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Fan C, Zhang W, Su X, Ji W, Luo H, Zhang Y, Liu B, Yao B, Huang H, Xu X. CRISPR/Cas9-mediated genome editing directed by a 5S rRNA-tRNA Gly hybrid promoter in the thermophilic filamentous fungus Humicola insolens. Biotechnol Biofuels 2021; 14:206. [PMID: 34688310 PMCID: PMC8542335 DOI: 10.1186/s13068-021-02057-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Humicola insolens is a filamentous fungus with high potential of producing neutral and heat- and alkali-resistant cellulase. However, the genetic engineering tools, particularly the genome-editing tool, are scarce, hindering the study of cellulase expression regulation in this organism. RESULTS Herein, a CRISPR/Cas9 genome-editing system was established in H. insolens based on a hybrid 5S rRNA-tRNAGly promoter. This system is superior to the HDV (hepatitis delta virus) system in genome editing, allowing highly efficient single gene destruction in H. insolens with rates of deletion up to 84.1% (37/44). With this system, a putative pigment synthesis gene pks and the transcription factor xyr1 gene were disrupted with high efficiency. Moreover, the extracellular protein concentration and cellulase activity largely decreased when xyr1 was deleted, demonstrating for the first time that Xyr1 plays an important role in cellulase expression regulation. CONCLUSIONS The established CRISPR/Cas9 system is a powerful genetic operation tool for H. insolens, which will accelerate studies on the regulation mechanism of cellulase expression and engineering of H. insolens for higher cellulase production.
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Affiliation(s)
- Chao Fan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Wei Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Xiaoyun Su
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China
| | - Wangli Ji
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Huiying Luo
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China
| | - Yuhong Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Bo Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Bin Yao
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China
| | - Huoqing Huang
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China.
| | - Xinxin Xu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China.
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Carniel A, Gomes ADC, Coelho MAZ, de Castro AM. Process strategies to improve biocatalytic depolymerization of post-consumer PET packages in bioreactors, and investigation on consumables cost reduction. Bioprocess Biosyst Eng 2020; 44:507-516. [PMID: 33111179 DOI: 10.1007/s00449-020-02461-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 10/07/2020] [Indexed: 11/28/2022]
Abstract
Massive plastics production has raised concerns about low recycling rates and disposal of these materials in nature, causing environmental and economic impacts. Poly(ethylene terephthalate) (PET) is one of main polymers used for manufacture of plastic packaging (e.g. bottles, trays). Enzymatic recycling of PET has been a route of increasing study aiming at to recover its monomers (terephthalic acid and ethylene glycol), resulting in a circular production chain. In this study, investigation of pH control and fractionation of enzyme feeding were explored in post-consumed PET (PC-PET) hydrolysis reactions catalyzed by Humicola insolens cutinase (HiC) in stirred reactors. It was found that the unbuffered reaction provided of pH control by 0.5 M NaOH addition showed 2.39-fold improvement in the released monomers (to a total of 26.3 mM), comparatively to the Tris-HCl-buffered reaction. In addition, it was observed a possibility of reducing the enzyme loading used in the process by half, leading to an increase of 2.41-fold in the specific terephthalic acid concentration released per protein amount, whilst maintaining a high products concentration (97 mM). A simplified cost analysis of reaction consumables was performed, and the data reported here demonstrates that these alternative process strategies contribute to costs reduction on the enzymatic depolymerization reactions of PET.
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Affiliation(s)
- Adriano Carniel
- Falcão Bauer, R. Aquinos, 111. Água Branca, São Paulo, 05036‑070, Brazil.,Department of Biochemical Engineering, Escola de Química, Universidade Federal do Rio de Janeiro, Ilha do Fundão, Rio de Janeiro, 21949-900, Brazil
| | - Absai da Conceição Gomes
- Biotechnology Division, Research and Development Center, PETROBRAS, Av. Horácio Macedo, 950, Ilha do Fundão, Rio de Janeiro, 21941‑915, Brazil
| | - Maria Alice Zarur Coelho
- Department of Biochemical Engineering, Escola de Química, Universidade Federal do Rio de Janeiro, Ilha do Fundão, Rio de Janeiro, 21949-900, Brazil
| | - Aline Machado de Castro
- Biotechnology Division, Research and Development Center, PETROBRAS, Av. Horácio Macedo, 950, Ilha do Fundão, Rio de Janeiro, 21941‑915, Brazil.
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Xu X, Fan C, Song L, Li J, Chen Y, Zhang Y, Liu B, Zhang W. A Novel CreA-Mediated Regulation Mechanism of Cellulase Expression in the Thermophilic Fungus Humicola insolens. Int J Mol Sci 2019; 20:ijms20153693. [PMID: 31357701 PMCID: PMC6696435 DOI: 10.3390/ijms20153693] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 07/23/2019] [Accepted: 07/26/2019] [Indexed: 12/24/2022] Open
Abstract
The thermophilic fungus Humicola insolens produces cellulolytic enzymes that are of great scientific and commercial interest; however, few reports have focused on its cellulase expression regulation mechanism. In this study, we constructed a creA gene (carbon catabolite repressor gene) disruption mutant strain of H. insolens that exhibited a reduced radial growth rate and stouter hyphae compared to the wild-type (WT) strain. The creA disruption mutant also expressed elevated pNPCase (cellobiohydrolase activities), pNPGase (β-glucosidase activities), and xylanase levels in non-inducing fermentation with glucose. Unlike other fungi, the H. insolenscreA disruption mutant displayed lower FPase (filter paper activity), CMCase (carboxymethyl cellulose activity), pNPCase, and pNPGase activity than observed in the WT strain when fermentation was induced using Avicel, whereas its xylanase activity was higher than that of the parental strain. These results indicate that CreA acts as a crucial regulator of hyphal growth and is part of a unique cellulase expression regulation mechanism in H. insolens. These findings provide a new perspective to improve the understanding of carbon catabolite repression regulation mechanisms in cellulase expression, and enrich the knowledge of metabolism diversity and molecular regulation of carbon metabolism in thermophilic fungi.
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Affiliation(s)
- Xinxin Xu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South St., Haidian District, Beijing 100081, China
| | - Chao Fan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South St., Haidian District, Beijing 100081, China
| | - Liya Song
- Beijing Key Lab of Plant Resource Research and Development, Beijing Technology and Business University, No.11 Fucheng Road, Haidian District, Beijing 100048, China
| | - Jinyang Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South St., Haidian District, Beijing 100081, China
| | - Yuan Chen
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South St., Haidian District, Beijing 100081, China
| | - Yuhong Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South St., Haidian District, Beijing 100081, China
| | - Bo Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South St., Haidian District, Beijing 100081, China.
| | - Wei Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South St., Haidian District, Beijing 100081, China.
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Chen J, Guo X, Zhu M, Chen C, Li D. Polysaccharide monooxygenase-catalyzed oxidation of cellulose to glucuronic acid-containing cello-oligosaccharides. Biotechnol Biofuels 2019; 12:42. [PMID: 30858879 PMCID: PMC6391835 DOI: 10.1186/s13068-019-1384-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 02/20/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Polysaccharide monooxygenases (PMOs) play an important role in the enzymatic degradation of cellulose. They have been demonstrated to able to C6-oxidize cellulose to produce C6-hexodialdoses. However, the biological function of C6 oxidation of PMOs remains unknown. In particular, it is unclear whether C6-hexodialdoses can be further oxidized to uronic acid (glucuronic acid-containing oligosaccharides). RESULTS A PMO gene, Hipmo1, was isolated from Humicola insolens and expressed in Pichia pastoris. This PMO (HiPMO1), belonging to the auxiliary activity 9 (AA9) family, was shown to able to cleave cellulose to yield non-oxidized and oxidized cello-oligosaccharides. The enzyme oxidizes C6 positions in cellulose to form glucuronic acid-containing cello-oligosaccharides, followed by hydrolysis with beta-glucosidase and beta-glucuronidase to yield glucose, glucuronic acid, and saccharic acid. This indicates that HiPMO1 can catalyze C6 oxidation of hydroxyl groups of cellulose to carboxylic groups. CONCLUSIONS HiPMO1 oxidizes C6 of cellulose to form glucuronic acid-containing cello-oligosaccharides followed by hydrolysis with beta-glucosidase and beta-glucuronidase to yield glucose, glucuronic acid, and saccharic acid, and even possibly by beta-eliminative cleavage to produce unsaturated cello-oligosaccharides. This study provides a new mechanism for cellulose cleavage by C6 oxidation of HiPMO1.
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Affiliation(s)
- Jinyin Chen
- Department of Mycology, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Xiuna Guo
- Department of Mycology, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Min Zhu
- Department of Mycology, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Chen Chen
- Department of Mycology, Shandong Agricultural University, Taian, 271018 Shandong China
| | - Duochuan Li
- Department of Mycology, Shandong Agricultural University, Taian, 271018 Shandong China
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Fan C, Xu X, Song L, Guan W, Li J, Liu B, Shi P, Zhang W. The use of Agrobacterium-mediated insertional mutagenesis sequencing to identify novel genes of Humicola insolens involved in cellulase production. 3 Biotech 2018; 8:153. [PMID: 29492372 DOI: 10.1007/s13205-018-1166-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 02/09/2018] [Indexed: 10/17/2022] Open
Abstract
A transfer DNA (T-DNA)-tagged mutant library of Humicola insolens was screened for mutants with altered cellulase production using the plate-clearing zone assay. Three selected mutants (5-A7, 5-C6, and 13-B7) exhibited significantly depressed FPase, CMCase and xylanase activities compared with the wild-type strain upon shake-flask fermentation, while the pNPCase and pNPGase activities of the three mutants were relatively higher than those of the parental strain. Combined with the results of SDS-PAGE and mass spectrometry, we suggest that expression of the CMCases Cel6B, Cel7B, CMC3, and XynA/B/C was reduced in the mutant strains. Twelve putative T-DNA insertion sites were identified in the three mutants via Agrobacterium-mediated insertional mutagenesis sequencing (AIM-Seq). Bioinformatics analysis suggested that a putative dolichyl pyrophosphate phosphatase, two hypothetical proteins encoding genes of unknown function, and/or nine intergenic fragments may be involved in cellulase and hemicellulase production by H. insolens. This provides promising new candidate genes relevant to cellulase production by the fungus, which will be crucial not only for our understanding of the molecular mechanism underlying cellulase production, but also for strain improvement.
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Kogo T, Yoshida Y, Koganei K, Matsumoto H, Watanabe T, Ogihara J, Kasumi T. Production of rice straw hydrolysis enzymes by the fungi Trichoderma reesei and Humicola insolens using rice straw as a carbon source. Bioresour Technol 2017; 233:67-73. [PMID: 28258998 DOI: 10.1016/j.biortech.2017.01.075] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 01/20/2017] [Accepted: 01/21/2017] [Indexed: 06/06/2023]
Abstract
Rice straw was evaluated as a carbon source for the fungi, Trichoderma reesei and Humicola insolens, to produce enzymes for rice straw hydrolysis. The enzyme activity of T. reesei and H. insolens cultivated in medium containing non-treated rice straw were almost equivalent to the enzyme of T. reesei cultivated in Avicel medium, a form of refined cellulose. The enzyme activity of T. reesei cultivated in medium containing NH4OH-treated rice straw was 4-fold higher than enzyme from cultures grown in Avicel medium. In contrast, H. insolens enzyme from cultures grown in NH4OH-treated rice straw had significantly lower activity compared with non-treated rice straw or Avicel. The combined use of T. reesei and H. insolens enzymes resulted in a significant synergistic enhancement in enzymatic activity. Our data suggest that rice straw is a promising low-cost carbon source for fungal enzyme production for rice straw hydrolysis.
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Affiliation(s)
- Takashi Kogo
- Applied Microbiology and Biotechnology Laboratory, Department of Chemistry and Lifescience, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Yuki Yoshida
- Applied Microbiology and Biotechnology Laboratory, Department of Chemistry and Lifescience, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Keisuke Koganei
- Applied Microbiology and Biotechnology Laboratory, Department of Chemistry and Lifescience, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Hitoshi Matsumoto
- Applied Microbiology and Biotechnology Laboratory, Department of Chemistry and Lifescience, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Taisuke Watanabe
- Applied Microbiology and Biotechnology Laboratory, Department of Chemistry and Lifescience, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Jun Ogihara
- Applied Microbiology and Biotechnology Laboratory, Department of Chemistry and Lifescience, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Takafumi Kasumi
- Applied Microbiology and Biotechnology Laboratory, Department of Chemistry and Lifescience, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan.
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Matsumoto H, Koganei K, Nishida N, Koyama Y, Saito S, Kataoka H, Ogihara J, Kasumi T. Cell dispersion culture for the effective growth of Humicola insolens and efficient enzyme production. J Biosci Bioeng 2014; 117:257-62. [PMID: 24064300 DOI: 10.1016/j.jbiosc.2013.08.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 08/22/2013] [Accepted: 08/26/2013] [Indexed: 10/26/2022]
Abstract
We have developed a method for the effective growth of Humicola insolens conducive to efficient enzyme production using a medium containing glucose as a carbon source and extruded soybean meal (ExSBM) as a nitrogen source. Enzymes from Humicola sp. hold promise for biomass degradation, especially of lignocellulosic materials such as rice straw, wood chips, and corn stover. The strain, however, is hard to disperse, so an aggregated form of the fungus in a liquid culture media is generally used, resulting in poor control of the growth process and low enzyme production. This has greatly limited the utilization of this strain, in spite of its potential as an enzyme producer. Surprisingly, the addition of ExSBM improves mycelium dispersion and enzyme production of H. insolens, and the dispersive effect is applicable to other fungi such as Trichoderma and Aspergillus sp. In contrast, defatted soybean meal not treated with an extrusion process has little effect on mycelium cohesion. It therefore appears that the specific three-dimensional structure of ExSBM arising from the extrusion process provides a favorable environment for cell growth, since the composition of ExSBM and soybean meal is essentially identical. The optimum medium for cell dispersion culture essentially consisted of 5% glucose and 0.3% ExSBM.
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Affiliation(s)
- Hitoshi Matsumoto
- Enzymology and Molecular Biology Laboratory, Department of Chemistry and Life Science, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Keisuke Koganei
- Enzymology and Molecular Biology Laboratory, Department of Chemistry and Life Science, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Naoko Nishida
- Enzymology and Molecular Biology Laboratory, Department of Chemistry and Life Science, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Yoshiyuki Koyama
- Biomolecular Engineering Laboratory, National Food Research Institute, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan
| | - Sanshiro Saito
- Oilseed Protein Laboratory, J-Oil Mills, Inc., 7-41 Daikoku-cho, Tsurumi-ku, Yokohama 230-0053, Japan
| | - Hisashi Kataoka
- Oilseed Protein Laboratory, J-Oil Mills, Inc., 7-41 Daikoku-cho, Tsurumi-ku, Yokohama 230-0053, Japan
| | - Jun Ogihara
- Enzymology and Molecular Biology Laboratory, Department of Chemistry and Life Science, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan
| | - Takafumi Kasumi
- Enzymology and Molecular Biology Laboratory, Department of Chemistry and Life Science, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan.
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