151
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A Preliminary Study of the Effect of Bioavailable Fe and Co on the Anaerobic Digestion of Rice Straw. ENERGIES 2019. [DOI: 10.3390/en12040577] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Rice straw is an abundant and sustainable substrate for anaerobic digestion (AD), but it is often deficient in essential trace elements (TEs) for proper microbial growth and metabolism. A lack of TEs leads to AD imbalances and suboptimal biogas yields. However, the total TE concentration is not a sufficient indicator of the amount of TEs available to the microorganisms. Therefore, this study investigated the degree of bioavailability of iron (Fe) and cobalt (Co) during the AD of rice straw, and correlated it to the biomethane yields and volatile fatty acids (VFAs) produced. When the two TEs were dosed at 205 µg Fe/g TS and 18 µg Co/g TS of rice straw, the biomethane production was approximately 260 mL CH4/g VS, i.e., similar to that obtained when Fe and Co were not added. Despite an increased bioavailable fraction of 23 and 48% for Fe and Co, respectively, after TEs addition, the AD performance was not enhanced. Moreover, VFAs did not exceed 250 mg HAc/L both in the presence and absence of added TEs, confirming no enhancement of the methanogenesis step. Therefore, the bioavailability of Fe and Co was not a limiting factor for the biomethane production at low total VFAs concentration.
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152
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Nakabayashi M, Kamachi S, Malle D, Yanamoto T, Kishishita S, Fujii T, Inoue H, Ishikawa K. Construction of thermostable cellobiohydrolase I from the fungus Talaromyces cellulolyticus by protein engineering. Protein Eng Des Sel 2019; 32:33-40. [DOI: 10.1093/protein/gzz001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 11/09/2018] [Accepted: 01/07/2019] [Indexed: 11/14/2022] Open
Abstract
Abstract
Fungus-derived GH-7 family cellobiohydrolase I (CBHI, EC 3.2.1.91) is one of the most important industrial enzymes for cellulosic biomass saccharification. Talaromyces cellulolyticus is well known as a mesophilic fungus producing a high amount of CBHI. Thermostability enhances the economic value of enzymes by making them more robust. However, CBHI has proven difficult to engineer, a fact that stems in part from its low expression in heterozygous hosts and its complex structure. Here, we report the successful improvement of the thermostability of CBHI from T. cellulolyticus using our homologous expression system and protein engineering method. We examined the key structures that seem to contribute to its thermostability using the 3D structural information of CBHI. Some parts of the structure of the Talaromyces emersonii CBHI were grafted into T. cellulolyticus CBHI and thermostable mutant CBHIs were constructed. The thermostability was primarily because of the improvement in the loop structures, and the positive effects of the mutations for thermostability were additive. By combing the mutations, the constructed thermophilic CBHI exhibits high hydrolytic activity toward crystalline cellulose with an optimum temperature at over 70°C. In addition, the strategy can be applied to the construction of the other thermostable CBHIs.
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Affiliation(s)
- Makoto Nakabayashi
- Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
| | - Saori Kamachi
- Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
| | - Dominggus Malle
- Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
- Faculty of Agriculture, Pattimura University, Jl. Ir. M. Putuhena, Kampus Poka, Ambon, Maluku, Indonesia
| | - Toshiaki Yanamoto
- Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
| | - Seiichiro Kishishita
- Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
| | - Tatsuya Fujii
- Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
- Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
| | - Hiroyuki Inoue
- Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
- Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
| | - Kazuhiko Ishikawa
- Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka, Japan
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153
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Myco-Nanotechnological Approach for Improved Degradation of Lignocellulosic Waste: Its Future Aspect. Fungal Biol 2019. [DOI: 10.1007/978-3-030-23834-6_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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154
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Buijs Y, Bech PK, Vazquez-Albacete D, Bentzon-Tilia M, Sonnenschein EC, Gram L, Zhang SD. Marine Proteobacteria as a source of natural products: advances in molecular tools and strategies. Nat Prod Rep 2019; 36:1333-1350. [DOI: 10.1039/c9np00020h] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This review covers the recent advances in molecular tools and strategies for studies and use of natural products from marine Proteobacteria.
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Affiliation(s)
- Yannick Buijs
- Department of Biotechnology and Biomedicine
- Technical University of Denmark
- DK-2800 Kgs Lyngby
- Denmark
| | - Pernille Kjersgaard Bech
- Department of Biotechnology and Biomedicine
- Technical University of Denmark
- DK-2800 Kgs Lyngby
- Denmark
| | - Dario Vazquez-Albacete
- Department of Biotechnology and Biomedicine
- Technical University of Denmark
- DK-2800 Kgs Lyngby
- Denmark
| | - Mikkel Bentzon-Tilia
- Department of Biotechnology and Biomedicine
- Technical University of Denmark
- DK-2800 Kgs Lyngby
- Denmark
| | - Eva C. Sonnenschein
- Department of Biotechnology and Biomedicine
- Technical University of Denmark
- DK-2800 Kgs Lyngby
- Denmark
| | - Lone Gram
- Department of Biotechnology and Biomedicine
- Technical University of Denmark
- DK-2800 Kgs Lyngby
- Denmark
| | - Sheng-Da Zhang
- Department of Biotechnology and Biomedicine
- Technical University of Denmark
- DK-2800 Kgs Lyngby
- Denmark
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155
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Recent Advancements in Mycodegradation of Lignocellulosic Biomass for Bioethanol Production. Fungal Biol 2019. [DOI: 10.1007/978-3-030-23834-6_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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156
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Mamo G. Alkaline Active Hemicellulases. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2019; 172:245-291. [PMID: 31372682 DOI: 10.1007/10_2019_101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Xylan and mannan are the two most abundant hemicelluloses, and enzymes that modify these polysaccharides are prominent hemicellulases with immense biotechnological importance. Among these enzymes, xylanases and mannanases which play the vital role in the hydrolysis of xylan and mannan, respectively, attracted a great deal of interest. These hemicellulases have got applications in food, feed, bioethanol, pulp and paper, chemical, and beverage producing industries as well as in biorefineries and environmental biotechnology. The great majority of the enzymes used in these applications are optimally active in mildly acidic to neutral range. However, in recent years, alkaline active enzymes have also become increasingly important. This is mainly due to some benefits of utilizing alkaline active hemicellulases over that of neutral or acid active enzymes. One of the advantages is that the alkaline active enzymes are most suitable to applications that require high pH such as Kraft pulp delignification, detergent formulation, and cotton bioscouring. The other benefit is related to the better solubility of hemicelluloses at high pH. Since the efficiency of enzymatic hydrolysis is often positively correlated to substrate solubility, the hydrolysis of hemicelluloses can be more efficient if performed at high pH. High pH hydrolysis requires the use of alkaline active enzymes. Moreover, alkaline extraction is the most common hemicellulose extraction method, and direct hydrolysis of the alkali-extracted hemicellulose could be of great interest in the valorization of hemicellulose. Direct hydrolysis avoids the time-consuming extensive washing, and neutralization processes required if non-alkaline active enzymes are opted to be used. Furthermore, most alkaline active enzymes are relatively active in a wide range of pH, and at least some of them are significantly or even optimally active in slightly acidic to neutral pH range. Such enzymes can be eligible for non-alkaline applications such as in feed, food, and beverage industries.This chapter largely focuses on the most important alkaline active hemicellulases, endo-β-1,4-xylanases and β-mannanases. It summarizes the relevant catalytic properties, structural features, as well as the real and potential applications of these remarkable hemicellulases in textile, paper and pulp, detergent, feed, food, and prebiotic producing industries. In addition, the chapter depicts the role of these extremozymes in valorization of hemicelluloses to platform chemicals and alike in biorefineries. It also reviews hemicelluloses and discusses their biotechnological importance.
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157
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Ćorović M, Simović M, Milivojević A, Banjanac K, Katić K, Bezbradica D. Immobilization of Aspergillus Niger cellulase onto Lifetech TM carriers and its application in the hydrolysis of sunflower seed meal lignocellulosic fraction. FOOD AND FEED RESEARCH 2019. [DOI: 10.5937/ffr1902161c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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158
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Roscini L, Favaro L, Corte L, Cagnin L, Colabella C, Basaglia M, Cardinali G, Casella S. A yeast metabolome-based model for an ecotoxicological approach in the management of lignocellulosic ethanol stillage. ROYAL SOCIETY OPEN SCIENCE 2019; 6:180718. [PMID: 30800340 PMCID: PMC6366221 DOI: 10.1098/rsos.180718] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 11/30/2018] [Indexed: 05/07/2023]
Abstract
Lignocellulosic bioethanol production results in huge amounts of stillage, a potentially polluting by-product. Stillage, rich in heavy metals and, mainly, inhibitors, requires specific toxicity studies to be adequately managed. To this purpose, we applied an FTIR ecotoxicological bioassay to evaluate the toxicity of lignocellulosic stillage. Two weak acids and furans, most frequently found in lignocellulosic stillage, have been tested in different mixtures against three Saccharomyces cerevisiae strains. The metabolomic reaction of the test microbes and the mortality induced at various levels of inhibitor concentration showed that the strains are representative of three different types of response. Furthermore, the relationship between concentrations and FTIR synthetic stress indexes has been studied, with the aim of defining a model able to predict the concentrations of inhibitors in stillage, resulting in an optimized predictive model for all the strains. This approach represents a promising tool to support the ecotoxicological management of lignocellulosic stillage.
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Affiliation(s)
- Luca Roscini
- Department of Pharmaceutical Sciences-Microbiology, CEMIN, Centre of Excellence on Nanostructured Innovative Materials, University of Perugia, Perugia, Italy
| | - Lorenzo Favaro
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), University of Padova, Legnaro, Italy
- Author for correspondence: Lorenzo Favaro e-mail:
| | - Laura Corte
- Department of Pharmaceutical Sciences-Microbiology, CEMIN, Centre of Excellence on Nanostructured Innovative Materials, University of Perugia, Perugia, Italy
| | - Lorenzo Cagnin
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), University of Padova, Legnaro, Italy
| | - Claudia Colabella
- Department of Pharmaceutical Sciences-Microbiology, CEMIN, Centre of Excellence on Nanostructured Innovative Materials, University of Perugia, Perugia, Italy
| | - Marina Basaglia
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), University of Padova, Legnaro, Italy
| | - Gianluigi Cardinali
- Department of Pharmaceutical Sciences-Microbiology, CEMIN, Centre of Excellence on Nanostructured Innovative Materials, University of Perugia, Perugia, Italy
- Department of Chemistry, Biology and Biotechnology, CEMIN, Centre of Excellence on Nanostructured Innovative Materials, University of Perugia, Perugia, Italy
| | - Sergio Casella
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), University of Padova, Legnaro, Italy
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159
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Saini JK, Gupta R, Hemansi, Verma A, Gaur P, Saini R, Shukla R, Kuhad RC. Integrated Lignocellulosic Biorefinery for Sustainable Bio-Based Economy. BIOFUEL AND BIOREFINERY TECHNOLOGIES 2019. [DOI: 10.1007/978-3-319-94797-6_2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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160
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Müller MJ, Stachurski S, Stoffels P, Schipper K, Feldbrügge M, Büchs J. Online evaluation of the metabolic activity of Ustilago maydis on (poly)galacturonic acid. J Biol Eng 2018; 12:34. [PMID: 30574186 PMCID: PMC6299674 DOI: 10.1186/s13036-018-0128-1] [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: 09/21/2018] [Accepted: 12/03/2018] [Indexed: 11/10/2022] Open
Abstract
Background Pectin is a rather complex and highly branched polysaccharide strengthening the plant cell wall. Thus, many different pectinases are required for an efficient microbial conversion of biomass waste streams with a high pectin content like citrus peel, apple pomace or sugar beet pulp. The screening and optimization of strains growing on pectic substrates requires both, quantification of the residual substrate and an accurate determination of the enzymatic activity. Galacturonic acid, the main sugar unit of pectin, is an uncommon substrate for microbial fermentations. Thus, growth and enzyme production of the applied strain has to be characterized in detail to understand the microbial system. An essential step to reach this goal is the development of online monitoring tools. Results In this study, a method for the online determination of residual substrate was developed for the growth of the plant pathogenic fungus Ustilago maydis on pectic substrates such as galacturonic acid. To this end, an U. maydis strain was used that expressed a heterologous exo-polygalacturonase for growth on polygalacturonic acid. The growth behavior on galacturonic acid was analyzed by online measurement of the respiration activity. A method for the online prediction of the residual galacturonic acid concentration during the cultivation, based on the overall oxygen consumption, was developed and verified by offline sampling. This sensitive method was extended towards polygalacturonic acid, which is challenging to quantify via offline measurements. Finally, the enzymatic activity in the culture supernatant was calculated and the enzyme stability during the course of the cultivation was confirmed. Conclusion The introduced method can reliably predict the residual (poly)galacturonic acid concentration based on the overall oxygen consumption. Based on this method, the enzymatic activity of the culture broth of an U. maydis strain expressing a heterologous exo-polygalacturonase could be calculated. It was demonstrated that the method is especially advantageous for determination of low enzymatic activities. In future, it will be applied to U. maydis strains in which the number of produced hydrolytic enzymes is increased for more efficient degradation. Electronic supplementary material The online version of this article (10.1186/s13036-018-0128-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Markus Jan Müller
- 1AVT - Biochemical Engineering, RWTH Aachen University, Jochen Büchs, Forckenbeckstr. 51, 52074 Aachen, Germany.,Bioeconomy Science Center (BioSC), 52426 Jülich, Germany
| | - Sarah Stachurski
- 1AVT - Biochemical Engineering, RWTH Aachen University, Jochen Büchs, Forckenbeckstr. 51, 52074 Aachen, Germany
| | - Peter Stoffels
- 2Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich-Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.,Bioeconomy Science Center (BioSC), 52426 Jülich, Germany
| | - Kerstin Schipper
- 2Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich-Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.,Bioeconomy Science Center (BioSC), 52426 Jülich, Germany
| | - Michael Feldbrügge
- 2Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich-Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.,Bioeconomy Science Center (BioSC), 52426 Jülich, Germany
| | - Jochen Büchs
- 1AVT - Biochemical Engineering, RWTH Aachen University, Jochen Büchs, Forckenbeckstr. 51, 52074 Aachen, Germany.,Bioeconomy Science Center (BioSC), 52426 Jülich, Germany
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161
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Bioconversion of oily bilge waste to polyhydroxybutyrate (PHB) by marine Ochrobactrum intermedium. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.biteb.2018.08.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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162
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Multiple thermostable enzyme hydrolases on magnetic nanoparticles: An immobilized enzyme-mediated approach to saccharification through simultaneous xylanase, cellulase and amylolytic glucanotransferase action. Int J Biol Macromol 2018; 120:1650-1658. [DOI: 10.1016/j.ijbiomac.2018.09.106] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 09/14/2018] [Accepted: 09/18/2018] [Indexed: 11/19/2022]
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163
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Kim S, Tsang YF, Kwon EE, Lin KYA, Lee J. Recently developed methods to enhance stability of heterogeneous catalysts for conversion of biomass-derived feedstocks. KOREAN J CHEM ENG 2018. [DOI: 10.1007/s11814-018-0174-x] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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164
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Abstract
Energy is a key driver of the modern economy, therefore modeling and simulation of energy systems has received significant research attention. We review the major developments in this area and propose two ways to categorize the diverse contributions. The first categorization is according to the modeling approach, namely into computational, mathematical, and physical models. With this categorization, we highlight certain novel hybrid approaches that combine aspects of the different groups proposed. The second categorization is according to field namely Process Systems Engineering (PSE) and Energy Economics (EE). We use the following criteria to illustrate the differences: the nature of variables, theoretical underpinnings, level of technological aggregation, spatial and temporal scales, and model purposes. Traditionally, the Process Systems Engineering approach models the technological characteristics of the energy system endogenously. However, the energy system is situated in a broader economic context that includes several stakeholders both within the energy sector and in other economic sectors. Complex relationships and feedback effects exist between these stakeholders, which may have a significant impact on strategic, tactical, and operational decision-making. Leveraging the expertise built in the Energy Economics field on modeling these complexities may be valuable to process systems engineers. With this categorization, we present the interactions between the two fields, and make the case for combining the two approaches. We point out three application areas: (1) optimal design and operation of flexible processes using demand and price forecasts, (2) sustainability analysis and process design using hybrid methods, and (3) accounting for the feedback effects of breakthrough technologies. These three examples highlight the value of combining Process Systems Engineering and Energy Economics models to get a holistic picture of the energy system in a wider economic and policy context.
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165
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Yuan Y, Zhai R, Li Y, Chen X, Jin M. Developing fast enzyme recycling strategy through elucidating enzyme adsorption kinetics on alkali and acid pretreated corn stover. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:316. [PMID: 30479661 PMCID: PMC6245881 DOI: 10.1186/s13068-018-1315-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/08/2018] [Indexed: 06/01/2023]
Abstract
BACKGROUND Although various pre-treatment methods have been developed to disrupt the structure of lignocellulosic biomass, high dosage of cellulases is still required to hydrolyze lignocellulose to fermentable sugars. Enzyme recycling via recycling unhydrolyzed solids after enzymatic hydrolysis is a promising strategy to reduce enzyme loading for production of cellulosic ethanol. RESULTS To develop effective enzyme recycling method via recycling unhydrolyzed solids, this work investigated both enzymatic hydrolysis kinetics and enzyme adsorption kinetics on dilute acid and dilute alkali pre-treated corn stover (CS). It was found that most of the hydrolysable biomass was hydrolyzed in the first 24 h and about 40% and 55% of the enzymes were adsorbed on unhydrolyzed solids for dilute alkali-CS and dilute acid-CS, respectively, at 24 h of enzymatic hydrolysis. Lignin played a significant role in such adsorption and lignin materials derived from dilute acid-CS and dilute alkali-CS possessed different enzyme adsorption properties. Enzyme recycling was performed by recycling unhydrolyzed solids after 24 h enzymatic hydrolysis for five successive rounds, and successfully reduced 40% and 50% of the enzyme loadings for hydrolysis of dilute alkali-CS and for hydrolysis of dilute acid-CS, respectively. CONCLUSIONS This study presents that the enzymes adsorbed on the unhydrolyzed solids after short-time hydrolysis could be recycled effectively for efficient enzymatic hydrolysis. Lignin derived from dilute acid-CS has higher enzyme adsorption capacity than the lignin derived from dilute alkali-CS, which led to more enzymes recycled. By applying the enzyme recycling strategy developed in this study, the enzyme dosage needed for effective cellulose hydrolysis can be significantly reduced.
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Affiliation(s)
- Ye Yuan
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing, 210094 China
| | - Rui Zhai
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing, 210094 China
| | - Ying Li
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing, 210094 China
| | - Xiangxue Chen
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing, 210094 China
| | - Mingjie Jin
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing, 210094 China
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166
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Costa S, Rugiero I, Larenas Uria C, Pedrini P, Tamburini E. Lignin Degradation Efficiency of Chemical Pre-Treatments on Banana Rachis Destined to Bioethanol Production. Biomolecules 2018; 8:biom8040141. [PMID: 30423995 PMCID: PMC6316140 DOI: 10.3390/biom8040141] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 10/26/2018] [Accepted: 11/02/2018] [Indexed: 01/13/2023] Open
Abstract
Valuable biomass conversion processes are highly dependent on the use of effective pretreatments for lignocellulose degradation and enzymes for saccharification. Among the nowadays available treatments, chemical delignification represents a promising alternative to physical-mechanical treatments. Banana is one of the most important fruit crops around the world. After harvesting, it generates large amounts of rachis, a lignocellulosic residue, that could be used for second generation ethanol production, via saccharification and fermentation. In the present study, eight chemical pretreatments for lignin degradation (organosolv based on organic solvents, sodium hypochlorite, hypochlorous acid, hydrogen peroxide, alkaline hydrogen peroxide, and some combinations thereof) have been tested on banana rachis and the effects evaluated in terms of lignin removal, material losses, and chemical composition of pretreated material. Pretreatment based on lignin oxidation have demonstrated to reach the highest delignification yield, also in terms of monosaccharides recovery. In fact, all the delignified samples were then saccharified with enzymes (cellulase and beta-glucosidase) and hydrolysis efficiency was evaluated in terms of final sugars recovery before fermentation. Analysis of Fourier transform infrared spectra (FTIR) has been carried out on treated samples, in order to better understand the structural effects of delignification on lignocellulose. Active chlorine oxidations, hypochlorous acid in particular, were the best effective for lignin removal obtaining in the meanwhile the most promising cellulose-to-glucose conversion.
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Affiliation(s)
- Stefania Costa
- Department of Life Science and Biotechnology, University of Ferrara, Via L. Borsari 46, 44121 Ferrara, Italy.
| | - Irene Rugiero
- Department of Life Science and Biotechnology, University of Ferrara, Via L. Borsari 46, 44121 Ferrara, Italy.
| | - Christian Larenas Uria
- Laboratorio de Biotecnología, Universidad Poilitécnica Salesiana, Av. Isabel La Católica N 23-52 y Madrid, Quito-Ecuador 170109, Quito, Ecuador.
| | - Paola Pedrini
- Department of Life Science and Biotechnology, University of Ferrara, Via L. Borsari 46, 44121 Ferrara, Italy.
| | - Elena Tamburini
- Department of Life Science and Biotechnology, University of Ferrara, Via L. Borsari 46, 44121 Ferrara, Italy.
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167
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Zhang R, Li C, Wang J, Yan Y. Microbial Ligninolysis: Toward a Bottom-Up Approach for Lignin Upgrading. Biochemistry 2018; 58:1501-1510. [DOI: 10.1021/acs.biochem.8b00920] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Ruihua Zhang
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, Georgia 30602, United States
| | - Chenyi Li
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, Georgia 30602, United States
| | - Jian Wang
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, Georgia 30602, United States
| | - Yajun Yan
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, Georgia 30602, United States
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168
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Rabelo CABS, Soares LA, Sakamoto IK, Silva EL, Varesche MBA. Optimization of hydrogen and organic acids productions with autochthonous and allochthonous bacteria from sugarcane bagasse in batch reactors. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 223:952-963. [PMID: 30007891 DOI: 10.1016/j.jenvman.2018.07.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 07/03/2018] [Accepted: 07/05/2018] [Indexed: 06/08/2023]
Abstract
The individual and mutual effects of substrate concentration (from 0.8 to 9.2 g/L) and pH (from 4.6 to 7.4) on hydrogen and volatile fatty acids production from sugarcane bagasse (SCB) were investigated in batch reactors, using a response surface methodology (RSM) and central composite design (CCD). The maximum of 23.10 mmoL H2/L was obtained under optimized conditions of 7.0 g SCB/L and pH 7.2, at 37 °C through the acetic acid pathway (1.57 g/L). Butyric and succinic acids were the major volatile fatty acids (VFA) produced in the fermentation process (from 0.66 to 1.88 g/L and from 1.06 to 1.65 g/L, respectively). According to the results, the RSM and CCD were useful tools to achieve high hydrogen production rates using Clostridium, Bacillus and Enterobacter, identified by Illumina sequencing (16S RNAr) in the fermentative consortium, and Clostridium and Paenibacillus, autochthonous bacteria from SCB. Significant changes were observed in the microbial community according to the changes in the independent variables, since the genera in the central point condition (5.0 g SCB/L and pH 6.0) were Lactobacillus, Escherichia and Clostridium, and Bacteroides and Enterobacter, which were identified in the optimized condition (7.0 g SCB/L and pH 7.2).
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Affiliation(s)
| | - Laís Américo Soares
- University of São Paulo, João Dagnone Avenue, 1100, CEP 13563-120, São Carlos, SP, Brazil.
| | - Isabel Kimiko Sakamoto
- University of São Paulo, João Dagnone Avenue, 1100, CEP 13563-120, São Carlos, SP, Brazil.
| | - Edson Luiz Silva
- Federal University of São Carlos, Rod Washington Luis, Km 235, 13565-905, São Carlos, SP, Brazil.
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169
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Zhou X, Zhou X, Liu G, Xu Y, Balan V. Integrated production of gluconic acid and xylonic acid using dilute acid pretreated corn stover by two-stage fermentation. Biochem Eng J 2018. [DOI: 10.1016/j.bej.2018.05.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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170
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Xia Y, Yang L, Xia L. Combined strategy of transcription factor manipulation and β-glucosidase gene overexpression in Trichoderma reesei and its application in lignocellulose bioconversion. ACTA ACUST UNITED AC 2018; 45:803-811. [DOI: 10.1007/s10295-018-2041-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 04/27/2018] [Indexed: 12/01/2022]
Abstract
Abstract
The industrial application of Trichoderma reesei has been greatly limited by insufficient β-glucosidase activity in its cellulase system. In this study, a novel β-glucosidase expression cassette was constructed and integrated at the target site in T. reesei ZU-02, which achieved the overexpression of β-glucosidase gene and in situ disruption of the cellulase transcriptional repressor ACE1. The resulting transformants showed significant increase in both β-glucosidase activity (BGA) and filter paper activity (FPA). The BGA and FPA increased to 25.13 IU/mL and 20.06 FPU/mL, respectively, 167- and 2.45-fold higher than that of the host strain. Meanwhile, the obtained cellulase system exhibited improved ratio of BGA to FPA, leading to better synergistic effect between cellulase components. Furthermore, submerged fermentation of the transformant was established in 50 m3 fermenter yielding 112.2 IU/mL β-glucosidase and 89.76 FPU/mL total cellulase. The newly constructed T. reesei transformant achieved improved hydrolysis yield (90.6%) with reduced enzyme loading (15 FPU/g substrate).
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Affiliation(s)
- Ying Xia
- 0000 0004 1759 700X grid.13402.34 Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering Zhejiang University 310027 Hangzhou China
| | - Lirong Yang
- 0000 0004 1759 700X grid.13402.34 Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering Zhejiang University 310027 Hangzhou China
| | - Liming Xia
- 0000 0004 1759 700X grid.13402.34 Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering Zhejiang University 310027 Hangzhou China
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171
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Rassinger A, Gacek-Matthews A, Strauss J, Mach RL, Mach-Aigner AR. Truncation of the transcriptional repressor protein Cre1 in Trichoderma reesei Rut-C30 turns it into an activator. Fungal Biol Biotechnol 2018; 5:15. [PMID: 30151221 PMCID: PMC6100732 DOI: 10.1186/s40694-018-0059-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 08/02/2018] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei (T. reesei) is a natural producer of cellulolytic and xylanolytic enzymes and is therefore industrially used. Many industries require high amounts of enzymes, in particular cellulases. Strain improvement strategies by random mutagenesis yielded the industrial ancestor strain Rut-C30. A key property of Rut-C30 is the partial release from carbon catabolite repression caused by a truncation of the repressor Cre1 (Cre1-96). In the T. reesei wild-type strain a full cre1 deletion leads to pleiotropic effects and strong growth impairment, while the truncated cre1-96 enhances cellulolytic activity without the effect of growth deficiencies. However, it is still unclear which function Cre1-96 has in Rut-C30. RESULTS In this study, we deleted and constitutively expressed cre1-96 in Rut-C30. We found that the presence of Cre1-96 in Rut-C30 is crucial for its cellulolytic and xylanolytic performance under inducing conditions. In the case of the constitutively expressed Cre1-96, the cellulase activity could further be improved approximately twofold. The deletion of cre1-96 led to growth deficiencies and morphological abnormalities. An in silico domain prediction revealed that Cre1-96 has all necessary properties that a classic transactivator needs. Consequently, we investigated the cellular localization of Cre1-96 by fluorescence microscopy using an eYFP-tag. Cre1-96 is localized in the fungal nuclei under both, inducing and repressing conditions. Furthermore, chromatin immunoprecipitation revealed an enrichment of Cre1-96 in the upstream regulatory region of the main transactivator of cellulases and xylanases, Xyr1. Interestingly, transcript levels of cre1-96 show the same patterns as the ones of xyr1 under inducing conditions. CONCLUSIONS The findings suggest that the truncation turns Cre1 into an activating regulator, which primarily exerts its role by approaching the upstream regulatory region of xyr1. The conversion of repressor proteins to potential activators in other biotechnologically used filamentous fungi can be applied to increase their enzyme production capacities.
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Affiliation(s)
- Alice Rassinger
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
| | - Agnieszka Gacek-Matthews
- Fungal Genetics and Genomics Lab, Department of Applied Genetics and Cell Biology, BOKU-University of Natural Resources and Life Sciences, Konrad Lorenz Str. 24, 3430 Tulln/Donau, Austria
- Institute of Microbiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria
| | - Joseph Strauss
- Fungal Genetics and Genomics Lab, Department of Applied Genetics and Cell Biology, BOKU-University of Natural Resources and Life Sciences, Konrad Lorenz Str. 24, 3430 Tulln/Donau, Austria
| | - Robert L. Mach
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
| | - Astrid R. Mach-Aigner
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
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172
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Sweygers N, Somers MH, Appels L. Optimization of hydrothermal conversion of bamboo (Phyllostachys aureosulcata) to levulinic acid via response surface methodology. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 219:95-102. [PMID: 29734015 DOI: 10.1016/j.jenvman.2018.04.105] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 04/22/2018] [Accepted: 04/24/2018] [Indexed: 06/08/2023]
Abstract
In this study, the dilute acid hydrolysis of lignocellulosic bamboo (Phyllostachys aureosulcata) particles to levulinic acid in a hydrothermal synthesis reactor is reported. The aim of the study was to optimize the reaction conditions for maximum levulinic acid production in terms of reaction time (t), reaction temperature (T) and HCl concentration (cHCl) via Response Surface Methodology (RSM). A maximum levulinic acid yield of 9.46 w% was predicted at the following reaction conditions: t of 3 h, T of 160 °C and cHCl of 0.37 M. A maximal experimental yield of levulinic acid of 10.13 w% was observed, which in respect to the cellulose fraction of the bamboo particles corresponds to 34.60 w% or 48.05 mol%. Furfural, which is formed by the hemicellulose fraction of bamboo, has not been observed within the boundaries of the RSM model, since it is already degraded under the given reaction conditions. The conversion of levulinic acid and furfural occurred more or less simultaneously, however, furfural was more vulnerable to degradation reactions at the given process conditions. Therefore, if both fractions (cellulose + hemicellulose) are required to be valorized, further optimization is required. However, the global results of this study provide insight in the potential of lignocellulosic bamboo as an alternative platform to fossil sources.
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Affiliation(s)
- Nick Sweygers
- KU Leuven, Department of Chemical Engineering, Process and Environmental Technology Lab, J. De Nayerlaan 5, B-2860 Sint-Katelijne-Waver, Belgium
| | - Matthijs H Somers
- KU Leuven, Department of Chemical Engineering, Process and Environmental Technology Lab, J. De Nayerlaan 5, B-2860 Sint-Katelijne-Waver, Belgium
| | - Lise Appels
- KU Leuven, Department of Chemical Engineering, Process and Environmental Technology Lab, J. De Nayerlaan 5, B-2860 Sint-Katelijne-Waver, Belgium.
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173
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Poorakbar E, Shafiee A, Saboury AA, Rad BL, Khoshnevisan K, Ma'mani L, Derakhshankhah H, Ganjali MR, Hosseini M. Synthesis of magnetic gold mesoporous silica nanoparticles core shell for cellulase enzyme immobilization: Improvement of enzymatic activity and thermal stability. Process Biochem 2018. [DOI: 10.1016/j.procbio.2018.05.012] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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174
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Using response surface methodology in combination with Plackett-Burman design for optimization of culture media and extracellular expression of Trichoderma reesei synthetic endoglucanase II in Escherichia coli. Mol Biol Rep 2018; 45:1197-1208. [PMID: 30032381 DOI: 10.1007/s11033-018-4272-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 07/17/2018] [Indexed: 10/28/2022]
Abstract
Cellulases like endoglucanase II (EGII) from Trichoderma reesei are the industrial enzymes responsible for breakdown of cellulosic materials. Due to its importance for production of eco-friendly commercial products such as alternative biofuels, industrial EGII production and optimization of its production conditions merit consideration. The gene responsible for EGII expression was designed and sub-cloned in to pET26b expression vector and transformed into BL21 (DE3) pLysS cells. Protein expression and purification was followed by a RSM design (20 experiments) to optimize the IPTG Concentration, post induction period and cell density (OD600). Thereafter, another RSM design (20 experiments) was performed to find and optimize the most important permeabilizing factors to achieve higher extracellular EGII expression. The EGII expression levels were assessed by Ghose method. The EGII gene was sub-cloned and protein expression and purification were successfully performed. The RSM experiments indicated that 0.331 mM for IPTG Concentration, 10.89 H for post induction period and 3.41 for cell density (OD600) were the optimum culture. Glycine (0.99%), Triton X-100 (0.73%) and CaCl2 (0.232) have been assigned as the most effective membrane permeabalizing factors. Optimization of culture medium components has led to a 3.06 fold increase in extracellular expression of EGII. RSM is an amenable method to optimize the expression of commercially significant enzymes. Our results indicated that optimization of IPTG concentration, post induction period and cell density along with glycine, Triton X-100 and Ca2+ concentration could lead to more cost effective industrial production of EGII.
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175
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Ghosh D, Jana BB, Lahiri S, Bhakta J, Bhattacharjee A. Assessing the cellulase enzyme heterogeneity of bacterial strains and their feedback to cattle manure degradation in a greenhouse model of in vivo pond ecosystem. ENVIRONMENTAL MONITORING AND ASSESSMENT 2018; 190:452. [PMID: 29982862 DOI: 10.1007/s10661-018-6821-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 06/19/2018] [Indexed: 06/08/2023]
Abstract
The responses of cellulase enzymes of three bacterial isolates and their impacts on cattle manure decomposition were assessed in a greenhouse model in vivo pond ecosystem. Fifty grams of fresh cattle manure was placed in a fastened nylon bag (mesh size ~ 50 μm dia.) and placed in triplicate in a plastic bucket with 10 l of pond water which was hung inside the enclosed polyhouse, semi-closed and open systems for 4 weeks. Samples of manure residue directly from nylon bag and water from manure leached bucket water, water, and soil from the enclosed polyhouse were collected for enzymatic assays, enumeration of aerobic cellulose decomposing and heterotrophic bacteria, and determination of water and soil quality parameters. Responses of cellulases to different temperatures in situ were also elucidated. The values of test bacteria, endoglucanase, exoglucanase and β-glucosidase, and organic carbon were significantly (P ˂ 0.05) higher in the closed system compared to semi-closed or open system. Priming of all the enzymes coupled with the peak of aerobic cellulose decomposing bacteria and heterotrophic bacterial populations occurred on the day 14 or 21 in vivo. Since the peaks of three cellulases of bacterial isolates (KUPH1, KUPH6, and KUPH8) were demonstrated between 35 and 40 °C, and that temperature coincided with temperature of the greenhouse model, this temperature range appeared to favor the growth of cellulose decomposing bacterial populations and involved cellulase enzymes.
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Affiliation(s)
- Debarati Ghosh
- International Centre for Ecological Engineering & Department of Ecological Studies, University of Kalyani, Kalyani, West Bengal, 741235, India
| | - Bana Bihari Jana
- International Centre for Ecological Engineering & Department of Ecological Studies, University of Kalyani, Kalyani, West Bengal, 741235, India.
- Centre for Environmental Protection and Human Resource Development (KSI), Kalyani, West Bengal, 741235, India.
| | - Susmita Lahiri
- International Centre for Ecological Engineering & Department of Ecological Studies, University of Kalyani, Kalyani, West Bengal, 741235, India
| | - Jatridranath Bhakta
- International Centre for Ecological Engineering & Department of Ecological Studies, University of Kalyani, Kalyani, West Bengal, 741235, India
| | - Ankita Bhattacharjee
- International Centre for Ecological Engineering & Department of Ecological Studies, University of Kalyani, Kalyani, West Bengal, 741235, India
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176
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Cloning, molecular modeling and characterization of acidic cellulase from buffalo rumen and its applicability in saccharification of lignocellulosic biomass. Int J Biol Macromol 2018; 113:73-81. [DOI: 10.1016/j.ijbiomac.2018.02.100] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 02/13/2018] [Accepted: 02/14/2018] [Indexed: 11/21/2022]
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177
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Lepcha K, Ghosh S. Glycoside hydrolases from a thermophilic microbial consortium and their implication in the saccharification of agroresidues. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2018. [DOI: 10.1016/j.bcab.2018.05.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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178
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Cizeikiene D, Juodeikiene G, Damasius J. Use of wheat straw biomass in production of L-lactic acid applying biocatalysis and combined lactic acid bacteria strains belonging to the genus Lactobacillus. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2018. [DOI: 10.1016/j.bcab.2018.06.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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179
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Olajuyigbe FM, Fatokun CO, Oyelere OM. Biodelignification of some agro-residues by Stenotrophomonas sp. CFB-09 and enhanced production of ligninolytic enzymes. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2018. [DOI: 10.1016/j.bcab.2018.05.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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180
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Functional characterization of ligninolytic Klebsiella spp. strains associated with soil and freshwater. Arch Microbiol 2018; 200:1267-1278. [PMID: 29947838 DOI: 10.1007/s00203-018-1532-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 05/16/2018] [Accepted: 05/26/2018] [Indexed: 10/14/2022]
Abstract
Overcoming recalcitrance of lignin has motivated bioprospecting of high-yielding enzymes from environmental ligninolytic microorganisms associated with lignocellulose degrading-systems. Here, we performed isolation of 21 ligninolytic strains belonging to the genus Klebsiella spp., driven by the presence of lignin in the media. The fastest-growing strains (FP10-5.23, FP10-5.22 and P3TM1) reached the stationary phase in approximately 24 h, in the media containing lignin as the main carbon source. The strains showed biochemical evidence of ligninolytic potential in liquid- and solid media-converting dyes, which the molecular structures are similar to lignin fragments. In liquid medium, higher levels of dye decolorization was observed for P3TM.1 in the presence of methylene blue, reaching 98% decolorization in 48 h. The highest index values (1.25) were found for isolates P3TM.1 and FP10-5.23, in the presence of toluidine blue. The genomic analysis revealed the presence of more than 20 genes associated with known prokaryotic lignin-degrading systems. Identification of peroxidases (lignin peroxidase-LiP, dye-decolorizing peroxidase-DyP, manganese peroxidase-MnP) and auxiliary activities (AA2, AA3, AA6 and AA10 families) among the genetic repertoire suggest the ability to produce extracellular enzymes able to attack phenolic and non-phenolic lignin structures. Our results suggest that the Klebsiella spp. associated with fresh water and soil may play important role in the cycling of recalcitrant molecules in the Caatinga (desert-like Brazilian biome), and represent a potential source of lignin-degrading enzymes with biotechnological applications.
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181
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Nie H, Wang Z, You J, Zhu G, Wang H, Wang F. Comparison of in vitro digestibility and chemical composition among four crop straws treated by Pleurotus ostreatus. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2018; 33:24-34. [PMID: 29879812 PMCID: PMC6946984 DOI: 10.5713/ajas.18.0023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 01/03/2018] [Indexed: 11/27/2022]
Abstract
Objective The effects of Pleurotus ostreatus on the feed utilization of broad bean stalks (BBS), rape straw (RS), paddy straw (PS), and corn stalk (CS) was examined. Methods The four roughages were co-cultured with Pleurotus ostreatus. The chemical composition; enzyme activities of laccase, carboxymethylcellulase (CMCase) and xylanase; carbohydrate and protein fractions (based on The Cornell Net Carbohydrate and Protein System [CNCPS]) were assessed at different days after inoculation (7, 14, 21, 28 d) and un-inoculated roughages (control, 0 d). The digestibility of nutrient components and the gas production of roughage with various incubation times were monitored at 0, 2, 4, 6, 9, 12, 24, 36, 48, 60, and 72 h using an in vitro ruminal fermentation method. Results A higher CMCase activity (0.1039 U/mL) and earlier time to peak (14 d) were detected in Pleurotus ostreatus cultured with CS (p<0.05). Significantly, the incubation length-dependent responses of cumulative gas production were observed from 24 to 72 hours post fermentation (p<0.05), and these incubation length-dependent effects on cumulative gas production of PS and CS appeared earlier (24 h) for PS and CS than those (48 h) for BBS and RS (p<0.05). The fast-degradable carbohydrate (CA) content for all four roughages significantly increased over time (p<0.05). Nonetheless, increased degradation efficiency for CA treated with Pleurotus ostreatus was detected at both 21 and 28 days of incubation (p<0.05). With the exception of PS (p<0.05), there were no significant difference among the roughages (p>0.05) in slowly-degradable carbohydrate (CB2) at different incubation times (p<0.05). Conclusion Assessment of the alterations in chemical composition, CNCPS system fractions, and the fermentation kinetics after biological pretreatment may yield a valuable database for evaluating the biological pretreatment of Pleurotus ostreatus in ruminant feed.
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Affiliation(s)
- Haitao Nie
- Deparment of Jiangsu Engineering Technology Research Center of Meat Sheep & Goat Industry, Nanjing Agricultural University, Nanjing 210095, China
| | - Ziyu Wang
- Deparment of Jiangsu Engineering Technology Research Center of Meat Sheep & Goat Industry, Nanjing Agricultural University, Nanjing 210095, China
| | - Jihao You
- Deparment of Jiangsu Engineering Technology Research Center of Meat Sheep & Goat Industry, Nanjing Agricultural University, Nanjing 210095, China
| | - Gang Zhu
- Animal Husbandry and Veterinary Station of Guannan, Lianyungang 222500, China
| | - Hengchang Wang
- Animal Husbandry and Veterinary Station of Guannan, Lianyungang 222500, China
| | - Feng Wang
- Deparment of Jiangsu Engineering Technology Research Center of Meat Sheep & Goat Industry, Nanjing Agricultural University, Nanjing 210095, China
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182
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Molecular Characterization and Potential Synthetic Applications of GH1 β-Glucosidase from Higher Termite Microcerotermes annandalei. Appl Biochem Biotechnol 2018; 186:877-894. [PMID: 29779183 DOI: 10.1007/s12010-018-2781-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/08/2018] [Indexed: 10/16/2022]
Abstract
A novel β-glucosidase from higher termite Microcerotermes annandalei (MaBG) was obtained via a screening method targeting β-glucosidases with increased activities in the presence of glucose. The purified natural MaBG showed a subunit molecular weight of 55 kDa and existed in a native form as a dimer without any glycosylation. Gene-specific primers designed from its partial amino acid sequences were used to amplify the corresponding 1,419-bp coding sequence of MaBG which encodes a 472-amino acid glycoside hydrolase family 1 (GH1) β-glucosidase. When expressed in Komagataella pastoris, the recombinant MaBG appeared as a ~ 55-kDa protein without glycosylation modifications. Kinetic parameters as well as the lack of secretion signal suggested that MaBG is an intracellular enzyme and not involved in cellulolysis. The hydrolytic activities of MaBG were enhanced in the presence of up to 3.5-4.5 M glucose, partly due to its strong transglucosylation activity, which suggests its applicability in biosynthetic processes. The potential synthetic activities of the recombinant MaBG were demonstrated in the synthesis of para-nitrophenyl-β-D-gentiobioside via transglucosylation and octyl glucoside via reverse hydrolysis. The information obtained from this study has broadened our insight into the functional characteristics of this variant of termite GH1 β-glucosidase and its applications in bioconversion and biotechnology.
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183
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Sweygers N, Alewaters N, Dewil R, Appels L. Microwave effects in the dilute acid hydrolysis of cellulose to 5-hydroxymethylfurfural. Sci Rep 2018; 8:7719. [PMID: 29769623 PMCID: PMC5956001 DOI: 10.1038/s41598-018-26107-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 04/27/2018] [Indexed: 11/09/2022] Open
Abstract
In this study, the effect of microwaves on the production of 5-hydroxymethylfurfural (HMF) in a biphasic system was evaluated via a kinetic analysis. The reaction system consisted of an acidified aqueous phase and methyl isobutyl ketone (MIBK) as an organic phase, in which HMF is extracted directly upon formation during the reaction. Two identically shaped reactors were used to assess the influence of microwaves on the production of HMF. A borosilicate glass reactor was used to heat the reaction mixture via microwaves directly, whereas the silicon carbide (SiC) wall of the second reactor absorbed all microwaves and hence the reactor content was heated via convective heat transfer. An identical temperature profile was imposed on both reactors. Cellulose, glucose and fructose were chosen as feedstocks for the conversion to HMF. It was observed that microwaves have a significant effect on the reactions. The hydrolysis of cellulose to glucose was a 2.3 folds faster in the presence of microwaves at the process conditions (0.046 M HCl, 177 °C). The isomerization of glucose to fructose showed a similar increase (factor 2.5). The required energy input for the reaction was systematically higher for the SiC reactor.
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Affiliation(s)
- Nick Sweygers
- KU Leuven, Department of Chemical Engineering, Process and Environmental Technology Lab, J. De Nayerlaan 5, B-2860, Sint-Katelijne-Waver, Belgium
| | - Niels Alewaters
- KU Leuven, Department of Chemical Engineering, Process and Environmental Technology Lab, J. De Nayerlaan 5, B-2860, Sint-Katelijne-Waver, Belgium
| | - Raf Dewil
- KU Leuven, Department of Chemical Engineering, Process and Environmental Technology Lab, J. De Nayerlaan 5, B-2860, Sint-Katelijne-Waver, Belgium
| | - Lise Appels
- KU Leuven, Department of Chemical Engineering, Process and Environmental Technology Lab, J. De Nayerlaan 5, B-2860, Sint-Katelijne-Waver, Belgium.
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184
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Cayetano RDA, Kim TH. Two-stage processing of Miscanthus giganteus using anhydrous ammonia and hot water for effective xylan recovery and improved enzymatic saccharification. BIORESOURCE TECHNOLOGY 2018; 255:163-170. [PMID: 29414163 DOI: 10.1016/j.biortech.2018.01.135] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/26/2018] [Accepted: 01/29/2018] [Indexed: 06/08/2023]
Abstract
A two-stage method using gaseous ammonia and hot water was proposed to recover xylan and lignin from Miscanthus. In this method, Miscanthus was treated with gaseous ammonia at elevated temperatures (60-150 °C) for various reaction times (1-48 h) in the first stage, termed as LMAA (low-moisture anhydrous ammonia) treatment. In the following stage, the LMAA-treated solid was subjected to hot-water treatment in a flow-through column reactor under various reaction conditions (170-220 °C, 30-90 min). After two-stage processing, the remaining solid contained mostly glucan (∼80% cellulose), which became highly digestible by enzymes. The optimal treatment conditions for sugar recovery using two-stage process were 120 °C and 12 h for the 1st stage and 190 °C, 90 min, and 5 mL/min for the 2nd stage, which resulted in 84.2% xylan recovery in liquid phase and 95.3% glucan digestibility of the treated solid, using 15 FPU/g-glucan enzyme loading after the two-stage treatment.
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Affiliation(s)
- Roent Dune A Cayetano
- Department of Environmental Engineering, Daegu University, Gyeongsan, Gyeongbuk 38453, Republic of Korea
| | - Tae Hyun Kim
- Department of Materials Science and Chemical Engineering, Hanyang University, Ansan, Gyeonggi-do 15588, Republic of Korea.
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185
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Liang J, Fang X, Lin Y, Wang D. A new screened microbial consortium OEM2 for lignocellulosic biomass deconstruction and chlorophenols detoxification. JOURNAL OF HAZARDOUS MATERIALS 2018; 347:341-348. [PMID: 29335216 DOI: 10.1016/j.jhazmat.2018.01.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 12/13/2017] [Accepted: 01/10/2018] [Indexed: 06/07/2023]
Abstract
Recalcitrance limits biomass application in biorefinery. It is even more so when toxic chlorophenols are present. In this study, we screened a microbial consortium, OEM2, for lignocellulose deconstruction and chlorophenols detoxification through a short-term and efficient screening process. Microbial consortium OEM2 had a good buffer capability in the cultivation process and exhibited a high xylanase activity, with over 85% hemicellulose degradation within 12 days. Throughout the treatment process, 41.5% rice straw decomposition on day 12 and around 75% chlorophenols (MCP, 2,4-DCP, 2,4,6-TCP) removal on day 9, were recorded. Moreover, Fourier translation infrared spectroscopy (FTIR) analysis indicated that chemical bonds and groups (eg. hydrogen-bond, β-1,4 glycosidic bond, lignin-carbohydrate cross-linking) in the rice straw were broken. Cuticle and silica layer destruction and subsequent exposed cellulose fibers were observed by scanning electron microscopy (SEM). Microbial consortium OEM2 diversity analysis by 16S rRNA gene sequencing indicated that Proteobacteria (41.3%) was the most abundant phylum and the genera Paenibacillus and Pseudomonas played an important role in the lignocellulose decomposition and chlorophenols detoxification. This study developed a faster and more efficient strategy to screen a specific microbial consortium. And the new microbial consortium, OEM2, makes lignocellulose more accessible and complex pollutants unproblematic in the further biorefinery process.
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Affiliation(s)
- Jiajin Liang
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong 510642, PR China
| | - Xiuxiu Fang
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong 510642, PR China; Integrate Microbiology Research Center, South China Agricultural University, Guangzhou, Guangdong 510642, PR China
| | - Yunqin Lin
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong 510642, PR China; Integrate Microbiology Research Center, South China Agricultural University, Guangzhou, Guangdong 510642, PR China.
| | - Dehan Wang
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong 510642, PR China; Integrate Microbiology Research Center, South China Agricultural University, Guangzhou, Guangdong 510642, PR China
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186
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Degradation behavior and kinetics of sisal fiber in pore solutions of sustainable cementitious composite containing metakaolin. Polym Degrad Stab 2018. [DOI: 10.1016/j.polymdegradstab.2018.01.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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187
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Till P, Pucher ME, Mach RL, Mach-Aigner AR. A long noncoding RNA promotes cellulase expression in Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:78. [PMID: 29588663 PMCID: PMC5865335 DOI: 10.1186/s13068-018-1081-4] [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: 09/01/2017] [Accepted: 03/14/2018] [Indexed: 05/31/2023]
Abstract
BACKGROUND Due to its capability to secrete large quantities of plant biomass degrading enzymes (PBDE), Trichoderma reesei is widely applied for industrial purposes. In nature, expression of PBDE is efficiently regulated in this fungus. Several factors involved in this regulatory network have been identified. However, most of them are transcription factors. Long noncoding RNAs (lncRNAs) emerged as common players acting on epigenetic or transcriptional regulation in several eukaryotic organisms. To date, no lncRNA has been described in filamentous fungi. RESULTS A lncRNA termed HAX1 was identified in T. reesei QM9414. In this study, it was characterized and evidence for its regulatory impact on cellulase expression was provided. Interestingly, different versions of HAX1 were identified in different strains (namely, QM6a, QM9414, and Rut-C30), varying in terms of RNA length. Remarkably, considerable longer variants of this lncRNA are present in hypercellulolytic strains compared to the wild-type strain QM6a. Based on these results, a correlation between RNA length and the functional impact of HAX1 on PBDE expression was supposed. This assumption was verified by overexpressing the most abundant HAX1 versions identified in QM6a, QM9414, and Rut-C30. Such HAX1 overexpression on the one hand was suitable for regaining the function in hax1 disruption strains, and on the other hand resulted in notably higher cellulase activities in QM6a, especially by the expression of longer HAX1 versions. CONCLUSION With HAX1, for the first time the regulatory role of a lncRNA in filamentous fungi was uncovered. Besides this, a new player involved in the complex regulation of PBDE expression in T. reesei was identified. Due to its enhancing effect on cellulase activity, HAX1 was shown to be not only interesting for basic research, but also a promising candidate for expanding the set of biotechnological tools for industrial application of T. reesei.
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Affiliation(s)
- Petra Till
- Christian Doppler Laboratory for Optimized Expression of Carbohydrate-active Enzymes, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
| | - Marion E. Pucher
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
| | - Robert L. Mach
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
| | - Astrid R. Mach-Aigner
- Christian Doppler Laboratory for Optimized Expression of Carbohydrate-active Enzymes, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
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188
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The features that distinguish lichenases from other polysaccharide-hydrolyzing enzymes and the relevance of lichenases for biotechnological applications. Appl Microbiol Biotechnol 2018; 102:3951-3965. [DOI: 10.1007/s00253-018-8904-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 02/23/2018] [Accepted: 02/26/2018] [Indexed: 01/16/2023]
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189
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Krivobok AS, Berkovich YA, Shcherbakova VA, Chuvilskaya NA. Developing a technique to enhance durability of fibrous ion-exchange resin substrate for space greenhouses. LIFE SCIENCES IN SPACE RESEARCH 2018; 16:1-7. [PMID: 29475514 DOI: 10.1016/j.lssr.2017.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 09/29/2017] [Accepted: 10/03/2017] [Indexed: 06/08/2023]
Abstract
One way to cut consumables for space plant growth facilities (PGF) with artificial soil in the form of fibrous ion-exchange resin substrate (FIERS) is on-board regeneration of the used medium. After crop harvest the procedure includes removal of the roots from the fibrous media with preservation of the exchanger properties and capillary structure. One type of FIERS, namely BIONA-V3ۛ, has been used in Russian prototypes of space conveyors. We describe a two-stage treatment of BIONA-V3ۛ including primary microwave heating of the used FIERS until (90 ± 5) °C in alkali-peroxide solution during 3.5 hrs. The second stage of the treatment is decomposition of root vestiges inside pores of BIONA-V3ۛ by using thermophilic and mesophilic anaerobic bacteria Clostridium thermocellum, Clostridium cellulolyticum and Cellulosilyticum lentocellum during 7-10 days at 55 °C. The two-stage procedure allows extraction of 90% dead roots from the FIERS' pores and the preservation of root zone hydro-physical properties. A posterior enrichment of the FIERS by minerals makes BIONA- V3ۛ reusable.
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Affiliation(s)
- A S Krivobok
- State Scientific Center - Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia.
| | - Yu A Berkovich
- State Scientific Center - Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia.
| | - V A Shcherbakova
- Skryabin Institute of Biochemistry and Physiology of Microorganisms of Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - N A Chuvilskaya
- Skryabin Institute of Biochemistry and Physiology of Microorganisms of Russian Academy of Sciences, Pushchino, Moscow Region, Russia
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190
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Wang Y, Okugawa K, Kunitake E, Sakka M, Kimura T, Sakka K. Development of an efficient host-vector system of Ruminiclostridium josui. J Basic Microbiol 2018; 58:448-458. [PMID: 29388680 DOI: 10.1002/jobm.201700620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/23/2017] [Accepted: 12/30/2017] [Indexed: 01/22/2023]
Abstract
Although Ruminiclostridium josui (formerly Clostridium josui), a strictly anaerobic mesophilic cellulolytic bacterium, is a promising candidate for biomass utilization via consolidated bioprocessing, its host-vector system has not yet been established. The existence of a restriction and modification system is a significant barrier to the transformation of R. josui. Here, we partially purified restriction endonuclease RjoI from R. josui cell extract using column chromatography. Further characterization showed that RjoI is an isoschizomer of DpnI, recognizing the sequence 5'-Gmet ATC-3', where the A nucleotide is Dam-methylated. RjoI cleaved the recognition sequence between the A and T nucleotides, producing blunt ends. We then successfully introduced plasmids prepared from Escherichia coli C2925 (dam- /dcm- ) into R. josui by electroporation. The highest transformation efficiency of 6.6 × 103 transformants/μg of DNA was obtained using a square-wave pulse (750 V, 1 ms). When the R. josui cel48A gene, devoid of the dockerin-encoding region, cloned into newly developed plasmid pKKM801 was introduced into R. josui, a truncated form of RjCel48A, RjCel48AΔdoc, was detected in the culture supernatant but not in the intracellular fraction. This is the first report on the establishment of fundamental technology for molecular breeding of R. josui.
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Affiliation(s)
- Yayun Wang
- Graduate School of Bioresources, Mie University, Mie, Japan
| | - Kei Okugawa
- Graduate School of Bioresources, Mie University, Mie, Japan
| | - Emi Kunitake
- Graduate School of Bioresources, Mie University, Mie, Japan
| | - Makiko Sakka
- Graduate School of Bioresources, Mie University, Mie, Japan
| | - Tetsuya Kimura
- Graduate School of Bioresources, Mie University, Mie, Japan
| | - Kazuo Sakka
- Graduate School of Bioresources, Mie University, Mie, Japan
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191
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Cologna NDMD, Gómez-Mendoza DP, Zanoelo FF, Giannesi GC, Guimarães NCDA, Moreira LRDS, Filho EXF, Ricart CAO. Exploring Trichoderma and Aspergillus secretomes: Proteomics approaches for the identification of enzymes of biotechnological interest. Enzyme Microb Technol 2018; 109:1-10. [DOI: 10.1016/j.enzmictec.2017.08.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 08/17/2017] [Accepted: 08/18/2017] [Indexed: 12/13/2022]
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192
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Understanding Functional Roles of Native Pentose-Specific Transporters for Activating Dormant Pentose Metabolism in Yarrowia lipolytica. Appl Environ Microbiol 2018; 84:AEM.02146-17. [PMID: 29150499 DOI: 10.1128/aem.02146-17] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 11/02/2017] [Indexed: 01/08/2023] Open
Abstract
Pentoses, including xylose and arabinose, are the second most prevalent sugars in lignocellulosic biomass that can be harnessed for biological conversion. Although Yarrowia lipolytica has emerged as a promising industrial microorganism for production of high-value chemicals and biofuels, its native pentose metabolism is poorly understood. Our previous study demonstrated that Y. lipolytica (ATCC MYA-2613) has endogenous enzymes for d-xylose assimilation, but inefficient xylitol dehydrogenase causes Y. lipolytica to assimilate xylose poorly. In this study, we investigated the functional roles of native sugar-specific transporters for activating the dormant pentose metabolism in Y. lipolytica By screening a comprehensive set of 16 putative pentose-specific transporters, we identified two candidates, YALI0C04730p and YALI0B00396p, that enhanced xylose assimilation. The engineered mutants YlSR207 and YlSR223, overexpressing YALI0C04730p and YALI0B00396p, respectively, improved xylose assimilation approximately 23% and 50% in comparison to YlSR102, a parental engineered strain overexpressing solely the native xylitol dehydrogenase gene. Further, we activated and elucidated a widely unknown native l-arabinose assimilation pathway in Y. lipolytica through transcriptomic and metabolic analyses. We discovered that Y. lipolytica can coconsume xylose and arabinose, where arabinose utilization shares transporters and metabolic enzymes of some intermediate steps of the xylose assimilation pathway. Arabinose assimilation is synergistically enhanced in the presence of xylose, while xylose assimilation is competitively inhibited by arabinose. l-Arabitol dehydrogenase is the rate-limiting step responsible for poor arabinose utilization in Y. lipolytica Overall, this study sheds light on the cryptic pentose metabolism of Y. lipolytica and, further, helps guide strain engineering of Y. lipolytica for enhanced assimilation of pentose sugars.IMPORTANCE The oleaginous yeast Yarrowia lipolytica is a promising industrial-platform microorganism for production of high-value chemicals and fuels. For decades since its isolation, Y. lipolytica has been known to be incapable of assimilating pentose sugars, xylose and arabinose, that are dominantly present in lignocellulosic biomass. Through bioinformatic, transcriptomic, and enzymatic studies, we have uncovered the dormant pentose metabolism of Y. lipolytica Remarkably, unlike most yeast strains, which share the same transporters for importing hexose and pentose sugars, we discovered that Y. lipolytica possesses the native pentose-specific transporters. By overexpressing these transporters together with the rate-limiting d-xylitol and l-arabitol dehydrogenases, we activated the dormant pentose metabolism of Y. lipolytica Overall, this study provides a fundamental understanding of the dormant pentose metabolism of Y. lipolytica and guides future metabolic engineering of Y. lipolytica for enhanced conversion of pentose sugars to high-value chemicals and fuels.
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193
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Zhang J, Yuan J, Zhang WX, Tu F, Jiang Y, Sun CZ. Anaerobic detoxification fermentation by Rhodospirillum rubrum for rice straw as feed with moderate pretreatment. Prep Biochem Biotechnol 2018; 48:75-83. [PMID: 29194020 DOI: 10.1080/10826068.2017.1405023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A novel and effective process was put forward for converting rice straw into feed by combining diluted acid hydrolysis and ammonization with Rhodospirillum rubrum fermentation. After pretreatment with dilute sulfuric or phosphoric acid (1%, w/w) at 100°C, materials were subjected to fermentation under several gases (N2, CO2, and air) and different light intensities in a 2-L fermentor. The key indexes of feed for fermented materials were estimated and several toxic substances were investigated during the fermentation. Following sulfuric acid treatment, the true protein of rice straw increased from 29 to 143 g kg-1 and the crude fiber decreased from 359 to 136 g kg-1 after fermentation at 0.3 L min-1 L-1 of N2 flow and a light intensity of 3400 lux; and following phosphoric acid treatment, the true protein increased by 286% and the crude fiber decreased by 52% after fermentation at 0.4 L min-1 L-1 of N2 flow and a light intensity of 3000 lux. Other key contents were also improved for use as feed, and some toxic substances (i.e., furfural, hydroxymethylfurfural, acetic acid, phenol, cresol) produced by the pretreatments could be removed at low levels during the fermentations.
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Affiliation(s)
- Jian Zhang
- a Department of Life Science and Food Engineering/Key Laboratory of Fermentation Resource and Application in Sichuan/Department of Library , Yibin University , Yibin , Sichuan , China
| | - Jie Yuan
- a Department of Life Science and Food Engineering/Key Laboratory of Fermentation Resource and Application in Sichuan/Department of Library , Yibin University , Yibin , Sichuan , China
| | - Wen-Xue Zhang
- b Food microbiology laboratory, College of Light Industry, Textile and Food Engineering , Sichuan University , Chengdu , Sichuan , China
| | - Fang Tu
- a Department of Life Science and Food Engineering/Key Laboratory of Fermentation Resource and Application in Sichuan/Department of Library , Yibin University , Yibin , Sichuan , China
| | - Ya Jiang
- a Department of Life Science and Food Engineering/Key Laboratory of Fermentation Resource and Application in Sichuan/Department of Library , Yibin University , Yibin , Sichuan , China
| | - Chuan-Ze Sun
- c Production Department , Xu Fu Liquor Company , Yibin , Sichuan , China
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194
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Yousuf A, Ethiraj B, Khan MR, Pirozzi D. Fungal Biorefinery for the Production of Single Cell Oils as Advanced Biofuels. Fungal Biol 2018. [DOI: 10.1007/978-3-319-90379-8_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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195
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De Bhowmick G, Sarmah AK, Sen R. Lignocellulosic biorefinery as a model for sustainable development of biofuels and value added products. BIORESOURCE TECHNOLOGY 2018; 247:1144-1154. [PMID: 28993055 DOI: 10.1016/j.biortech.2017.09.163] [Citation(s) in RCA: 144] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/18/2017] [Accepted: 09/23/2017] [Indexed: 05/18/2023]
Abstract
A constant shift of society's dependence from petroleum-based energy resources towards renewable biomass-based has been the key to tackle the greenhouse gas emissions. Effective use of biomass feedstock, particularly lignocellulosic, has gained worldwide attention lately. Lignocellulosic biomass as a potent bioresource, however, cannot be a sustainable alternative if the production cost is too high and/ or the availability is limited. Recycling the lignocellulosic biomass from various sources into value added products such as bio-oil, biochar or other biobased chemicals in a bio-refinery model is a sensible idea. Combination of integrated conversion techniques along with process integration is suggested as a sustainable approach. Introducing 'series concept' accompanying intermittent dark/photo fermentation with co-cultivation of microalgae is conceptualised. While the cost of downstream processing for a single type of feedstock would be high, combining different feedstocks and integrating them in a bio-refinery model would lessen the production cost and reduce CO2 emission.
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Affiliation(s)
- Goldy De Bhowmick
- Department of Civil and Environmental Engineering, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Ajit K Sarmah
- Department of Civil and Environmental Engineering, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
| | - Ramkrishna Sen
- Department of Biotechnology, Indian Institute of Technology Kharagpur, West Bengal 721302, India
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196
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Production of thermostable β-glucosidase and CMCase by Penicillium sp. LMI01 isolated from the Amazon region. ELECTRON J BIOTECHN 2018. [DOI: 10.1016/j.ejbt.2017.11.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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197
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Song B, Li B, Wang X, Shen W, Park S, Collings C, Feng A, Smith SJ, Walton JD, Ding SY. Real-time imaging reveals that lytic polysaccharide monooxygenase promotes cellulase activity by increasing cellulose accessibility. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:41. [PMID: 29467819 PMCID: PMC5815216 DOI: 10.1186/s13068-018-1023-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 01/11/2018] [Indexed: 05/08/2023]
Abstract
BACKGROUND The high cost of enzymes is one of the key technical barriers that must be overcome to realize the economical production of biofuels and biomaterials from biomass. Supplementation of enzyme cocktails with lytic polysaccharide monooxygenase (LPMO) can increase the efficiency of these cellulase mixtures for biomass conversion. The previous studies have revealed that LPMOs cleave polysaccharide chains by oxidization of the C1 and/or C4 carbons of the monomeric units. However, how LPMOs enhance enzymatic degradation of lignocellulose is still poorly understood. RESULTS In this study, we combined enzymatic assays and real-time imaging using atomic force microscopy (AFM) to study the molecular interactions of an LPMO [TrAA9A, formerly known as TrCel61A) from Trichoderma reesei] and a cellobiohydrolase I (TlCel7A from T. longibrachiatum) with bacterial microcrystalline cellulose (BMCC) as a substrate. Cellulose conversion by TlCel7A alone was enhanced from 46 to 54% by the addition of TrAA9A. Conversion by a mixture of TlCel7A, endoglucanase, and β-glucosidase was increased from 79 to 87% using pretreated BMCC with TrAA9A for 72 h. AFM imaging demonstrated that individual TrAA9A molecules exhibited intermittent random movement along, across, and penetrating into the ribbon-like microfibril structure of BMCC, which was concomitant with the release of a small amount of oxidized sugars and the splitting of large cellulose ribbons into fibrils with smaller diameters. The dividing effect of the cellulose microfibril occurred more rapidly when TrAA9A and TlCel7A were added together compared to TrAA9A alone; TlCel7A alone caused no separation. CONCLUSIONS TrAA9A increases the accessible surface area of BMCC by separating large cellulose ribbons, and thereby enhances cellulose hydrolysis yield. By providing the first direct observation of LPMO action on a cellulosic substrate, this study sheds new light on the mechanisms by which LPMO enhances biomass conversion.
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Affiliation(s)
- Bo Song
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
| | - Bingyao Li
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824 USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 USA
| | - Xiaoyan Wang
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
| | - Wei Shen
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 USA
| | - Sungjin Park
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
| | - Cynthia Collings
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 USA
| | - Anran Feng
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
| | - Steve J. Smith
- Nanoscience and Nanoengineering Program, South Dakota School of Mines and Technology, Rapid City, SD 57701 USA
| | - Jonathan D. Walton
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824 USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 USA
| | - Shi-You Ding
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 USA
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198
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Stappler E, Walton JD, Beier S, Schmoll M. Abundance of Secreted Proteins of Trichoderma reesei Is Regulated by Light of Different Intensities. Front Microbiol 2017; 8:2586. [PMID: 29375497 PMCID: PMC5770571 DOI: 10.3389/fmicb.2017.02586] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 12/12/2017] [Indexed: 11/22/2022] Open
Abstract
In Trichoderma reesei light is an important factor in the regulation of glycoside hydrolase gene expression. We therefore investigated the influence of different light intensities on cellulase activity and protein secretion. Differentially secreted proteins in light and darkness as identified by mass spectrometry included members of different glycoside hydrolase families, such as CBH1, Cel3A, Cel61B, XYN2, and XYN4. Several of the associated genes showed light-dependent regulation on the transcript level. Deletion of the photoreceptor genes blr1 and blr2 resulted in a diminished difference of protein abundance between light and darkness. The amount of secreted proteins including that of the major exo-acting beta-1,4-glucanases CBH1 and CBH2 was generally lower in light-grown cultures than in darkness. In contrast, cbh1 transcript levels increased with increasing light intensity from 700 to 2,000 lux but dopped at high light intensity (5,000 lux). In the photoreceptor mutants Δblr1 and Δblr2 cellulase activity in light was reduced compared to activity in darkness, showing a discrepancy between transcript levels and secreted cellulase activity. Furthermore, evaluation of different light sensitivities revealed an increased light tolerance with respect to cellulase expression of QM9414 compared to its parental strain QM6a. Investigation of one of the differentially expressed proteins between light and darkness, CLF1, revealed its function as a factor involved in regulation of secreted protease activity. T. reesei secretes a different set of proteins in light compared to darkness, this difference being mainly due to the function of the major known photoreceptors. Moreover, cellulase regulation is adjusted to light intensity and improved light tolerance was correlated with increased cellulase production. Our findings further support the hypothesis of a light intensity dependent post-transcriptional regulation of cellulase gene expression in T. reesei.
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Affiliation(s)
- Eva Stappler
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
| | - Jonathan D. Walton
- MSU-DOE Plant Research Laboratory, Department of Plant Biology, Michigan State University, East Lansing, MI, United States
| | - Sabrina Beier
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
| | - Monika Schmoll
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
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Auer L, Lazuka A, Sillam-Dussès D, Miambi E, O'Donohue M, Hernandez-Raquet G. Uncovering the Potential of Termite Gut Microbiome for Lignocellulose Bioconversion in Anaerobic Batch Bioreactors. Front Microbiol 2017; 8:2623. [PMID: 29312279 PMCID: PMC5744482 DOI: 10.3389/fmicb.2017.02623] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 12/15/2017] [Indexed: 11/16/2022] Open
Abstract
Termites are xylophages, being able to digest a wide variety of lignocellulosic biomass including wood with high lignin content. This ability to feed on recalcitrant plant material is the result of complex symbiotic relationships, which involve termite-specific gut microbiomes. Therefore, these represent a potential source of microorganisms for the bioconversion of lignocellulose in bioprocesses targeting the production of carboxylates. In this study, gut microbiomes of four termite species were studied for their capacity to degrade wheat straw and produce carboxylates in controlled bioreactors. All of the gut microbiomes successfully degraded lignocellulose and up to 45% w/w of wheat straw degradation was observed, with the Nasutitermes ephratae gut-microbiome displaying the highest levels of wheat straw degradation, carboxylate production and enzymatic activity. Comparing the 16S rRNA gene diversity of the initial gut inocula to the bacterial communities in lignocellulose degradation bioreactors revealed important changes in community diversity. In particular, taxa such as Spirochaetes and Fibrobacteres that were highly abundant in the initial gut inocula were replaced by Firmicutes and Proteobacteria at the end of incubation in wheat straw bioreactors. Overall, this study demonstrates that termite-gut microbiomes constitute a reservoir of lignocellulose-degrading bacteria that can be harnessed in artificial conditions for biomass conversion processes that lead to the production of useful molecules.
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Affiliation(s)
- Lucas Auer
- Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés, Université de Toulouse, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, INSA, Toulouse, France
| | - Adèle Lazuka
- Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés, Université de Toulouse, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, INSA, Toulouse, France
| | - David Sillam-Dussès
- Laboratoire d'Éthologie Expérimentale et Comparée, Université Paris 13 - Sorbonne Paris Cité, Villetaneuse, France
- Institut d'Ecologie et des Sciences de l'Environnement de Paris, Institut de Recherche Pour le Développement – Sorbonne Universités, Bondy, France
| | - Edouard Miambi
- Institut d'Ecologie et des Sciences de l'Environnement de Paris, Université Paris-Est Créteil, Créteil, France
| | - Michael O'Donohue
- Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés, Université de Toulouse, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, INSA, Toulouse, France
| | - Guillermina Hernandez-Raquet
- Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés, Université de Toulouse, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, INSA, Toulouse, France
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200
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Wong MT, Wang W, Couturier M, Razeq FM, Lombard V, Lapebie P, Edwards EA, Terrapon N, Henrissat B, Master ER. Comparative Metagenomics of Cellulose- and Poplar Hydrolysate-Degrading Microcosms from Gut Microflora of the Canadian Beaver ( Castor canadensis) and North American Moose ( Alces americanus) after Long-Term Enrichment. Front Microbiol 2017; 8:2504. [PMID: 29326667 PMCID: PMC5742341 DOI: 10.3389/fmicb.2017.02504] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 12/01/2017] [Indexed: 11/13/2022] Open
Abstract
To identify carbohydrate-active enzymes (CAZymes) that might be particularly relevant for wood fiber processing, we performed a comparative metagenomic analysis of digestive systems from Canadian beaver (Castor canadensis) and North American moose (Alces americanus) following 3 years of enrichment on either microcrystalline cellulose or poplar hydrolysate. In total, 9,386 genes encoding CAZymes and carbohydrate-binding modules (CBMs) were identified, with up to half predicted to originate from Firmicutes, Bacteroidetes, Chloroflexi, and Proteobacteria phyla, and up to 17% from unknown phyla. Both PCA and hierarchical cluster analysis distinguished the annotated glycoside hydrolase (GH) distributions identified herein, from those previously reported for grass-feeding mammals and herbivorous foragers. The CAZyme profile of moose rumen enrichments also differed from a recently reported moose rumen metagenome, most notably by the absence of GH13-appended dockerins. Consistent with substrate-driven convergence, CAZyme profiles from both poplar hydrolysate-fed cultures differed from cellulose-fed cultures, most notably by increased numbers of unique sequences belonging to families GH3, GH5, GH43, GH53, and CE1. Moreover, pairwise comparisons of moose rumen enrichments further revealed higher counts of GH127 and CE15 families in cultures fed with poplar hydrolysate. To expand our scope to lesser known carbohydrate-active proteins, we identified and compared multi-domain proteins comprising both a CBM and domain of unknown function (DUF) as well as proteins with unknown function within the 416 predicted polysaccharide utilization loci (PULs). Interestingly, DUF362, identified in iron-sulfur proteins, was consistently appended to CBM9; on the other hand, proteins with unknown function from PULs shared little identity unless from identical PULs. Overall, this study sheds new light on the lignocellulose degrading capabilities of microbes originating from digestive systems of mammals known for fiber-rich diets, and highlights the value of enrichment to select new CAZymes from metagenome sequences for future biochemical characterization.
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Affiliation(s)
- Mabel T Wong
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Weijun Wang
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Marie Couturier
- Centre de Recherches sur les Macromolécules Végétales - Université Grenoble Alpes, Grenoble, France.,Centre National de la Recherche Scientifique, Centre de Recherches sur les Macromolécules Végétales, Grenoble, France
| | - Fakhria M Razeq
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Vincent Lombard
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, Marseille, France.,UMR 7257, Centre National de la Recherche Scientifique, Marseille, France
| | - Pascal Lapebie
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, Marseille, France
| | - Elizabeth A Edwards
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Nicolas Terrapon
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, Marseille, France
| | - Bernard Henrissat
- UMR 7257, Centre National de la Recherche Scientifique, Marseille, France.,Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Emma R Master
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada.,Department of Bioproducts and Biosystems, Aalto University, Espoo, Finland
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