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Ansari S, Aliasgharzad N, Sarikhani MR, Najafi N, Arzanlou M, Ölmez F. Nitrogen sources alter ligninase and cellulase activities of thermophilic fungi isolated from compost and vermicompost. Folia Microbiol (Praha) 2024; 69:323-332. [PMID: 37338677 DOI: 10.1007/s12223-023-01065-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 05/18/2023] [Indexed: 06/21/2023]
Abstract
Fungi harboring lignocellulolytic activity accelerate the composting process of agricultural wastes; however, using thermophilic fungal isolates for this process has been paid little attention. Moreover, exogenous nitrogen sources may differently affect fungal lignocellulolytic activity. A total of 250 thermophilic fungi were isolated from local compost and vermicompost samples. First, the isolates were qualitative assayed for ligninase and cellulase activities using Congo red (CR) and carboxymethyl cellulose (CMC) as substrates, respectively. Then, twenty superior isolates harboring higher ligninase and cellulase activities were selected and quantitatively assayed for both enzymes in basic mineral (BM) liquid medium supplemented with the relevant substrates and nitrogen sources including (NH4)2SO4 (AS), NH4NO3 (AN), urea (U), AS + U (1:1), or AN + U (1:1) with final nitrogen concentration of 0.3 g/L. The highest ligninase activities of 99.94, 89.82, 95.42, 96.25, and 98.34% of CR decolorization were recorded in isolates VC85, VC94, VC85, C145, and VC85 in the presence of AS, U, AS + U, AN, and AN + U, respectively. Mean ligninase activity of 63.75% in superior isolates was achieved in the presence of AS and ranked the highest among other N compounds. The isolates C200 and C184 exhibited the highest cellulolytic activity in the presence of AS and AN + U by 8.8 and 6.5 U/ml, respectively. Mean cellulase activity of 3.90 U/mL was achieved in AN + U and ranked the highest among other N compounds. Molecular identification of twenty superior isolates confirmed that all of them are belonging to Aspergillus fumigatus group. Focusing on the highest ligninase activity of the isolate VC85 in the presence of AS, the combination can be recommended as a potential bio-accelerator for compost production.
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Affiliation(s)
- Saeideh Ansari
- Department of Soil Science, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
| | - Nasser Aliasgharzad
- Department of Soil Science, Faculty of Agriculture, University of Tabriz, Tabriz, Iran.
| | | | - Nosratollah Najafi
- Department of Soil Science, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
| | - Mahdi Arzanlou
- Department of Plant Protection, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
| | - Fatih Ölmez
- Department of Plant Protection, Faculty of Agriculture, Sivas University of Science and Technology, Sivas, Turkey
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A Combined Study on Optimization, In Silico Modeling, and Genetic Modification of Large Scale Microbial Cellulase Production. Biochem Res Int 2022; 2022:4598937. [PMID: 36589721 PMCID: PMC9797302 DOI: 10.1155/2022/4598937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/28/2022] [Accepted: 11/29/2022] [Indexed: 12/24/2022] Open
Abstract
Cellulase is a biocatalyst that hydrolyzes cellulosic biomass and is considered a major group of industrial enzymes for its applications. Extensive work has been done on microbial cellulase but fungi are considered a novel strain for their maximum cellulase production. Production cost and novel microbial strains are major challenges for its improvement where cheap agro wastes can be essential sources of cellulose as substrates. The researcher searches for more cellulolytic microbes from natural sources but the production level of isolated strains is comparatively low. So genetic modification or mutation can be employed for large-scale cellulase production before optimization. After genetic modification than in silico molecular modeling can be evaluated for substrate molecule's binding affinity. In this review, we focus not only on the conventional methods of cellulase production but also on modern biotechnological approaches applied to cellulase production by a sequential study on common cellulase-producing microbes, modified microbes, culture media, carbon sources, substrate pretreatment process, and the importance of optimum pH and temperature on fermentation. In this review, we also compare different cellulase activity determination methods. As a result, this review provides insights into the interrelationship between the characteristics of optimizing different culture conditions, genetic modification, and in silico enzyme modeling for the production of cellulase enzymes, which may aid in the advancement of large-scale integrated enzyme manufacturing of substrate-specific enzymes.
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Iram A, Cekmecelioglu D, Demirci A. Salt and nitrogen amendment and optimization for cellulase and xylanase production using dilute acid hydrolysate of distillers' dried grains with solubles (DDGS) as the feedstock. Bioprocess Biosyst Eng 2022; 45:527-540. [PMID: 35013794 DOI: 10.1007/s00449-021-02676-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 11/29/2021] [Indexed: 11/30/2022]
Abstract
Distillers' dried grains with solubles (DDGS) is a by-product of dry-mill corn ethanol production comprising a high nutritional value due to residual fiber, protein, and lipid contents. The fiber content of DDGS is high enough to be considered a valuable source for the production of hydrolytic enzymes, such as cellulase and xylanases, which can be used for hydrolysis of lignocellulosic feedstock during ethanol production. The DDGS-based medium prepared after acid hydrolysis provides adequate sugars for enzyme production, while additional macronutrients, such as salts and nitrogen sources, can enhance the enzyme production. Therefore, this study was undertaken to evaluate the effect of salts (KH2PO4, CaCl2·2H2O, MgSO4·7H2O, FeSO4·7H2O, CoCl2·6H2O, and MnSO4·H2O), peptone, and yeast extract on enzyme secretion by four different Aspergillus niger strains and to optimize the nitrogen source for maximum enzyme production. Yeast extract improved the cellulase production (0.38 IU/ml) for A. niger (NRRL 1956) as compared to peptone (0.29 IU/ml). However, maximum cellulase productions of 0.42 IU/ml and 0.45 IU/ml were obtained by A. niger (NRRL 330) and A. niger (NRRL 567), respectively, in presence of ammonium sulfate. The optimized nitrogen amounts resulted in a significant increase in the cellulase production from 0.174 to 0.63 IU/ml on day 9 of the fermentation with A. niger (NRRL 330). The composite model improved both cellulase and xylanase production. In conclusion, the optimization of all three nitrogen sources improved both cellulase and xylanase production in the DDGS-based media.
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Affiliation(s)
- Attia Iram
- Department of Agricultural and Biological Engineering, Pennsylvania State University, 221 Agricultural Engineering Building, University Park, PA, 16802, USA
| | - Deniz Cekmecelioglu
- Department of Food Engineering, Middle East Technical University, 06800, Ankara, Turkey
| | - Ali Demirci
- Department of Agricultural and Biological Engineering, Pennsylvania State University, 221 Agricultural Engineering Building, University Park, PA, 16802, USA.
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Pang AP, Zhang F, Hu X, Luo Y, Wang H, Durrani S, Wu FG, Li BZ, Zhou Z, Lu Z, Lin F. Glutamine involvement in nitrogen regulation of cellulase production in fungi. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:199. [PMID: 34645509 PMCID: PMC8513308 DOI: 10.1186/s13068-021-02046-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/23/2021] [Indexed: 05/27/2023]
Abstract
BACKGROUND Cellulase synthesized by fungi can environment-friendly and sustainably degrades cellulose to fermentable sugars for producing cellulosic biofuels, biobased medicine and fine chemicals. Great efforts have been made to study the regulation mechanism of cellulase biosynthesis in fungi with the focus on the carbon sources, while little attention has been paid to the impact and regulation mechanism of nitrogen sources on cellulase production. RESULTS Glutamine displayed the strongest inhibition effect on cellulase biosynthesis in Trichoderma reesei, followed by yeast extract, urea, tryptone, ammonium sulfate and L-glutamate. Cellulase production, cell growth and sporulation in T. reesei RUT-C30 grown on cellulose were all inhibited with the addition of glutamine (a preferred nitrogen source) with no change for mycelium morphology. This inhibition effect was attributed to both L-glutamine itself and the nitrogen excess induced by its presence. In agreement with the reduced cellulase production, the mRNA levels of 44 genes related to the cellulase production were decreased severely in the presence of glutamine. The transcriptional levels of genes involved in other nitrogen transport, ribosomal biogenesis and glutamine biosynthesis were decreased notably by glutamine, while the expression of genes relevant to glutamate biosynthesis, amino acid catabolism, and glutamine catabolism were increased noticeably. Moreover, the transcriptional level of cellulose signaling related proteins ooc1 and ooc2, and the cellular receptor of rapamycin trFKBP12 was increased remarkably, whose deletion exacerbated the cellulase depression influence of glutamine. CONCLUSION Glutamine may well be the metabolite effector in nitrogen repression of cellulase synthesis, like the role of glucose plays in carbon catabolite repression. Glutamine under excess nitrogen condition repressed cellulase biosynthesis significantly as well as cell growth and sporulation in T. reesei RUT-C30. More importantly, the presence of glutamine notably impacted the transport and metabolism of nitrogen. Genes ooc1, ooc2, and trFKBP12 are associated with the cellulase repression impact of glutamine. These findings advance our understanding of nitrogen regulation of cellulase production in filamentous fungi, which would aid in the rational design of strains and fermentation strategies for cellulase production in industry.
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Affiliation(s)
- Ai-Ping Pang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Funing Zhang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Xin Hu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Yongsheng Luo
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Haiyan Wang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Samran Durrani
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Fu-Gen Wu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Bing-Zhi Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Zhihua Zhou
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Zuhong Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Fengming Lin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
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Novy V, Nielsen F, Cullen D, Sabat G, Houtman CJ, Hunt CG. The characteristics of insoluble softwood substrates affect fungal morphology, secretome composition, and hydrolytic efficiency of enzymes produced by Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:105. [PMID: 33902680 PMCID: PMC8074412 DOI: 10.1186/s13068-021-01955-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 04/11/2021] [Indexed: 05/04/2023]
Abstract
BACKGROUND On-site enzyme production using Trichoderma reesei can improve yields and lower the overall cost of lignocellulose saccharification by exploiting the fungal gene regulatory mechanism that enables it to continuously adapt enzyme secretion to the substrate used for cultivation. To harness this, the interrelation between substrate characteristics and fungal response must be understood. However, fungal morphology or gene expression studies often lack structural and chemical substrate characterization. Here, T. reesei QM6a was cultivated on three softwood substrates: northern bleached softwood Kraft pulp (NBSK) and lodgepole pine pretreated either by dilute-acid-catalyzed steam pretreatment (LP-STEX) or mild alkaline oxidation (LP-ALKOX). With different pretreatments of similar starting materials, we presented the fungus with systematically modified substrates. This allowed the elucidation of substrate-induced changes in the fungal response and the testing of the secreted enzymes' hydrolytic strength towards the same substrates. RESULTS Enzyme activity time courses correlated with hemicellulose content and cellulose accessibility. Specifically, increased amounts of side-chain-cleaving hemicellulolytic enzymes in the protein produced on the complex substrates (LP-STEX; LP-ALKOX) was observed by secretome analysis. Confocal laser scanning micrographs showed that fungal micromorphology responded to changes in cellulose accessibility and initial culture viscosity. The latter was caused by surface charge and fiber dimensions, and likely restricted mass transfer, resulting in morphologies of fungi in stress. Supplementing a basic cellulolytic enzyme mixture with concentrated T. reesei supernatant improved saccharification efficiencies of the three substrates, where cellulose, xylan, and mannan conversion was increased by up to 27, 45, and 2800%, respectively. The improvement was most pronounced for proteins produced on LP-STEX and LP-ALKOX on those same substrates, and in the best case, efficiencies reached those of a state-of-the-art commercial enzyme preparation. CONCLUSION Cultivation of T. reesei on LP-STEX and LP-ALKOX produced a protein mixture that increased the hydrolytic strength of a basic cellulase mixture to state-of-the-art performance on softwood substrates. This suggests that the fungal adaptation mechanism can be exploited to achieve enhanced performance in enzymatic hydrolysis without a priori knowledge of specific substrate requirements.
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Affiliation(s)
- Vera Novy
- US Department of Agriculture, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI, 53726, USA.
- Department of Biology and Bioengineering, Division of Industrial Biotechnology, Chalmers University of Technology, Kemivägen 10, 412 96, Göteborg, Sweden.
| | - Fredrik Nielsen
- US Department of Agriculture, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI, 53726, USA
| | - Daniel Cullen
- US Department of Agriculture, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI, 53726, USA
| | - Grzegorz Sabat
- University of Wisconsin Biotechnology Center, Madison, WI, 53706, USA
| | - Carl J Houtman
- US Department of Agriculture, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI, 53726, USA
| | - Christopher G Hunt
- US Department of Agriculture, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI, 53726, USA
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Shen L, Su Y, Sun Y, Wang G, Chen H, Yu X, Zhang S, Chen G. Establishment of a highly efficient and low cost mixed cellulase system for bioconversion of corn stover by Trichoderma reesei and Aspergillus niger. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2021. [DOI: 10.1016/j.bcab.2020.101849] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Novy V, Nielsen F, Seiboth B, Nidetzky B. The influence of feedstock characteristics on enzyme production in Trichoderma reesei: a review on productivity, gene regulation and secretion profiles. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:238. [PMID: 31624500 PMCID: PMC6781402 DOI: 10.1186/s13068-019-1571-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 09/20/2019] [Indexed: 05/21/2023]
Abstract
Biorefineries, designed for the production of lignocellulose-based chemicals and fuels, are receiving increasing attention from the public, governments, and industries. A major obstacle for biorefineries to advance to commercial scale is the high cost of the enzymes required to derive the fermentable sugars from the feedstock used. As summarized in this review, techno-economic studies suggest co-localization and integration of enzyme manufacturing with the cellulosic biorefinery as the most promising alternative to alleviate this problem. Thus, cultivation of Trichoderma reesei, the principal producer of lignocellulolytic enzymes, on the lignocellulosic biomass processed on-site can reduce the cost of enzyme manufacturing. Further, due to a complex gene regulation machinery, the fungus can adjust the gene expression of the lignocellulolytic enzymes towards the characteristics of the feedstock, increasing the hydrolytic efficiency of the produced enzyme cocktail. Despite extensive research over decades, the underlying regulatory mechanisms are not fully elucidated. One aspect that has received relatively little attention in literature is the influence the characteristics of a lignocellulosic substrate, i.e., its chemical and physical composition, has on the produced enzyme mixture. Considering that the fungus is dependent on efficient enzymatic degradation of the lignocellulose for continuous supply of carbon and energy, a relationship between feedstock characteristics and secretome composition can be expected. The aim of this review was to systematically collect, appraise, and aggregate data and integrate results from studies analyzing enzyme production by T. reesei on insoluble cellulosic model substrates and lignocellulosic biomass. The results show that there is a direct effect of the substrate's complexity (rated by structure, composition of the lignin-carbohydrate complex, and recalcitrance in enzymatic saccharification) on enzyme titers and the composition of specific activities in the secretome. It further shows that process-related factors, such as substrate loading and cultivation set-up, are direct targets for increasing enzyme yields. The literature on transcriptome and secretome composition further supports the proposed influence of substrate-related factors on the expression of lignocellulolytic enzymes. This review provides insights into the interrelation between the characteristics of the substrate and the enzyme production by T. reesei, which may help to advance integrated enzyme manufacturing of substrate-specific enzymes cocktails at scale.
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Affiliation(s)
- Vera Novy
- Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Graz University of Technology, Graz, Austria
- Present Address: Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, Canada
| | - Fredrik Nielsen
- Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Graz University of Technology, Graz, Austria
- Present Address: Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, Canada
| | - Bernhard Seiboth
- Institute of Chemical, Environmental and Bioscience Engineering, Vienna University of Technology, Vienna, Austria
- Austrian Centre of Industrial Biotechnology (acib) GmbH, Graz, Austria
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Graz University of Technology, Graz, Austria
- Austrian Centre of Industrial Biotechnology (acib) GmbH, Graz, Austria
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Bai H, Zi H, Huang Y, Han M, Irfan M, Liu N, Yang J, Wang H, Han X. Catalytic Properties of Carboxymethyl Cellulase Produced from Newly Isolated Novel Fungus Penicillium ochrochloron ZH1 in Submerged Fermentation. Catal Letters 2017. [DOI: 10.1007/s10562-017-2119-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Nutrient control for stationary phase cellulase production in Trichoderma reesei Rut C-30. Enzyme Microb Technol 2016; 82:8-14. [DOI: 10.1016/j.enzmictec.2015.08.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 08/16/2015] [Accepted: 08/18/2015] [Indexed: 11/23/2022]
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Druzhinina IS, Kopchinskiy AG, Kubicek EM, Kubicek CP. A complete annotation of the chromosomes of the cellulase producer Trichoderma reesei provides insights in gene clusters, their expression and reveals genes required for fitness. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:75. [PMID: 27030800 PMCID: PMC4812632 DOI: 10.1186/s13068-016-0488-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 03/15/2016] [Indexed: 05/15/2023]
Abstract
BACKGROUND Investigations on a few eukaryotic model organisms showed that many genes are non-randomly distributed on chromosomes. In addition, chromosome ends frequently possess genes that are important for the fitness of the organisms. Trichoderma reesei is an industrial producer of enzymes for food, feed and biorefinery production. Its seven chromosomes have recently been assembled, thus making an investigation of its chromosome architecture possible. RESULTS We manually annotated and mapped 9194 ORFs on their respective chromosomes and investigated the clustering of the major gene categories and of genes encoding carbohydrate-active enzymes (CAZymes), and the relationship between clustering and expression. Genes responsible for RNA processing and modification, amino acid metabolism, transcription, translation and ribosomal structure and biogenesis indeed showed loose clustering, but this had no impact on their expression. A third of the genes encoding CAZymes also occurred in loose clusters that also contained a high number of genes encoding small secreted cysteine-rich proteins. Five CAZyme clusters were located less than 50 kb apart from the chromosome ends. These genes exhibited the lowest basal (but not induced) expression level, which correlated with an enrichment of H3K9 methylation in the terminal 50 kb areas indicating gene silencing. No differences were found in the expression of CAZyme genes present in other parts of the chromosomes. The putative subtelomeric areas were also enriched in genes encoding secreted proteases, amino acid permeases, enzyme clusters for polyketide synthases (PKS)-non-ribosomal peptide synthase (NRPS) fusion proteins (PKS-NRPS) and proteins involved in iron scavenging. They were strongly upregulated during conidiation and interaction with other fungi. CONCLUSIONS Our findings suggest that gene clustering on the T. reesei chromosomes occurs but generally has no impact on their expression. CAZyme genes, located in subtelomers, however, exhibited a much lower basal expression level. The gene inventory of the subtelomers suggests a major role of competition for nitrogen and iron supported by antibiosis for the fitness of T. reesei. The availability of fully annotated chromosomes will facilitate the use of genetic crossings in identifying still unknown genes responsible for specific traits of T. reesei.
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Affiliation(s)
- Irina S. Druzhinina
- />Research Area Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, 1060 Vienna, Austria
| | - Alexey G. Kopchinskiy
- />Research Area Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, 1060 Vienna, Austria
| | - Eva M. Kubicek
- />Research Area Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, 1060 Vienna, Austria
- />Steinschötelgasse 7, 1100 Vienna, Austria
| | - Christian P. Kubicek
- />Research Area Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, 1060 Vienna, Austria
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Tiwari R, Pranaw K, Singh S, Nain PKS, Shukla P, Nain L. Two-step statistical optimization for cold active β-glucosidase production from Pseudomonas lutea BG8 and its application for improving saccharification of paddy straw. Biotechnol Appl Biochem 2015. [PMID: 26202604 DOI: 10.1002/bab.1415] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
β-Glucosidase is an essential part of cellulase enzyme system for efficient and complete hydrolysis of biomass. Psychrotolerant Pseudomonas lutea BG8 produced β-glucosidase with lower temperature optima and hence can play important role in bringing down the energy requirement for bioethanol production. To enhance β-glucosidase production, two statistical tools: Taguchi and Box-Behnken designs were applied to reveal the most influential factors and their respective concentration for maximum production of β-glucosidase under submerged fermentation. The optimal medium composition for maximum β-glucosidase production were 2.99% (w/v) bagasse, 0.33% (w/v) yeast extract, 0.38% (w/v) Triton X-100, 0.39% (w/v) NaNO3 , and pH 8.0 at temperature 30 °C. Under optimized conditions, β-glucosidase production increased up to 9.12-fold (17.52 ± 0.24 IU/g) in shake flask. Large-scale production in 7-L stirred tank bioreactor resulted in higher β-glucosidase production (23.29 ± 0.23 IU/g) within 80 H of incubation, which was 1.34-fold higher than shake flask studies. Commercial cellulase (Celluclast® 1.5L) when supplemented with this crude β-glucosidase resulted in improved sugar release (548.4 ± 2.76 mg/gds) from paddy straw at comparatively low temperature (40 °C) of saccharification. P. lutea BG8 therefore showed great potential for cold active β-glucosidase production and can be used as accessory enzyme along with commercial cellulase to improve saccharification efficiency.
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Affiliation(s)
- Rameshwar Tiwari
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi, India.,Laboratory of Enzyme Technology and Protein Bioinformatics, Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Kumar Pranaw
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Surender Singh
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Pawan K S Nain
- School of Mechanical Engineering, Galgotias University, Greater Noida, Uttar Pradesh, India
| | - Pratyoosh Shukla
- Laboratory of Enzyme Technology and Protein Bioinformatics, Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Lata Nain
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi, India.
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Tiwari R, Singh S, Nain PKS, Rana S, Sharma A, Pranaw K, Nain L. Harnessing the hydrolytic potential of phytopathogenic fungus Phoma exigua ITCC 2049 for saccharification of lignocellulosic biomass. BIORESOURCE TECHNOLOGY 2013; 150:228-34. [PMID: 24177155 DOI: 10.1016/j.biortech.2013.10.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 09/27/2013] [Accepted: 10/01/2013] [Indexed: 05/08/2023]
Abstract
Phytopathogenic fungi develop unique systems for fast invasion by producing hydrolases, which may be explored as a source of hydrolytic enzymes for biofuel research. The present work deals with evaluation of a potato pathogen Phoma exigua ITCC 2049 for its potential to produce cellulase and xylanase enzyme. Taguchi methodology was applied to reveal the influence and contribution of five important factors (carbon source, organic and inorganic nitrogen source, surfactant, and pH) on hydrolytic enzyme production by Phoma. Cultivation of fungus under optimized condition produced endoglucanase (37.00 IU/ml), FPase (1.13 IU/ml), β-glucosidase (2.67 IU/ml) and xylanase (24.92 IU/ml) within 8 days of submerged fermentation. Saccharification of biopretreated Parthenium and paddy straw with cocktail of Phoma secretome supplemented with commercial β-glucosidase resulted in the significantly higher reducing sugar yield (651.04-698.11 mg/gds). This study proves the potential of Phoma as an alternative source of enzymes for biomass saccharification.
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Affiliation(s)
- Rameshwar Tiwari
- Division of Microbiology, Indian Agricultural Research Institute, New Delhi 110 012, India
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