51
|
Feldman D, Kowbel DJ, Cohen A, Glass NL, Hadar Y, Yarden O. Identification and manipulation of Neurospora crassa genes involved in sensitivity to furfural. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:210. [PMID: 31508149 PMCID: PMC6724289 DOI: 10.1186/s13068-019-1550-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 08/24/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Biofuels derived from lignocellulosic biomass are a viable alternative to fossil fuels required for transportation. Following plant biomass pretreatment, the furan derivative furfural is present at concentrations which are inhibitory to yeasts. Detoxification of furfural is thus important for efficient fermentation. Here, we searched for new genetic attributes in the fungus Neurospora crassa that may be linked to furfural tolerance. The fact that furfural is involved in the natural process of sexual spore germination of N. crassa and that this fungus is highly amenable to genetic manipulations makes it a rational candidate for this study. RESULTS Both hypothesis-based and unbiased (random promotor mutagenesis) approaches were performed to identify N. crassa genes associated with the response to furfural. Changes in the transcriptional profile following exposure to furfural revealed that the affected processes were, overall, similar to those observed in Saccharomyces cerevisiae. N. crassa was more tolerant (by ~ 30%) to furfural when carboxymethyl cellulose was the main carbon source as opposed to sucrose, indicative of a link between carbohydrate metabolism and furfural tolerance. We also observed increased tolerance in a Δcre-1 mutant (CRE-1 is a key transcription factor that regulates the ability of fungi to utilize non-preferred carbon sources). In addition, analysis of aldehyde dehydrogenase mutants showed that ahd-2 (NCU00378) was involved in tolerance to furfural as well as the predicted membrane transporter NCU05580 (flr-1), a homolog of FLR1 in S. cerevisiae. Further to the rational screening, an unbiased approach revealed additional genes whose inactivation conferred increased tolerance to furfural: (i) NCU02488, which affected the abundance of the non-anchored cell wall protein NCW-1 (NCU05137), and (ii) the zinc finger protein NCU01407. CONCLUSIONS We identified attributes in N. crassa associated with tolerance or degradation of furfural, using complementary research approaches. The manipulation of the genes involved in furan sensitivity can provide a means for improving the production of biofuel producing strains. Similar research approaches can be utilized in N. crassa and other filamentous fungi to identify additional attributes relevant to other furans or toxic chemicals.
Collapse
Affiliation(s)
- Daria Feldman
- Department of Plant Pathology and Microbiology, The R.H. Smith Faculty Agriculture, Food and Environment, The Hebrew University of Jerusalem, 7600001 Rehovot, Israel
| | - David J. Kowbel
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720 USA
| | - Adi Cohen
- Department of Plant Pathology and Microbiology, The R.H. Smith Faculty Agriculture, Food and Environment, The Hebrew University of Jerusalem, 7600001 Rehovot, Israel
| | - N. Louise Glass
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720 USA
- Environmental Genomics and Systems Biology Division, The Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
| | - Yitzhak Hadar
- Department of Plant Pathology and Microbiology, The R.H. Smith Faculty Agriculture, Food and Environment, The Hebrew University of Jerusalem, 7600001 Rehovot, Israel
| | - Oded Yarden
- Department of Plant Pathology and Microbiology, The R.H. Smith Faculty Agriculture, Food and Environment, The Hebrew University of Jerusalem, 7600001 Rehovot, Israel
| |
Collapse
|
52
|
Petrović DM, Várnai A, Dimarogona M, Mathiesen G, Sandgren M, Westereng B, Eijsink VGH. Comparison of three seemingly similar lytic polysaccharide monooxygenases from Neurospora crassa suggests different roles in plant biomass degradation. J Biol Chem 2019; 294:15068-15081. [PMID: 31431506 DOI: 10.1074/jbc.ra119.008196] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 08/02/2019] [Indexed: 11/06/2022] Open
Abstract
Many fungi produce multiple lytic polysaccharide monooxygenases (LPMOs) with seemingly similar functions, but the biological reason for this multiplicity remains unknown. To address this question, here we carried out comparative structural and functional characterizations of three cellulose-active C4-oxidizing family AA9 LPMOs from the fungus Neurospora crassa, NcLPMO9A (NCU02240), NcLPMO9C (NCU02916), and NcLPMO9D (NCU01050). We solved the three-dimensional structure of copper-bound NcLPMO9A at 1.6-Å resolution and found that NcLPMO9A and NcLPMO9C, containing a CBM1 carbohydrate-binding module, bind cellulose more strongly and were less susceptible to inactivation than NcLPMO9D, which lacks a CBM. All three LPMOs were active on tamarind xyloglucan and konjac glucomannan, generating similar products but clearly differing in activity levels. Importantly, in some cases, the addition of phosphoric acid-swollen cellulose (PASC) had a major effect on activity: NcLPMO9A was active on xyloglucan only in the presence of PASC, and PASC enhanced NcLPMO9D activity on glucomannan. Interestingly, the three enzymes also exhibited large differences in their interactions with enzymatic electron donors, which could reflect that they are optimized to act with different reducing partners. All three enzymes efficiently used H2O2 as a cosubstrate, yielding product profiles identical to those obtained in O2-driven reactions with PASC, xyloglucan, or glucomannan. Our results indicate that seemingly similar LPMOs act preferentially on different types of copolymeric substructures in the plant cell wall, possibly because these LPMOs are functionally adapted to distinct niches differing in the types of available reductants.
Collapse
Affiliation(s)
- Dejan M Petrović
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432 Ås, Norway
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432 Ås, Norway
| | - Maria Dimarogona
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden.,Laboratory of Biotechnology and Structural Biology, Department of Chemical Engineering, University of Patras, 26504 Patras, Greece
| | - Geir Mathiesen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432 Ås, Norway
| | - Mats Sandgren
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden
| | - Bjørge Westereng
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432 Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432 Ås, Norway
| |
Collapse
|
53
|
Crosstalk of Cellulose and Mannan Perception Pathways Leads to Inhibition of Cellulase Production in Several Filamentous Fungi. mBio 2019; 10:mBio.00277-19. [PMID: 31266859 PMCID: PMC6606794 DOI: 10.1128/mbio.00277-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In fungi, the production of enzymes for polysaccharide degradation is controlled by complex signaling networks. Previously, these networks were studied in response to simple sugars or single polysaccharides. Here, we tackled for the first time the molecular interplay between two seemingly unrelated perception pathways: those for cellulose and the hemicellulose (gluco)mannan. We identified a so far unknown competitive inhibition between the respective degradation products acting as signaling molecules. Competition was detected both at the level of the uptake and intracellularly, upstream of the main transcriptional regulator CLR-2. Our findings provide novel insights into the molecular communication between perception pathways. Also, they present possible targets for the improvement of industrial strains for higher cellulase production through the engineering of mannan insensitivity. It is essential for microbes to acquire information about their environment. Fungi use soluble degradation products of plant cell wall components to understand the substrate composition they grow on. Individual perception pathways have been well described. However, the interconnections between pathways remain poorly understood. In the present work, we provide evidence of crosstalk between the perception pathways for cellulose and the hemicellulose mannan being conserved in several filamentous fungi and leading to the inhibition of cellulase expression. We used the functional genomics tools available for Neurospora crassa to investigate this overlap at the molecular level. Crosstalk and competitive inhibition could be identified both during uptake by cellodextrin transporters and intracellularly. Importantly, the overlap is independent of CRE-1-mediated catabolite repression. These results provide novel insights into the regulatory networks of lignocellulolytic fungi and will contribute to the rational optimization of fungal enzyme production for efficient plant biomass depolymerization and utilization.
Collapse
|
54
|
Silva RN, Monteiro VN, Steindorff AS, Gomes EV, Noronha EF, Ulhoa CJ. Trichoderma/pathogen/plant interaction in pre-harvest food security. Fungal Biol 2019; 123:565-583. [PMID: 31345411 DOI: 10.1016/j.funbio.2019.06.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 06/13/2019] [Accepted: 06/14/2019] [Indexed: 01/17/2023]
Abstract
Large losses before crop harvesting are caused by plant pathogens, such as viruses, bacteria, oomycetes, fungi, and nematodes. Among these, fungi are the major cause of losses in agriculture worldwide. Plant pathogens are still controlled through application of agrochemicals, causing human disease and impacting environmental and food security. Biological control provides a safe alternative for the control of fungal plant pathogens, because of the ability of biocontrol agents to establish in the ecosystem. Some Trichoderma spp. are considered potential agents in the control of fungal plant diseases. They can interact directly with roots, increasing plant growth, resistance to diseases, and tolerance to abiotic stress. Furthermore, Trichoderma can directly kill fungal plant pathogens by antibiosis, as well as via mycoparasitism strategies. In this review, we will discuss the interactions between Trichoderma/fungal pathogens/plants during the pre-harvest of crops. In addition, we will highlight how these interactions can influence crop production and food security. Finally, we will describe the future of crop production using antimicrobial peptides, plants carrying pathogen-derived resistance, and plantibodies.
Collapse
Affiliation(s)
- Roberto N Silva
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil.
| | - Valdirene Neves Monteiro
- Campus of Exact Sciences and Technologies, Campus Henrique Santillo, Anapolis, Goiás State, Brazil
| | - Andrei Stecca Steindorff
- U.S. Department of Energy (DOE) Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Eriston Vieira Gomes
- Department of Biofunctional, Center of Higher Education Morgana Potrich Eireli, Morgana Potrich College, Mineiros, Goiás, Brazil
| | | | - Cirano J Ulhoa
- Department of Biochemistry and Cellular Biology, Biological Sciences Institute, Campus Samambaia, Federal University of Goiás (UFG), Goiânia, Goiás, Brazil
| |
Collapse
|
55
|
Antunes FAF, Chandel AK, Terán-Hilares R, Ingle AP, Rai M, Dos Santos Milessi TS, da Silva SS, Dos Santos JC. Overcoming challenges in lignocellulosic biomass pretreatment for second-generation (2G) sugar production: emerging role of nano, biotechnological and promising approaches. 3 Biotech 2019; 9:230. [PMID: 31139545 DOI: 10.1007/s13205-019-1761-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 05/13/2019] [Indexed: 01/12/2023] Open
Abstract
Production of green chemicals and biofuels in biorefineries is the potential alternative for petrochemicals and gasoline in transitioning of petro-economy into bioeconomy. However, an efficient biomass pretreatment process must be considered for the successful deployment of biorefineries, mainly for use of lignocellulosic raw materials. However, biomass recalcitrance plays a key role in its saccharification to obtain considerable sugar which can be converted into ethanol or other biochemicals. In the last few decades, several pretreatment methods have been developed, but their feasibility at large-scale operations remains as a persistent bottleneck in biorefineries. Pretreatment methods such as hydrodynamic cavitation, ionic liquids, and supercritical fluids have shown promising results in terms of either lignin or hemicellulose removal, thus making remaining carbohydrate fraction amenable to the enzymatic hydrolysis for clean and high amount of fermentable sugar production. However, their techno-economic feasibility at industrial scale has not been yet studied in detail. Besides, nanotechnological-based technologies could play an important role in the economically viable 2G sugar production in future. Considering these facts, in the present review, we have discussed the existing promising pretreatment methods for lignocellulosic biomass and their challenges, besides this strategic role of nano and biotechnological approaches towards the viability and sustainability of biorefineries is also discussed.
Collapse
Affiliation(s)
- Felipe Antonio Fernandes Antunes
- 1Department of Biotechnology, Engineering School of Lorena, University of São Paulo, Estrada Municipal do Campinho, s/n-Campinho, Lorena, 12602-810 Brazil
| | - Anuj Kumar Chandel
- 1Department of Biotechnology, Engineering School of Lorena, University of São Paulo, Estrada Municipal do Campinho, s/n-Campinho, Lorena, 12602-810 Brazil
| | - Ruly Terán-Hilares
- 1Department of Biotechnology, Engineering School of Lorena, University of São Paulo, Estrada Municipal do Campinho, s/n-Campinho, Lorena, 12602-810 Brazil
| | - Avinash P Ingle
- 3Nanotechnology Laboratory, Department of Biotechnology, SGB Amravati University, Amravati, 444 602 India
| | - Mahendra Rai
- 3Nanotechnology Laboratory, Department of Biotechnology, SGB Amravati University, Amravati, 444 602 India
| | | | - Silvio Silvério da Silva
- 1Department of Biotechnology, Engineering School of Lorena, University of São Paulo, Estrada Municipal do Campinho, s/n-Campinho, Lorena, 12602-810 Brazil
| | - Júlio César Dos Santos
- 1Department of Biotechnology, Engineering School of Lorena, University of São Paulo, Estrada Municipal do Campinho, s/n-Campinho, Lorena, 12602-810 Brazil
| |
Collapse
|
56
|
Direct production of commodity chemicals from lignocellulose using Myceliophthora thermophila. Metab Eng 2019; 61:416-426. [PMID: 31078793 DOI: 10.1016/j.ymben.2019.05.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 04/18/2019] [Accepted: 05/08/2019] [Indexed: 02/08/2023]
Abstract
The production of fuels and chemicals from renewable plant biomass has been proposed as a feasible strategy for global sustainable development. However, the economic efficiency of biorefineries is low. Here, through metabolic engineering, Myceliophthora thermophila, a cellulolytic thermophilic fungus, was constructed into a platform that can efficiently convert lignocellulose into important bulk chemicals-four carbon 1, 4-diacids (malic and succinic acid), building blocks for biopolymers-without the need for extra hydrolytic enzymes. Titers of >200 g/L from crystalline cellulose and 110 g/L from plant biomass (corncob) were achieved during fed-batch fermentation. Our study represents a milestone in consolidated bioprocessing technology and offers a new and promising system for the cost-effective production of chemicals and fuels from biomass.
Collapse
|
57
|
An Q, Wu XJ, Dai YC. Comparative genomics of 40 edible and medicinal mushrooms provide an insight into the evolution of lignocellulose decomposition mechanisms. 3 Biotech 2019; 9:157. [PMID: 30944804 DOI: 10.1007/s13205-019-1689-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/19/2019] [Indexed: 11/28/2022] Open
Abstract
Diversity comparison and phylogenetic analyses of carbohydrate-active enzymes (CAZymes), auxiliary activities (AAs) and cytochromes P450 among 40 fungi, which are based on different nutritional pathways, help clarify and explain their divergence and improvement of various life-styles. Molecular clock analyses allow us to understand the evolutionary and developmental rules in decomposition gene families. Our results suggested that fungi in different ecological types acquired an obvious preference on specific decomposing gene families during evolutionary selection. White rot and litter saprotrophic fungi possessed more complete types of varied degradation gene families and were superior in quantities. With evolution and development of lignocellulose decomposition mechanism, certain families (like CBM1, GH6, GH7, GH10, and CYP53) disappeared in brown rot fungi and symbiotic fungi. In addition, the earlier time of phylogenetic divergence determined the more integrated and larger decomposition families. And various gains and losses in gene quantity of varied decomposition families led in particularly phylogenetic clades or nodes, then accelerated in forming varied ecotypes of species.
Collapse
Affiliation(s)
- Qi An
- 1Institute of Microbiology, Beijing Forestry University, Beijing, 100083 People's Republic of China
- 2Edible and Medicinal Fungi Research and Development Center, Universities/Colleges in Hebei Province, Langfang Normal University, Langfang, 065000 Hebei People's Republic of China
| | - Xue-Jun Wu
- 1Institute of Microbiology, Beijing Forestry University, Beijing, 100083 People's Republic of China
| | - Yu-Cheng Dai
- 1Institute of Microbiology, Beijing Forestry University, Beijing, 100083 People's Republic of China
- 3Beijing Advanced Innovation Center for Tree Breeding By Molecular Design, Beijing Forestry University, 35 Qinghuadong Road, Haidian District, Beijing, 100083 People's Republic of China
| |
Collapse
|
58
|
Wilken SE, Swift CL, Podolsky IA, Lankiewicz TS, Seppälä S, O'Malley MA. Linking ‘omics’ to function unlocks the biotech potential of non-model fungi. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.coisb.2019.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
59
|
Podolsky IA, Seppälä S, Lankiewicz TS, Brown JL, Swift CL, O'Malley MA. Harnessing Nature's Anaerobes for Biotechnology and Bioprocessing. Annu Rev Chem Biomol Eng 2019; 10:105-128. [PMID: 30883214 DOI: 10.1146/annurev-chembioeng-060718-030340] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Industrial biotechnology has the potential to decrease our reliance on petroleum for fuel and bio-based chemical production and also enable valorization of waste streams. Anaerobic microorganisms thrive in resource-limited environments and offer an array of novel bioactivities in this regard that could revolutionize biomanufacturing. However, they have not been adopted for widespread industrial use owing to their strict growth requirements, limited number of available strains, difficulty in scale-up, and genetic intractability. This review provides an overview of current and future uses for anaerobes in biotechnology and bioprocessing in the postgenomic era. We focus on the recently characterized anaerobic fungi (Neocallimastigomycota) native to the digestive tract of large herbivores, which possess a trove of enzymes, pathways, transporters, and other biomolecules that can be harnessed for numerous biotechnological applications. Resolving current genetic intractability, scale-up, and cultivation challenges will unlock the potential of these lignocellulolytic fungi and other nonmodel micro-organisms to accelerate bio-based production.
Collapse
Affiliation(s)
- Igor A Podolsky
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| | - Susanna Seppälä
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| | - Thomas S Lankiewicz
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| | - Jennifer L Brown
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| | - Candice L Swift
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| | - Michelle A O'Malley
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| |
Collapse
|
60
|
Yang J, Deng L, Zhao C, Fang H. Heterologous expression of Neurospora crassa cbh1 gene in Pichia pastoris resulted in production of a neutral cellobiohydrolase I. Biotechnol Prog 2019; 35:e2795. [PMID: 30816014 DOI: 10.1002/btpr.2795] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 01/14/2019] [Accepted: 02/20/2019] [Indexed: 11/10/2022]
Abstract
The high production cost of cellulase is one of the limitations that hinder the commercialization of lignocellulose-based biorefineries. As one of the important cellulases, Neurospora crassa cellulase is not so intensively investigated as T. reesei cellulase. In this study, the cbh1gene (NCU07340) cloned from N. crassa was expressed in Pichia pastoris under the control of alcohol oxidase 1 (AOX1) promotor. Six transformants with the highest resistance to G418 were selected by two rounds of transformant screening, among which the most robust producer of the recombinant cellobiohydrolase I (CBHI) has an Avicelase activity of 0.22 U/mL. After fermentation optimization, it was improved to 0.30 U/mL. Interestingly, the optimal temperature and pH of the recombinant CBHI were 60°C and 7.2, respectively, and it was quite stable within the wide ranges of temperature and pH. This work is a good example for the future improvement and optimization of N. crassa cellulase.
Collapse
Affiliation(s)
- Jie Yang
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China.,Biomass Energy Center for Arid and Semi-arid Lands, Northwest A&F University, Yangling, Shaanxi, China
| | - Lu Deng
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China.,Biomass Energy Center for Arid and Semi-arid Lands, Northwest A&F University, Yangling, Shaanxi, China
| | - Chen Zhao
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China.,Biomass Energy Center for Arid and Semi-arid Lands, Northwest A&F University, Yangling, Shaanxi, China
| | - Hao Fang
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China.,Biomass Energy Center for Arid and Semi-arid Lands, Northwest A&F University, Yangling, Shaanxi, China
| |
Collapse
|
61
|
de Paula RG, Antoniêto ACC, Ribeiro LFC, Srivastava N, O'Donovan A, Mishra PK, Gupta VK, Silva RN. Engineered microbial host selection for value-added bioproducts from lignocellulose. Biotechnol Adv 2019; 37:107347. [PMID: 30771467 DOI: 10.1016/j.biotechadv.2019.02.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 01/27/2019] [Accepted: 02/08/2019] [Indexed: 12/12/2022]
Abstract
Lignocellulose is a rich and sustainable globally available carbon source and is considered a prominent alternative raw material for producing biofuels and valuable chemical compounds. Enzymatic hydrolysis is one of the crucial steps of lignocellulose degradation. Cellulolytic and hemicellulolytic enzyme mixes produced by different microorganisms including filamentous fungi, yeasts and bacteria, are used to degrade the biomass to liberate monosaccharides and other compounds for fermentation or conversion to value-added products. During biomass pretreatment and degradation, toxic compounds are produced, and undesirable carbon catabolic repression (CCR) can occur. In order to solve this problem, microbial metabolic pathways and transcription factors involved have been investigated along with the application of protein engineering to optimize the biorefinery platform. Engineered Microorganisms have been used to produce specific enzymes to breakdown biomass polymers and metabolize sugars to produce ethanol as well other biochemical compounds. Protein engineering strategies have been used for modifying lignocellulolytic enzymes to overcome enzymatic limitations and improving both their production and functionality. Furthermore, promoters and transcription factors, which are key proteins in this process, are modified to promote microbial gene expression that allows a maximum performance of the hydrolytic enzymes for lignocellulosic degradation. The present review will present a critical discussion and highlight the aspects of the use of microorganisms to convert lignocellulose into value-added bioproduct as well combat the bottlenecks to make the biorefinery platform from lignocellulose attractive to the market.
Collapse
Affiliation(s)
- Renato Graciano de Paula
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | - Liliane Fraga Costa Ribeiro
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Neha Srivastava
- Department of Chemical Engineering & Technology, IIT (BHU), Varanasi 221005, U.P, India
| | - Anthonia O'Donovan
- School of Science and Computing, Galway-Mayo Institute of Technology, Galway, Ireland
| | - P K Mishra
- Department of Chemical Engineering & Technology, IIT (BHU), Varanasi 221005, U.P, India
| | - Vijai K Gupta
- ERA Chair of Green Chemistry, Department of Chemistry and Biotechnology, Tallinn University of Technology, 12618 Tallinn, Estonia.
| | - Roberto N Silva
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil.
| |
Collapse
|
62
|
Xia C, Li Z, Xu Y, Yang P, Gao L, Yan Q, Li S, Wang Y, Qu Y, Song X. Introduction of heterologous transcription factors and their target genes into Penicillium oxalicum leads to increased lignocellulolytic enzyme production. Appl Microbiol Biotechnol 2019; 103:2675-2687. [DOI: 10.1007/s00253-018-09612-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 12/18/2018] [Accepted: 12/28/2018] [Indexed: 12/16/2022]
|
63
|
Gao M, Ploessl D, Shao Z. Enhancing the Co-utilization of Biomass-Derived Mixed Sugars by Yeasts. Front Microbiol 2019; 9:3264. [PMID: 30723464 PMCID: PMC6349770 DOI: 10.3389/fmicb.2018.03264] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 12/14/2018] [Indexed: 12/11/2022] Open
Abstract
Plant biomass is a promising carbon source for producing value-added chemicals, including transportation biofuels, polymer precursors, and various additives. Most engineered microbial hosts and a select group of wild-type species can metabolize mixed sugars including oligosaccharides, hexoses, and pentoses that are hydrolyzed from plant biomass. However, most of these microorganisms consume glucose preferentially to non-glucose sugars through mechanisms generally defined as carbon catabolite repression. The current lack of simultaneous mixed-sugar utilization limits achievable titers, yields, and productivities. Therefore, the development of microbial platforms capable of fermenting mixed sugars simultaneously from biomass hydrolysates is essential for economical industry-scale production, particularly for compounds with marginal profits. This review aims to summarize recent discoveries and breakthroughs in the engineering of yeast cell factories for improved mixed-sugar co-utilization based on various metabolic engineering approaches. Emphasis is placed on enhanced non-glucose utilization, discovery of novel sugar transporters free from glucose repression, native xylose-utilizing microbes, consolidated bioprocessing (CBP), improved cellulase secretion, and creation of microbial consortia for improving mixed-sugar utilization. Perspectives on the future development of biorenewables industry are provided in the end.
Collapse
Affiliation(s)
- Meirong Gao
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, United States.,NSF Engineering Research Center for Biorenewable Chemicals (CBiRC), Iowa State University, Ames, IA, United States
| | - Deon Ploessl
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, United States.,NSF Engineering Research Center for Biorenewable Chemicals (CBiRC), Iowa State University, Ames, IA, United States
| | - Zengyi Shao
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, United States.,NSF Engineering Research Center for Biorenewable Chemicals (CBiRC), Iowa State University, Ames, IA, United States.,The Ames Laboratory, Iowa State University, Ames, IA, United States.,The Interdisciplinary Microbiology Program, Biorenewables Research Laboratory, Iowa State University, Ames, IA, United States
| |
Collapse
|
64
|
An Insight into Fungal Cellulases and Their Industrial Applications. Fungal Biol 2019. [DOI: 10.1007/978-3-030-14726-6_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
65
|
Liao LS, Li CX, Zhang FF, Yan YS, Luo XM, Zhao S, Feng JX. How an essential Zn2Cys6 transcription factor PoxCxrA regulates cellulase gene expression in ascomycete fungi? BIOTECHNOLOGY FOR BIOFUELS 2019; 12:105. [PMID: 31073329 PMCID: PMC6498484 DOI: 10.1186/s13068-019-1444-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Accepted: 04/16/2019] [Indexed: 05/07/2023]
Abstract
BACKGROUND Soil ascomycete fungi produce plant-biomass-degrading enzymes to facilitate nutrient and energy uptake in response to exogenous stress. This is controlled by a complex signal network, but the regulatory mechanisms are poorly understood. An essential Zn2Cys6 transcription factor (TF) PoxCxrA was identified to be required for cellulase and xylanase production in Penicillium oxalicum. The genome-wide regulon and DNA binding sequences of PoxCxrA were further identified through RNA-Sequencing, DNase I footprinting experiments and in vitro electrophoretic mobility shift assays. Moreover, a minimal DNA-binding domain in PoxCxrA was recognised. RESULTS A PoxCxrA regulon of 1970 members was identified in P. oxalicum, and it was displayed that PoxCxrA regulated the expression of genes encoding major plant cell wall-degrading enzymes, as well as important cellodextrin and/or glucose transporters. Interestingly, PoxCxrA positively regulated the expression of a known important TF PoxClrB. DNase I footprinting experiments and in vitro electrophoretic mobility shift assays further revealed that PoxCxrA directly bound the promoter regions of PoxClrB and a cellobiohydrolase gene cbh1 (POX05587/Cel7A-2) at different nucleic acid sequences. Remarkably, PoxCxrA autoregulated its own PoxCxrA gene expression. Additionally, a minimal 42-amino-acid PoxCxrA DNA-binding domain was identified. CONCLUSION PoxCxrA could directly regulate the expression of cellulase genes and the regulatory gene PoxClrB via binding their promoters at different nucleic acid sequences. This work expands the diversity of DNA-binding motifs known to be recognised by Zn2Cys6 TFs, and demonstrates novel regulatory mechanisms of fungal cellulase gene expression.
Collapse
Affiliation(s)
- Lu-Sheng Liao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Cheng-Xi Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Feng-Fei Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Yu-Si Yan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Xue-Mei Luo
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Shuai Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Jia-Xun Feng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| |
Collapse
|
66
|
Karkehabadi S, Hansson H, Mikkelsen NE, Kim S, Kaper T, Sandgren M, Gudmundsson M. Structural studies of a glycoside hydrolase family 3 β-glucosidase from the model fungus Neurospora crassa. Acta Crystallogr F Struct Biol Commun 2018; 74:787-796. [PMID: 30511673 PMCID: PMC6277957 DOI: 10.1107/s2053230x18015662] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 11/05/2018] [Indexed: 11/29/2022] Open
Abstract
The glycoside hydrolase family 3 (GH3) β-glucosidases are a structurally diverse family of enzymes. Cel3A from Neurospora crassa (NcCel3A) belongs to a subfamily of key enzymes that are crucial for industrial biomass degradation. β-Glucosidases hydrolyse the β-1,4 bond at the nonreducing end of cellodextrins. The hydrolysis of cellobiose is of special importance as its accumulation inhibits other cellulases acting on crystalline cellulose. Here, the crystal structure of the biologically relevant dimeric form of NcCel3A is reported. The structure has been refined to 2.25 Å resolution, with an Rcryst and Rfree of 0.18 and 0.22, respectively. NcCel3A is an extensively N-glycosylated glycoprotein that shares 46% sequence identity with Hypocrea jecorina Cel3A, the structure of which has recently been published, and 61% sequence identity with the thermophilic β-glucosidase from Rasamsonia emersonii. NcCel3A is a three-domain protein with a number of extended loops that deepen the active-site cleft of the enzyme. These structures characterize this subfamily of GH3 β-glucosidases and account for the high cellobiose specificity of this subfamily.
Collapse
Affiliation(s)
- Saeid Karkehabadi
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, PO Box 7015, SE-750 07 Uppsala, Sweden
| | - Henrik Hansson
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, PO Box 7015, SE-750 07 Uppsala, Sweden
| | - Nils Egil Mikkelsen
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, PO Box 7015, SE-750 07 Uppsala, Sweden
| | - Steve Kim
- DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, CA 94304, USA
| | - Thijs Kaper
- DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, CA 94304, USA
| | - Mats Sandgren
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, PO Box 7015, SE-750 07 Uppsala, Sweden
| | - Mikael Gudmundsson
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, PO Box 7015, SE-750 07 Uppsala, Sweden
| |
Collapse
|
67
|
Liu Q, Li J, Gao R, Li J, Ma G, Tian C. CLR-4, a novel conserved transcription factor for cellulase gene expression in ascomycete fungi. Mol Microbiol 2018; 111:373-394. [DOI: 10.1111/mmi.14160] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Qian Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin 300308 China
| | - Jingen Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin 300308 China
| | - Ranran Gao
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin 300308 China
| | - Jinyang Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin 300308 China
| | - Guoli Ma
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin 300308 China
| | - Chaoguang Tian
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology; Chinese Academy of Sciences; Tianjin 300308 China
| |
Collapse
|
68
|
In-Situ Vacuum Assisted Gas Stripping Recovery System for Ethanol Removal from a Column Bioreactor. FIBERS 2018. [DOI: 10.3390/fib6040088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A three-step process consisting of biomass hydrolysis, fermentation and in-situ gas stripping by a vacuum assisted recovery system, was optimized to increase the ethanol production from sugar beet pulp. The process combines the advantages of stripping and vacuum separation and enhances the fermentation productivity through in-situ ethanol removal. Using the design of experiment and response surface methodology, the effect of major factors in the process, such as pressure, recycling ratio and solids concentration, was tested to efficiently remove ethanol after the combined hydrolysis and fermentation step. Statistical analysis indicates that a decreased pressure rate and an increased liquid phase recycling ratio enhance the productivity and the yield of the strip-vacuum fermentation process. The results also highlight further possibilities of this process to improve integrated bioethanol production processes. According to the statistical analysis, ethanol production is strongly influenced by recycling ratio and vacuum ratio. Mathematical models that were established for description of investigated processes can be used for the optimization of the ethanol production.
Collapse
|
69
|
Wang Z, Gudibanda A, Ugwuowo U, Trail F, Townsend JP. Using evolutionary genomics, transcriptomics, and systems biology to reveal gene networks underlying fungal development. FUNGAL BIOL REV 2018. [DOI: 10.1016/j.fbr.2018.02.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
70
|
Liang B, Du XJ, Li P, Sun CC, Wang S. Investigation of Citrinin and Pigment Biosynthesis Mechanisms in Monascus purpureus by Transcriptomic Analysis. Front Microbiol 2018; 9:1374. [PMID: 30002650 PMCID: PMC6031731 DOI: 10.3389/fmicb.2018.01374] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 06/06/2018] [Indexed: 12/23/2022] Open
Abstract
Monascus purpureus YY-1 is widely used in food colorant production in China. Our previous study clearly illustrated the whole-genome data for YY-1 and provided useful insight into evolutionary research and industrial applications. However, the presence of citrinin, which has nephrotoxic, hepatotoxic, and carcinogenic activities, has attracted attention to the safety of Monascus products. In an effort to reduce the harmful effects of citrinin in Monascus-related products, a random mutant of M. purpureus YY-1 with low citrinin production (designated as "winter") was obtained in this study. To analyze the biosynthesis and regulation mechanisms of pigment and citrinin, a transcriptomic analysis of the M. purpureus YY-1 and winter strains was performed. Comparative transcriptomic analysis reveals pksCT, the essential gene for citrinin synthesis, showed a low expression level in M. purpureus YY-1 and winter, which suggested there might be isoenzymes in M. purpureus YY-1 that were responsible for the citrinin synthesis during evolution. In addition, changes in transcription factor expression may also influence the network regulating the citrinin synthesis pathway in M. purpureus. Moreover, the yields of pigments produced by the winter mutant were significantly increased. Repressing the central carbon metabolism and improving the acetyl-CoA pool can contribute to a high pigment yield, and enhanced NADPH regeneration can also lead to the metabolic flux of pigment production in M. purpureus. Investigations into the biosynthesis and regulation of citrinin and pigment production in M. purpureus will enhance our knowledge of the mechanisms behind the biosynthesis of fungal secondary metabolites.
Collapse
Affiliation(s)
- Bin Liang
- Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Ministry of Education, Tianjin, China
| | - Xin-Jun Du
- Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Ministry of Education, Tianjin, China
| | - Ping Li
- Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Ministry of Education, Tianjin, China
| | - Chan-Chan Sun
- Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Ministry of Education, Tianjin, China
| | - Shuo Wang
- Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Ministry of Education, Tianjin, China.,Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing, China
| |
Collapse
|
71
|
Lin L, Sun Z, Li J, Chen Y, Liu Q, Sun W, Tian C. Disruption of gul-1 decreased the culture viscosity and improved protein secretion in the filamentous fungus Neurospora crassa. Microb Cell Fact 2018; 17:96. [PMID: 29908565 PMCID: PMC6004096 DOI: 10.1186/s12934-018-0944-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 06/12/2018] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND The cellulolytic fungus Neurospora crassa is considered a potential host for enzyme and bioethanol production. However, large scale applications are hindered by its filamentous growth. Although previous investigations have shown that mycelial morphology in submerged culture can be controlled by altering physical factors, there is little knowledge available about the potential for morphology control by genetic modification. RESULTS In this study, we screened morphological mutants in the filamentous fungus N. crassa. Of the 90 morphological mutants screened, 14 mutants exhibited considerably higher viscosity compared with that of the wild type strain, and only two mutants showed low-viscosity morphologies in submerged culture. We observed that disruption of gul-1 (NCU01197), which encodes an mRNA binding protein involved in cell wall remodeling, caused pellet formation as the fermentation progressed, and resulted in the most significant decrease in viscosity of culture broth. Moreover, over-expression of gul-1 caused dramatically increased viscosity, suggesting that the gul-1 had an important function in mycelial morphology during submerged cultivation. Transcriptional profiling showed that expression of genes encoding eight GPI-anchored cell wall proteins was lowered in Δgul-1 while expression of genes associated with two non-anchored cell wall proteins was elevated. Meanwhile, the expression levels of two hydrophobin genes were also significantly altered. These results suggested that GUL-1 affected the transcription of cell wall-related genes, thereby influencing cell wall structure and mycelial morphology. Additionally, the deletion of gul-1 caused increased protein secretion, probably due to a defect in cell wall integrity, suggesting this as an alternative strategy of strain improvement for enzyme production. To confirm practical applications, deletion of gul-1 in the hyper-cellulase producing strain (∆ncw-1∆Ncap3m) significantly reduced the viscosity of culture broth. CONCLUSIONS Using the model filamentous fungus N. crassa, genes that affect mycelial morphology in submerged culture were explored through systematic screening of morphological mutants. Disrupting several candidate genes altered viscosities in submerged culture. This work provides an example for controlling fungal morphology in submerged fermentation by genetic engineering, and will be beneficial for industrial fungal strain improvement.
Collapse
Affiliation(s)
- Liangcai Lin
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Zhiyong Sun
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Jingen Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Yong Chen
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Qian Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Wenliang Sun
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Chaoguang Tian
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| |
Collapse
|
72
|
Frommhagen M, Westphal AH, van Berkel WJH, Kabel MA. Distinct Substrate Specificities and Electron-Donating Systems of Fungal Lytic Polysaccharide Monooxygenases. Front Microbiol 2018; 9:1080. [PMID: 29896168 PMCID: PMC5987398 DOI: 10.3389/fmicb.2018.01080] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/07/2018] [Indexed: 12/27/2022] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are powerful enzymes that oxidatively cleave glycosidic bonds in polysaccharides. The ability of these copper enzymes to boost the degradation of lignocellulose has greatly stimulated research efforts and biocatalytic applications within the biorefinery field. Initially found as oxidizing recalcitrant substrates, such as chitin and cellulose, it is now clear that LPMOs cleave a broad range of oligo- and poly-saccharides and make use of various electron-donating systems. Herein, substrate specificities and electron-donating systems of fungal LPMOs are summarized. A closer look at LPMOs as part of the fungal enzyme machinery might provide insights into their role in fungal growth and plant-pathogen interactions to further stimulate the search for novel LPMO applications.
Collapse
Affiliation(s)
- Matthias Frommhagen
- Laboratory of Food Chemistry, Wageningen University and Research, Wageningen, Netherlands
| | - Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University and Research, Wageningen, Netherlands
| | - Willem J H van Berkel
- Laboratory of Biochemistry, Wageningen University and Research, Wageningen, Netherlands
| | - Mirjam A Kabel
- Laboratory of Food Chemistry, Wageningen University and Research, Wageningen, Netherlands
| |
Collapse
|
73
|
Tovar-Herrera OE, Martha-Paz AM, Pérez-LLano Y, Aranda E, Tacoronte-Morales JE, Pedroso-Cabrera MT, Arévalo-Niño K, Folch-Mallol JL, Batista-García RA. Schizophyllum commune: An unexploited source for lignocellulose degrading enzymes. Microbiologyopen 2018; 7:e00637. [PMID: 29785766 PMCID: PMC6011954 DOI: 10.1002/mbo3.637] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 03/09/2018] [Accepted: 03/09/2018] [Indexed: 02/01/2023] Open
Abstract
Lignocellulose represents the most abundant source of carbon in the Earth. Thus, fraction technology of the biomass turns up as an emerging technology for the development of biorefineries. Saccharification and fermentation processes require the formulation of enzymatic cocktails or the development of microorganisms (naturally or genetically modified) with the appropriate toolbox to produce a cost‐effective fermentation technology. Therefore, the search for microorganisms capable of developing effective cellulose hydrolysis represents one of the main challenges in this era. Schizophyllum commune is an edible agarical with a great capability to secrete a myriad of hydrolytic enzymes such as xylanases and endoglucanases that are expressed in a high range of substrates. In addition, a large number of protein‐coding genes for glycoside hydrolases, oxidoreductases like laccases (Lacs; EC 1.10.3.2), as well as some sequences encoding for lytic polysaccharide monooxygenases (LPMOs) and expansins‐like proteins demonstrate the potential of this fungus to be applied in different biotechnological process. In this review, we focus on the enzymatic toolbox of S. commune at the genetic, transcriptomic, and proteomic level, as well as the requirements to be employed for fermentable sugars production in biorefineries. At the end the trend of its use in patent registration is also reviewed.
Collapse
Affiliation(s)
- Omar Eduardo Tovar-Herrera
- Instituto de Biotecnología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Ciudad Universitaria, San Nicolás de los Garza, Nuevo León, México
| | - Adriana Mayrel Martha-Paz
- Laboratorio de Micología y Fitopatología, Unidad de manipulación genética, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Ciudad Universitaria, San Nicolás de los Garza, Nuevo León, México
| | - Yordanis Pérez-LLano
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, México
| | - Elisabet Aranda
- Instituto del Agua, Universidad de Granada, Granada, Granada, Spain
| | | | | | - Katiushka Arévalo-Niño
- Instituto de Biotecnología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Ciudad Universitaria, San Nicolás de los Garza, Nuevo León, México
| | - Jorge Luis Folch-Mallol
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, México
| | - Ramón Alberto Batista-García
- Centro de Investigación en Dinámica Celular, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, México
| |
Collapse
|
74
|
Matsu-ura T, Dovzhenok AA, Coradetti ST, Subramanian KR, Meyer DR, Kwon JJ, Kim C, Salomonis N, Glass NL, Lim S, Hong CI. Synthetic Gene Network with Positive Feedback Loop Amplifies Cellulase Gene Expression in Neurospora crassa. ACS Synth Biol 2018; 7:1395-1405. [PMID: 29625007 DOI: 10.1021/acssynbio.8b00011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Second-generation or lignocellulosic biofuels are a tangible source of renewable energy, which is critical to combat climate change by reducing the carbon footprint. Filamentous fungi secrete cellulose-degrading enzymes called cellulases, which are used for production of lignocellulosic biofuels. However, inefficient production of cellulases is a major obstacle for industrial-scale production of second-generation biofuels. We used computational simulations to design and implement synthetic positive feedback loops to increase gene expression of a key transcription factor, CLR-2, that activates a large number of cellulases in a filamentous fungus, Neurospora crassa. Overexpression of CLR-2 reveals previously unappreciated roles of CLR-2 in lignocellulosic gene network, which enabled simultaneous induction of approximately 50% of 78 lignocellulosic degradation-related genes in our engineered Neurospora strains. This engineering results in dramatically increased cellulase activity due to cooperative orchestration of multiple enzymes involved in the cellulose degradation pathway. Our work provides a proof of principle in utilizing mathematical modeling and synthetic biology to improve the efficiency of cellulase synthesis for second-generation biofuel production.
Collapse
Affiliation(s)
- Toru Matsu-ura
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio 45267-0529, United States
| | - Andrey A. Dovzhenok
- Department of Mathematical Sciences, University of Cincinnati, Cincinnati, Ohio 45221-0025, United States
| | - Samuel T. Coradetti
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, United States
| | - Krithika R. Subramanian
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio 45267-0529, United States
- Department of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio 45229-3039, United States
| | - Daniel R. Meyer
- Department of Biomedical, Chemical, and Environmental Engineering, University of Cincinnati, Cincinnati, Ohio 45221-0012, United States
| | - Jaesang J. Kwon
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio 45267-0529, United States
| | - Caleb Kim
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio 45267-0529, United States
| | - Nathan Salomonis
- Department of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio 45229-3039, United States
- Division of Developmental Biology, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio 45229-3039, United States
| | - N. Louise Glass
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, United States
| | - Sookkyung Lim
- Department of Mathematical Sciences, University of Cincinnati, Cincinnati, Ohio 45221-0025, United States
| | - Christian I. Hong
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio 45267-0529, United States
- Division of Developmental Biology, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio 45229-3039, United States
| |
Collapse
|
75
|
Hangasky JA, Iavarone AT, Marletta MA. Reactivity of O 2 versus H 2O 2 with polysaccharide monooxygenases. Proc Natl Acad Sci U S A 2018; 115:4915-4920. [PMID: 29686097 PMCID: PMC5949000 DOI: 10.1073/pnas.1801153115] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Enzymatic conversion of polysaccharides into lower-molecular-weight, soluble oligosaccharides is dependent on the action of hydrolytic and oxidative enzymes. Polysaccharide monooxygenases (PMOs) use an oxidative mechanism to break the glycosidic bond of polymeric carbohydrates, thereby disrupting the crystalline packing and creating new chain ends for hydrolases to depolymerize and degrade recalcitrant polysaccharides. PMOs contain a mononuclear Cu(II) center that is directly involved in C-H bond hydroxylation. Molecular oxygen was the accepted cosubstrate utilized by this family of enzymes until a recent report indicated reactivity was dependent on H2O2 Reported here is a detailed analysis of PMO reactivity with H2O2 and O2, in conjunction with high-resolution MS measurements. The cosubstrate utilized by the enzyme is dependent on the assay conditions. PMOs will directly reduce O2 in the coupled hydroxylation of substrate (monooxygenase activity) and will also utilize H2O2 (peroxygenase activity) produced from the uncoupled reduction of O2 Both cosubstrates require Cu reduction to Cu(I), but the reaction with H2O2 leads to nonspecific oxidation of the polysaccharide that is consistent with the generation of a hydroxyl radical-based mechanism in Fenton-like chemistry, while the O2 reaction leads to regioselective substrate oxidation using an enzyme-bound Cu/O2 reactive intermediate. Moreover, H2O2 does not influence the ability of secretome from Neurospora crassa to degrade Avicel, providing evidence that molecular oxygen is a physiologically relevant cosubstrate for PMOs.
Collapse
Affiliation(s)
- John A Hangasky
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720
| | - Anthony T Iavarone
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Michael A Marletta
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720;
- Department of Chemistry, University of California, Berkeley, CA 94720
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| |
Collapse
|
76
|
Casarrubia S, Daghino S, Kohler A, Morin E, Khouja HR, Daguerre Y, Veneault-Fourrey C, Martin FM, Perotto S, Martino E. The Hydrophobin-Like OmSSP1 May Be an Effector in the Ericoid Mycorrhizal Symbiosis. FRONTIERS IN PLANT SCIENCE 2018; 9:546. [PMID: 29765384 PMCID: PMC5938622 DOI: 10.3389/fpls.2018.00546] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 04/09/2018] [Indexed: 06/08/2023]
Abstract
Mutualistic and pathogenic plant-colonizing fungi use effector molecules to manipulate the host cell metabolism to allow plant tissue invasion. Some small secreted proteins (SSPs) have been identified as fungal effectors in both ectomycorrhizal and arbuscular mycorrhizal fungi, but it is currently unknown whether SSPs also play a role as effectors in other mycorrhizal associations. Ericoid mycorrhiza is a specific endomycorrhizal type that involves symbiotic fungi mostly belonging to the Leotiomycetes (Ascomycetes) and plants in the family Ericaceae. Genomic and RNASeq data from the ericoid mycorrhizal fungus Oidiodendron maius led to the identification of several symbiosis-upregulated genes encoding putative SSPs. OmSSP1, the most highly symbiosis up-regulated SSP, was found to share some features with fungal hydrophobins, even though it lacks the Pfam hydrophobin domain. Sequence alignment with other hydrophobins and hydrophobin-like fungal proteins placed OmSSP1 within Class I hydrophobins. However, the predicted features of OmSSP1 may suggest a distinct type of hydrophobin-like proteins. The presence of a predicted signal peptide and a yeast-based signal sequence trap assay demonstrate that OmSSP1 is secreted. OmSSP1 null-mutants showed a reduced capacity to form ericoid mycorrhiza with Vaccinium myrtillus roots, suggesting a role as effectors in the ericoid mycorrhizal interaction.
Collapse
Affiliation(s)
- Salvatore Casarrubia
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Stefania Daghino
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Annegret Kohler
- INRA (Institut National de la Recherche Agronomique), UMR 1136 INRA-Université de Lorraine Interactions Arbres/Microorganismes, Laboratoire d'Excellence ARBRE, Centre INRA-Lorraine, Champenoux, France
| | - Emmanuelle Morin
- INRA (Institut National de la Recherche Agronomique), UMR 1136 INRA-Université de Lorraine Interactions Arbres/Microorganismes, Laboratoire d'Excellence ARBRE, Centre INRA-Lorraine, Champenoux, France
| | | | - Yohann Daguerre
- INRA (Institut National de la Recherche Agronomique), UMR 1136 INRA-Université de Lorraine Interactions Arbres/Microorganismes, Laboratoire d'Excellence ARBRE, Centre INRA-Lorraine, Champenoux, France
| | - Claire Veneault-Fourrey
- INRA (Institut National de la Recherche Agronomique), UMR 1136 INRA-Université de Lorraine Interactions Arbres/Microorganismes, Laboratoire d'Excellence ARBRE, Centre INRA-Lorraine, Champenoux, France
- Université de Lorraine, UMR 1136 INRA-Université de Lorraine Interactions Arbres/Microorganismes, Laboratoire d'Excellence ARBRE, Faculté des Sciences et Technologies, Vandoeuvre les Nancy, France
| | - Francis M. Martin
- INRA (Institut National de la Recherche Agronomique), UMR 1136 INRA-Université de Lorraine Interactions Arbres/Microorganismes, Laboratoire d'Excellence ARBRE, Centre INRA-Lorraine, Champenoux, France
| | - Silvia Perotto
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Elena Martino
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
- INRA (Institut National de la Recherche Agronomique), UMR 1136 INRA-Université de Lorraine Interactions Arbres/Microorganismes, Laboratoire d'Excellence ARBRE, Centre INRA-Lorraine, Champenoux, France
| |
Collapse
|
77
|
Liu H, Sun J, Chang JS, Shukla P. Engineering microbes for direct fermentation of cellulose to bioethanol. Crit Rev Biotechnol 2018; 38:1089-1105. [DOI: 10.1080/07388551.2018.1452891] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Hao Liu
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China
| | - Jianliang Sun
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China
| | - Jo-Shu Chang
- Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, China
| | - Pratyoosh Shukla
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak, India
| |
Collapse
|
78
|
Cheng J, Guo X, Cai P, Cheng X, Piškur J, Ma Y, Jiang H, Gu Z. Parallel Evolution of Chromatin Structure Underlying Metabolic Adaptation. Mol Biol Evol 2018; 34:2870-2878. [PMID: 28961859 DOI: 10.1093/molbev/msx220] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Parallel evolution occurs when a similar trait emerges in independent evolutionary lineages. Although changes in protein coding and gene transcription have been investigated as underlying mechanisms for parallel evolution, parallel changes in chromatin structure have never been reported. Here, Saccharomyces cerevisiae and a distantly related yeast species, Dekkera bruxellensis, are investigated because both species have independently evolved the capacity of aerobic fermentation. By profiling and comparing genome sequences, transcriptomic landscapes, and chromatin structures, we revealed that parallel changes in nucleosome occupancy in the promoter regions of mitochondria-localized genes led to concerted suppression of mitochondrial functions by glucose, which can explain the metabolic convergence in these two independent yeast species. Further investigation indicated that similar mutational processes in the promoter regions of these genes in the two independent evolutionary lineages underlay the parallel changes in chromatin structure. Our results indicate that, despite several hundred million years of separation, parallel changes in chromatin structure, can be an important adaptation mechanism for different organisms. Due to the important role of chromatin structure changes in regulating gene expression and organism phenotypes, the novel mechanism revealed in this study could be a general phenomenon contributing to parallel adaptation in nature.
Collapse
Affiliation(s)
- Jian Cheng
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Xiaoxian Guo
- Division of Nutritional Sciences, Cornell University, Ithaca, NY
| | - Pengli Cai
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Xiaozhi Cheng
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Jure Piškur
- Department of Biology, Lund University, Lund, Sweden
| | - Yanhe Ma
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Huifeng Jiang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Zhenglong Gu
- Division of Nutritional Sciences, Cornell University, Ithaca, NY
| |
Collapse
|
79
|
Bilal M, Iqbal HM, Hu H, Wang W, Zhang X. Metabolic engineering and enzyme-mediated processing: A biotechnological venture towards biofuel production – A review. RENEWABLE & SUSTAINABLE ENERGY REVIEWS 2018. [DOI: 10.1016/j.rser.2017.09.070] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
|
80
|
Nogueira KMV, de Paula RG, Antoniêto ACC, dos Reis TF, Carraro CB, Silva AC, Almeida F, Rechia CGV, Goldman GH, Silva RN. Characterization of a novel sugar transporter involved in sugarcane bagasse degradation in Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:84. [PMID: 29619080 PMCID: PMC5879799 DOI: 10.1186/s13068-018-1084-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 03/17/2018] [Indexed: 05/05/2023]
Abstract
BACKGROUND Trichoderma reesei is a saprophytic fungus implicated in the degradation of polysaccharides present in the cell wall of plants. T. reesei has been recognized as the most important industrial fungus that secretes and produces cellulase enzymes that are employed in the production of second generation bioethanol. A few of the molecular mechanisms involved in the process of biomass deconstruction by T. reesei; in particular, the effect of sugar transporters and induction of xylanases and cellulases expression are yet to be known. RESULTS In our study, we characterized a novel sugar transporter, which was previously identified by our group through in silico analysis of RNA-seq data. The novel T. reesei 69957-sugar transport system (Tr69957) is capable of transporting xylose, mannose, and cellobiose using a T. reesei 69957-sugar transport system in Saccharomyces cerevisiae. The deletion of Tr69957 in T. reesei affected the fungal growth and biomass accumulation, and the sugar uptake in the presence of mannose, cellobiose, and xylose. Molecular docking studies revealed that Tr69957 shows reduced protein-ligand binding energy for interactions towards disaccharides in comparison with monosaccharides. Furthermore, the deletion of Tr69957 affected the gene expression of cellobiohydrolases (cel7a and cel6a), β-glucosidases (cel3a and cel1a), and xylanases (xyn1 and xyn2) in the cultures of parental and mutant strains in the presence of cellobiose and sugarcane bagasse (SCB). CONCLUSION The transporter Tr69957 of T. reesei can transport cellobiose, xylose, and mannose, and can affect the expression of a few genes encoding enzymes, such as cellulases and xylanases, in the presence of SCB. We showed for the first time that a filamentous fungus (T. reesei) contains a potential mannose transporter that may be involved in the degradation of cellulose.
Collapse
Affiliation(s)
- Karoline M. V. Nogueira
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP Brazil
| | - Renato Graciano de Paula
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP Brazil
| | | | - Thaila F. dos Reis
- Department of Pharmaceutical Sciences, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP Brazil
| | - Cláudia Batista Carraro
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP Brazil
| | - Alinne Costa Silva
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP Brazil
| | - Fausto Almeida
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP Brazil
| | - Carem Gledes Vargas Rechia
- Department of Pharmaceutical Sciences, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP Brazil
| | - Gustavo H. Goldman
- Department of Pharmaceutical Sciences, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP Brazil
| | - Roberto N. Silva
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP Brazil
| |
Collapse
|
81
|
Chang JJ, Lin YJ, Lay CH, Thia C, Wu YC, Hou YH, Huang CC, Li WH. Constructing a cellulosic yeast host with an efficient cellulase cocktail. Biotechnol Bioeng 2017; 115:751-761. [PMID: 29197184 DOI: 10.1002/bit.26507] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 10/26/2017] [Accepted: 11/28/2017] [Indexed: 01/13/2023]
Abstract
Cellulose is a renewable feedstock for green industry. It is therefore important to develop a technique to construct a host with a high cellulolytic efficiency to digest cellulose. In this study, we developed a convenient host-engineering technique to adjust the expression levels of heterologous genes in the host by promoter rearrangement and gene copy number adjustment. Using genes from different glycoside hydrolase (GH) families including GH2, GH3, GH5, GH6, GH7, and GH12 from Aspergillus niger, Trichoderma reesei, and Neocallimastix patriciarum, we constructed a cellulolytic Kluyveromyces marxianus with eight cellulase gene-cassettes that produced a cellulase cocktail with a high cellulolytic efficiency, leading to a significant reduction in enzyme cost in a rice straw saccharification process. Our technique can be used to design a host that can efficiently convert biomass feedstock to biofuel.
Collapse
Affiliation(s)
- Jui-Jen Chang
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan.,Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Yu-Ju Lin
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan.,Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Chyi-How Lay
- Master Program of Green Energy Science and Technology, Feng Chia University, Taichung, Taiwan.,Green Energy Development Center, Feng Chia University, Taichung, Taiwan
| | - Caroline Thia
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Yueh-Chin Wu
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
| | - Yu-Han Hou
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
| | - Chieh-Chen Huang
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Wen-Hsiung Li
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan.,Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| |
Collapse
|
82
|
Li S, Shao N, Luo Y, Liu H, Cai S, Dong X. Transcriptome and Zymogram Analyses Reveal a Cellobiose-Dose Related Reciprocal Regulatory Effect on Cellulase Synthesis in Cellulosilyticum ruminicola H1. Front Microbiol 2017; 8:2497. [PMID: 29312203 PMCID: PMC5733062 DOI: 10.3389/fmicb.2017.02497] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 11/30/2017] [Indexed: 11/21/2022] Open
Abstract
The rumen bacterium Cellulosilyticum ruminicola H1 efficiently hydrolyzes cellulose. To gain insights into the regulatory mechanisms of cellulase synthesis, comparative transcriptome analysis was conducted for cultures grown on 2% filter paper, 0.5 and 0.05% cellobiose, and 0.5% birchwood xylan. It was found that cellulose induced a majority of (hemi)cellulases, including 33 cellulases and a cellulosomal scaffoldin (1.3- to 22.7-fold); seven endoxylanases, two mannanases, and two pectatelyases (2- to 16-fold); and pyruvate formate-lyase (PFL, 1.5- to 7-fold). Noticeably, 3- and 2.5-fold increased transcription of a cellobiohydrolase and the cellulosomal scaffoldin precursor were detected in 0.05% than in 0.5% cellobiose. Consistently, 9- and 4-fold higher specific cellobiohydrolase activities were detected in the filter paper and 0.05% cellobiose culture. SDS- and native-PAGE zymograms of cellulose-enriched proteins from the filter paper culture displayed cellulase activities, and cellulolytic “complexes” were enriched from the filter paper- and 0.05% cellobiose-cultures, but not from the 0.5% cellobiose culture. LC-MS/MS identified the cellulosomal scaffoldin precursor in the “complexes” in addition to cellulase, hemicellulase, and PFL proteins. The addition of 0.5% cellobiose, but not 0.05% cellobiose remarkably inhibited strain H1 to degrade filter paper. Therefore, this work reveals a cellobiose-dose related regulatory mechanism of cellulase synthesis by lower for induction and higher for repression, which has extended our understanding of the regulation of microbial cellulase synthesis.
Collapse
Affiliation(s)
- Shanzhen Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Microbial Resources, University of Chinese Academy of Sciences, Beijing, China
| | - Nana Shao
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Microbial Resources, University of Chinese Academy of Sciences, Beijing, China
| | - Yuanming Luo
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Hongcan Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Shichun Cai
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xiuzhu Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
83
|
Starr TL, Gonçalves AP, Meshgin N, Glass NL. The major cellulases CBH-1 and CBH-2 of Neurospora crassa rely on distinct ER cargo adaptors for efficient ER-exit. Mol Microbiol 2017; 107:229-248. [PMID: 29131484 DOI: 10.1111/mmi.13879] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2017] [Indexed: 12/17/2022]
Abstract
Filamentous fungi are native secretors of lignocellulolytic enzymes and are used as protein-producing factories in the industrial biotechnology sector. Despite the importance of these organisms in industry, relatively little is known about the filamentous fungal secretory pathway or how it might be manipulated for improved protein production. Here, we use Neurospora crassa as a model filamentous fungus to interrogate the requirements for trafficking of cellulase enzymes from the endoplasmic reticulum to the Golgi. We characterized the localization and interaction properties of the p24 and ERV-29 cargo adaptors, as well as their role in cellulase enzyme trafficking. We find that the two most abundantly secreted cellulases, CBH-1 and CBH-2, depend on distinct ER cargo adaptors for efficient exit from the ER. CBH-1 depends on the p24 proteins, whereas CBH-2 depends on the N. crassa homolog of yeast Erv29p. This study provides a first step in characterizing distinct trafficking pathways of lignocellulolytic enzymes in filamentous fungi.
Collapse
Affiliation(s)
- Trevor L Starr
- The Energy Biosciences Institute, The University of California, Berkeley, CA 94720, USA
| | - A Pedro Gonçalves
- The Energy Biosciences Institute, The University of California, Berkeley, CA 94720, USA.,Plant and Microbial Biology Department, The University of California, Berkeley, CA 94720, USA
| | - Neeka Meshgin
- The Energy Biosciences Institute, The University of California, Berkeley, CA 94720, USA
| | - N Louise Glass
- The Energy Biosciences Institute, The University of California, Berkeley, CA 94720, USA.,Plant and Microbial Biology Department, The University of California, Berkeley, CA 94720, USA.,Environmental Genomics and Systems Biology Division, The Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| |
Collapse
|
84
|
Construction of a cellulose-metabolizing Komagataella phaffii (Pichia pastoris) by co-expressing glucanases and β-glucosidase. Appl Microbiol Biotechnol 2017; 102:1297-1306. [DOI: 10.1007/s00253-017-8656-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/12/2017] [Accepted: 11/14/2017] [Indexed: 12/22/2022]
|
85
|
Gruben BS, Mäkelä MR, Kowalczyk JE, Zhou M, Benoit-Gelber I, De Vries RP. Expression-based clustering of CAZyme-encoding genes of Aspergillus niger. BMC Genomics 2017; 18:900. [PMID: 29169319 PMCID: PMC5701360 DOI: 10.1186/s12864-017-4164-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 10/05/2017] [Indexed: 11/29/2022] Open
Abstract
Background The Aspergillus niger genome contains a large repertoire of genes encoding carbohydrate active enzymes (CAZymes) that are targeted to plant polysaccharide degradation enabling A. niger to grow on a wide range of plant biomass substrates. Which genes need to be activated in certain environmental conditions depends on the composition of the available substrate. Previous studies have demonstrated the involvement of a number of transcriptional regulators in plant biomass degradation and have identified sets of target genes for each regulator. In this study, a broad transcriptional analysis was performed of the A. niger genes encoding (putative) plant polysaccharide degrading enzymes. Microarray data focusing on the initial response of A. niger to the presence of plant biomass related carbon sources were analyzed of a wild-type strain N402 that was grown on a large range of carbon sources and of the regulatory mutant strains ΔxlnR, ΔaraR, ΔamyR, ΔrhaR and ΔgalX that were grown on their specific inducing compounds. Results The cluster analysis of the expression data revealed several groups of co-regulated genes, which goes beyond the traditionally described co-regulated gene sets. Additional putative target genes of the selected regulators were identified, based on their expression profile. Notably, in several cases the expression profile puts questions on the function assignment of uncharacterized genes that was based on homology searches, highlighting the need for more extensive biochemical studies into the substrate specificity of enzymes encoded by these non-characterized genes. The data also revealed sets of genes that were upregulated in the regulatory mutants, suggesting interaction between the regulatory systems and a therefore even more complex overall regulatory network than has been reported so far. Conclusions Expression profiling on a large number of substrates provides better insight in the complex regulatory systems that drive the conversion of plant biomass by fungi. In addition, the data provides additional evidence in favor of and against the similarity-based functions assigned to uncharacterized genes. Electronic supplementary material The online version of this article (10.1186/s12864-017-4164-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Birgit S Gruben
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.,Microbiology, Utrecht University, Padualaan 8, 3584, CH, Utrecht, The Netherlands
| | - Miia R Mäkelä
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.,Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.,Department of Food and Environmental Sciences, Division of Microbiology and Biotechnology, Viikki Biocenter 1, University of Helsinki, Helsinki, Finland
| | - Joanna E Kowalczyk
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.,Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands
| | - Miaomiao Zhou
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.,Current affiliation: ATGM, Avans University of Applied Sciences, Lovensdijkstraat 61-63, 4818, AJ, Breda, The Netherlands
| | - Isabelle Benoit-Gelber
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.,Microbiology, Utrecht University, Padualaan 8, 3584, CH, Utrecht, The Netherlands.,Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.,Current affiliation: Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke St. W, Montreal, QC, Canada
| | - Ronald P De Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands. .,Microbiology, Utrecht University, Padualaan 8, 3584, CH, Utrecht, The Netherlands. .,Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.
| |
Collapse
|
86
|
Hassan L, Reppke MJ, Thieme N, Schweizer SA, Mueller CW, Benz JP. Comparing the physiochemical parameters of three celluloses reveals new insights into substrate suitability for fungal enzyme production. Fungal Biol Biotechnol 2017; 4:10. [PMID: 29119000 PMCID: PMC5669031 DOI: 10.1186/s40694-017-0039-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 10/23/2017] [Indexed: 11/30/2022] Open
Abstract
Background The industrial applications of cellulases are mostly limited by the costs associated with their production. Optimized production pathways are therefore desirable. Based on their enzyme inducing capacity, celluloses are commonly used in fermentation media. However, the influence of their physiochemical characteristics on the production process is not well understood. In this study, we examined how physical, structural and chemical properties of celluloses influence cellulase and hemicellulase production in an industrially-optimized and a non-engineered filamentous fungus: Trichoderma reesei RUT-C30 and Neurospora crassa. The performance was evaluated by quantifying gene induction, protein secretion and enzymatic activities. Results Among the three investigated substrates, the powdered cellulose was found to be the most impure, and the residual hemicellulosic content was efficiently perceived by the fungi. It was furthermore found to be the least crystalline substrate and consequently was the most readily digested cellulose in vitro. In vivo however, only RUT-C30 was able to take full advantage of these factors. When comparing carbon catabolite repressed and de-repressed strains of T. reesei and N. crassa, we found that cre1/cre-1 is at least partially responsible for this observation, but that the different wiring of the molecular signaling networks is also relevant. Conclusions Our findings indicate that crystallinity and hemicellulose content are major determinants of performance. Moreover, the genetic background between WT and modified strains greatly affects the ability to utilize the cellulosic substrate. By highlighting key factors to consider when choosing the optimal cellulosic product for enzyme production, this study has relevance for the optimization of a critical step in the biotechnological (hemi-) cellulase production process. Electronic supplementary material The online version of this article (10.1186/s40694-017-0039-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Lara Hassan
- HFM, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Manfred J Reppke
- HFM, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Nils Thieme
- HFM, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Steffen A Schweizer
- Chair of Soil Science, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Carsten W Mueller
- Chair of Soil Science, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - J Philipp Benz
- HFM, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| |
Collapse
|
87
|
Investigation of the indigenous fungal community populating barley grains: Secretomes and xylanolytic potential. J Proteomics 2017; 169:153-164. [DOI: 10.1016/j.jprot.2017.03.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/03/2017] [Accepted: 03/13/2017] [Indexed: 11/23/2022]
|
88
|
Enhancement of Environmental Hazard Degradation in the Presence of Lignin: a Proteomics Study. Sci Rep 2017; 7:11356. [PMID: 28900110 PMCID: PMC5595786 DOI: 10.1038/s41598-017-10132-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 07/06/2017] [Indexed: 11/08/2022] Open
Abstract
Proteomics studies of fungal systems have progressed dramatically based on the availability of more fungal genome sequences in recent years. Different proteomics strategies have been applied toward characterization of fungal proteome and revealed important gene functions and proteome dynamics. Presented here is the application of shot-gun proteomic technology to study the bio-remediation of environmental hazards by white-rot fungus. Lignin, a naturally abundant component of the plant biomass, is discovered to promote the degradation of Azo dye by white-rot fungus Irpex lacteus CD2 in the lignin/dye/fungus system. Shotgun proteomics technique was used to understand degradation mechanism at the protein level for the lignin/dye/fungus system. Our proteomics study can identify about two thousand proteins (one third of the predicted white-rot fungal proteome) in a single experiment, as one of the most powerful proteomics platforms to study the fungal system to date. The study shows a significant enrichment of oxidoreduction functional category under the dye/lignin combined treatment. An in vitro validation is performed and supports our hypothesis that the synergy of Fenton reaction and manganese peroxidase might play an important role in DR5B dye degradation. The results could guide the development of effective bioremediation strategies and efficient lignocellulosic biomass conversion.
Collapse
|
89
|
Gandini C, Tarraran L, Kalemasi D, Pessione E, Mazzoli R. RecombinantLactococcus lactisfor efficient conversion of cellodextrins into L-lactic acid. Biotechnol Bioeng 2017; 114:2807-2817. [DOI: 10.1002/bit.26400] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 08/01/2017] [Accepted: 08/07/2017] [Indexed: 12/31/2022]
Affiliation(s)
- Chiara Gandini
- Department of Life Sciences and Systems Biology, Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes; University of Turin; Torino Italy
| | - Loredana Tarraran
- Department of Life Sciences and Systems Biology, Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes; University of Turin; Torino Italy
| | - Denis Kalemasi
- Department of Life Sciences and Systems Biology, Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes; University of Turin; Torino Italy
| | - Enrica Pessione
- Department of Life Sciences and Systems Biology, Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes; University of Turin; Torino Italy
| | - Roberto Mazzoli
- Department of Life Sciences and Systems Biology, Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes; University of Turin; Torino Italy
| |
Collapse
|
90
|
Comparative analysis of basidiomycete transcriptomes reveals a core set of expressed genes encoding plant biomass degrading enzymes. Fungal Genet Biol 2017; 112:40-46. [PMID: 28803908 DOI: 10.1016/j.fgb.2017.08.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 07/25/2017] [Accepted: 08/07/2017] [Indexed: 01/21/2023]
Abstract
Basidiomycete fungi can degrade a wide range of plant biomass, including living and dead trees, forest litter, crops, and plant matter in soils. Understanding the process of plant biomass decay by basidiomycetes could facilitate their application in various industrial sectors such as food & feed, detergents and biofuels, and also provide new insights into their essential biological role in the global carbon cycle. The fast expansion of basidiomycete genomic and functional genomics data (e.g. transcriptomics, proteomics) has facilitated exploration of key genes and regulatory mechanisms of plant biomass degradation. In this study, we comparatively analyzed 22 transcriptome datasets from basidiomycetes related to plant biomass degradation, and identified 328 commonly induced genes and 318 repressed genes, and defined a core set of carbohydrate active enzymes (CAZymes), which was shared by most of the basidiomycete species. High conservation of these CAZymes in genomes and similar regulation pattern in transcriptomics data from lignocellulosic substrates indicate their key role in plant biomass degradation and need for their further biochemical investigation.
Collapse
|
91
|
De Los Santos H, Hurley JM, Collins EJ, Bennett KP. Circadian Rhythms in Neurospora Exhibit Biologically Relevant Driven and Damped Harmonic Oscillations. ACM-BCB ... ... : THE ... ACM CONFERENCE ON BIOINFORMATICS, COMPUTATIONAL BIOLOGY AND BIOMEDICINE. ACM CONFERENCE ON BIOINFORMATICS, COMPUTATIONAL BIOLOGY AND BIOMEDICINE 2017; 2017:455-463. [PMID: 31844846 PMCID: PMC6913202 DOI: 10.1145/3107411.3107420] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Circadian rhythms are endogenous cycles of approximately 24 hours reinforced by external cues such as light. These cycles are typically modeled as harmonic oscillators with fixed amplitude peaks. Using experimental data measuring global gene transcription in Neurospora crassa over 48 hours in the dark (i.e. with external queues removed), we demonstrate that many circadian genes frequently exhibit either damped harmonic oscillations, in which the peak amplitudes decrease each day, or driven harmonic oscillations, in which the peak amplitudes increase each day. By fitting extended harmonic oscillator models which include a damping ratio coefficient, we detected additional circadian genes that were not identified by the current standard tools that use fixed amplitude waves as reference, e.g. JTK_CYCLE. Functional Catalogue analysis confirms that our identified damped or driven genes exhibit distinct biological functions. The application of extended damped/driven harmonic oscillator models thus can elucidate, not only previously unidentified circadian genes, but also characterize gene subsets with expression patterns of biological relevance. Thus, expanded harmonic oscillators provide a powerful new tool for circadian system biology.
Collapse
Affiliation(s)
- Hannah De Los Santos
- Rensselaer Polytechnic Institute Institute for Data Exploration and Applications/Department of Mathematical Sciences Troy, NY 12180
| | - Jennifer M Hurley
- Rensselaer Polytechnic Institute Department of Biological Sciences/Center for Biotechnology and Interdisciplinary Sciences Troy, NY 12180
| | - Emily J Collins
- Rensselaer Polytechnic Institute Department of Biological Sciences/Center for Biotechnology and Interdisciplinary Sciences Troy, NY 12180
| | - Kristin P Bennett
- Rensselaer Polytechnic Institute Institute for Data Exploration and Applications/Department of Mathematical Sciences Troy, NY 12180
| |
Collapse
|
92
|
Ezeilo UR, Zakaria II, Huyop F, Wahab RA. Enzymatic breakdown of lignocellulosic biomass: the role of glycosyl hydrolases and lytic polysaccharide monooxygenases. BIOTECHNOL BIOTEC EQ 2017. [DOI: 10.1080/13102818.2017.1330124] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
|
93
|
Span EA, Suess DLM, Deller MC, Britt RD, Marletta MA. The Role of the Secondary Coordination Sphere in a Fungal Polysaccharide Monooxygenase. ACS Chem Biol 2017; 12:1095-1103. [PMID: 28257189 DOI: 10.1021/acschembio.7b00016] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Polysaccharide monooxygenases (PMOs) are secreted metalloenzymes that catalyze the oxidative degradation of polysaccharides in a copper-, oxygen-, and reductant-dependent manner. Cellulose-active fungal PMOs degrade cellulosic substrates to be utilized as a carbon source for fungal growth. To gain insight into the PMO mechanism, the role of conserved residues in the copper coordination sphere was investigated. Here, we report active-site hydrogen-bonding motifs in the secondary copper coordination sphere of MtPMO3*, a C1-oxidizing PMO from the ascomycete fungus Myceliophthora thermophila. A series of point substitutions that disrupt this conserved network are used to interrogate its function. Activity assays, in conjunction with EPR spectroscopy, demonstrate that residues H161 and Q167 are involved in stabilizing bound oxygen, and H161 appears to play a role in proton transfer. Additionally, Q167 increases the ligand donor strength of Y169 to the copper via a hydrogen-bonding interaction. Altogether, H161 and Q167 are important for oxygen activation, and the results are suggestive of a copper-oxyl active intermediate.
Collapse
Affiliation(s)
- Elise A. Span
- Biophysics
Graduate Group, University of California, Berkeley, Berkeley, California 94720, United States
| | - Daniel L. M. Suess
- Department
of Chemistry, University of California, Davis, Davis, California 95616, United States
| | - Marc C. Deller
- The
Joint Center for Structural Genomics, The Scripps Research Institute, La
Jolla, California 92037, United States
| | - R. David Britt
- Department
of Chemistry, University of California, Davis, Davis, California 95616, United States
| | - Michael A. Marletta
- Department
of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
- Department
of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, United States
| |
Collapse
|
94
|
Deciphering the Regulatory Network between the SREBP Pathway and Protein Secretion in Neurospora crassa. mBio 2017; 8:mBio.00233-17. [PMID: 28420736 PMCID: PMC5395666 DOI: 10.1128/mbio.00233-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Sterol regulatory element binding proteins (SREBPs) are conserved from yeast to mammalian cells and function in the regulation of sterol homeostasis. In fungi, the SREBP pathway has been implicated in the adaptation to hypoxia and in virulence. In Neurospora crassa and Trichoderma reesei, the SREBP pathway also negatively regulates protein secretion under lignocellulolytic conditions. Here we utilized global transcriptional profiling combined with genetic and physiological analyses to address the regulatory link between the SREBP pathway and protein secretion in N. crassa. Our results demonstrated that the function of the SREBP pathway in ergosterol biosynthesis and adaptation to hypoxia was conserved in N. crassa. Under lignocellulolytic conditions, the SREBP pathway was highly activated, resulting in the reduced expression of lytic polysaccharide monooxygenases, which require molecular oxygen for catalytic activity. Additionally, activation of the SREBP pathway under lignocellulolytic conditions repressed a set of genes predicted to be involved in the endoplasmic reticulum stress response. Here we show that the inability of a hac-1 mutant, which bears a deletion of the major regulator of the unfolded protein response (UPR), to efficiently produce cellulases and utilize cellulose was suppressed by mutations in the SREBP pathway. The analyses presented here demonstrated new SREBP pathway functions, including linkages to the UPR, and provide new clues for genetic engineering of filamentous fungi to improve their production of extracellular proteins. The role of SREBP transcription factors in the regulation of sterol biosynthesis is conserved from humans to yeast. In filamentous fungi, this pathway regulates the secretion of lignocellulolytic enzymes during plant biomass deconstruction. Here we show that the SREBP pathway in Neurospora crassa regulates the production of specific cellulases, lytic polysaccharide monooxygenases that utilize molecular oxygen. Via global transcriptional profile and genetic analyses, a relationship between the SREBP pathway and the unfolded protein response (UPR) pathway was revealed, suggesting a regulatory interplay of these two pathways in the trafficking of plant biomass-degrading enzymes. These findings have implications for our understanding of the cross talk of the SREBP and UPR pathways in other organisms and will guide the rational engineering of fungal strains to improve cellulolytic enzyme production.
Collapse
|
95
|
Hedegård ED, Ryde U. Multiscale Modelling of Lytic Polysaccharide Monooxygenases. ACS OMEGA 2017; 2:536-545. [PMID: 31457454 PMCID: PMC6641039 DOI: 10.1021/acsomega.6b00521] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 01/26/2017] [Indexed: 05/27/2023]
Abstract
Lytic polysaccharide monooxygenase (LPMO) enzymes have attracted considerable attention owing to their ability to enhance polysaccharide depolymerization, making them interesting with respect to production of biofuel from cellulose. LPMOs are metalloenzymes that contain a mononuclear copper active site, capable of activating dioxygen. However, many details of this activation are unclear. Some aspects of the mechanism have previously been investigated from a computational angle. Yet, either these studies have employed only molecular mechanics (MM), which are inaccurate for metal active sites, or they have described only the active site with quantum mechanics (QM) and neglected the effect of the protein. Here, we employ hybrid QM and MM (QM/MM) methods to investigate the first steps of the LPMO mechanism, which is reduction of CuII to CuI and the formation of a CuII-superoxide complex. In the latter complex, the superoxide can bind either in an equatorial or an axial position. For both steps, we obtain structures that are markedly different from previous suggestions, based on small QM-cluster calculations. Our calculations show that the equatorial isomer of the superoxide complex is over 60 kJ/mol more stable than the axial isomer because it is stabilized by interactions with a second-coordination-sphere glutamine residue, suggesting a possible role for this residue. The coordination of superoxide in this manner agrees with recent experimental suggestions.
Collapse
|
96
|
Daly P, van Munster JM, Blythe MJ, Ibbett R, Kokolski M, Gaddipati S, Lindquist E, Singan VR, Barry KW, Lipzen A, Ngan CY, Petzold CJ, Chan LJG, Pullan ST, Delmas S, Waldron PR, Grigoriev IV, Tucker GA, Simmons BA, Archer DB. Expression of Aspergillus niger CAZymes is determined by compositional changes in wheat straw generated by hydrothermal or ionic liquid pretreatments. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:35. [PMID: 28184248 PMCID: PMC5294722 DOI: 10.1186/s13068-017-0700-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 01/05/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND The capacity of fungi, such as Aspergillus niger, to degrade lignocellulose is harnessed in biotechnology to generate biofuels and high-value compounds from renewable feedstocks. Most feedstocks are currently pretreated to increase enzymatic digestibility: improving our understanding of the transcriptomic responses of fungi to pretreated lignocellulosic substrates could help to improve the mix of activities and reduce the production costs of commercial lignocellulose saccharifying cocktails. RESULTS We investigated the responses of A. niger to untreated, ionic liquid and hydrothermally pretreated wheat straw over a 5-day time course using RNA-seq and targeted proteomics. The ionic liquid pretreatment altered the cellulose crystallinity while retaining more of the hemicellulosic sugars than the hydrothermal pretreatment. Ionic liquid pretreatment of straw led to a dynamic induction and repression of genes, which was correlated with the higher levels of pentose sugars saccharified from the ionic liquid-pretreated straw. Hydrothermal pretreatment of straw led to reduced levels of transcripts of genes encoding carbohydrate-active enzymes as well as the derived proteins and enzyme activities. Both pretreatments abolished the expression of a large set of genes encoding pectinolytic enzymes. These reduced levels could be explained by the removal of parts of the lignocellulose by the hydrothermal pretreatment. The time course also facilitated identification of temporally limited gene induction patterns. CONCLUSIONS The presented transcriptomic and biochemical datasets demonstrate that pretreatments caused modifications of the lignocellulose, to both specific structural features as well as the organisation of the overall lignocellulosic structure, that determined A. niger transcript levels. The experimental setup allowed reliable detection of substrate-specific gene expression patterns as well as hitherto non-expressed genes. Our data suggest beneficial effects of using untreated and IL-pretreated straw, but not HT-pretreated straw, as feedstock for CAZyme production.
Collapse
Affiliation(s)
- Paul Daly
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre, Utrecht University, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
| | - Jolanda M. van Munster
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- Chemical Biology, Manchester Institute for Biotechnology, University of Manchester, 131 Princess Street, Manchester, M1 7DN UK
| | - Martin J. Blythe
- Deep Seq, Faculty of Medicine and Health Sciences, Queen’s Medical Centre, University of Nottingham, Nottingham, NG7 2UH UK
| | - Roger Ibbett
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Matt Kokolski
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Sanyasi Gaddipati
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Erika Lindquist
- US Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Vasanth R. Singan
- US Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Kerrie W. Barry
- US Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Anna Lipzen
- US Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Chew Yee Ngan
- US Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | | | | | - Steven T. Pullan
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- TB Programme, Microbiology Services, Public Health England, Salisbury, UK
| | - Stéphane Delmas
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
- UPMC, Univ. Paris 06, CNRS UMR7238, Sorbonne Universités, 15 rue de l’Ecole de Médecine, 75270 Paris, France
| | - Paul R. Waldron
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Igor V. Grigoriev
- US Department of Energy Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Gregory A. Tucker
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | | | - David B. Archer
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| |
Collapse
|
97
|
Campos Antoniêto AC, Ramos Pedersoli W, dos Santos Castro L, da Silva Santos R, Cruz AHDS, Nogueira KMV, Silva-Rocha R, Rossi A, Silva RN. Deletion of pH Regulator pac-3 Affects Cellulase and Xylanase Activity during Sugarcane Bagasse Degradation by Neurospora crassa. PLoS One 2017; 12:e0169796. [PMID: 28107376 PMCID: PMC5249074 DOI: 10.1371/journal.pone.0169796] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 12/21/2016] [Indexed: 11/18/2022] Open
Abstract
Microorganisms play a vital role in bioethanol production whose usage as fuel energy is increasing worldwide. The filamentous fungus Neurospora crassa synthesize and secrete the major enzymes involved in plant cell wall deconstruction. The production of cellulases and hemicellulases is known to be affected by the environmental pH; however, the regulatory mechanisms of this process are still poorly understood. In this study, we investigated the role of the pH regulator PAC-3 in N. crassa during their growth on sugarcane bagasse at different pH conditions. Our data indicate that secretion of cellulolytic enzymes is reduced in the mutant Δpac-3 at alkaline pH, whereas xylanases are positively regulated by PAC-3 in acidic (pH 5.0), neutral (pH 7.0), and alkaline (pH 10.0) medium. Gene expression profiles, evaluated by real-time qPCR, revealed that genes encoding cellulases and hemicellulases are also subject to PAC-3 control. Moreover, deletion of pac-3 affects the expression of transcription factor-encoding genes. Together, the results suggest that the regulation of holocellulase genes by PAC-3 can occur as directly as in indirect manner. Our study helps improve the understanding of holocellulolytic performance in response to PAC-3 and should thereby contribute to the better use of N. crassa in the biotechnology industry.
Collapse
Affiliation(s)
- Amanda Cristina Campos Antoniêto
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Wellington Ramos Pedersoli
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Lílian dos Santos Castro
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Rodrigo da Silva Santos
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Aline Helena da Silva Cruz
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Karoline Maria Vieira Nogueira
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Rafael Silva-Rocha
- Systems and Synthetic Biology Laboratory, Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Antonio Rossi
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Roberto Nascimento Silva
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
- * E-mail:
| |
Collapse
|
98
|
Identification of Glutaminyl Cyclase Genes Involved in Pyroglutamate Modification of Fungal Lignocellulolytic Enzymes. mBio 2017; 8:mBio.02231-16. [PMID: 28096492 PMCID: PMC5241404 DOI: 10.1128/mbio.02231-16] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The breakdown of plant biomass to simple sugars is essential for the production of second-generation biofuels and high-value bioproducts. Currently, enzymes produced from filamentous fungi are used for deconstructing plant cell wall polysaccharides into fermentable sugars for biorefinery applications. A post-translational N-terminal pyroglutamate modification observed in some of these enzymes occurs when N-terminal glutamine or glutamate is cyclized to form a five-membered ring. This modification has been shown to confer resistance to thermal denaturation for CBH-1 and EG-1 cellulases. In mammalian cells, the formation of pyroglutamate is catalyzed by glutaminyl cyclases. Using the model filamentous fungus Neurospora crassa, we identified two genes (qc-1 and qc-2) that encode proteins homologous to mammalian glutaminyl cyclases. We show that qc-1 and qc-2 are essential for catalyzing the formation of an N-terminal pyroglutamate on CBH-1 and GH5-1. CBH-1 and GH5-1 produced in a Δqc-1 Δqc-2 mutant, and thus lacking the N-terminal pyroglutamate modification, showed greater sensitivity to thermal denaturation, and for GH5-1, susceptibility to proteolytic cleavage. QC-1 and QC-2 are endoplasmic reticulum (ER)-localized proteins. The pyroglutamate modification is predicted to occur in a number of additional fungal proteins that have diverse functions. The identification of glutaminyl cyclases in fungi may have implications for production of lignocellulolytic enzymes, heterologous expression, and biotechnological applications revolving around protein stability. Pyroglutamate modification is the post-translational conversion of N-terminal glutamine or glutamate into a cyclized amino acid derivative. This modification is well studied in animal systems but poorly explored in fungal systems. In Neurospora crassa, we show that this modification takes place in the ER and is catalyzed by two well-conserved enzymes, ubiquitously conserved throughout the fungal kingdom. We demonstrate that the modification is important for the structural stability and aminopeptidase resistance of CBH-1 and GH5-1, two important cellulase enzymes utilized in industrial plant cell wall deconstruction. Many additional fungal proteins predicted in the genome of N. crassa and other filamentous fungi are predicted to carry an N-terminal pyroglutamate modification. Pyroglutamate addition may also be a useful way to stabilize secreted proteins and peptides, which can be easily produced in fungal production systems.
Collapse
|
99
|
Characterization of four endophytic fungi as potential consolidated bioprocessing hosts for conversion of lignocellulose into advanced biofuels. Appl Microbiol Biotechnol 2017; 101:2603-2618. [PMID: 28078400 DOI: 10.1007/s00253-017-8091-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 12/13/2016] [Accepted: 12/21/2016] [Indexed: 10/20/2022]
Abstract
Recently, several endophytic fungi have been demonstrated to produce volatile organic compounds (VOCs) with properties similar to fossil fuels, called "mycodiesel," while growing on lignocellulosic plant and agricultural residues. The fact that endophytes are plant symbionts suggests that some may be able to produce lignocellulolytic enzymes, making them capable of both deconstructing lignocellulose and converting it into mycodiesel, two properties that indicate that these strains may be useful consolidated bioprocessing (CBP) hosts for the biofuel production. In this study, four endophytes Hypoxylon sp. CI4A, Hypoxylon sp. EC38, Hypoxylon sp. CO27, and Daldinia eschscholzii EC12 were selected and evaluated for their CBP potential. Analysis of their genomes indicates that these endophytes have a rich reservoir of biomass-deconstructing carbohydrate-active enzymes (CAZys), which includes enzymes active on both polysaccharides and lignin, as well as terpene synthases (TPSs), enzymes that may produce fuel-like molecules, suggesting that they do indeed have CBP potential. GC-MS analyses of their VOCs when grown on four representative lignocellulosic feedstocks revealed that these endophytes produce a wide spectrum of hydrocarbons, the majority of which are monoterpenes and sesquiterpenes, including some known biofuel candidates. Analysis of their cellulase activity when grown under the same conditions revealed that these endophytes actively produce endoglucanases, exoglucanases, and β-glucosidases. The richness of CAZymes as well as terpene synthases identified in these four endophytic fungi suggests that they are great candidates to pursue for development into platform CBP organisms.
Collapse
|
100
|
Ivanova C, Ramoni J, Aouam T, Frischmann A, Seiboth B, Baker SE, Le Crom S, Lemoine S, Margeot A, Bidard F. Genome sequencing and transcriptome analysis of Trichoderma reesei QM9978 strain reveals a distal chromosome translocation to be responsible for loss of vib1 expression and loss of cellulase induction. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:209. [PMID: 28912831 PMCID: PMC5588705 DOI: 10.1186/s13068-017-0897-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 08/29/2017] [Indexed: 05/05/2023]
Abstract
BACKGROUND The hydrolysis of biomass to simple sugars used for the production of biofuels in biorefineries requires the action of cellulolytic enzyme mixtures. During the last 50 years, the ascomycete Trichoderma reesei, the main source of industrial cellulase and hemicellulase cocktails, has been subjected to several rounds of classical mutagenesis with the aim to obtain higher production levels. During these random genetic events, strains unable to produce cellulases were generated. Here, whole genome sequencing and transcriptomic analyses of the cellulase-negative strain QM9978 were used for the identification of mutations underlying this cellulase-negative phenotype. RESULTS Sequence comparison of the cellulase-negative strain QM9978 to the reference strain QM6a identified a total of 43 mutations, of which 33 were located either close to or in coding regions. From those, we identified 23 single-nucleotide variants, nine InDels, and one translocation. The translocation occurred between chromosomes V and VII, is located upstream of the putative transcription factor vib1, and abolishes its expression in QM9978 as detected during the transcriptomic analyses. Ectopic expression of vib1 under the control of its native promoter as well as overexpression of vib1 under the control of a strong constitutive promoter restored cellulase expression in QM9978, thus confirming that the translocation event is the reason for the cellulase-negative phenotype. Gene deletion of vib1 in the moderate producer strain QM9414 and in the high producer strain Rut-C30 reduced cellulase expression in both cases. Overexpression of vib1 in QM9414 and Rut-C30 had no effect on cellulase production, most likely because vib1 is already expressed at an optimal level under normal conditions. CONCLUSION We were able to establish a link between a chromosomal translocation in QM9978 and the cellulase-negative phenotype of the strain. We identified the transcription factor vib1 as a key regulator of cellulases in T. reesei whose expression is absent in QM9978. We propose that in T. reesei, as in Neurospora crassa, vib1 is involved in cellulase induction, although the exact mechanism remains to be elucidated. The data presented here show an example of a combined genome sequencing and transcriptomic approach to explain a specific trait, in this case the QM9978 cellulase-negative phenotype, and how it helps to better understand the mechanisms during cellulase gene regulation. When focusing on mutations on the single base-pair level, changes on the chromosome level can be easily overlooked and through this work we provide an example that stresses the importance of the big picture of the genomic landscape during analysis of sequencing data.
Collapse
Affiliation(s)
- Christa Ivanova
- IFP Energies Nouvelles, 1-4 Avenue de Bois-Préau, 92852 Rueil-Malmaison, France
- Present Address: Genetics of Biofilms Unit, Department of Microbiology, Institut Pasteur, 25-28 Rue du Dr Roux, 75015 Paris, France
| | - Jonas Ramoni
- Molecular Biotechnology, Research Division Biochemical Technology, Institute of Chemical Engineering, TU-Wien, 1060 Vienna, Austria
| | - Thiziri Aouam
- IFP Energies Nouvelles, 1-4 Avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| | - Alexa Frischmann
- Molecular Biotechnology, Research Division Biochemical Technology, Institute of Chemical Engineering, TU-Wien, 1060 Vienna, Austria
| | - Bernhard Seiboth
- Molecular Biotechnology, Research Division Biochemical Technology, Institute of Chemical Engineering, TU-Wien, 1060 Vienna, Austria
| | - Scott E. Baker
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99354 USA
| | - Stéphane Le Crom
- Evolution Paris Seine-Institut de Biologie Paris Seine (EPS-IBPS), Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles, Univ Nice Sophia Antipolis, CNRS, 75005 Paris, France
| | - Sophie Lemoine
- École normale supérieure, PSL Research University, CNRS, Inserm, Institut de Biologie de l’École normale supérieure (IBENS), Plateforme Génomique, 75005 Paris, France
| | - Antoine Margeot
- IFP Energies Nouvelles, 1-4 Avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| | - Frédérique Bidard
- IFP Energies Nouvelles, 1-4 Avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| |
Collapse
|