1
|
Qi DY, Shao YZ, Yang R, Liu CL, Feng GH, Pan WY, Feng MG, Tong SM. Emulsifiable oil-formulated Beauveria bassiana competes with imidacloprid for seasonal control of cereal aphids in Zhejiang, China. PEST MANAGEMENT SCIENCE 2024; 80:2929-2936. [PMID: 38285453 DOI: 10.1002/ps.8001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 01/08/2024] [Accepted: 01/28/2024] [Indexed: 01/30/2024]
Abstract
BACKGROUND Alternatives to neonicotinoids against cereal aphids are needed to mitigate aphid resistance and non-target effects. The emulsifiable oil formulations of two Beauveria bassiana strains, namely Bb registered as a mycoinsecticide and TBb overexpressing an endogenous virulence factor, were tested for seasonal control of cereal aphids at the elongating (April 7) to milk ripening (May 12) stages of winter wheat crop in Yuhang, Zhejiang. Each of three field trials consisted of blank control and the treatments (three randomized 100-m2 plots per capita) of each fungal strain sprayed biweekly at rates of 1.0 × 1013 and 1.5 × 1013 conidia ha-1 and 10% imidacloprid WP sprayed biweekly at a label rate. RESULTS Tiller infestation percentage and aphid density in the 5-week field trials after the first spray were reduced to 18.7-22.4% and 9.1-12.4 aphids per tiller in the fungal treatments, and 12.8-25.3% and 2.8-20.9 aphids per tiller in the chemical treatment, contrasting with 49.2-60.3% and 37.1-108.5 aphids per tiller in the control. Percent control efficacies (±SD) computed with weekly aphid densities over the period averaged 84.0 ± 1.6 and 85.3 ± 1.8 versus 78.0 ± 4.0 and 79.9 ± 3.2 in the high-rate versus low-rate treatments of Bb and TBb, respectively, and 84.5 ± 7.8 in the chemical treatment. Imidacloprid showed faster kill action but more variable efficacy than the fungal treatments throughout the trials. CONCLUSION Either Bb or TBb formulation competes with imidacloprid in reducing percent infestation and aphid density. The overall efficacy was significantly higher in the treatments of TBb than of Bb. © 2024 Society of Chemical Industry.
Collapse
Affiliation(s)
- Dan-Yi Qi
- College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou, China
| | - Yan-Zhi Shao
- College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou, China
| | - Ru Yang
- College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou, China
| | - Chun-Ling Liu
- College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou, China
| | - Guan-Hua Feng
- College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou, China
| | - Wen-Yue Pan
- College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou, China
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Sen-Miao Tong
- College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou, China
| |
Collapse
|
2
|
Roles of BrlA and AbaA in Mediating Asexual and Insect Pathogenic Lifecycles of Metarhizium robertsii. J Fungi (Basel) 2022; 8:jof8101110. [PMID: 36294676 PMCID: PMC9604561 DOI: 10.3390/jof8101110] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/19/2022] [Accepted: 10/19/2022] [Indexed: 11/07/2022] Open
Abstract
BrlA and AbaA are key activators of the central developmental pathway (CDP) that controls asexual development in Aspergillus but their roles remain insufficiently understood in hypocerealean insect pathogens. Here, regulatory roles of BrlA and AbaA orthologs in Metarhizium robertsii (Clavicipitaceae) were characterized for comparison to those elucidated previously in Beauveria bassiana (Cordycipitaceae) at phenotypic and transcriptomic levels. Time-course transcription profiles of brlA, abaA, and the other CDP activator gene wetA revealed that they were not so sequentially activated in M. robertsii as learned in Aspergillus. Aerial conidiation essential for fungal infection and dispersal, submerged blastospore production mimicking yeast-like budding proliferation in insect hemocoel, and insect pathogenicity via cuticular penetration were all abolished as a consequence of brlA or abaA disruption, which had little impact on normal hyphal growth. The disruptants were severely compromised in virulence via cuticle-bypassing infection (intrahemocoel injection) and differentially impaired in cellular tolerance to oxidative and cell wall-perturbing stresses. The ΔbrlA and ΔabaA mutant shad 255 and 233 dysregulated genes (up/down ratios: 52:203 and 101:122) respectively, including 108 genes co-dysregulated. These counts were small compared with 1513 and 2869 dysregulated genes (up/down ratios: 707:806 and 1513:1356) identified in ΔbrlA and ΔabaA mutants of B. bassiana. Results revealed not only conserved roles for BrlA and AbaA in asexual developmental control but also their indispensable roles in fungal adaptation to the insect-pathogenic lifecycle and host habitats. Intriguingly, BrlA- or AbaA-controlled gene expression networks are largely different between the two insect pathogens, in which similar phenotypes were compromised in the absence of either brlA or abaA.
Collapse
|
3
|
Current developments in the resistance, quality, and production of entomopathogenic fungi. World J Microbiol Biotechnol 2022; 38:115. [PMID: 35581403 DOI: 10.1007/s11274-022-03301-9] [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: 03/24/2022] [Accepted: 05/05/2022] [Indexed: 10/18/2022]
Abstract
There is a worldwide concern to achieve food security with a sustainable approach, including the generation and implementation of techniques for the production of high-quality chemical-free crops. This food revolution has promoted the development and consolidation of programmes for integrated pest management. Some of those programmes include the use of diverse organisms (biological control agents) to suppress populations of pests potentially harmful to the crops. Among these biological control agents are entomopathogenic fungi that are highly effective in suppressing a diversity of insects and have, therefore, been produced and marketed throughout the world. However, the bottleneck for applying entomopathogenic fungi is the production of propagules (blastospores and conidia) with resistance to environment conditions and abiotic factors, maintaining high quality in terms of virulence. Therefore, this manuscript presents recent studies related to increasing resistance and quality using different bioreactors to produce conidia. The above presents a global panorama related to current developments that contribute to improving the resistance, quality, and production of entomopathogenic fungal propagules.
Collapse
|
4
|
Cando-Narvaez A, Loera O, Méndez-Hernández JE. Rice recycling: a simple strategy to improve conidia production in solid-state cultures. Lett Appl Microbiol 2021; 74:385-394. [PMID: 34825719 DOI: 10.1111/lam.13614] [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: 10/23/2021] [Revised: 11/17/2021] [Accepted: 11/19/2021] [Indexed: 11/30/2022]
Abstract
Here we studied at a laboratory scale a potential strategy to revalorize the residual rice remaining at the end of a conventional conidia production process in solid-state culture. The conidia production of Trichoderma asperellum Th-T4 (3) and Metarhizium robertsii Xoch-8.1 started with the use of fresh rice (unrecycled rice) as the substrate (cycle one), and continued with the use of recycled rice in successive cycles of conidia production. The rice remaining at the end of the first cycle was reused without any further sterilization or reinoculation. As a result, it was observed that the conidia production and productivity significantly increased in both fungi. Conidia production in T. asperellum Th-T4 (3) increased from 1 × 109 (first cycle) to 2·9 × 109 conidia per gram of initial dry substrate (con⋅gds-1 ) (second cycle using recycled rice), while in M. robertsii Xoch-8.1, this parameter increased form 5·7 × 108 to 1·4 × 109 con⋅gds-1 . Both fungi grew faster and conidiated earlier when recycled rice was used as the substrate, therefore, conidia productivity was also significantly improved. Furthermore, the use of recycled rice did not affect conidia viability. This is the first report about a recycling methodology completely free of extra-processing steps, and useful to increase conidia production and productivity.
Collapse
Affiliation(s)
- A Cando-Narvaez
- Agricultural Parasitology Department, Universidad Autónoma Chapingo, Texcoco, México
| | - O Loera
- Biotechnology Department, Universidad Autónoma Metropolitana Iztapalapa, Mexico City, Mexico
| | - J E Méndez-Hernández
- Biotechnology Department, Universidad Autónoma Metropolitana Iztapalapa, Mexico City, Mexico
| |
Collapse
|
5
|
Smt3, a homologue of yeast SUMO, contributes to asexual development, environmental adaptation, and host infection of a filamentous entomopathogen. Fungal Biol 2020; 124:924-931. [PMID: 33059844 DOI: 10.1016/j.funbio.2020.07.010] [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: 05/01/2020] [Revised: 06/30/2020] [Accepted: 07/29/2020] [Indexed: 11/24/2022]
Abstract
Small ubiquitin-like modifiers (SUMOs) act as the modifiers that regulate several important eukaryotic cell events during sumoylation, but little is known about the functions of SUMO or sumoylation in filamentous entomopathogens. Here, we report the important roles of a single SUMO-encoding gene, smt3, in Beauveria bassiana, a filamentous fungal insect pathogen that serves as a main source of wide-spectrum fungal insecticides. The deletion of smt3 led to significant growth defects on the minimal media with different carbon and nitrogen sources, an obvious reduction (45.7 %) in aerial conidiation during optimal cultivation, and increasing sensitivities to metal ions, oxidation, cell wall perturbation, and the fungicide carbendazim during conidial germination and/or colony growth. Compared with the wild-type, the percentage of germination of conidia stored at 4 °C decreased by 83.9 %, and virulence to Galleria mellonella via normal infection was delayed by 24.6 %. However, conidial thermotolerance increased slightly by 11.4 % in Δsmt3. These findings concurred with the repressed transcripts of some phenotype-related genes and decreased activities of antioxidant enzymes. Taken together, smt3 or sumoylation plays vital roles in the asexual development, environmental adaptation, and pathogenicity of B. bassiana.
Collapse
|
6
|
Phenotypic and molecular insights into heat tolerance of formulated cells as active ingredients of fungal insecticides. Appl Microbiol Biotechnol 2020; 104:5711-5724. [PMID: 32405755 DOI: 10.1007/s00253-020-10659-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/23/2020] [Accepted: 04/29/2020] [Indexed: 12/25/2022]
Abstract
Formulated conidia of insect-pathogenic fungi, such as Beauveria and Metarhizium, serve as the active ingredients of fungal insecticides but are highly sensitive to persistent high temperatures (32-35 °C) that can be beyond their upper thermal limits especially in tropical areas and during summer months. Fungal heat tolerance and inter- or intra-specific variability are critical factors and limitations to field applications of fungal pesticides during seasons favoring outbreaks of pest populations. The past decades have witnessed tremendous advances in improving fungal pesticides through selection of heat-tolerant strains from natural isolates, improvements and innovations in terms of solid-state fermentation technologies for the production of more heat-tolerant conidia, and the use of genetic engineering of candidate strains for enhancing heat tolerance. More recently, with the entry into a post-genomic era, a large number of signaling and effector genes have been characterized as important sustainers of heat tolerance in both Beauveria and Metarhizium, which represent the main species used as fungal pesticides worldwide. This review focuses on recent advances and provides an overview into the broad molecular basis of fungal heat tolerance and its multiple regulatory pathways. Emphases are placed on approaches for screening of heat-tolerant strains, methods for optimizing conidial quality linked to virulence and heat tolerance particularly involving cell wall architecture and optimized trehalose/mannitol contents, and how molecular determinants can be exploited for genetic improvement of heat tolerance and pest-control potential. Examples of fungal pesticides with different host spectra and their appropriateness for use in apiculture are given. KEY POINTS: • Heat tolerance is critical for field stability and efficacy of fungal insecticides. • Inter- and intra-specific variability exists in insect-pathogenic fungi. • Optimized production technology and biotechnology can improve heat tolerance. • Fungal heat tolerance is orchestrated by multiple molecular pathways.
Collapse
|
7
|
Serna-Díaz MG, Mercado-Flores Y, Jiménez-González A, Anducho-Reyes MA, Medina-Marín J, Seck Tuoh-Mora JC, Téllez-Jurado A. Use of barley straw as a support for the production of conidiospores of Trichoderma harzianum. BIOTECHNOLOGY REPORTS (AMSTERDAM, NETHERLANDS) 2020; 26:e00445. [PMID: 32280603 PMCID: PMC7139161 DOI: 10.1016/j.btre.2020.e00445] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/02/2020] [Accepted: 03/08/2020] [Indexed: 11/07/2022]
Abstract
Barley straw is an excellent support of conidiospores production. The addition of mineral salts substantially improves of conidiospores production. Pre-treating the barley straw with a water wash favors the conidiation process. 80 % humidity favors the conidiation of T. harzianum.
In this work was to evaluate the conidiospores production of Trichoderma harzianum using barley straw as substrate. Four growth conditions were used; washed and unwashed barley straw and washed and unwashed barley straw supplemented with mineral salts. The highest spore production was observed when washed barley straw supplemented with mineral salts with 1.56 × 1010 conidiospores/gram of dry matter (gdm) at 216 h of cultivation was used. The effect of substrate moisture on spore production was studied, three initial moisture levels of the substrate were tested and it was observed that a humidity of 80 % of the substrate improves the production of conidiospores reaching a concentration of 2.35 × 1010 conidiospores/gdm at 136 h. Finally, conidiospores viability was evaluated for 12 months by keeping them on the conidia and substrate, and viability of 71 % of the conidiospores was observed, so this maintenance method is an excellent means of conserving the conidiospores viability.
Collapse
Affiliation(s)
- M G Serna-Díaz
- Engineering Department, Autonomous University of Hidalgo State, Carretera Pachuca-Tulancingo, Km 4.5, Col. Carboneras, C.P. 42184, Mineral De La Reforma, Hidalgo, Mexico
| | - Y Mercado-Flores
- Agrobiotechnology Laboratory, Polytechnic University of Pachuca, Carretera Pachuca-Cd. Sahagún, Km 20, ExHacienda De Santa Bárbara, C.P. 43830, Zempoala, Hidalgo, Mexico
| | - A Jiménez-González
- Agrobiotechnology Laboratory, Polytechnic University of Pachuca, Carretera Pachuca-Cd. Sahagún, Km 20, ExHacienda De Santa Bárbara, C.P. 43830, Zempoala, Hidalgo, Mexico
| | - M A Anducho-Reyes
- Agrobiotechnology Laboratory, Polytechnic University of Pachuca, Carretera Pachuca-Cd. Sahagún, Km 20, ExHacienda De Santa Bárbara, C.P. 43830, Zempoala, Hidalgo, Mexico
| | - J Medina-Marín
- Engineering Department, Autonomous University of Hidalgo State, Carretera Pachuca-Tulancingo, Km 4.5, Col. Carboneras, C.P. 42184, Mineral De La Reforma, Hidalgo, Mexico
| | - J C Seck Tuoh-Mora
- Engineering Department, Autonomous University of Hidalgo State, Carretera Pachuca-Tulancingo, Km 4.5, Col. Carboneras, C.P. 42184, Mineral De La Reforma, Hidalgo, Mexico
| | - A Téllez-Jurado
- Agrobiotechnology Laboratory, Polytechnic University of Pachuca, Carretera Pachuca-Cd. Sahagún, Km 20, ExHacienda De Santa Bárbara, C.P. 43830, Zempoala, Hidalgo, Mexico
| |
Collapse
|
8
|
Forced aeration promotes high production and productivity of infective conidia from Metarhizium robertsii in solid-state fermentation. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107492] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
|
9
|
The Effects of Trichoderma Fungi on the Tunneling, Aggregation, and Colony-Initiation Preferences of Black-Winged Subterranean Termites, Odontotermes formosanus (Blattodea: Termitidae). FORESTS 2019. [DOI: 10.3390/f10111020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The black-winged subterranean termite, Odontotermes formosanus Shiraki, is a severe pest of plantations and forests in China. This termite cultures symbiotic Termitomyces in the fungal combs, which are challenged by antagonistic microbes such as Trichoderma fungi. In a previous study we showed that O. formosanus workers made significantly fewer tunnels in sand containing commercially formulated conidia of Trichoderma viride Pers. ex Fries compared with untreated sand. Herein, we hypothesize that fungi in the genus Trichoderma exert repellent effects on O. formosanus. Different choice tests were conducted to evaluate the tunneling and aggregation behaviors of O. formosanus workers reacting to sand/soil containing the unformulated conidia of seven Trichoderma fungi (Trichoderma longibrachiatum Rifai, Trichoderma koningii Oud., Trichoderma harzianum Rifai, Trichoderma hamatum (Bon.) Bain, Trichoderma atroviride Karsten, Trichoderma spirale Indira and Kamala, and T. viride). We also investigated the colony-initiation preference of paired O. formosanus adults to soil treated with Trichoderma conidia (T. koningii or T. longibrachiatum) versus untreated soil. Tunneling-choice tests showed that sand containing conidia of nearly all Trichoderma fungi tested (except T. harzianum) significantly decreased tunneling activity in O. formosanus workers compared with untreated sand. Aggregation-choice test showed that T. koningii, T. atroviride and T. spirale repelled O. formosanus workers, whereas T. longibrachiatum and T. hamatum attracted termites. There was no significant difference in proportions of paired adults that stayed and laid eggs in the soil blocks treated with conidia of Trichoderma fungi and untreated ones. Our study showed that Trichoderma fungi generally repelled tunneling in O. formosanus, but may exert varied effects on aggregation preference by workers.
Collapse
|
10
|
He Q, Peng H, Sheng M, Hu S, Qiu J, Gu J. Humidity Control Strategies for Solid-State Fermentation: Capillary Water Supply by Water-Retention Materials and Negative-Pressure Auto-controlled Irrigation. Front Bioeng Biotechnol 2019; 7:263. [PMID: 31681743 PMCID: PMC6812397 DOI: 10.3389/fbioe.2019.00263] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 09/26/2019] [Indexed: 11/13/2022] Open
Abstract
Solid-state fermentation (SSF) has regained interest owing to its advantages in solid waste treatment and fermentation industries. However, heterogeneous heat and mass transfer are often caused by the absence of free water and noticeable water loss from microbial utilization and moisture evaporation in SSF. It is necessary to explore more effective ways to solve issues of water loss and water supplement in SSF based on online capillary water monitoring, because capillary water is the dominant form of water that is present and lost in substrate. Two novel capillary-water supply strategies were proposed, established and evaluated using three selected reference strains, including water-retention materials and negative-pressure auto-controlled irrigation (NPACI). This study employed superabsorbent polymer, a kind of water-retention material to enhance enzyme productivity with the most significant increase of 2.47 times. Moreover, the combination of NPACI and 0.1% superabsorbent polymers increased productivity by 2.80-fold, together with lowered gradients of temperature, moisture and products. Furthermore, a modified liquid-supply SSF was constructed through successful capillary water control by proposed humidity control strategies. This modified SSF system could address the shortcomings of inhomogeneous culture of traditional SSF.
Collapse
Affiliation(s)
- Qin He
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
- Imperial College Centre for Synthetic Biology and Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Huadong Peng
- Imperial College Centre for Synthetic Biology and Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Mengyao Sheng
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Shishan Hu
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Jiguo Qiu
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Jiayu Gu
- Nantong Lianhai Weijing Biology Co., Ltd., Haimen, China
| |
Collapse
|
11
|
da Cunha LP, Casciatori FP, de Cenço Lopes I, Thoméo JC. Production of conidia of the entomopathogenic fungus Metarhizium anisopliae ICB 425 in a tray bioreactor. Bioprocess Biosyst Eng 2019; 42:1757-1768. [PMID: 31327074 DOI: 10.1007/s00449-019-02172-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 07/09/2019] [Indexed: 11/26/2022]
Abstract
The use of Metarhizium anisopliae as a bioinsecticide is steeply increasing worldwide. However, to reduce the production costs, it is necessary to develop sophisticated techniques for conidia production. This work aimed to use a tray bioreactor to produce conidia of M. anisopliae ICB-425 in long rice and find the limiting bed depth in which the production is still viable. Experiments have been carried out to assess the influence of the air temperature and relative humidity on the spore concentration in order to determine the limiting temperature. Two scales of bioreactors in plastic packages have been used, containing 10 and 500 g of rice, and the results were similar. In the tray bioreactor, the bed depths of 2, 4 and 6 cm have been used, corresponding to the dry rice weights of 1, 2 and 3 kg, respectively, and the results were similar to the ones in plastic packages. A one-phase heat transfer model has been used to foresee the maximum temperature within the bed and the results agreed fairly well with the experimental ones. Using the model, a bed depth of 7 cm was found to be the limit for the tray bioreactor. The results obtained are very promising for the mass production of conidia of M. anisopliae at lower costs and with more effective control.
Collapse
Affiliation(s)
- Lucas Portilho da Cunha
- Food Engineering and Technology Department, Institute of Biosciences, Letters and Exact Sciences, São Paulo State University (UNESP), Cristóvão Colombo 2265, Jardim Nazareth, São José Do Rio Preto, SP, 15054-000, Brazil.
| | - Fernanda Perpétua Casciatori
- Chemical Engineering Department, Federal University of São Carlos (UFSCar), Rod. Washington Luiz, km 235, SP 310, Bairro Monjolinho, São Carlos, SP, 13565-905, Brazil
| | - Isabella de Cenço Lopes
- Food Engineering and Technology Department, Institute of Biosciences, Letters and Exact Sciences, São Paulo State University (UNESP), Cristóvão Colombo 2265, Jardim Nazareth, São José Do Rio Preto, SP, 15054-000, Brazil
| | - João Cláudio Thoméo
- Food Engineering and Technology Department, Institute of Biosciences, Letters and Exact Sciences, São Paulo State University (UNESP), Cristóvão Colombo 2265, Jardim Nazareth, São José Do Rio Preto, SP, 15054-000, Brazil
| |
Collapse
|
12
|
Lopes RB, Faria M, Glare TR. A nonconventional two-stage fermentation system for the production of aerial conidia of entomopathogenic fungi utilizing surface tension. J Appl Microbiol 2018; 126:155-164. [PMID: 30353989 DOI: 10.1111/jam.14137] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 09/20/2018] [Accepted: 10/11/2018] [Indexed: 11/27/2022]
Abstract
AIM To describe a new approach in which production of conidia of an entomopathogenic fungus takes place on the surface of an unstirred shallow liquid culture kept in nonabsorbent wells distributed in plastic sheets resembling a honeycomb. METHODS AND RESULTS First, liquid incubation time and medium composition for production of Beauveria bassiana aerial conidia were optimized. Wells inoculated with Sabouraud dextrose yeast extract produced 2·2 × 108 conidia per cm2 of liquid surface following 5 days of incubation. Finally, tests were carried out in a prototype comprised of stacked plastic sheets in a cylindrical container. Conidia production on liquid culture surface varied from 1·2 to 1·6 × 109 conidia per ml of fermented broth. Germination rates and insect activity towards Tenebrio molitor larvae were not negatively affected when compared to conidia produced on solid medium. CONCLUSIONS The two-stage fermentation process here described, based on a simple nonabsorbent inert support, has potential for the application in the production of aerial conidia of B. bassiana and other fungi. SIGNIFICANCE AND IMPACT OF THE STUDY Aerial conidia are the most extensive propagule type used in commercial mycopesticides, traditionally produced by solid-state fermentation (SSF). The industrial applications and other important benefits of the two-stage fermentation process here described may overcome some hurdles inherent to SSF aiming for the production of aerial conidia. Additionally, production consistency is increased by the use of chemically defined medium, and the better control of the environmental conditions could allow for more reproducible industrial batches.
Collapse
Affiliation(s)
- R B Lopes
- EMBRAPA Genetic Resources and Biotechnology, Brasilia, DF, Brazil
| | - M Faria
- EMBRAPA Genetic Resources and Biotechnology, Brasilia, DF, Brazil
| | - T R Glare
- Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand
| |
Collapse
|
13
|
Isolation and characterization of Metarhizium anisopliae TK29 and its mycoinsecticide effects against subterranean termite Coptotermes formosanus. Microb Pathog 2018; 123:52-59. [PMID: 29959038 DOI: 10.1016/j.micpath.2018.06.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/24/2018] [Accepted: 06/25/2018] [Indexed: 11/20/2022]
Abstract
The entomopathogenic fungus Metarhizium anisopliae is widely used as biocontrol agent against many insect pests. In the present study, the potential isolate of M. anisopliae TK29 was isolated from the agricultural soils in Thekkady, India. The taxonomic identity of the isolate was confirmed based on its morphology and 18S rDNA gene sequence homology. Phylogenetic analysis confirmed that the isolated strains were related to the same species. A potential isolate (TK29) was optimized for mass cultivation and conidial spore production was enhanced using three different raw substrates (Rice, Maize, black gram) by solid-state fermentation. The results showed higher conidial spore yield from rice (2.6 ± 0.32%) compared to black gram (2.1 ± 0.28%) and maize (1.9 ± 0.23%) substrates. Dry green conidia were applied against Formosan subterranean termite, Coptotermes formosanus at three different concentrations (1 × 106, 1 × 107, and 1 × 108 conidia/ml-1). The highest mortality rate was obtained from 1 × 108 conidia/ml-1 at 120 h post-treatment. Our study indicated that M. anisopliae TK29 had desirable attributes for the development of a mycoinsecticide against C. formosanus.
Collapse
|
14
|
Chepkirui C, Sum WC, Cheng T, Matasyoh JC, Decock C, Stadler M. Aethiopinolones A-E, New Pregnenolone Type Steroids from the East African Basidiomycete Fomitiporia aethiopica. Molecules 2018; 23:molecules23020369. [PMID: 29425150 PMCID: PMC6017562 DOI: 10.3390/molecules23020369] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 02/07/2018] [Accepted: 02/08/2018] [Indexed: 11/16/2022] Open
Abstract
A mycelial culture of the Kenyan basidiomycete Fomitiporia aethiopica was fermented on rice and the cultures were extracted with methanol. Subsequent HPLC profiling and preparative chromatography of its crude extract led to the isolation of five previously undescribed pregnenolone type triterpenes 1-5, for which we propose the trivial name aethiopinolones A-E. The chemical structures of the aethiopinolones were determined by extensive 1D- and 2D-NMR, and HRMS data analysis. The compounds exhibited moderate cytotoxic effects against various human cancer cell lines, but they were found devoid of significant nematicidal and antimicrobial activities.
Collapse
Affiliation(s)
- Clara Chepkirui
- Department of Microbial Drugs, Helmholtz Centre for Infection Research and German Centre for Infection Research (DZIF), Partner Site Hannover/Braunschweig, Inhoffenstrasse 7, 38124 Braunschweig, Germany.
| | - Winnie C Sum
- Department of Biochemistry, Egerton University, P.O. BOX 536, Njoro 20115, Kenya.
| | - Tian Cheng
- Department of Microbial Drugs, Helmholtz Centre for Infection Research and German Centre for Infection Research (DZIF), Partner Site Hannover/Braunschweig, Inhoffenstrasse 7, 38124 Braunschweig, Germany.
| | - Josphat C Matasyoh
- Department of Chemistry, Egerton University, P.O. BOX 536, Njoro 20115, Kenya.
| | - Cony Decock
- Mycothéque de l' Universite Catholique de Louvain (BCCM/MUCL), Place Croix du Sud 3, B-1348 Louvain-la-Neuve, Belgium.
| | - Marc Stadler
- Department of Microbial Drugs, Helmholtz Centre for Infection Research and German Centre for Infection Research (DZIF), Partner Site Hannover/Braunschweig, Inhoffenstrasse 7, 38124 Braunschweig, Germany.
| |
Collapse
|
15
|
Wang J, Zhu XG, Ying SH, Feng MG. Differential Roles for Six P-Type Calcium ATPases in Sustaining Intracellular Ca 2+ Homeostasis, Asexual Cycle and Environmental Fitness of Beauveria bassiana. Sci Rep 2017; 7:1420. [PMID: 28469160 PMCID: PMC5431182 DOI: 10.1038/s41598-017-01570-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 03/31/2017] [Indexed: 12/18/2022] Open
Abstract
A global insight into the roles of multiple P-type calcium ATPase (CA) pumps in sustaining the life of a filamentous fungal pathogen is lacking. Here we elucidated the functions of five CA pumps (Eca1, Spf1 and PmcA/B/C) following previous characterization of Pmr1 in Beauveria bassiana, a fungal insect pathogen. The fungal CA pumps interacted at transcriptional level, at which singular deletions of five CA genes depressed eca1 expression by 76–98% and deletion of spf1 resulted in drastic upregulation of four CA genes by 36–50-fold. Intracellular Ca2+ concentration increased differentially in most deletion mutants exposed to the stresses of Ca2+, EDTA chelator, and/or endoplasmic reticulum and calcineurin inhibitors, accompanied with their changed sensitivities to not only the mentioned agents but also Fe2+, Cu2+ and Zn2+. Liquid culture acidification was delayed in the Δspf1, Δpmr1 and ΔpmcA mutants, coinciding well with altered levels of their extracellular lactic and oxalic acids. Moreover, all deletion mutants showed differential defects in conidial germination, vegetative growth, conidiation capacity, antioxidant activity, cell wall integrity, conidial UV-B resistance and/or virulence. Our results provide the first global insight into differential roles for six CA pumps in sustaining intracellular Ca2+ level, asexual cycle and environmental fitness of B. bassiana.
Collapse
Affiliation(s)
- Jie Wang
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.,College of Food Science, South China Agricultural University, Guangzhou, 510642, Guangdong, China
| | - Xiao-Guan Zhu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Sheng-Hua Ying
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
| |
Collapse
|
16
|
Muñiz-Paredes F, Garza-López PM, Viniegra-González G, Loera O. Comparison between superficial and solid-state cultures of Isaria fumosorosea: conidial yields, quality and sensitivity to oxidant conditions. World J Microbiol Biotechnol 2016; 32:111. [PMID: 27263006 DOI: 10.1007/s11274-016-2072-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 04/23/2016] [Indexed: 12/24/2022]
Abstract
Conidia production and quality from mycoinsecticides in solid-state cultures (SSC) are frequently inferred from superficial culture (SC) results. Both parameters were evaluated for two Isaria fumosorosea strains (ARSEF 3302 and CNRCB1), in SC and SSC, using culture media with the same chemical composition. For both strains, conidia production was higher in SC than SSC in terms of conidia per gram of dry substrate. Germination in both strains did not show significant differences between SC and SSC (>90 %). Similarly, conidia viability in ARSEF 3302 strain did not show differences at early stages between SC and SSC, but was higher in SC compared to SSC in the late stage of culture; in contrast, conidia from CNRCB1 strain did not differ between both culture systems. Some infectivity parameters improved in conidia from SSC, compared to SC at the early stages, but these differences disappeared at the final stage, independently of the strain. Both strains showed decreased conidia production when 26 % O2 pulses were applied; nevertheless, conidiation in SSC was two orders of magnitude more sensitive to oxidant pulses. In SC with 26 % O2 pulses, conidia viability for both strains at early stages, was higher than in normal atmospheric conditions. Infectivity towards Galleria mellonella larvae was similar between conidia from normal atmosphere and oxidant conditions; notably, for the strain ARSEF 3302 infectivity decreased at the final stage. This study shows the intrinsic differences between SC and SSC, which should be considered when using SC as a model to design production processes in SSC.
Collapse
Affiliation(s)
- Facundo Muñiz-Paredes
- Departamento de Biotecnología, Universidad Autónoma Metropolitana Iztapalapa, 09340, Iztapalapa, Mexico City, Mexico
| | - Paul Misael Garza-López
- Instituto de Ciencias Agropecuarias, Universidad Autónoma del Estado de Hidalgo, 43600, Tulancingo, Hidalgo, Mexico
| | - Gustavo Viniegra-González
- Departamento de Biotecnología, Universidad Autónoma Metropolitana Iztapalapa, 09340, Iztapalapa, Mexico City, Mexico
| | - Octavio Loera
- Departamento de Biotecnología, Universidad Autónoma Metropolitana Iztapalapa, 09340, Iztapalapa, Mexico City, Mexico.
| |
Collapse
|
17
|
Pérez-Guzmán D, Montesinos-Matías R, Arce-Cervantes O, Gómez-Quiroz LE, Loera O, Garza-López PM. Reactive oxygen species production, induced by atmospheric modification, alter conidial quality of Beauveria bassiana. J Appl Microbiol 2016; 121:453-60. [PMID: 27107399 DOI: 10.1111/jam.13156] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 04/04/2016] [Accepted: 04/20/2016] [Indexed: 11/27/2022]
Abstract
AIM The aim of this study was to determine the relationship between reactive oxygen species (ROS) production and conidial infectivity in Beauveria bassiana. METHODS AND RESULTS Beauveria bassiana Bb 882.5 was cultured in solid-state culture (SSC) using rice under three oxygen conditions (21%, or pulses at 16 and 26%). Hydrophobicity was determined using exclusion phase assay. Bioassays with larvae or adults of Tenebrio molitor allowed the measurements of infectivity parameters. A fluorometric method was used for ROS quantification (superoxide and total peroxides). NADPH oxidase (NOX) activity was determined by specific inhibition. Conidial hydrophobicity decreased by O2 pulses. Mortality of larvae was only achieved with conidia harvested from cultures under 21% O2 ; whereas for adult insects, the infectivity parameters deteriorated in conidia obtained after pulses at 16 and 26% O2 . At day 7, ROS production increased after 16 and 26% O2 treatments. NOX activity induced ROS production at early stages of the culture. CONCLUSION Modification of atmospheric oxygen increases ROS production, reducing conidial quality and infectivity. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first study in which conidial infectivity and ROS production in B. bassiana has been related, enhancing the knowledge of the effect of O2 pulses in B. bassiana.
Collapse
Affiliation(s)
- D Pérez-Guzmán
- División de Ingeniería Ambiental, Tecnológico de Estudios Superiores del Oriente del Estado de México, La Paz, Estado de México, Mexico
| | | | - O Arce-Cervantes
- Instituto de Ciencias Agropecuarias, Universidad Autónoma del Estado de Hidalgo, Tulancingo, Hidalgo, Mexico
| | - L E Gómez-Quiroz
- Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, México D.F, Mexico
| | - O Loera
- Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, México D.F, Mexico
| | - P M Garza-López
- Instituto de Ciencias Agropecuarias, Universidad Autónoma del Estado de Hidalgo, Tulancingo, Hidalgo, Mexico
| |
Collapse
|
18
|
Fuller K, Dunlap J, Loros J. Fungal Light Sensing at the Bench and Beyond. ADVANCES IN GENETICS 2016; 96:1-51. [DOI: 10.1016/bs.adgen.2016.08.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
19
|
Nian XG, He YR, Lu LH, Zhao R. Evaluation of alternative Plutella xylostella control by two Isaria fumosorosea conidial formulations - oil-based formulation and wettable powder - combined with Bacillus thuringiensis. PEST MANAGEMENT SCIENCE 2015; 71:1675-1684. [PMID: 25641869 DOI: 10.1002/ps.3977] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 12/05/2014] [Accepted: 01/07/2015] [Indexed: 06/04/2023]
Abstract
BACKGROUND Entomopathogenic fungi are potential candidates for controlling the diamondback moth Plutella xylostella (L.) (Lepidoptera: Plutellidae). The control efficacy of two Isaria fumosorosea conidial formulations - wettable powder and oil-based formulation - combined with Bacillus thuringiensis against P. xylostella was tested. RESULTS In the laboratory, the combined application of two pathogens increased larval mortality either in an additive or a synergistic way. P. xylostella larvae treated with oil-based formulation died sooner than larvae infected with wettable powder. For pot and field experiments, each formulation was applied alone or combined with B. thuringiensis 668 µg mL(-1) , and then larval mortality, pupation rate, adult emergence rate, female longevity and fecundity were recorded. In pot experiments there was no evidence of any antagonistic effects between the two pathogens. Combined application of B. thuringiensis and a high concentration of the two I. fumosorosea formulations resulted in higher mortality (84.4 and 86.2%) with minimum pupation (15.6 and 11.9%) and adult emergence rates (8.7 and 7.0%). Female longevity and fecundity were significantly reduced by the two formulations at high concentration compared with the control. Similar results were also observed in field experiments. CONCLUSION The combined application of I. fumosorosea and B. thuringiensis is a promising alternative strategy for P. xylostella control. © 2015 Society of Chemical Industry.
Collapse
Affiliation(s)
- Xiao-Ge Nian
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong, China
| | - Yu-Rong He
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong, China
| | - Li-Hua Lu
- Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong, China
| | - Rui Zhao
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong, China
| |
Collapse
|
20
|
WetA and VosA are distinct regulators of conidiation capacity, conidial quality, and biological control potential of a fungal insect pathogen. Appl Microbiol Biotechnol 2015; 99:10069-81. [DOI: 10.1007/s00253-015-6823-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 07/01/2015] [Accepted: 07/05/2015] [Indexed: 12/31/2022]
|
21
|
Critical Values of Porosity in Rice Cultures of Isaria fumosorosea by Adding Water Hyacinth: Effect on Conidial Yields and Quality. Appl Biochem Biotechnol 2015; 177:446-57. [PMID: 26184013 DOI: 10.1007/s12010-015-1754-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 07/06/2015] [Indexed: 10/23/2022]
Abstract
Conidia of the entomopathogenic fungus Isaria fumosorosea are used to control insect pests in crops. Commercially available mycoinsecticides manufactured with this fungus are produced on a large scale via solid-state cultures (SSC). In order to favour gaseous exchange in SCC, texturizers can be added to increase porosity fraction (ε). This work presents results of water hyacinth (Eichhornia crassipes) as a novel texturizer. A mixture of parboiled rice (PR), with a ε = 0.23, was used as a substrate, which was then mixed with water hyacinth (WH amendment) as a texturizer at different proportions affecting ε. Strains CNRCB1 and ARSEF3302 of I. fumosorosea yielded 1.6 (1.49-1.71) × 10(9) and 7.3 (7.02-7.58) × 10(9) conidia per gram of initial dry rice after 8 days, at ε values of 0.34 and 0.36, respectively. Improvement of conidial yields corresponded to 1.33 and 1.55 times, respectively, compared to rice alone using WH amendment in the mixtures PR:WH (%) at 90-10 and 80-20. In addition, infectivity against Galleria mellonella larvae was maintained. This is the first report of the use of water hyacinth as a texturizer in SSC, affecting ε, which is proposed a key parameter in conidia production by I. fumosorosea, without affecting conidial infectivity.
Collapse
|
22
|
Rodriguez-Gomez D, Marcial-Quino J, Loera O. Modulation of conidia production and expression of the gene bbrgs1 from Beauveria bassiana by oxygen pulses and light. J Invertebr Pathol 2015; 130:82-7. [PMID: 26166809 DOI: 10.1016/j.jip.2015.07.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 07/07/2015] [Accepted: 07/08/2015] [Indexed: 11/29/2022]
Abstract
Light and oxidant states affect the conidiation in diverse fungi, although the response has not been described when both stimuli are applied simultaneously. Conidial production and quality in Beauveria bassiana were analysed under four conditions for a wild-type (wt) strain and a previously isolated mutant (mt): normal atmosphere (21% O2; NA) or oxygen-enriched pulses (26% O2; OEP), with either light (L) or darkness (D). The response was complemented by following the expression of the bbrgs1 gene, encoding a regulator of the G-protein signal associated to conidia production. Conidiation was not significantly affected in the mutant strain by any condition (highest value with NA-L: 2.7×10(8)concm(-2)). Relative to maximal levels under NA (NA-D: 4×10(7)concm(2)), the wt strain diminished conidiation by 34-fold under OEP. The expression of bbrgs1 was higher (up to 188 times) in the mutant strain in every condition relative to the wt strain, in fact expression levels were consistent with the conidiation yields between strains. Viability and hydrophobicity were less affected by culture conditions, although pathogenicity parameters improved in conidia from OEP. The response to OEP, either with light or darkness, was strain-dependent for conidial production, viability, hydrophobicity and infectivity of conidia, then these parameters could be modulated in mass production processes.
Collapse
Affiliation(s)
- Divanery Rodriguez-Gomez
- Departmento de Biotecnologia, Universidad Autonoma Metropolitana-Iztapalapa, 09340 Mexico, D.F., Mexico
| | - Jaime Marcial-Quino
- Cátedras CONACyT, comissioned to Instituto Nacional de Pediatrıa, S.S., 04530 Mexico, D.F., Mexico
| | - Octavio Loera
- Departmento de Biotecnologia, Universidad Autonoma Metropolitana-Iztapalapa, 09340 Mexico, D.F., Mexico.
| |
Collapse
|
23
|
Garza-López PM, Suárez-Vergel G, Hamdan-Partida A, Loera O. Variations in oxygen concentration cause differential antioxidant response and expression of related genes in Beauveria bassiana. Fungal Biol 2015; 119:257-63. [PMID: 25813512 DOI: 10.1016/j.funbio.2014.12.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 12/17/2014] [Accepted: 12/23/2014] [Indexed: 10/24/2022]
Abstract
The entomopathogenic fungus Beauveria bassiana is widely used in pest biocontrol strategies. We evaluated both the antioxidant response mediated by compatible solutes, trehalose or mannitol, and the expression of related genes using oxygen pulses at three oxygen concentrations in solid state culture (SSC): normal atmosphere (21% O2), low oxygen (16% O2) and enriched oxygen (26% O2). Trehalose concentration decreased 75% after atmospheric modifications in the cultures, whereas mannitol synthesis was three-fold higher under the 16% O2 pulses relative to normal atmosphere (100 and 30 μg mannitol mg(-1) biomass, respectively). Confirming this result, expression of the mpd gene, coding for mannitol-1-P dehydrogenase (MPD), increased up to 1.4 times after O2 pulses. The expression of the bbrgs1 gene, encoding a regulatory G protein related to conidiation, was analysed to explain previously reported differences in conidial production. Surprisingly, expression of bbrgs1 decreased after atmospheric modification. Finally, principal component analysis (PCA) indicated that 83.39% of the variability in the data could be explained by two components. This analysis corroborated the positive correlation between mannitol concentration and mpd gene expression, as well as the negative correlation between conidial production and bbrgs1 gene expression. This study contributes to understanding of antioxidant and molecular response of B. bassiana induced under oxidant conditions.
Collapse
Affiliation(s)
- Paul Misael Garza-López
- Universidad Autónoma Metropolitana Iztapalapa, Departamento de Biotecnología, San Rafael Atlixco 186, Col. Vicentina, C. P. 09340, México D. F., Mexico
| | - Gerardo Suárez-Vergel
- Universidad Autónoma Metropolitana Iztapalapa, Departamento de Biotecnología, San Rafael Atlixco 186, Col. Vicentina, C. P. 09340, México D. F., Mexico
| | - Aida Hamdan-Partida
- Universidad Autónoma Metropolitana Xochimilco, Departamento de Sistemas Biológicos, Calz. del Hueso 1100, Col. Villa Quietud, C. P. 04960, México, D. F., Mexico
| | - Octavio Loera
- Universidad Autónoma Metropolitana Iztapalapa, Departamento de Biotecnología, San Rafael Atlixco 186, Col. Vicentina, C. P. 09340, México D. F., Mexico.
| |
Collapse
|
24
|
Nian XG, He YR, Lu LH, Zhao R. Evaluation of the time-concentration-mortality responses of Plutella xylostella larvae to the interaction of Isaria fumosorosea with the insecticides beta-cypermethrin and Bacillus thuringiensis. PEST MANAGEMENT SCIENCE 2015; 71:216-224. [PMID: 24668916 DOI: 10.1002/ps.3784] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/09/2014] [Accepted: 03/21/2014] [Indexed: 06/03/2023]
Abstract
BACKGROUND Entomopathogenic fungi are potential candidates for controlling Plutella xylostella, a cosmopolitan pest of crucifers. In this study, bioassays were conducted to evaluate the interaction between Isaria fumosorosea and sublethal doses of two insecticides, beta-cypermethrin and Bacillus thuringiensis, against P. xylostella. RESULTS Data of each assay were in good agreement with the time-concentration-mortality model, indicating a strong dependence of the fungus and insecticide interaction on both concentration and post-exposure time. Using beta-cypermethrin 58-116 µg mL(-1) or B. thuringiensis 222.5-890 µg mL(-1) with the fungus significantly enhanced fungal efficacy. The LC50 values of the fungus declined over a 1-7 day period after exposure, and the LT50 values decreased with increasing concentration. Based on LC50 or LC90 estimates, synergism between the fungus and beta-cypermethrin resulted in a 2.7-28.3-fold reduction in LC50 values and a 12.1-19.6-fold reduction in LC90 values, while synergism of the fungus with B. thuringiensis led to a 2.4-385.0-fold reduction in LC50 values and a 4.4-151.7-fold reduction in LC90 values. CONCLUSION Results show that sublethal doses of B. thuringiensis and beta-cypermethrin can synergise I. fumosorosea activity on P. xylostella, suggesting that combination of I. fumosorosea with the two insecticides might offer an integrated approach to controlling P. xylostella in practice. © 2014 Society of Chemical Industry.
Collapse
Affiliation(s)
- Xiao-ge Nian
- College of Resources and Environment, South China Agricultural University, Guangdong, Guangzhou, China
| | | | | | | |
Collapse
|
25
|
He PH, Wang XX, Chu XL, Feng MG, Ying SH. RNA sequencing analysis identifies the metabolic and developmental genes regulated by BbSNF1 during conidiation of the entomopathogenic fungus Beauveria bassiana. Curr Genet 2014; 61:143-52. [DOI: 10.1007/s00294-014-0462-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 11/13/2014] [Accepted: 11/14/2014] [Indexed: 10/24/2022]
|
26
|
Wang JJ, Qiu L, Cai Q, Ying SH, Feng MG. Three α-1,2-mannosyltransferases contribute differentially to conidiation, cell wall integrity, multistress tolerance and virulence of Beauveria bassiana. Fungal Genet Biol 2014; 70:1-10. [PMID: 24981201 DOI: 10.1016/j.fgb.2014.06.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 06/02/2014] [Accepted: 06/22/2014] [Indexed: 11/25/2022]
Abstract
Members of α-1,2-mannosyltransferase (Ktr) family are required for protein O-mannosylation for the elongation of Ser/Thr mannose residues in yeasts but functionally unknown in most filamentous fungi. Here we characterized the functions of the Ktr orthologues Ktr1, Ktr4 and Kre2/Mnt1 in Beauveria bassiana, a filamentous enotmopathogen, and found that they were positive, but differential, mediators of many biological traits. Inactivation of Ktr4 and Kre2 resulted in 92% reduction of conidial yield on a standard medium and growth defects on substrates with altered carbon or nitrogen sources and availability, accompanied with reduced conidial size and complexity. This contrasts to the dispensability of Ktr1 for fungal growth and conidiation. More cell wall damage occurred in Δktr4 and Δkre2 than in Δktr1, including altered contents of the cell wall components mannoproteins, α-glucans and chitin, more carbohydrate epitopes changed on conidial surfaces, much lower conidial hydrophobicity, and thinner cell walls. Consequently, Δktr4 and Δkre2 became more sensitive to oxidation and cell wall perturbation than Δktr1 during colony growth or conidial germination despite less difference in their sensitivities to two osmotic agents. Conidial thermotolerance, UV-B resistance and virulence were all lowered greatly in Δktr4 and Δkre2 but only the thermotolerance decreased in Δktr1. All the phenotypical changes were well restored to wild-type levels by the complementation of each target gene. Our results indicate that Ktr4 and Kre2 contribute more to the biocontrol potential of B. bassiana than Ktr1 although all of them are significant contributors.
Collapse
Affiliation(s)
- Juan-Juan Wang
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, People's Republic of China
| | - Lei Qiu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, People's Republic of China
| | - Qing Cai
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, People's Republic of China
| | - Sheng-Hua Ying
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, People's Republic of China
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, People's Republic of China.
| |
Collapse
|
27
|
Qiu L, Wang JJ, Chu ZJ, Ying SH, Feng MG. Phytochrome controls conidiation in response to red/far-red light and daylight length and regulates multistress tolerance inBeauveria bassiana. Environ Microbiol 2014; 16:2316-28. [DOI: 10.1111/1462-2920.12486] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 04/03/2014] [Indexed: 12/13/2022]
Affiliation(s)
- Lei Qiu
- Institute of Microbiology; College of Life Sciences; Zhejiang University; Hangzhou Zhejiang China
| | - Juan-Juan Wang
- Institute of Microbiology; College of Life Sciences; Zhejiang University; Hangzhou Zhejiang China
| | - Zhen-Jian Chu
- Institute of Microbiology; College of Life Sciences; Zhejiang University; Hangzhou Zhejiang China
| | - Sheng-Hua Ying
- Institute of Microbiology; College of Life Sciences; Zhejiang University; Hangzhou Zhejiang China
| | - Ming-Guang Feng
- Institute of Microbiology; College of Life Sciences; Zhejiang University; Hangzhou Zhejiang China
| |
Collapse
|
28
|
Zhang L, Shi WB, Feng MG. Histopathological and molecular insights into the ovicidal activities of two entomopathogenic fungi against two-spotted spider mite. J Invertebr Pathol 2014; 117:73-8. [DOI: 10.1016/j.jip.2014.02.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 02/12/2014] [Indexed: 11/26/2022]
|
29
|
Lopez-Perez M, Rodriguez-Gomez D, Loera O. Production of conidia ofBeauveria bassianain solid-state culture: current status and future perspectives. Crit Rev Biotechnol 2014; 35:334-41. [DOI: 10.3109/07388551.2013.857293] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
30
|
A fungal insecticide engineered for fast per os killing of caterpillars has high field efficacy and safety in full-season control of cabbage insect pests. Appl Environ Microbiol 2013; 79:6452-8. [PMID: 23956386 DOI: 10.1128/aem.01594-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fungal insecticides developed from filamentous pathogens of insects are notorious for their slow killing action through cuticle penetration, depressing commercial interest and practical application. Genetic engineering may accelerate their killing action but cause ecological risk. Here we show that a Beauveria bassiana formulation, HV8 (BbHV8), engineered for fast per os killing of caterpillars by an insect midgut-acting toxin (Vip3Aa1) overexpressed in conidia has both high field efficacy and safety in full-season protection of cabbage from the damage of an insect pest complex dominated by Pieris rapae larvae, followed by Plutella xylostella larvae and aphids. In two fields repeatedly sprayed during summer, BbHV8 resulted in overall mean efficacies of killing of 71% and 75%, which were similar or close to the 70% and 83% efficacies achieved by commercially recommended emamectin benzoate but much higher than the 31% and 48% efficacies achieved by the same formulation of the parental wild-type strain (WT). Both BbHV8 and WT sprays exerted no adverse effect on a nontarget spider community during the trials, and the sprays did not influence saprophytic fungi in soil samples taken from the field plots during 4 months after the last spray. Strikingly, BbHV8 and the WT showed low fitness when they were released into the environment because both were decreasingly recovered from the field lacking native B. bassiana strains (undetectable 5 months after the spray), and the recovered isolates became much less tolerant to high temperature and UV-B irradiation. Our results highlight for the first time that a rationally engineered fungal insecticide can compete with a chemical counterpart to combat insect pests at an affordable cost and with low ecological risk.
Collapse
|
31
|
Abstract
Conidia of Beauveria bassiana Bb-202, which have the potential for the control of the coleopteran pests, were produced on rice by solid-state fermentation (SSF) using tray bioreactor. As the solid substrate thickness increased, the production of conidia decreased. By cutting substrate into many small uniform pieces, metabolic heat and gas transfer in center of substrate could be improved. We concluded that the highest yield of 3.94×1012 conidia kg-1 rice was obtained as the substrate of 2cm thickness was cut into many small pieces (6cm×4cm×2cm). And the average yield of conidia increases by 45%. It indicated that cut solid substrate into many pieces would increasing the surface area of substrate. So the conidia yields were significantly increased.
Collapse
|
32
|
Garza-López PM, Konigsberg M, Gómez-Quiroz LE, Loera O. Physiological and antioxidant response by Beauveria bassiana Bals (Vuill.) to different oxygen concentrations. World J Microbiol Biotechnol 2011; 28:353-9. [PMID: 22806811 DOI: 10.1007/s11274-011-0827-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 06/18/2011] [Indexed: 12/25/2022]
Abstract
The effect of three levels of oxygen (normal atmosphere (21% O(2)), low oxygen (16% O(2)) and enriched oxygen (26% O(2))) on the production and germination of conidia by Beauveria bassiana was evaluated using rice as a substrate. The maximum yield of conidia was achieved under hypoxia (16% O(2)) after 8 days of culture (1.51 × 10(9) conidia per gram of initial dry substrate), representing an increase of 32% compared to the normal atmosphere. However, germination was reduced by at least 27% due to atmospheric modifications. Comparison of antioxidant enzyme activity (superoxide dismutases and catalases) with the oxidation profiles of biomolecules (proteins and lipids) showed that a decrease in catalase activity in the final days of culture coincided with an increase in the amount of oxidized lipids, showing that oxidative stress was a consequence of pulses of different concentrations of O(2). This is the first study describing oxidative stress induction by atmospheric modification, with practical implications for conidia production.
Collapse
Affiliation(s)
- Paul Misael Garza-López
- Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, 09340, México, DF, Mexico
| | | | | | | |
Collapse
|
33
|
Ying SH, Feng MG. A conidial protein (CP15) of Beauveria bassiana contributes to the conidial tolerance of the entomopathogenic fungus to thermal and oxidative stresses. Appl Microbiol Biotechnol 2011; 90:1711-20. [PMID: 21455593 DOI: 10.1007/s00253-011-3205-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2011] [Revised: 02/07/2011] [Accepted: 02/07/2011] [Indexed: 11/25/2022]
Abstract
Aerial conidia are central dispersing structures for most fungi and represent the infectious propagule for entomopathogenic fungus Beauveria bassiana, thus the active ingredients of commercial mycoinsecticides. Although a number of formic-acid-extractable (FAE) cell wall proteins from conidia have been characterized, the functions of many such proteins remain obscure. We report that a conidial FAE protein, termed CP15, isolated from B. bassiana is related to fungal tolerance to thermal and oxidative stresses. The full-length genomic sequence of CP15 was shown to lack introns, encoding for a 131 amino acid protein (15.0 kDa) with no sequence identity to any known proteins in the NCBI database. The function of this new gene with two genomic copies was examined using the antisense-RNA method. Five transgenic strains displayed various degrees of silenced CP15 expression, resulting in significantly reduced conidial FAE protein profiles. The FAE protein contents of the strains were linearly correlated to the survival indices of their conidia when exposed to 30-min wet stress at 48°C (r (2) = 0.93). Under prolonged 75-min heat stress, the median lethal times (LT(50)s) of their conidia were significantly reduced by 13.6-29.5%. The CP15 silenced strains were also 20-50% less resistant to oxidative stress but were not affected with respect to UV-B or hyperosmotic stress. Our data indicate that discrete conidial proteins may mediate resistance to some abiotic stresses, and that manipulation of such proteins may be a viable approach to enhancing the environmental fitness of B. bassiana for more persisting control of insect pests in warmer climates.
Collapse
Affiliation(s)
- Sheng-Hua Ying
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | | |
Collapse
|
34
|
Ansari M, Butt T. Effects of successive subculturing on stability, virulence, conidial yield, germination and shelf-life of entomopathogenic fungi. J Appl Microbiol 2011; 110:1460-9. [DOI: 10.1111/j.1365-2672.2011.04994.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
35
|
Shan LT, Feng MG. Evaluation of the biocontrol potential of various Metarhizium isolates against green peach aphid Myzus persicae (Homoptera: Aphididae). PEST MANAGEMENT SCIENCE 2010; 66:669-675. [PMID: 20201034 DOI: 10.1002/ps.1928] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
BACKGROUND Twenty-three isolates of Metarhizium anisopliae (Metschnikof) Sorokin and M. acridum (Driver & Milner) JF Bischoff, Rehner & Humber from non-aphid host insects around the globe were evaluated for their aphid biocontrol potential, which is not well known. RESULTS The apterous adults of green peach aphid Myzus persicae (Sulzer) were exposed to the fungal sprays of 11.5, 99 and 1179 conidia mm(-2) and blank control in three leaf-dish bioassays. All the tested isolates except one were proven to be infective to the aphid species at 21 +/- 1 degrees C and 14:10 h light:dark photoperiod, causing corrected mortalities of 10.1-95.3% at the high spore concentration. The data from ten isolates causing > 50% mortality at the high concentration were found to fit a time-concentration-mortality model well, yielding parameters for the estimates of their LC(50) and LT(50) that vary with post-spray time and spore concentration respectively. Four isolates of M. anisopliae (ARSEF 759, 4132, 2080 and 576) had LC(50) values of 44-80 conidia mm(-2) on day 8 and LT(50) values of 4.9-6.8 days at 100 conidia mm(-2), with 91-98% of the killed aphids being well mycotised after death. CONCLUSION The Metarhizium infectivity to M. persicae differs greatly among the tested isolates. The four mentioned isolates with desired virulence and sporulation potential are excellent candidates for microbial control of aphids.
Collapse
Affiliation(s)
- Le-Tian Shan
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, People's Republic of China
| | | |
Collapse
|
36
|
Integration of insecticidal protein Vip3Aa1 into Beauveria bassiana enhances fungal virulence to Spodoptera litura larvae by cuticle and per Os infection. Appl Environ Microbiol 2010; 76:4611-8. [PMID: 20495052 DOI: 10.1128/aem.00302-10] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The entomopathogenic fungus Beauveria bassiana acts slowly on insect pests through cuticle infection. Vegetative insecticidal proteins (Vip3A) of Bacillus thuringiensis kill lepidopteran pests rapidly, via per os infection, but their use for pest control is restricted to integration into transgenic plants. A transgenic B. bassiana strain (BbV28) expressing Vip3Aa1 (a Vip3A toxin) was thus created to infect the larvae of the oriental leafworm moth Spodoptera litura through conidial ingestion and cuticle adhesion. Vip3Aa1 ( approximately 88 kDa) was highly expressed in the conidial cytoplasm of BbV28 and was detected as a digested form ( approximately 62 kDa) in the larval midgut 18 and 36 h after conidial ingestion. The median lethal concentration (LC(50)) of BbV28 against the second-instar larvae feeding on cabbage leaves sprayed with conidial suspensions was 26.2-fold lower than that of the wild-type strain on day 3 and 1.1-fold lower on day 7. The same sprays applied to both larvae and leaves for their feeding reduced the LC(50) of the transformant 17.2- and 1.3-fold on days 3 and 7, respectively. Median lethal times (LT(50)s) of BbV28 were shortened by 23 to 35%, declining with conidial concentrations. The larvae infected by ingestion of BbV28 conidia showed typical symptoms of Vip3A action, i.e., shrinkage and palsy. However, neither LC(50) nor LT(50) trends differed between BbV28 and its parental strain if the infection occurred through the cuticle only. Our findings indicate that fungal conidia can be used as vectors for spreading the highly insecticidal Vip3A protein for control of foliage feeders such as S. litura.
Collapse
|
37
|
Shan LT, Wang ZL, Ying SH, Feng MG. Hydrophobicity-Related Protein Contents and Surface Areas of Aerial Conidia are Useful Traits for Formulation Design of Fungal Biocontrol Agents. Mycopathologia 2010; 169:483-94. [DOI: 10.1007/s11046-010-9283-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Accepted: 02/02/2010] [Indexed: 10/19/2022]
|
38
|
Luiza de Farias V, Ximenes Monteiro K, Rodrigues S, André Narciso Fernandes F, Adolfo Saavedra Pinto G. Comparison of Aspergillus niger spore production on Potato Dextrose Agar (PDA) and crushed corncob medium. J GEN APPL MICROBIOL 2010; 56:399-402. [DOI: 10.2323/jgam.56.399] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
39
|
Shi WB, Feng MG, Liu SS. Sprays of emulsifiable Beauveria bassiana formulation are ovicidal towards Tetranychus urticae (Acari: Tetranychidae) at various regimes of temperature and humidity. EXPERIMENTAL & APPLIED ACAROLOGY 2008; 46:247-257. [PMID: 18584129 DOI: 10.1007/s10493-008-9172-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Accepted: 06/09/2008] [Indexed: 05/26/2023]
Abstract
Aerial conidia of Beauveria bassiana in an emulsifiable formulation germinated by >95% after 24 h exposure to the regimes of 20, 25 and 30 degrees C with 51%, 74% and 95% RH. Ovicidal activities of the formulation towards two-spotted spider mite, Tetranychus urticae, were assayed at the concentrations of 0, 18, 160 and 693 conidia mm(-2) sprayed separately onto fava bean leaves including 39 (25-76) eggs per capita. All the sprayed eggs on the leaves were directly exposed to the different regimes for hatch after 24 h maintenance in covered Petri dishes. Generally, hatched proportions increased over post-spray days and decreased with the elevated fungal concentrations; no more eggs hatched from day 9 or 10 onwards. Based on the counts of the hatched/non-hatched eggs in the different regimes, the final egg mortalities were 15.0-40.4%, 48.9-66.6% and 62.9-87.5% at the low, medium and high concentrations, respectively, but only 5.6-11.3% in blank controls. The RH effect on the fungal action was significant at 20 and 25 degrees C but not at 30 degrees C whereas the effect of temperature was significant at 51% and 74% RH but not at 95% RH. Probit analysis of the egg mortalities versus the fungal sprays generated median lethal concentrations (LC(50)) of 65-320 conidia mm(-2) at all the regimes, and of only 65-78 conidia mm(-2) at 25-30 degrees C with 74-95% RH. The results highlight ovicidal activities of the emulsifiable formulation against the mite species at the tested regimes and its potential use in spider mite control.
Collapse
Affiliation(s)
- Wei-Bing Shi
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | | | | |
Collapse
|
40
|
Jin SF, Feng MG, Chen JQ. Selection of global Metarhizium isolates for the control of the rice pest Nilaparvata lugens (Homoptera: Delphacidae). PEST MANAGEMENT SCIENCE 2008; 64:1008-1014. [PMID: 18438960 DOI: 10.1002/ps.1597] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
BACKGROUND This study was initiated to search for fungal candidates for microbial control of brown planthopper (BPH) Nilaparvata lugens Stål, to which little attention has been paid in the past two decades. RESULTS Thirty-five isolates of Metarhizium anisopliae (Metschnikoff) Sorokin and M. flavoviride Gams & Rozsypal from different host insects worldwide were bioassayed for their lethal effects against third-instar BPH nymphs at 25 degrees C and a 14:10 h light:dark photoperiod at ca 1000 conidia mm(-2). On day 9 post-treatment, mortality attributable to mycosis ranged from 6.5 to 64.2% and differed significantly among the tested isolates with no apparent relationship to their host origin. Only two BPH-derived M. anisopliae isolates from the Philippines (ARSEF456) and Indonesia (ARSEF576) killed >50% of the nymphs. Both isolates were further bioassayed for time-concentration-mortality responses of the nymphs to the sprays of 19-29, 118-164 and 978-1088 conidia mm(-2) in repeated bioassays. The resultant data fitted a time-concentration-mortality model very well. Their LC(50) values were estimated as 731 and 1124 conidia mm(-2) on day 7 and fell to 284 and 306 conidia mm(-2), respectively, on day 10. CONCLUSION The two M. anisopliae isolates are potential biocontrol agents of BPH for further research. This is the first report of the lethal effects of global Metarhizium isolates on the rice pest.
Collapse
Affiliation(s)
- Shao-Feng Jin
- Institute of Microbiology, College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310058, People's Republic of China
| | | | | |
Collapse
|
41
|
Li J, Feng MG. Intraspecific tolerance of Metarhizium anisopliae conidia to the upper thermal limits of summer with a description of a quantitative assay system. ACTA ACUST UNITED AC 2008; 113:93-9. [PMID: 18804165 DOI: 10.1016/j.mycres.2008.08.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2007] [Revised: 02/10/2008] [Accepted: 08/12/2008] [Indexed: 10/21/2022]
Abstract
Conidial tolerance to the upper thermal limits of summer is important for fungal biocontrol agents, whose conidia are formulated into mycoinsecticides for field application. To develop an efficient assay system, aerial conidia of eight Metarhizium anisopliae, four M. anisopliae var. anisopliae, and six M. anisopliae var. acridum isolates with different host and geographic origins were wet-stressed for <or=180 min at 48 degrees C or incubated for 14 d colony growths at 10-35 degrees C. The survival ratios (relative to unstressed conidia) of each isolate, examined at 15-min intervals, fit a logistic equation (r2>or=0.975), yielding median lethal times (LT50s) of 14.3-150.3 min for the 18 isolates stressed at 48 degrees C. Seven grasshopper isolates from Africa had a mean LT50 of 110 (73-150) min, but could not grow at 10 or 15 degrees C. The mean LT50 of five non-grasshopper isolates capable of growing at 10-35 degrees C was 16 (10-26) min only. Three isolates with typically low (type I), medium (type II), and high (type III) levels of tolerance to 48 degrees C were further assayed for <or=4-d tolerance of their conidia to the wet stress at 38, 40, 42, or 45 degrees C. The resultant LT50s decreased to 20, 53 and 167 min at 48 degrees C from 507, 1612, and 8256 min at 38 degrees C for types I, II and III, respectively. For the distinguished types, the logarithms of the LT50s were significantly correlated to the temperatures of 38-48 degrees C with an inverse linearity (r2>or=0.88). The method developed to assay quantitatively fungal thermotolerance would be useful for screening of fungal candidates for improved pest control in summer.
Collapse
Affiliation(s)
- Jun Li
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China
| | | |
Collapse
|
42
|
Bhanu Prakash GVS, Padmaja V, Siva Kiran RR. Statistical optimization of process variables for the large-scale production of Metarhizium anisopliae conidiospores in solid-state fermentation. BIORESOURCE TECHNOLOGY 2008; 99:1530-7. [PMID: 17590331 DOI: 10.1016/j.biortech.2007.04.031] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2006] [Revised: 04/14/2007] [Accepted: 04/15/2007] [Indexed: 05/16/2023]
Abstract
Optimization of conidial production was achieved by response surface methodology (RSM), a powerful mathematical approach widely applied in the optimization of fermentation process, using the three substrates; rice, barley and sorghum at variable pH, moisture content and yeast extract concentrations. These three factors were found to be important, affecting Metarhizium anisopliae spore production. A 2(3) full factorial central composite design and RSM were applied to determine the optimal concentration of each variable. A second-order polynomial was determined by the multiple regression analysis of the experimental data. Moisture content of 75.68% for sorghum, 73.21% for barley and 22.34% for rice produced optimal results. Maximal conidial yield was recorded for rice at a pH of 7.01; at 7.06 for sorghum and at 6.76 for barley.
Collapse
Affiliation(s)
- G V S Bhanu Prakash
- Department of Botany, Andhra University, Visakhapatnam 530 003, Andhra Pradesh, India
| | | | | |
Collapse
|
43
|
Posada-Flórez FJ. Production of Beauveria bassiana Fungal Spores on Rice to Control the Coffee Berry Borer, Hypothenemus hampei, in Colombia. JOURNAL OF INSECT SCIENCE 2008; 8:41. [PMCID: PMC3127422 DOI: 10.1673/031.008.4101] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2005] [Accepted: 08/28/2007] [Indexed: 06/02/2023]
Abstract
Two isolates of fungal entomopathogen Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) were grown on cooked rice using diphasic liquid-solid fermentation in plastic bags to produce and harvest spore powder. The cultures were dried and significant differences were found for isolates and time of harvest. The spores were harvested manually and mechanically and after the cultures were dried for nine days, when moisture content was near 10%. After harvesting, spores were submitted to quality control to assess concentration, germination, purity, moisture content, particle size and pathogenicity to the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae). Spore productivity on cooked rice was less than 1×1010 spores/g using both manually and mechanically harvesting methodologies. Germination at 24 hours was over 75% and pathogenicity against H. hampei was over 92.5%. This methodology is suitable for laboratory and field studies, but not for industrial production when a high concentration of spores are required for formulation and field applications.
Collapse
|
44
|
Ying SH, Feng MG. Means to mediating accumulation of hydrophobin-like proteins in the wall of Beauveria bassiana conidia for improved tolerance to thermal stress. J GEN APPL MICROBIOL 2007; 53:309-14. [DOI: 10.2323/jgam.53.309] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|