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Mohammadi M, Alian M, Dale B, Ubanwa B, Balan V. Multifaced application of AFEX-pretreated biomass in producing second-generation biofuels, ruminant animal feed, and value-added bioproducts. Biotechnol Adv 2024; 72:108341. [PMID: 38499256 DOI: 10.1016/j.biotechadv.2024.108341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 03/06/2024] [Accepted: 03/15/2024] [Indexed: 03/20/2024]
Abstract
Lignocellulosic biomass holds a crucial position in the prospective bio-based economy, serving as a sustainable and renewable source for a variety of bio-based products. These products play a vital role in displacing fossil fuels and contributing to environmental well-being. However, the inherent recalcitrance of biomass poses a significant obstacle to the efficient access of sugar polymers. Consequently, the bioconversion of lignocellulosic biomass into fermentable sugars remains a prominent challenge in biorefinery processes to produce biofuels and biochemicals. In addressing these challenges, extensive efforts have been dedicated to mitigating biomass recalcitrance through diverse pretreatment methods. One noteworthy process is Ammonia Fiber Expansion (AFEX) pretreatment, characterized by its dry-to-dry nature and minimal water usage. The volatile ammonia, acting as a catalyst in the process, is recyclable. AFEX contributes to cleaning biomass ester linkages and facilitating the opening of cell wall structures, enhancing enzyme accessibility and leading to a fivefold increase in sugar conversion compared to untreated biomass. Over the last decade, AFEX has demonstrated substantial success in augmenting the efficiency of biomass conversion processes. This success has unlocked the potential for sustainable and economically viable biorefineries. This paper offers a comprehensive review of studies focusing on the utilization of AFEX-pretreated biomass in the production of second-generation biofuels, ruminant feed, and additional value-added bioproducts like enzymes, lipids, proteins, and mushrooms. It delves into the details of the AFEX pretreatment process at both laboratory and pilot scales, elucidates the mechanism of action, and underscores the role of AFEX in the biorefinery for developing biofuels and bioproducts, and nutritious ruminant animal feed production. While highlighting the strides made, the paper also addresses current challenges in the commercialization of AFEX pretreatment within biorefineries. Furthermore, it outlines critical considerations that must be addressed to overcome these challenges, ensuring the continued progress and widespread adoption of AFEX in advancing sustainable and economically viable bio-based industries.
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Affiliation(s)
- Maedeh Mohammadi
- Department of Engineering Technology, Cullen College of Engineering, University of Houston, Sugarland, TX 77479, USA
| | - Mahsa Alian
- Department of Engineering Technology, Cullen College of Engineering, University of Houston, Sugarland, TX 77479, USA
| | - Bruce Dale
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI 48824, USA
| | - Bryan Ubanwa
- Department of Engineering Technology, Cullen College of Engineering, University of Houston, Sugarland, TX 77479, USA
| | - Venkatesh Balan
- Department of Engineering Technology, Cullen College of Engineering, University of Houston, Sugarland, TX 77479, USA.
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Devi R, Thakur R, Kapoor S, Joshi SJ, Kumar A. Comparative assessment on lignocellulose degrading enzymes and bioethanol production from spent mushroom substrate of Calocybe indica and Volvariella volvacea. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-26988-1. [PMID: 37071368 DOI: 10.1007/s11356-023-26988-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 04/09/2023] [Indexed: 06/19/2023]
Abstract
In the current study, we compared the production of extracellular lignocellulose degrading enzymes and bioethanol from the spent mushroom substrate (SMS) of Calocybe indica and Volvariella volvacea. From SMS at different stages of the mushroom development cycle, ligninolytic and hydrolytic enzymes were analysed. The activities of lignin-degrading enzymes, including lignin peroxidase (LiP), laccase, and manganese peroxidase (MnP) were maximal in the spawn run and primordial stages, while hydrolytic enzymes including xylanase, cellobiohydrolase (CBH), and carboxymethyl cellulase (CMCase) showed higher activity during fruiting bodies development and at the end of the mushroom growth cycle. SMS of V. volvacea showed relatively lower ligninase activity than the SMS of C. indica, but had the maximum activity of hydrolytic enzymes. The enzyme was precipitated with acetone and further purified with the DEAE cellulose column. The maximum yield of reducing sugars was obtained after hydrolysis of NaOH (0.5 M) pretreated SMS with a cocktail of partially purified enzymes (50% v/v). After enzymatic hydrolysis, the total reducing sugars were 18.68 ± 0.34 g/l (SMS of C. indica) and 20.02 ± 0.87 g/l (SMS of V. volvacea). We observed the highest fermentation efficiency and ethanol productivity (54.25%, 0.12 g/l h) obtained from SMS hydrolysate of V. volvacea after 48 h at 30 ± 2 °C, using co-culture of Saccharomyces cerevisiae MTCC 11,815 and Pachysolen tannophilus MTCC 1077.
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Affiliation(s)
- Rajni Devi
- Department of Microbiology, Punjab Agricultural University, 141004, Ludhiana, Punjab, India
| | - Richa Thakur
- Department of Biochemistry, Punjab Agricultural University, 141004, Ludhiana, Punjab, India
| | - Shammi Kapoor
- Department of Microbiology, Punjab Agricultural University, 141004, Ludhiana, Punjab, India
| | - Sanket J Joshi
- Oil & Gas Research Center, and Central Analytical and Applied Research Unit, Sultan Qaboos University, 123, Muscat, Oman.
| | - Amit Kumar
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, India
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A Combined Study on Optimization, In Silico Modeling, and Genetic Modification of Large Scale Microbial Cellulase Production. Biochem Res Int 2022; 2022:4598937. [PMID: 36589721 PMCID: PMC9797302 DOI: 10.1155/2022/4598937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/28/2022] [Accepted: 11/29/2022] [Indexed: 12/24/2022] Open
Abstract
Cellulase is a biocatalyst that hydrolyzes cellulosic biomass and is considered a major group of industrial enzymes for its applications. Extensive work has been done on microbial cellulase but fungi are considered a novel strain for their maximum cellulase production. Production cost and novel microbial strains are major challenges for its improvement where cheap agro wastes can be essential sources of cellulose as substrates. The researcher searches for more cellulolytic microbes from natural sources but the production level of isolated strains is comparatively low. So genetic modification or mutation can be employed for large-scale cellulase production before optimization. After genetic modification than in silico molecular modeling can be evaluated for substrate molecule's binding affinity. In this review, we focus not only on the conventional methods of cellulase production but also on modern biotechnological approaches applied to cellulase production by a sequential study on common cellulase-producing microbes, modified microbes, culture media, carbon sources, substrate pretreatment process, and the importance of optimum pH and temperature on fermentation. In this review, we also compare different cellulase activity determination methods. As a result, this review provides insights into the interrelationship between the characteristics of optimizing different culture conditions, genetic modification, and in silico enzyme modeling for the production of cellulase enzymes, which may aid in the advancement of large-scale integrated enzyme manufacturing of substrate-specific enzymes.
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Bhalla A, Arce J, Ubanwa B, Singh G, Sani RK, Balan V. Thermophilic Geobacillus WSUCF1 Secretome for Saccharification of Ammonia Fiber Expansion and Extractive Ammonia Pretreated Corn Stover. Front Microbiol 2022; 13:844287. [PMID: 35694290 PMCID: PMC9176393 DOI: 10.3389/fmicb.2022.844287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 03/18/2022] [Indexed: 11/13/2022] Open
Abstract
A thermophilic Geobacillus bacterial strain, WSUCF1 contains different carbohydrate-active enzymes (CAZymes) capable of hydrolyzing hemicellulose in lignocellulosic biomass. We used proteomic, genomic, and bioinformatic tools, and genomic data to analyze the relative abundance of cellulolytic, hemicellulolytic, and lignin modifying enzymes present in the secretomes. Results showed that CAZyme profiles of secretomes varied based on the substrate type and complexity, composition, and pretreatment conditions. The enzyme activity of secretomes also changed depending on the substrate used. The secretomes were used in combination with commercial and purified enzymes to carry out saccharification of ammonia fiber expansion (AFEX)-pretreated corn stover and extractive ammonia (EA)-pretreated corn stover. When WSUCF1 bacterial secretome produced at different conditions was combined with a small percentage of commercial enzymes, we observed efficient saccharification of EA-CS, and the results were comparable to using a commercial enzyme cocktail (87% glucan and 70% xylan conversion). It also opens the possibility of producing CAZymes in a biorefinery using inexpensive substrates, such as AFEX-pretreated corn stover and Avicel, and eliminates expensive enzyme processing steps that are used in enzyme manufacturing. Implementing in-house enzyme production is expected to significantly reduce the cost of enzymes and biofuel processing cost.
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Affiliation(s)
- Aditya Bhalla
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD, United States
- Department of Chemistry, Biology and Health Science, South Dakota School of Mines and Technology, Rapid City, SD, United States
- Great Lakes Bioenergy Center, Michigan State University, East Lansing, MI, United States
| | - Jessie Arce
- Department of Engineering Technology, College of Technology, University of Houston, Houston, TX, United States
| | - Bryan Ubanwa
- Department of Engineering Technology, College of Technology, University of Houston, Houston, TX, United States
| | - Gursharan Singh
- Department of Medical Laboratory Sciences, Lovely Professional University, Phagwara, India
| | - Rajesh K. Sani
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD, United States
- Department of Chemistry, Biology and Health Science, South Dakota School of Mines and Technology, Rapid City, SD, United States
| | - Venkatesh Balan
- Great Lakes Bioenergy Center, Michigan State University, East Lansing, MI, United States
- Department of Engineering Technology, College of Technology, University of Houston, Houston, TX, United States
- *Correspondence: Venkatesh Balan,
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Fang H, Li C, Zhao J, Zhao C. Biotechnological Advances and Trends in Engineering Trichoderma reesei towards Cellulase Hyperproducer. BIOTECHNOL BIOPROC E 2021. [DOI: 10.1007/s12257-020-0243-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Li C, Lin X, Ling X, Li S, Fang H. Consolidated bioprocessing of lignocellulose for production of glucaric acid by an artificial microbial consortium. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:110. [PMID: 33931115 PMCID: PMC8086319 DOI: 10.1186/s13068-021-01961-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 04/21/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND The biomanufacturing of D-glucaric acid has attracted increasing interest because it is one of the top value-added chemicals produced from biomass. Saccharomyces cerevisiae is regarded as an excellent host for D-glucaric acid production. RESULTS The opi1 gene was knocked out because of its negative regulation on myo-inositol synthesis, which is the limiting step of D-glucaric acid production by S. cerevisiae. We then constructed the biosynthesis pathway of D-glucaric acid in S. cerevisiae INVSc1 opi1Δ and obtained two engineered strains, LGA-1 and LGA-C, producing record-breaking titers of D-glucaric acid: 9.53 ± 0.46 g/L and 11.21 ± 0.63 g/L D-glucaric acid from 30 g/L glucose and 10.8 g/L myo-inositol in fed-batch fermentation mode, respectively. However, LGA-1 was preferable because of its genetic stability and its superior performance in practical applications. There have been no reports on D-glucaric acid production from lignocellulose. Therefore, the biorefinery processes, including separated hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF) and consolidated bioprocessing (CBP) were investigated and compared. CBP using an artificial microbial consortium composed of Trichoderma reesei (T. reesei) Rut-C30 and S. cerevisiae LGA-1 was found to have relatively high D-glucaric acid titers and yields after 7 d of fermentation, 0.54 ± 0.12 g/L D-glucaric acid from 15 g/L Avicel and 0.45 ± 0.06 g/L D-glucaric acid from 15 g/L steam-exploded corn stover (SECS), respectively. In an attempt to design the microbial consortium for more efficient CBP, the team consisting of T. reesei Rut-C30 and S. cerevisiae LGA-1 was found to be the best, with excellent work distribution and collaboration. CONCLUSIONS Two engineered S. cerevisiae strains, LGA-1 and LGA-C, with high titers of D-glucaric acid were obtained. This indicated that S. cerevisiae INVSc1 is an excellent host for D-glucaric acid production. Lignocellulose is a preferable substrate over myo-inositol. SHF, SSF, and CBP were studied, and CBP using an artificial microbial consortium of T. reesei Rut-C30 and S. cerevisiae LGA-1 was found to be promising because of its relatively high titer and yield. T. reesei Rut-C30 and S. cerevisiae LGA-1were proven to be the best teammates for CBP. Further work should be done to improve the efficiency of this microbial consortium for D-glucaric acid production from lignocellulose.
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Affiliation(s)
- Chaofeng Li
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, Xianyang, 712100, Shaanxi, China
- Biomass Energy Center for Arid and Semi-Arid Lands, Northwest A&F University, 22 Xinong Road, Yangling, Xianyang, 712100, Shaanxi, China
| | - Xiaofeng Lin
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, Xianyang, 712100, Shaanxi, China
| | - Xing Ling
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, Xianyang, 712100, Shaanxi, China
| | - Shuo Li
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, Xianyang, 712100, Shaanxi, China
| | - Hao Fang
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, Xianyang, 712100, Shaanxi, China.
- Biomass Energy Center for Arid and Semi-Arid Lands, Northwest A&F University, 22 Xinong Road, Yangling, Xianyang, 712100, Shaanxi, China.
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Zhao Q, Liu Q, Wang Q, Qin Y, Zhong Y, Gao L, Liu G, Qu Y. Disruption of the Trichoderma reesei gul1 gene stimulates hyphal branching and reduces broth viscosity in cellulase production. J Ind Microbiol Biotechnol 2021; 48:6132311. [PMID: 33693788 PMCID: PMC9113457 DOI: 10.1093/jimb/kuab012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 02/05/2021] [Indexed: 12/03/2022]
Abstract
Hyphal morphology is considered to have a close relationship with the production
level of secreted proteins by filamentous fungi. In this study, the
gul1 gene, which encodes a putative mRNA-binding protein,
was disrupted in cellulase-producing fungus Trichoderma reesei.
The hyphae of Δgul1 strain produced more lateral
branches than the parent strain. Under the condition for cellulase production,
disruption of gul1 resulted in smaller mycelial clumps and
significantly lower viscosity of fermentation broth. In addition, cellulase
production was improved by 22% relative to the parent strain.
Transcriptome analysis revealed that a set of genes encoding cell wall
remodeling enzymes as well as hydrophobins were differentially expressed in the
Δgul1 strain. The results suggest that the
regulatory role of gul1 in cell morphogenesis is likely
conserved in filamentous fungi. To our knowledge, this is the first report on
the engineering of gul1 in an industrially important
fungus.
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Affiliation(s)
- Qinqin Zhao
- State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, 266237 Qingdao, China
| | - Qin Liu
- State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, 266237 Qingdao, China
| | - Qi Wang
- National Glycoengineering Research Center, Shandong University, 27 Binhai Road, 266237 Qingdao, China
| | - Yuqi Qin
- National Glycoengineering Research Center, Shandong University, 27 Binhai Road, 266237 Qingdao, China
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, 266237 Qingdao, China
| | - Liwei Gao
- State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, 266237 Qingdao, China.,Tobacco Research Institute of Chinese Academy of Agricultural Sciences, 11 Keyuanjingsi Road, 266101 Qingdao, China
| | - Guodong Liu
- State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, 266237 Qingdao, China.,National Glycoengineering Research Center, Shandong University, 27 Binhai Road, 266237 Qingdao, China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, 266237 Qingdao, China.,National Glycoengineering Research Center, Shandong University, 27 Binhai Road, 266237 Qingdao, China
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Novy V, Nielsen F, Cullen D, Sabat G, Houtman CJ, Hunt CG. The characteristics of insoluble softwood substrates affect fungal morphology, secretome composition, and hydrolytic efficiency of enzymes produced by Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:105. [PMID: 33902680 PMCID: PMC8074412 DOI: 10.1186/s13068-021-01955-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 04/11/2021] [Indexed: 05/04/2023]
Abstract
BACKGROUND On-site enzyme production using Trichoderma reesei can improve yields and lower the overall cost of lignocellulose saccharification by exploiting the fungal gene regulatory mechanism that enables it to continuously adapt enzyme secretion to the substrate used for cultivation. To harness this, the interrelation between substrate characteristics and fungal response must be understood. However, fungal morphology or gene expression studies often lack structural and chemical substrate characterization. Here, T. reesei QM6a was cultivated on three softwood substrates: northern bleached softwood Kraft pulp (NBSK) and lodgepole pine pretreated either by dilute-acid-catalyzed steam pretreatment (LP-STEX) or mild alkaline oxidation (LP-ALKOX). With different pretreatments of similar starting materials, we presented the fungus with systematically modified substrates. This allowed the elucidation of substrate-induced changes in the fungal response and the testing of the secreted enzymes' hydrolytic strength towards the same substrates. RESULTS Enzyme activity time courses correlated with hemicellulose content and cellulose accessibility. Specifically, increased amounts of side-chain-cleaving hemicellulolytic enzymes in the protein produced on the complex substrates (LP-STEX; LP-ALKOX) was observed by secretome analysis. Confocal laser scanning micrographs showed that fungal micromorphology responded to changes in cellulose accessibility and initial culture viscosity. The latter was caused by surface charge and fiber dimensions, and likely restricted mass transfer, resulting in morphologies of fungi in stress. Supplementing a basic cellulolytic enzyme mixture with concentrated T. reesei supernatant improved saccharification efficiencies of the three substrates, where cellulose, xylan, and mannan conversion was increased by up to 27, 45, and 2800%, respectively. The improvement was most pronounced for proteins produced on LP-STEX and LP-ALKOX on those same substrates, and in the best case, efficiencies reached those of a state-of-the-art commercial enzyme preparation. CONCLUSION Cultivation of T. reesei on LP-STEX and LP-ALKOX produced a protein mixture that increased the hydrolytic strength of a basic cellulase mixture to state-of-the-art performance on softwood substrates. This suggests that the fungal adaptation mechanism can be exploited to achieve enhanced performance in enzymatic hydrolysis without a priori knowledge of specific substrate requirements.
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Affiliation(s)
- Vera Novy
- US Department of Agriculture, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI, 53726, USA.
- Department of Biology and Bioengineering, Division of Industrial Biotechnology, Chalmers University of Technology, Kemivägen 10, 412 96, Göteborg, Sweden.
| | - Fredrik Nielsen
- US Department of Agriculture, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI, 53726, USA
| | - Daniel Cullen
- US Department of Agriculture, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI, 53726, USA
| | - Grzegorz Sabat
- University of Wisconsin Biotechnology Center, Madison, WI, 53706, USA
| | - Carl J Houtman
- US Department of Agriculture, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI, 53726, USA
| | - Christopher G Hunt
- US Department of Agriculture, Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI, 53726, USA
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Jones AM, Zhou Y, Held MA, Davis SC. Tissue Composition of Agave americana L. Yields Greater Carbohydrates From Enzymatic Hydrolysis Than Advanced Bioenergy Crops. FRONTIERS IN PLANT SCIENCE 2020; 11:654. [PMID: 32595656 PMCID: PMC7300260 DOI: 10.3389/fpls.2020.00654] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 04/28/2020] [Indexed: 05/25/2023]
Abstract
Agave americana L. is a highly productive, drought-tolerant species being investigated as a feedstock for biofuel production. Some Agave spp. yield crop biomass in semi-arid conditions that are comparable to C3 and C4 crops grown in areas with high rainfall. This study evaluates the bioethanol yield potential of A. americana by (1) examining the relationship between water use efficiency (WUE) and plant carbohydrates, (2) quantifying the carbohydrate and energy content of the plant tissue, and (3) comparing the products of enzymatic hydrolysis to that of other candidate feedstocks (Miscanthus x giganteus Greef et Deuter, Sorghum bicolor (L.) Moench, and Panicum virgatum L.). Results indicate that (1) WUE does not significantly affect soluble and insoluble (i.e., structural) carbohydrate composition per unit mass in A. americana; (2) without pretreatment, A. americana biomass had the lowest gross heat of combustion, or higher heating/calorific value, compared to high yielding C4 crops; and (3) after separation of soluble carbohydrates, A. americana cellulosic biomass was most easily hydrolyzed by enzymes with greater sugar yield per unit mass compared to the other biomass feedstocks. These results indicate that A. americana can produce substantial yields of soluble carbohydrates with minimal water inputs required for cultivation, and fiber portions of the crop can be readily deconstructed by cellulolytic enzymes for subsequent biochemical fermentation.
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Affiliation(s)
- Alexander M. Jones
- Voinovich School of Leadership and Public Affairs, Ohio University, Athens, OH, United States
| | - Yadi Zhou
- Department of Chemistry and Biochemistry, Ohio University, Athens, OH, United States
| | - Michael A. Held
- Department of Chemistry and Biochemistry, Ohio University, Athens, OH, United States
| | - Sarah C. Davis
- Voinovich School of Leadership and Public Affairs, Ohio University, Athens, OH, United States
- Department of Environmental and Plant Biology, Ohio University, Athens, OH, United States
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Novy V, Nielsen F, Seiboth B, Nidetzky B. The influence of feedstock characteristics on enzyme production in Trichoderma reesei: a review on productivity, gene regulation and secretion profiles. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:238. [PMID: 31624500 PMCID: PMC6781402 DOI: 10.1186/s13068-019-1571-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 09/20/2019] [Indexed: 05/21/2023]
Abstract
Biorefineries, designed for the production of lignocellulose-based chemicals and fuels, are receiving increasing attention from the public, governments, and industries. A major obstacle for biorefineries to advance to commercial scale is the high cost of the enzymes required to derive the fermentable sugars from the feedstock used. As summarized in this review, techno-economic studies suggest co-localization and integration of enzyme manufacturing with the cellulosic biorefinery as the most promising alternative to alleviate this problem. Thus, cultivation of Trichoderma reesei, the principal producer of lignocellulolytic enzymes, on the lignocellulosic biomass processed on-site can reduce the cost of enzyme manufacturing. Further, due to a complex gene regulation machinery, the fungus can adjust the gene expression of the lignocellulolytic enzymes towards the characteristics of the feedstock, increasing the hydrolytic efficiency of the produced enzyme cocktail. Despite extensive research over decades, the underlying regulatory mechanisms are not fully elucidated. One aspect that has received relatively little attention in literature is the influence the characteristics of a lignocellulosic substrate, i.e., its chemical and physical composition, has on the produced enzyme mixture. Considering that the fungus is dependent on efficient enzymatic degradation of the lignocellulose for continuous supply of carbon and energy, a relationship between feedstock characteristics and secretome composition can be expected. The aim of this review was to systematically collect, appraise, and aggregate data and integrate results from studies analyzing enzyme production by T. reesei on insoluble cellulosic model substrates and lignocellulosic biomass. The results show that there is a direct effect of the substrate's complexity (rated by structure, composition of the lignin-carbohydrate complex, and recalcitrance in enzymatic saccharification) on enzyme titers and the composition of specific activities in the secretome. It further shows that process-related factors, such as substrate loading and cultivation set-up, are direct targets for increasing enzyme yields. The literature on transcriptome and secretome composition further supports the proposed influence of substrate-related factors on the expression of lignocellulolytic enzymes. This review provides insights into the interrelation between the characteristics of the substrate and the enzyme production by T. reesei, which may help to advance integrated enzyme manufacturing of substrate-specific enzymes cocktails at scale.
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Affiliation(s)
- Vera Novy
- Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Graz University of Technology, Graz, Austria
- Present Address: Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, Canada
| | - Fredrik Nielsen
- Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Graz University of Technology, Graz, Austria
- Present Address: Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, Canada
| | - Bernhard Seiboth
- Institute of Chemical, Environmental and Bioscience Engineering, Vienna University of Technology, Vienna, Austria
- Austrian Centre of Industrial Biotechnology (acib) GmbH, Graz, Austria
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Graz University of Technology, Graz, Austria
- Austrian Centre of Industrial Biotechnology (acib) GmbH, Graz, Austria
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11
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Simultaneous enhancement of the beta-exo synergism and exo-exo synergism in Trichoderma reesei cellulase to increase the cellulose degrading capability. Microb Cell Fact 2019; 18:9. [PMID: 30657063 PMCID: PMC6337788 DOI: 10.1186/s12934-019-1060-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 01/10/2019] [Indexed: 11/18/2022] Open
Abstract
Background Cellulase is the one of the largest contributors to the high production costs of the lignocellulose-based biorefineries. As the most widely used cellulase producer, Trichoderma reesei has two weaknesses, deficiencies in β-glucosidase and cellobiohydrolase II. This work aimed at solving this problem by simultaneous enhancement of the beta–exo synergism and exo–exo synergism in T. reesei cellulase to increase the cellulose degrading capability, i.e. enhanced co-expression of the β-glucosidase gene the cellobiohydrolase II gene of T. reesei. Results Enhanced co-expression of the β-glucosidase gene and the cellobiohydrolase II gene in T. reesei using the strong promoter Pcbh1 was found successful in overcoming the two weaknesses. Filter paper activities of T. reesei cellulase were greatly elevated, which were 7.21 ± 0.45 (E7, Aabgl1 and Trcbh2) and 7.69 ± 0.42 (F6, Anbgl1 and Trcbh2) FPIU/mL. They were much higher than that of the parental strain Rut-C30, 2.45 ± 0.36 FPIU/mL. Enzymatic hydrolysis yields were also improved, from 67.22 ± 1.61% by Rut-C30 cellulase to 87.98 ± 0.65% by E7 cellulase and 86.50 ± 1.01% by F6 cellulase. The substrate loading for 1 g glucose release from SECS were decreased, from 2.9637 g SECS using Rut-C30 cellulase to 2.0291 g SECS using E7 cellulase and 2.0573 g SECS using F6 cellulase. As a result, the efficiency of the process from SECS to glucose was substantially improved. Conclusions Enhanced co-expression of the β-glucosidase gene and the cellobiohydrolase II gene in T. reesei using the strong promoter Pcbh1 in T. reesei was proven triumphal in the simultaneous enhancement of the beta–exo synergism and exo–exo synergism in T. reesei cellulase. This strategy also improved the cellulase production, enzymatic hydrolysis yield and the efficiency of the process from SECS to glucose in the context of on-site cellulase production. This work is a commendable attempt in the cellulase composition optimization at the transcriptional level.
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Hemansi, Gupta R, Yadav G, Kumar G, Yadav A, Saini JK, Kuhad RC. Second Generation Bioethanol Production: The State of Art. BIOFUEL AND BIOREFINERY TECHNOLOGIES 2019. [DOI: 10.1007/978-3-319-94797-6_8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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13
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Xia Y, Yang L, Xia L. Preparation of a novel soluble inducer by cellobiase-release microcapsules and its application in cellulase production. J Biotechnol 2018; 279:22-26. [DOI: 10.1016/j.jbiotec.2018.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 04/03/2018] [Accepted: 05/02/2018] [Indexed: 01/05/2023]
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Xia Y, Yang L, Xia L. High-level production of a fungal β-glucosidase with application potentials in the cost-effective production of Trichoderma reesei cellulase. Process Biochem 2018. [DOI: 10.1016/j.procbio.2018.03.031] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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15
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Li YH, Zhang XY, Zhang F, Peng LC, Zhang DB, Kondo A, Bai FW, Zhao XQ. Optimization of cellulolytic enzyme components through engineering Trichoderma reesei and on-site fermentation using the soluble inducer for cellulosic ethanol production from corn stover. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:49. [PMID: 29483942 PMCID: PMC5824536 DOI: 10.1186/s13068-018-1048-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/12/2018] [Indexed: 05/05/2023]
Abstract
BACKGROUND Cellulolytic enzymes produced by Trichoderma reesei are widely studied for biomass bioconversion, and enzymatic components vary depending on different inducers. In our previous studies, a mixture of glucose and disaccharide (MGD) was developed and used to induce cellulase production. However, the enzymatic profile induced by MGD is still not defined, and further optimization of the enzyme cocktail is also required for efficient ethanol production from lignocellulosic biomass. RESULTS In this study, cellulolytic enzymes produced by T. reesei Rut C30 using MGD and alkali-pretreated corn stover (APCS) as inducer were compared. Cellular secretome in response to each inducer was analyzed, which revealed a similar enzyme profile. However, significant difference in the content of cellulases and xylanase was detected. Although MGD induction enhanced β-glucosidase production, its activity was still not sufficient for biomass hydrolysis. To overcome such a disadvantage, aabgl1 encoding β-glucosidase in Aspergillus aculeatus was heterologously expressed in T. reesei Rut C30 under the control of the pdc1 promoter. The recombinant T. reesei PB-3 strain showed an improved β-glucosidase activity of 310 CBU/mL in the fed-batch fermentation, 71-folds higher than that produced by the parent strain. Meanwhile, cellulase activity of 50 FPU/mL was detected. Subsequently, the crude enzyme was applied for hydrolyzing corn stover with a solid loading of 20% through separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation, respectively, for ethanol production. Better performance was observed in the SHF process, through which a total of 119.9 g/L glucose was released within 12 h for concomitant ethanol production of 54.2 g/L. CONCLUSIONS The similar profile of cellulolytic enzymes was detected under the induction of MGD and APCS, but higher amount of cellulases was present in the crude enzyme induced by MGD. However, β-glucosidase activity induced by MGD was not sufficient for hydrolyzing lignocellulosic biomass. High titers of cellulases and β-glucosidase were achieved simultaneously by heterologous expression of aabgl1 in T. reesei and fed-batch fermentation through feeding MGD. We demonstrated that on-site cellulase production by T. reesei PB-3 has a potential for efficient biomass saccharification and ethanol production from lignocellulosic biomass.
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Affiliation(s)
- Yong-Hao Li
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
- Present Address: School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, Chongqing, 401331 China
| | - Xiao-Yue Zhang
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116023 China
| | - Fei Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Liang-Cai Peng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Da-Bing Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Akihiko Kondo
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Kobe, 657-8501 Japan
| | - Feng-Wu Bai
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Xin-Qing Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
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Zhao C, Fang H, Chen S. Single cell oil production by Trichosporon cutaneum from steam-exploded corn stover and its upgradation for production of long-chain α,ω-dicarboxylic acids. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:202. [PMID: 28852423 PMCID: PMC5568358 DOI: 10.1186/s13068-017-0889-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 08/16/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Single cell oil (SCO) production from lignocelluloses by oleaginous microorganisms is still high in production cost, making the subsequent production of biofuels inviable economically in such an era of low oil prices. Therefore, how to upgrade the final products of lignocellulose-based bioprocess to more valuable ones is becoming a more and more important issue. RESULTS Differently sourced cellulases were compared in the enzymatic hydrolysis of the steam-exploded corn stover (SECS) and the cellulase from the mixed culture of Trichoderma reesei and Aspergillus niger was found to have the highest enzymatic hydrolysis yield 86.67 ± 4.06%. Three-stage enzymatic hydrolysis could greatly improve the efficiency of the enzymatic hydrolysis of SECS, achieving a yield of 74.24 ± 2.69% within 30 h. Different bioprocesses from SECS to SCO were compared and the bioprocess C with the three-stage enzymatic hydrolysis was the most efficient, producing 57.15 g dry cell biomass containing 31.80 g SCO from 327.63 g SECS. An efficient and comprehensive process from corn stover to long-chain α,ω-dicarboxylic acids (DCAs) was established by employing self-metathesis, capable of producing 6.02 g long-chain DCAs from 409.54 g corn stover and 6.02 g alkenes as byproducts. CONCLUSIONS On-site cellulase production by the mixed culture of T. reesei and A. niger is proven the most efficient in providing cellulase to the lignocellulose-based bioprocess. Three-stage enzymatic hydrolysis was found to have very good application value in SCO production by Trichosporon cutaneum from SECS. A whole process from corn stover to long-chain DCAs via a combination of biological and chemical approaches was successfully established and it is an enlightening example of the comprehensive utilization of agricultural wastes.
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Affiliation(s)
- Chen Zhao
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, 712100 Shaanxi China
| | - Hao Fang
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, 712100 Shaanxi China
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122 Jiangsu China
| | - Shaolin Chen
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, 712100 Shaanxi China
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Li Y, Zhang X, Xiong L, Mehmood MA, Zhao X, Bai F. On-site cellulase production and efficient saccharification of corn stover employing cbh2 overexpressing Trichoderma reesei with novel induction system. BIORESOURCE TECHNOLOGY 2017; 238:643-649. [PMID: 28486197 DOI: 10.1016/j.biortech.2017.04.084] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/20/2017] [Accepted: 04/21/2017] [Indexed: 05/05/2023]
Abstract
Although on-site cellulase production offers cost-effective saccharification of lignocellulosic biomass, low enzyme titer is still a barrier for achieving robustness. In the present study, a strain of T. reesei was developed for enhanced production of cellulase via overexpression of Cellobiohydrolase II. Furthermore, optimum enzyme production was achieved using a novel inducer mixture containing synthesized glucose-sophorose (MGD) and alkali pre-treated corn stover (APCS). Within 60h, a remarkably higher cellulase productivity and activity were achieved in the fed-batch fermentation using the optimized ratio of MGD and APCS in the inducer mixture, compared to those reported using cellulosic biomass as the sole inducer. After the enzyme production, APCS was added directly into the fermentation broth at 20% solid loading, which produced 122.5g/L glucose and 40.21g/L xylose, leading to the highest yield reported so far. The improved enzyme titers during on-site cellulase production would benefit cost-competitive saccharification of lignocellulosic biomass.
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Affiliation(s)
- Yonghao Li
- State Key Laboratory of Microbial Metabolism & School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116023, China.
| | - Xiaoyue Zhang
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116023, China.
| | - Liang Xiong
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116023, China.
| | - Muhammad Aamer Mehmood
- State Key Laboratory of Microbial Metabolism & School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; Bioenergy Research Centre, Department of Bioinformatics & Biotechnology, Government College University Faisalabad, Faisalabad 38000, Pakistan.
| | - Xinqing Zhao
- State Key Laboratory of Microbial Metabolism & School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Fengwu Bai
- State Key Laboratory of Microbial Metabolism & School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116023, China.
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Zhang XY, Zi LH, Ge XM, Li YH, Liu CG, Bai FW. Development of Trichoderma reesei mutants by combined mutagenesis and induction of cellulase by low-cost corn starch hydrolysate. Process Biochem 2017. [DOI: 10.1016/j.procbio.2016.12.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Patel H, Divecha J, Shah A. Microwave assisted alkali treated wheat straw as a substrate for co-production of (hemi)cellulolytic enzymes and development of balanced enzyme cocktail for its enhanced saccharification. J Taiwan Inst Chem Eng 2017. [DOI: 10.1016/j.jtice.2016.12.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kamm B, Leiß S, Schönicke P, Bierbaum M. Biorefining of Lignocellulosic Feedstock by a Modified Ammonia Fiber Expansion Pretreatment and Enzymatic Hydrolysis for Production of Fermentable Sugars. CHEMSUSCHEM 2017; 10:48-52. [PMID: 27898203 DOI: 10.1002/cssc.201601511] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Indexed: 06/06/2023]
Abstract
Wheat straw was pretreated and afterwards enzymatically hydrolyzed using a modified ammonia fiber expansion (AFEX) process under different reaction conditions to produce fermentable sugars. Instead of liquid ammonia, aqueous ammonia (25 % w/v) was used to test its influence on the sugar concentration and yield of the sugars. It is shown that a protein extraction after the pretreatment can distinctly improve the result obtained for the enzymatic hydrolysis. This modified AFEX process using aqueous ammonia represents a simpler and less expensive variant of the AFEX process usually described in literature. Thus, the described process can be used for the primary refining of lignocellulosic feedstocks in the sense of a roadmap for biorefinery.
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Affiliation(s)
- Birgit Kamm
- Research Institute Biopos e.V. and BTU Cottbus-Senftenberg, Kantstraße 55, 14513, Teltow-Seehof, Germany
| | - Sebastian Leiß
- Biorefinery.de GmbH, Kantstraße 55, 14513, Teltow-Seehof, Germany
| | - Petra Schönicke
- Research Institute Biopos e.V. and BTU Cottbus-Senftenberg, Kantstraße 55, 14513, Teltow-Seehof, Germany
| | - Matthias Bierbaum
- Research Institute Biopos e.V. and BTU Cottbus-Senftenberg, Kantstraße 55, 14513, Teltow-Seehof, Germany
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Zhao C, Deng L, Fang H, Chen S. Microbial oil production byMortierella isabellinafrom corn stover under different pretreatments. RSC Adv 2017. [DOI: 10.1039/c7ra11900c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Mixed culture ofTrichoderma reeseiandAspergillus nigerwas employed to accomplish on-site cellulase production where cellulases were applied directly to the enzymatic hydrolysis of pretreated corn stover.
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Affiliation(s)
- Chen Zhao
- College of Life Sciences
- Northwest A&F University
- Yangling 712100
- China
- Biomass Energy Center for Arid and Semi-arid Lands
| | - Lu Deng
- College of Life Sciences
- Northwest A&F University
- Yangling 712100
- China
- Biomass Energy Center for Arid and Semi-arid Lands
| | - Hao Fang
- College of Life Sciences
- Northwest A&F University
- Yangling 712100
- China
- Biomass Energy Center for Arid and Semi-arid Lands
| | - Shaolin Chen
- College of Life Sciences
- Northwest A&F University
- Yangling 712100
- China
- Biomass Energy Center for Arid and Semi-arid Lands
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Fang H, Zhao C, Chen S. Single cell oil production by Mortierella isabellina from steam exploded corn stover degraded by three-stage enzymatic hydrolysis in the context of on-site enzyme production. BIORESOURCE TECHNOLOGY 2016; 216:988-95. [PMID: 27343451 DOI: 10.1016/j.biortech.2016.06.051] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 06/14/2016] [Accepted: 06/15/2016] [Indexed: 05/23/2023]
Abstract
Single cell oil (SCO), promising as alternative oil source, was produced from steam exploded corn stover (SECS) by Mortierella isabellina. Different bioprocesses from SECS to SCO were compared and the bioprocess C using the three-stage enzymatic hydrolysis was found to be the most efficient one. The bioprocess C used the lowest enzyme input 20FPIU cellulase/g glucan and the shortest time 222h, but produced 44.94g dry cell biomass and 25.77g lipid from 327.63g dry SECS. It had the highest lipid content 57.34%, and its productivities and yields were much higher than those of the bioprocess B and comparable to the bioprocess A, indicating that the three-stage enzymatic hydrolysis could greatly improve the efficiency of the bioprocess from high solid loading SECS to SCO by Mortierella isabellina. This work testified the application value of three-stage enzymatic hydrolysis in lignocellulose-based bioprocesses.
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Affiliation(s)
- Hao Fang
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi 712100, China; National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China.
| | - Chen Zhao
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi 712100, China
| | - Shaolin Chen
- College of Life Sciences, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi 712100, China
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Mihajlovski KR, Radovanović NR, Miljković MG, Šiler-Marinković S, Rajilić-Stojanović MD, Dimitrijević-Branković SI. β-Amylase production from packaging-industry wastewater using a novel strain Paenibacillus chitinolyticus CKS 1. RSC Adv 2015. [DOI: 10.1039/c5ra11964b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Transforming waste into valuable biotechnology products – the treatment of transport packaging wastewater withPaenibacillus chitinolyticusCKS1 for β-amylase and maltose production.
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Affiliation(s)
- Katarina R. Mihajlovski
- University of Belgrade
- Faculty of Technology and Metallurgy
- Department for Biochemical Engineering and Biotechnology
- Belgrade
- Serbia
| | - Neda R. Radovanović
- University of Belgrade
- Faculty of Technology and Metallurgy
- Department for Biochemical Engineering and Biotechnology
- Belgrade
- Serbia
| | - Miona G. Miljković
- University of Belgrade
- Faculty of Technology and Metallurgy
- Department for Biochemical Engineering and Biotechnology
- Belgrade
- Serbia
| | - Slavica Šiler-Marinković
- University of Belgrade
- Faculty of Technology and Metallurgy
- Department for Biochemical Engineering and Biotechnology
- Belgrade
- Serbia
| | - Mirjana D. Rajilić-Stojanović
- University of Belgrade
- Faculty of Technology and Metallurgy
- Department for Biochemical Engineering and Biotechnology
- Belgrade
- Serbia
| | - Suzana I. Dimitrijević-Branković
- University of Belgrade
- Faculty of Technology and Metallurgy
- Department for Biochemical Engineering and Biotechnology
- Belgrade
- Serbia
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Current challenges in commercially producing biofuels from lignocellulosic biomass. ISRN BIOTECHNOLOGY 2014; 2014:463074. [PMID: 25937989 PMCID: PMC4393053 DOI: 10.1155/2014/463074] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 02/19/2014] [Indexed: 11/17/2022]
Abstract
Biofuels that are produced from biobased materials are a good alternative to petroleum based fuels. They offer several benefits to society and the environment. Producing second generation biofuels is even more challenging than producing first generation biofuels due the complexity of the biomass and issues related to producing, harvesting, and transporting less dense biomass to centralized biorefineries. In addition to this logistic challenge, other challenges with respect to processing steps in converting biomass to liquid transportation fuel like pretreatment, hydrolysis, microbial fermentation, and fuel separation still exist and are discussed in this review. The possible coproducts that could be produced in the biorefinery and their importance to reduce the processing cost of biofuel are discussed. About $1 billion was spent in the year 2012 by the government agencies in US to meet the mandate to replace 30% existing liquid transportation fuels by 2022 which is 36 billion gallons/year. Other countries in the world have set their own targets to replace petroleum fuel by biofuels. Because of the challenges listed in this review and lack of government policies to create the demand for biofuels, it may take more time for the lignocellulosic biofuels to hit the market place than previously projected.
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Novello M, Vilasboa J, Schneider WDH, Reis LD, Fontana RC, Camassola M. Enzymes for second generation ethanol: exploring new strategies for the use of xylose. RSC Adv 2014. [DOI: 10.1039/c4ra00909f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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