization in tropical and subtropical regions, but the degradation potentiality of their gut microbiota has long been neglected. The high quality and quantity of intestinal microbial DNA are indispensable for exploring new cellulose genes from termites by function-based screening. Here, using a refined intestinal microbial DNA extraction method followed by multiple-displacement amplification (MDA), a fosmid library was constructed from the total microbial DNA isolated from the gut of a termite growing in fungi. Functional screening for endoglucanase, cellobiohydrolase, β-glucosidase, and xylanase resulted in 12 β-glucosidase-positive clones and one xylanase-positive clone. The sequencing result of the xylanase-positive clone revealed an 1,818-bp open reading frame (ORF) encoding a 64.5-kDa multidomain endo-1,4-β-xylanase, designated Xyl6E7, which consisted of an N-terminal GH11 family catalytic domain, a CBM_4_9 domain, and a Listeria-Bacteroides repeat domain. Xyl6E7 was a highly active, substrate-specific, and endo-acting alkaline xylanase with considerably wide pH tolerance and stability but extremely low thermostability.
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Zhou Y, Deng T, Pan C, Chen C, Mo J. Purification of a laccase from fungus combs in the nest of Odontotermes formosanus. Process Biochem 2010. [DOI: 10.1016/j.procbio.2010.03.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Taylor EC. Role of aerobic microbial populations in cellulose digestion by desert millipedes. Appl Environ Microbiol 2010; 44:281-91. [PMID: 16346074 PMCID: PMC242008 DOI: 10.1128/aem.44.2.281-291.1982] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
I examined the role of aerobic microbial populations in cellulose digestion by two sympatric species of desert millipedes, Orthoporus ornatus and Comanchelus sp. High numbers of bacteria able to grow on media containing cellulose, carboxymethyl cellulose, or cellobiose as the substrate were found in the alimentary tracts of the millipedes. Enzyme assays indicated that most cellulose and hemicellulose degradation occurred in the midgut, whereas the hindgut was an important site for pectin degradation. Hemicellulase and beta-glucosidase in both species and possibly C(x)-cellulase and pectinase in O. ornatus were of possible microbial origin. Degradation of [C]cellulose by millipedes whose gut floras were reduced by antibiotic treatment and starvation demonstrated a reduction in CO(2) release and C assimilation and an increase in C excretion over values for controls. It appears that the millipede-bacterium association is mutualistic and makes available to millipedes an otherwise mostly unutilizable substrate. Such an association may be an important pathway for decomposition in desert ecosystems.
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Affiliation(s)
- E C Taylor
- Department of Biology, University of New Mexico, Albuquerque, New Mexico 87131
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Abstract
Despite the presence of many carbohydrolytic activities in insects, their cellulolytic mechanisms are poorly understood. Whereas cellulase genes are absent from the genomes of Drosophila melanogaster or Bombyx mori, other insects such as termites produce their own cellulases. Recent studies using molecular biological techniques have brought new insights into the mechanisms by which the insects and their microbial symbionts digest cellulose in the small intestine. DNA sequences of cellulase and associated genes, as well as physiological and morphological information about the digestive systems of cellulase-producing insects, may allow the efficient use of cellulosic biomass as a sustainable energy source.
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Affiliation(s)
- Hirofumi Watanabe
- National Institute of Agrobiological Sciences, 1-2 Owashi, Tsukuba, Ibaraki, Japan.
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Klepzig KD, Adams AS, Handelsman J, Raffa KF. Symbioses: a key driver of insect physiological processes, ecological interactions, evolutionary diversification, and impacts on humans. ENVIRONMENTAL ENTOMOLOGY 2009; 38:67-77. [PMID: 19791599 DOI: 10.1603/022.038.0109] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Symbiosis is receiving increased attention among all aspects of biology because of the unifying themes it helps construct across ecological, evolutionary, developmental, semiochemical, and pest management theory. Insects show a vast array of symbiotic relationships with a wide diversity of microorganisms. These relationships may confer a variety of benefits to the host (macrosymbiont), such as direct or indirect nutrition, ability to counter the defenses of plant or animal hosts, protection from natural enemies, improved development and reproduction, and communication. Benefits to the microsymbiont (including a broad range of fungi, bacteria, mites, nematodes, etc.) often include transport, protection from antagonists, and protection from environmental extremes. Symbiotic relationships may be mutualistic, commensal, competitive, or parasitic. In many cases, individual relationships may include both beneficial and detrimental effects to each partner during various phases of their life histories or as environmental conditions change. The outcomes of insect-microbial interactions are often strongly mediated by other symbionts and by features of the external and internal environment. These outcomes can also have important effects on human well being and environmental quality, by affecting agriculture, human health, natural resources, and the impacts of invasive species. We argue that, for many systems, our understanding of symbiotic relationships will advance most rapidly where context dependency and multipartite membership are integrated into existing conceptual frameworks. Furthermore, the contribution of entomological studies to overall symbiosis theory will be greatest where preoccupation with strict definitions and artificial boundaries is minimized, and integration of emerging molecular and quantitative techniques is maximized. We highlight symbiotic relations involving bark beetles to illustrate examples of the above trends.
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Affiliation(s)
- K D Klepzig
- Southern Research Station, USDA Forest Service, 2500 Shreveport Highway, Pineville, LA 71360, USA.
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Nishida Y, Suzuki KI, Kumagai Y, Tanaka H, Inoue A, Ojima T. Isolation and primary structure of a cellulase from the Japanese sea urchin Strongylocentrotus nudus. Biochimie 2007; 89:1002-11. [PMID: 17485156 DOI: 10.1016/j.biochi.2007.03.015] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2007] [Accepted: 03/19/2007] [Indexed: 11/26/2022]
Abstract
Glycoside-hydrolase-family 9 (GHF9) cellulases are known to be widely distributed in metazoa. These enzymes have been appreciably well investigated in protostome invertebrates such as arthropods, nematodes, and mollusks but have not been characterized in deuterostome invertebrates such as sea squirts and sea urchins. In the present study, we isolated the cellulase from the Japanese purple sea urchin Strongylocentrotus nudus and determined its enzymatic properties and primary structure. The sea urchin enzyme was extracted from the acetone-dried powder of digestive tract of S. nudus and purified by conventional chromatographies. The purified enzyme, which we named SnEG54, showed a molecular mass of 54kDa on SDS-PAGE and exhibited high hydrolytic activity toward carboxymethyl cellulose with an optimum temperature and pH at 35 degrees C and 6.5, respectively. SnEG54 degraded cellulose polymer and cellooligosaccharides larger than cellotriose producing cellotriose and cellobiose but not these small cellooligosaccharides. From a cDNA library of the digestive tract we cloned 1822-bp cDNA encoding the amino-acid sequence of 444 residues of SnEG54. This sequence showed 50-57% identity with the sequences of GHF9 cellulases from abalone, sea squirt, and termite. The amino-acid residues crucial for the catalytic action of GHF9 cellulases are completely conserved in the SnEG54 sequence. An 8-kbp structural gene fragment encoding SnEG54 was amplified by PCR from chromosomal DNA of S. nudus. The positions of five introns are consistent with those in other animal GHF9 cellulase genes. Thus, we confirmed that the sea urchin produces an active GHF9 cellulase closely related to other animal cellulases.
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Affiliation(s)
- Yukiko Nishida
- Laboratory of Marine Biotechnology and Microbiology, Graduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate, Hokkaido 041-8611, Japan
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Johjima T, Taprab Y, Noparatnaraporn N, Kudo T, Ohkuma M. Large-scale identification of transcripts expressed in a symbiotic fungus (Termitomyces) during plant biomass degradation. Appl Microbiol Biotechnol 2006; 73:195-203. [PMID: 17021881 DOI: 10.1007/s00253-006-0570-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2006] [Revised: 06/29/2006] [Accepted: 07/09/2006] [Indexed: 11/28/2022]
Abstract
Fungus-growing termites have a symbiotic relationship with the basidiomycetes of the genus Termitomyces. This symbiotic system is able to degrade dead plant material efficiently. We conducted expressed sequence tag (EST) analysis of a symbiotic Termitomyces fungus degrading plant material in a field nest of the termite Macrotermes gilvus. A subtractive cDNA library was also investigated to facilitate the discovery of genes expressed specifically under the symbiotic conditions. A total of 2,613 ESTs were collected and resulted in 1,582 nonredundant tentative consensus sequences, of which approximately 59% showed significant similarity to known protein sequences. A number of homologous sequences to genes involved in plant cell wall degradation were identified and a majority of them encoded putative pectinolytic enzymes. Real-time quantitative reverse transcriptase polymerase chain reaction analyses confirmed significant upregulation of putative stress response genes under symbiotic conditions. The present ESTs database provides a valuable resource for molecular biological study of plant material degradation in the symbiosis between termites and fungi.
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Affiliation(s)
- Toru Johjima
- International Cooperative Research Project, Japan Science and Technology Agency (JST-ICORP), Wako, Saitama, 351-0198, Japan
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Bouchard SS, Bjorndal KA. Nonadditive interactions between animal and plant diet items in an omnivorous freshwater turtle Trachemys scripta. Comp Biochem Physiol B Biochem Mol Biol 2006; 144:77-85. [PMID: 16503179 DOI: 10.1016/j.cbpb.2006.01.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2005] [Revised: 01/11/2006] [Accepted: 01/18/2006] [Indexed: 11/18/2022]
Abstract
Nonadditive interactions occur when diet items interact with one another such that the net energy or nutrient gain from a mixed diet differs from that predicted by summing the gains from individual diet components. We quantified nonadditive effects between duckweed, Lemma valdiviana, and grass shrimp, Palaemontes paludosus, in the freshwater turtle Trachemys scripta. We fed turtles 100% duckweed, 100% shrimp, and two mixed diets containing 67% duckweed, 33% shrimp and 14% duckweed, 86% shrimp (dry matter basis). During each feeding trial, we measured intake, digestibility, and transit time of the diet, and upon conclusion, short-chain fatty acid concentrations in turtle digestive tracts. Digestibility was lower on the 67% duckweed diet, but higher on the 14% diet. These apparent nonadditive interactions may be due to differences in transit time of duckweed and shrimp. We believe this is the first evidence of two diet items producing opposing nonadditive effects when fed in different ratios.
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Affiliation(s)
- Sarah S Bouchard
- Department of Zoology, University of Florida, Gainesville, FL 32611, USA.
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Taprab Y, Johjima T, Maeda Y, Moriya S, Trakulnaleamsai S, Noparatnaraporn N, Ohkuma M, Kudo T. Symbiotic fungi produce laccases potentially involved in phenol degradation in fungus combs of fungus-growing termites in Thailand. Appl Environ Microbiol 2006; 71:7696-704. [PMID: 16332742 PMCID: PMC1317398 DOI: 10.1128/aem.71.12.7696-7704.2005] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fungus-growing termites efficiently decompose plant litter through their symbiotic relationship with basidiomycete fungi of the genus Termitomyces. Here, we investigated phenol-oxidizing enzymes in symbiotic fungi and fungus combs (a substrate used to cultivate symbiotic fungi) from termites belonging to the genera Macrotermes, Odontotermes, and Microtermes in Thailand, because these enzymes are potentially involved in the degradation of phenolic compounds during fungus comb aging. Laccase activity was detected in all the fungus combs examined as well as in the culture supernatants of isolated symbiotic fungi. Conversely, no peroxidase activity was detected in any of the fungus combs or the symbiotic fungal cultures. The laccase cDNA fragments were amplified directly from RNA extracted from fungus combs of five termite species and a fungal isolate using degenerate primers targeting conserved copper binding domains of basidiomycete laccases, resulting in a total of 13 putative laccase cDNA sequences being identified. The full-length sequences of the laccase cDNA and the corresponding gene, lcc1-2, were identified from the fungus comb of Macrotermes gilvus and a Termitomyces strain isolated from the same fungus comb, respectively. Partial purification of laccase from the fungus comb showed that the lcc1-2 gene product was a dominant laccase in the fungus comb. These findings indicate that the symbiotic fungus secretes laccase to the fungus comb. In addition to laccase, we report novel genes that showed a significant similarity with fungal laccases, but the gene product lacked laccase activity. Interestingly, these genes were highly expressed in symbiotic fungi of all the termite hosts examined.
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Affiliation(s)
- Yaovapa Taprab
- Environmental Molecular Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
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Hyodo F, Tayasu I, Inoue T, Azuma JI, Kudo T, Abe T. Differential role of symbiotic fungi in lignin degradation and food provision for fungus-growing termites (Macrotermitinae: Isoptera). Funct Ecol 2003. [DOI: 10.1046/j.1365-2435.2003.00718.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Suzuki KI, Ojima T, Nishita K. Purification and cDNA cloning of a cellulase from abalone Haliotis discus hannai. EUROPEAN JOURNAL OF BIOCHEMISTRY 2003; 270:771-8. [PMID: 12581217 DOI: 10.1046/j.1432-1033.2003.03443.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A cellulase [endo-beta-1,4-D-glucanase (EC 3.2.1.4)] was isolated from the hepatopancreas of abalone Haliotis discus hannai by successive chromatographies on TOYOPEARL CM-650M, hydroxyapatite and Sephacryl S-200 HR. The molecular mass of the cellulase was estimated to be 66 000 Da by SDS/PAGE, thus the enzyme was named HdEG66. The hydrolytic activity of HdEG66 toward carboxymethylcellulose showed optimal temperature and pH at 38 degrees C and 6.3, respectively. cDNAs encoding HdEG66 were amplified by the polymerase chain reaction from an abalone hepatopancreas cDNA library with primers synthesized on the basis of partial amino-acid sequences of HdEG66. By overlapping the nucleotide sequences of the cDNAs, a sequence of 1898 bp in total was determined. The coding region of 1785 bp located at nucleotide position 56-1840 gave an amino-acid sequence of 594 residues including the initiation methionine. The N-terminal region of 14 residues in the deduced sequence was regarded as the signal peptide as it was absent in HdEG66 protein and showed high similarity to the consensus sequence for signal peptides of eukaryote secretory proteins. Thus, matured HdEG66 was thought to consist of 579 residues. The C-terminal region of 453 residues in HdEG66, i.e. approximately the C-terminal three quarters of the protein, showed 42-44% identity to the catalytic domains of glycoside hydrolase family 9 (GHF9)-cellulases from arthropods and Thermomonospora fusca. While the N-terminal first quarter of HdEG66 showed 27% identity to the carbohydrate-binding module (CBM) of a Cellulomonas fimi cellulase, CenA. Thus, the HdEG66 was regarded as the GHF9-cellulase possessing a family II CBM in the N-terminal region. By genomic PCR using specific primers to the 3'-terminal coding sequences of HdEG66-cDNA, a DNA of 2186 bp including three introns was amplified. This strongly suggests that the origin of HdEG66 is not from symbiotic bacteria but abalone itself.
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Affiliation(s)
- Ken-ichi Suzuki
- Laboratory of Biochemistry and Biotechnology, Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Japan
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Coll M, Guershon M. Omnivory in terrestrial arthropods: mixing plant and prey diets. ANNUAL REVIEW OF ENTOMOLOGY 2002; 47:267-297. [PMID: 11729076 DOI: 10.1146/annurev.ento.47.091201.145209] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Many terrestrial communities include omnivorous arthropods that feed on both prey and plant resources. In this review we first discuss some unique morphological, physiological, and behavioral traits that enable omnivores to exploit such dissimilar foods, and we explore possible evolutionary pathways to omnivory. We then examine possible benefits and costs of omnivory, describe the relationships between omnivory and other high-order complex trophic interactions, and consider the stability level of communities with closed-loop omnivory. Finally, we explore some of the implications of omnivory for crop damage and for biological, chemical, and cultural control practices. We conclude that the growing realization of the ubiquity of omnivory in nature may require a change in our view of the structure and function of ecological systems.
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Affiliation(s)
- Moshe Coll
- Department of Entomology, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
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Reinhard J, Lacey MJ, Ibarra F, Schroeder FC, Kaib M, Lenz M. Hydroquinone: a general phagostimulating pheromone in termites. J Chem Ecol 2002; 28:1-14. [PMID: 11868667 DOI: 10.1023/a:1013554100310] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The organization of termite societies depends predominantly on intraspecific chemical signals (pheromones) produced by exocrine glands, which induce and modulate individual behavioral responses. Here, the saliva-producing labial glands of termites were investigated with respect to their pheromonal role in communal food exploitation of termite colonies. From these glands, we identified for the first time hydroquinone (1,4-dihydroxybenzene) as a phagostimulating pheromone in the Australian termite species Mastotermes darwiniensis. Hydroquinone is released from the labial glands of termite workers and applied onto the food. It stimulates nestmates to feed at the spot of application and is, thus, employed to mark feeding sites. No synergistic effect with other identified labial gland compounds, such as glucose, inositol, and arbutin, was evident. Significantly, we show that termite species from all over the world, irrespective of taxonomic position and biological traits, produce and employ hydroquinone as phagostimulating signal. The use of the same chemical signal throughout an order is a unique phenomenon, not reported before in animals. Its possible biosynthetic pathway, ecological significance, and evolution are discussed.
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Affiliation(s)
- Judith Reinhard
- Termite Research Group, CSIRO Entomology, Canberra ACT, Australia.
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Reinhard J, Kaib M. Thin-layer chromatography assessing feeding stimulation by labial gland secretion compared to synthetic chemicals in the subterranean termite Reticulitermes santonensis. J Chem Ecol 2001; 27:175-87. [PMID: 11382062 DOI: 10.1023/a:1005684420399] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The labial gland of the French subterranean termite Reticulitermes santonensis De Feytaud contains a polar, heat-resistent, and persistent chemical signal that is released onto the food during food exploitation and stimulates feeding in nestmates. Separation of the labial gland secretion by thin-layer chromatography on cellulose plates revealed that the secretion contains components with reducing and amino groups. In feeding bioassays conducted on the cellulose plate after TLC, termites preferred the area between Rf 0.46 and 0.88 (biologically active zone) for feeding, indicating the location of the feeding-stimulating signal. Thirty-five synthetic chemicals with similar chemical properties as the feeding-stimulating signal were analyzed with TLC. None of them covered the biologically active zone. Therefore, all chemical classes tested, such as sugars, amino acids, and salts, are unlikely as possible sources for the signal structure. In feeding choice tests with synthetic chemicals, termites showed clear feeding preference only for sugarlike components with physiologically excessive concentrations of 10 mmol and 100 mmol. Amino acids induced only light feeding preference. The intensity of feeding stimulation by the natural signal from the labial gland as compared to synthetic phagostimulants is discussed.
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Affiliation(s)
- J Reinhard
- Bundesanstalt für Materialforschung und -prüfung 12200 Berlin, Germany
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Reinhard J, Kaib M. Food exploitation in termites: indication for a general feeding-stimulating signal in labial gland secretion of isoptera. J Chem Ecol 2001; 27:189-201. [PMID: 11382063 DOI: 10.1023/a:1005636504469] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The paired labial glands are located in all termite species in the thorax. During food exploitation workers of the French termite Reticulitermes santonensis and the African termite Schedorhinotermes lamanianus release the secretion of their labial glands directly onto the food. The secretion carries a water-soluble, heat-resistant, nonvolatile signal that stimulates gnawing and feeding and leads to aggregations of feeding workers. In a feeding bioassay, extracts of the labial glands of 11 termite species from five families all proved to have this feeding-stimulating effect both on R. santonensis and S. lamanianus. The heat resistance of the feeding-stimulating signal also could be shown for selected species from all termite families tested. A combined thin layer chromatography-feeding bioassay on cellulose TLC plates showed that after chromatography of labial gland secretion, the feeding-stimulating signal is located in all 11 species in the same area from Rf 0.46 to 0.88. An extract of labial glands of cockroaches stimulated feeding in R. santonensis and S. lamanianus as well, but was not active after heat treatment and after TLC. This points towards a general feeding-stimulating signal having evolved only in the labial gland secretion of termites.
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Affiliation(s)
- J Reinhard
- Bundesanstalt für Materialforschung und -prüfung 12200 Berlin, Germany
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Metzler DE, Metzler CM, Sauke DJ. Some Pathways of Carbohydrate Metabolism. Biochemistry 2001. [DOI: 10.1016/b978-012492543-4/50023-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Abstract
Despite the abundance and diversity of species that include living or dead plant tissue in their diets, the ability to digest cellulose is rare in insects and is restricted to a small number of orders and families. In this paper it is argued that cellulolytic capacity is uncommon in insects simply because it is a trait that is rarely advantageous to possess. Although there is a growing body of evidence for the occurrence of symbiont-independent cellulose digestion in cockroaches and in higher termites from the subfamily Nasutitermitinae, cellulose digestion in insects is usually mediated by microorganisms. It is proposed that non-cellulolytic omnivorous scavengers and detritivores may be preadapted to evolve symbiont-mediated cellulolytic mechanisms because of the prevalence of mutualistic associations between such species and the microorganisms that normally reside in their hindguts. A scenario is proposed for the evolution of symbiont-mediated cellulolytic capacity in roaches and lower termites. Finally, it is suggested that biochemical studies of insect cellulases might provide crucial insights that would greatly advance our understanding of the evolution of cellulose digestion in insects.
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Matoub M, Rouland C. Purification and properties of the xylanases from the termite Macrotermes bellicosus and its symbiotic fungus Termitomyces sp. Comp Biochem Physiol B Biochem Mol Biol 1995; 112:629-35. [PMID: 8590378 DOI: 10.1016/0305-0491(95)00103-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Four xylanases were purified, two from the termite Macrotermes bellicosus workers (XIT and X2T) and two from its symbiotic fungus Termitomyces sp. (X1Mc and X2Mc). The analysis of the step required for the purification of X1T and X1Mc and the comparison of their different properties suggested that xylanases X1T and X1Mc were the same enzyme, X1. The determination of the reducing sugars by TLC revealed that X1 was an endoxylanase (EC 3.2.1.8) and X2T and X2Mc were endoxylanases (EC 3.2.1.37). The apparent molecular weights of the three xylanases, determined by SDS-polyacrylamide gel electrophoresis, were 36 kDa for X1, 56 kDa for X2T and 22.5 kDa for X2Mc. The optimal pH of the three xylanases was approximately 5.5, and Km values determined with birchwood xylan as substrate were 0.2% for X1, 0.1% for X2T and 0.3% for X2Mc, showing a high affinity for this substrate. The three enzymes differed also by their thermal stability.
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Affiliation(s)
- M Matoub
- Laboratoire d'Ecophysiologie des Invertébrés, Université Paris XII-Val de Marne, Créteil, France
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