Review
Biotechnology & Applied Microbiology
Juhi Sharma, Vinod Kumar, Rajendra Prasad, Naseem A. Gaur
Summary: Lignocellulosic biomass is an abundant material on earth and can be processed by microorganisms to produce biofuels. Saccharomyces cerevisiae is an ideal candidate for consolidated bio-processing (CBP) to produce cellulose-based ethanol. However, there are still challenges in the process, such as incomplete substrate catabolism and low expression of heterologous proteins.
BIOTECHNOLOGY ADVANCES
(2022)
Article
Biochemical Research Methods
Marcio D. N. Ramos, Juliana P. Sandri, Arne Claes, Bruna T. Carvalho, Johan M. Thevelein, Teresa C. Zangirolami, Thais S. Milessi
Summary: This study successfully applied immobilized yeast cells in integrated bioprocessing, enabling enzyme access to substrate polymers. The optimal cell load for consolidated bioprocessing (CBP) was selected, and diffusional effects were observed with immobilized cells under static conditions. However, agitation mitigated mass transfer limitations and achieved the same substrate consumption rate as free cells. Immobilized cells achieved 100% hydrolysis and consumption of all substrates offered within 12 hours. This is the first report of successful application of immobilized yeast cells in CBP processes, a promising technology for bioethanol production.
Article
Energy & Fuels
S. Kavitha, T. Gajendran, K. Saranya, V. Manivasagan
Summary: Contemporary studies show that macroalgae biomass, specifically Sargassum wightii, rich in cellulose, can be a promising source for ethanol production. This investigation focuses on the optimization of cellulose extraction and medium components for Lachnoclostridium phytofermentans KSM 1203 for bioethanol production through consolidated bioprocessing. The alkali pretreatment and sodium hypochlorite treatment were found to effectively remove lignin and hemicelluloses, resulting in the optimal conditions for ethanol yield of 13.75 g/L.
Article
Biotechnology & Applied Microbiology
Athanasios Drosos, Konstantina Boura, Agapi Dima, Ioannis K. Karabagias, Poonam S. Nigam, Maria Kanellaki, Athanasios A. Koutinas
Summary: The utilization of cell factory (CF) for starch alcoholic fermentation shows promising results in terms of improving production efficiency and achieving higher ethanol yield, productivity, and yield. The study indicates that freeze-dried CF could be a more effective biocatalyst for starch fermentation, offering potential benefits for environmental conservation and cost-effectiveness.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2021)
Article
Agricultural Engineering
Jie Li, Yu Zeng, Wei-Bin Wang, Qing-Qing Wan, Chen-Guang Liu, Riaan den Haan, Willem H. van Zyl, Xin-Qing Zhao
Summary: Sustainable bioproduction using carbon neutral feedstocks, especially lignocellulosic biomass, has attracted increasing attention. Consolidated bioprocessing (CBP) of lignocellulosic biomass using recombinant yeast has shown promise, but low enzyme secretion levels restrict its economic viability. In this study, overexpression of MIG1 spsc01, a glucose repression regulator derivative, was used to increase extracellular cellobiohydrolase (CBH) activity. Disruption of other genes related to MIG1 spsc01, such as CWP2, YGP1, and UTH1, also enhanced CBH secretion. By simultaneously disrupting YGP1 and overexpressing SED5, cellulase production was significantly improved.
BIORESOURCE TECHNOLOGY
(2022)
Article
Energy & Fuels
Lauren B. Soares, Marcel B. B. Santana Jr, Juliane M. da Silveira, Liana L. do Nascimento, Mateus Y. de Meirelles, Rosana O. Henriques, Eduardo Zanella, Michelle F. Araujo, Boris U. Stambuk, Aline C. da Costa, Jaciane L. Ienczak, Agenor Furigo Jr
Summary: The objective of this study was to evaluate the immobilization of Spathaspora passalidarum in raw, alkaline, and acid-pretreated sugarcane bagasse. Fermentation of hemicellulosic hydrolysate from acid-pretreated sugarcane bagasse was evaluated using immobilized and free cells. The results showed that immobilized cells had significantly higher growth and product yield compared to free cells.
BIOENERGY RESEARCH
(2023)
Article
Biotechnology & Applied Microbiology
Chaofeng Li, Xiaofeng Lin, Xing Ling, Shuo Li, Hao Fang
Summary: The study successfully knocked out the opi1 gene, constructed the biosynthesis pathway of d-glucaric acid, and obtained two engineered strains, LGA-1 and LGA-C, with record-breaking titers. In lignocellulosic biorefining processes, using an artificial microbial consortium of T. reesei Rut-C30 and S. cerevisiae LGA-1 showed promising results for efficient production. Further research is needed to enhance the effectiveness of this microbial consortium for d-glucaric acid production from lignocellulose.
BIOTECHNOLOGY FOR BIOFUELS
(2021)
Article
Economics
Teresa Cristina Garcia, Alvaro Durand-Morat, Wei Yang, Michael Popp, William Schreckhise
Summary: Although Brazil mainly produces first-generation ethanol, a study found that Brazilian consumers are willing to pay an average 8.5% premium for gasoline blended with second-generation ethanol (E2G), and consumers who are more informed about biofuels and have higher income are more likely to pay a premium for E2G. Informing consumers about E2G could enhance the likelihood of adoption.
Article
Agricultural Engineering
Vassilios Panagopoulos, Konstantina Boura, Agapi Dima, Ioannis K. Karabagias, Loulouda Bosnea, Poonam S. Nigam, Maria Kanellaki, Athanasios A. Koutinas
Summary: This study successfully utilized nonengineered Cell Factories to prepare two composite biocatalysts for the conversion of lactose into lactic acid and ethanol. The results showed that freeze-dried CF2 holds potential for future application due to its preservation and manageability.
BIORESOURCE TECHNOLOGY
(2022)
Article
Thermodynamics
Surbhi Vaid, Surbhi Sharma, Harish Chander Dutt, Ritu Mahajan, Bijender Kumar Bajaj
Summary: Lignocellulosic biomass-based ethanol biofuel offers a promising, sustainable, clean, and renewable energy resource, but faces challenges such as high cost, energy intensity, and environmentally-unsafe pretreatments. Deep-eutectic-solvent-based pretreatment and Consolidated bioprocessing present alternative approaches with potential benefits over traditional methods.
ENERGY CONVERSION AND MANAGEMENT
(2021)
Article
Agricultural Engineering
Surbhi Vaid, Surbhi Sharma, Bijender Kumar Bajaj
Summary: A novel strategy was developed using an ionic liquid stable enzyme preparation and SDS-assisted pretreatment of Saccharum spontaneum biomass for conversion into ethanol biofuel. Optimized pretreatment and saccharification variables enhanced sugar yield.
BIORESOURCE TECHNOLOGY
(2021)
Article
Biotechnology & Applied Microbiology
Punnita Pamueangmun, Aliyu Dantani Abdullahi, Md. Humayun Kabir, Kridsada Unban, Apinun Kanpiengjai, Joachim Venus, Kalidas Shetty, Chalermpong Saenjum, Chartchai Khanongnuch
Summary: This study proposes the use of sustainable and economically feasible processes and renewable lignocellulose biomass as a starting raw material for second-generation lactic acid production. Weizmannia coagulans MA42, isolated from a soil sample in Chiang Mai province, Thailand, showed the highest production of L-lactic acid and lignocellulolytic enzymes compared to other isolates. The study also found that pretreating the substrates with diluted sulfuric acid and diluted sodium hydroxide improved the efficiency of L-lactic acid production.
FERMENTATION-BASEL
(2023)
Article
Green & Sustainable Science & Technology
S. Kavitha, T. Gajendran, K. Saranya, P. Selvakumar, V Manivasagan, S. Jeevitha
Summary: This study investigates the use of a consortium of cellulolytic and ethanogenic bacteria for consolidated bioprocessing of bioethanol production. The pre-treatment conditions for Allium ascalonicum leaves were optimized to achieve efficient removal of hemicellulose and recovery of cellulose. By screening and optimizing the essential medium components, the bioethanol yield was maximized.
Article
Energy & Fuels
Caroline L. Perez, Thais S. Milessi, Juliana P. Sandri, Marcio D. N. Ramos, Bruna T. Carvalho, Arne Claes, Mekonnen M. Demeke, Johan M. Thevelein, Teresa C. Zangirolami
Summary: Overcoming key bottlenecks for 2G ethanol production, such as biomass pretreatment, process layout, and microorganism selection, is crucial for achieving a feasible technology. The study investigated the use of consolidated bioprocessing (CBP) with a recombinant strain of S. cerevisiae AC14 capable of producing multiple lignocellulosic enzymes and fermenting xylose and glucose. The results were promising, with high ethanol productivity and complete hydrolysis of cellulose and xylan.
BIOENERGY RESEARCH
(2023)
Article
Environmental Sciences
A. S. Duden, P. A. Verweij, Y. V. Kraak, L. P. H. van Beek, N. Wanders, D. J. Karssenberg, E. H. Sutanudjaja, F. van der Hilst
Summary: The study assesses the impacts of ethanol-driven sugarcane expansion on agricultural and hydrological drought in Brazil, revealing higher risks of drought in the Central West and Southeast regions, which could lead to significant agricultural losses and water scarcity issues. Policy makers can use this information to take precautionary measures to mitigate the negative hydrological impacts of increased ethanol demand.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Microbiology
Tyler B. Jacobson, Travis K. Korosh, David M. Stevenson, Charles Foster, Costas Maranas, Daniel G. Olson, Lee R. Lynd, Daniel Amador-Noguez
Article
Biotechnology & Applied Microbiology
Dhananjay Beri, Christopher D. Herring, Sofie Blahova, Suresh Poudel, Richard J. Giannone, Robert L. Hettich, Lee R. Lynd
Summary: This study found inhibition of C. thermocellum with increasing corn fiber concentration and inhibition of cellulase activity by xylooligosaccharides. However, further research is needed to understand the reasons why growth on cellobiose was inhibited by corn fiber fermentation broth. Our results support the importance of hemicellulose-utilizing coculture partners to augment C. thermocellum in the fermentation of lignocellulosic feedstocks at high solids loading.
BIOTECHNOLOGY FOR BIOFUELS
(2021)
Article
Biotechnology & Applied Microbiology
Johannes Yayo, Teun Kuil, Daniel G. Olson, Lee R. Lynd, Evert K. Holwerda, Antonius J. A. van Maris
Summary: This study demonstrates that C. thermocellum can be evolved for reproducible constitutive growth on glucose or fructose. Through laboratory evolution and subsequent genome sequencing, gene editing, and physiological characterization, two underlying mutations related to transport or metabolism of hexose sugars were identified, providing insights for engineering strains for fundamental studies and improving product yields in industrial settings.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2021)
Article
Microbiology
Christopher A. Fenton, Qingling Tang, Daniel G. Olson, Marybeth I. Maloney, Jeffrey L. Bose, Lee R. Lynd, Aron W. Fenton
Summary: The pyruvate kinase isozyme from Thermoanaerobacterium saccharolyticum has been studied for its activation by AMP and ribose-5-phosphate, as well as its inhibition by IMP and GMP. This inhibition by IMP is specific only to a subset of bacterial PYK enzymes, indicating unique regulatory mechanisms among different isozymes.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Food Science & Technology
Andrew Allee, Lee R. Lynd, Vikrant Vaze
Summary: The second UN Sustainable Development Goal emphasizes the importance of food security and examines the relationship between national-level food security performance indicators and various potential drivers.
Article
Biotechnology & Applied Microbiology
Teun Kuil, Shuen Hon, Johannes Yayo, Charles Foster, Giulia Ravagnan, Costas D. Maranas, Lee R. Lynd, Daniel G. Olson, Antonius J. A. van Maris
Summary: This study found that membrane-bound pyrophosphatase, glycogen cycling, Ppdk-malate shunt cycle, and acetate cycling are not significant sources of PPi supply in the atypical glycolysis of C. thermocellum. However, the true sources of PPi or alternative phosphorylating mechanisms that drive glycolysis in C. thermocellum remain elusive.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Biotechnology & Applied Microbiology
Anthony Lanahan, Kamila Zakowicz, Liang Tian, Daniel G. Olson, Lee R. Lynd
Summary: This study demonstrates a method to increase the mutation rate in the thermophilic, anaerobic bacterium Clostridium thermocellum, which is valuable for future directed evolution experiments.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2022)
Review
Chemistry, Multidisciplinary
Lee R. Lynd, Gregg T. Beckham, Adam M. Guss, Lahiru N. Jayakody, Eric M. Karp, Costas Maranas, Robert L. McCormick, Daniel Amador-Noguez, Yannick J. Bomble, Brian H. Davison, Charles Foster, Michael E. Himmel, Evert K. Holwerda, Mark S. Laser, Chiam Yu Ng, Daniel G. Olson, Yuriy Roman-Leshkov, Cong T. Trinh, Gerald A. Tuskan, Vikas Upadhayay, Derek R. Vardon, Lin Wang, Charles E. Wyman
Summary: This article identifies the technology challenges and opportunities for developing economically viable, scalable, and sustainable technologies for converting lignocellulosic polysaccharides to liquid fuels. The overview of feedstocks, processes, and products highlights the potential of anaerobic processing for fuel production and the distinctive challenges associated with microbial processing of cellulosic biomass. The article also discusses opportunities to increase product tolerance and decrease the cost of product recovery, as well as pathways for converting anaerobic fermentation products to larger fuel molecules using chemo-catalysis.
ENERGY & ENVIRONMENTAL SCIENCE
(2022)
Article
Biotechnology & Applied Microbiology
Charles Foster, Veda Sheersh Boorla, Satyakam Dash, Saratram Gopalakrishnan, Tyler B. Jacobson, Daniel G. Olson, Daniel Amador-Noguez, Lee R. Lynd, Costas D. Maranas
Summary: This study aims to reveal unknown factors in the metabolism of Clostridium thermocellum by analyzing metabolic fluxes and constructing a kinetic model. The findings provide valuable insights for improving ethanol yield and titer.
METABOLIC ENGINEERING
(2022)
Article
Biochemical Research Methods
Roberto Mazzoli, Daniel G. Olson, Angela Maria Concu, Evert K. Holwerda, Lee R. Lynd
Summary: Lactic acid has various applications in the food, cosmetics, pharmaceutical, and biodegradable plastic polymer industries. Improving the lactate tolerance of cellulolytic bacteria is crucial for cost-efficient lactic acid production.
Article
Multidisciplinary Sciences
Payal Chirania, Evert K. Holwerda, Richard J. Giannone, Xiaoyu Liang, Suresh Poudel, Joseph C. Ellis, Yannick J. Bomble, Robert L. Hettich, Lee R. Lynd
Summary: This study investigates the enzymatic strategies of a methanogenic microbiome deconstructing switchgrass at increasing solids loading, providing insights into the mechanisms of efficient lignocellulose utilization.
NATURE COMMUNICATIONS
(2022)
Article
Biotechnology & Applied Microbiology
Shuen Hon, Tyler Jacobson, David M. Stevenson, Marybeth Maloney, Richard J. Giannone, Robert L. Hettich, Daniel Amador-Noguez, Daniel G. Olson, Lee R. Lynd
Summary: This study investigates the impact of replacing pyrophosphate with ATP as the phosphate donor for the PFK reaction in C. thermocellum. The results show that this change increases the thermodynamic driving force of the reaction but does not significantly alter the final product titer and distribution of fermentation products.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Soil Science
Johnny R. Soares, Bruna R. Souza, Andre M. Mazzetto, Marcelo V. Galdos, Dave R. Chadwick, Eleanor E. Campbell, Deepak Jaiswal, Julianne C. Oliveira, Leonardo A. Monteiro, Murilo S. Vianna, Rubens A. C. Lamparelli, Gleyce K. D. A. Figueiredo, John J. Sheehan, Lee R. Lynd
Summary: Grasslands, due to livestock excreta and nitrogen fertilizers, are the main source of nitrous oxide (N2O) emissions in agriculture. The addition of nitrification inhibitors (NIs) to nitrogen inputs can effectively reduce N2O emissions, with efficiency depending on various factors. A meta-analysis study focused on grazing systems found that NIs reduced N2O emissions by 56.6% overall, regardless of the type of NI or nitrogen source. Higher N2O emissions and certain soil conditions were associated with greater NI efficiency. Understanding and managing NIs can contribute to improved sustainability in grazing systems.
NUTRIENT CYCLING IN AGROECOSYSTEMS
(2023)
Article
Biotechnology & Applied Microbiology
Bishal D. Sharma, Daniel G. Olson, Richard J. Giannone, Robert L. Hettich, Lee R. Lynd
Summary: In order to address the difficulties in measuring intracellular metabolites in C. thermocellum for bioethanol production, improvements were made including active pH control, investigation of different filter materials and pore sizes, and correction for extracellular metabolite concentrations. This resulted in the development of a technique for more accurate intracellular metabolite measurements at high substrate concentrations.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Biotechnology & Applied Microbiology
Matthew R. Kubis, Evert K. Holwerda, Lee R. Lynd
Summary: Diminishing fractional carbohydrate solubilization with increasing substrate loading was observed for C. thermocellum-mediated solubilization and fermentation of unpretreated lignocellulose feedstocks. Results of experiments involving spent broth addition do not support a major role for inhibitors present in the liquid phase. Mid-fermentation addition experiments confirm that C. thermocellum and its enzymes remain capable of converting model substrates during the middle of high solids lignocellulose fermentation. An increase in fractional carbohydrate solubilization was made possible by (1) mid-fermentation solid loading dilutions and (2) coculturing C. thermocellum with T. thermosaccharolyticum, which ferments solubilized hemicellulose. Incomplete utilization of solubilized carbohydrates suggests that a small fraction of the carbohydrates is unaffected by the extracellular carbohydrate-active enzymes present in the culture.
BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS
(2022)
