Alpha Creation EnterpriseBiofuel Research Journal2292-87827420201201Improving the co-production of triacylglycerol and isoprenoids in Chlamydomonas1235124411981910.18331/BRJ2020.7.4.2ENSupakorn PotijunMicroalgal Molecular Genetics and Functional genomics Special Research Unit, Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University (CASTNAR, NRU-KU), Kasetsart University, Bangkok 10900, Thailand.Suparat JaingamMicroalgal Molecular Genetics and Functional genomics Special Research Unit, Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University (CASTNAR, NRU-KU), Kasetsart University, Bangkok 10900, Thailand.Nuttha SanevasDepartment of Botany, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.Srunya VajrodayaDepartment of Botany, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.Anchalee SirikhachornkitMicroalgal Molecular Genetics and Functional genomics Special Research Unit, Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University (CASTNAR, NRU-KU), Kasetsart University, Bangkok 10900, Thailand.Journal Article20201101Biodiesel and natural products derived from microalgae require a smaller land area and have higher production rates compared to plants and animals and has recently attracted considerable interest. However, biodiesel production from microalgal triacylglycerol is still far from commercial realization due to its high production cost. One way to overcome this obstacle is to improve the triacylglycerol accumulation and couple its production with other high-value compounds. Of particular interest is the sterol biosynthetic pathway with squalene as an intermediate due to its close relationship with triacylglycerol and carotenoid biosynthetic pathways. Besides, both squalene and carotenoids are isoprenoid lipids that have health benefits. Perturbation of one pathway has been suggested to affect other pathways. Three terbinafine-sensitive mutants of the green microalga <em>Chlamydomonas reinhardtii</em> were isolated using terbinafine, a drug that inhibits squalene epoxidase, leading to squalene accumulation.One of the mutants, <em>tfs2</em>, accumulated twice the amount of wild-type triacylglycerol. As well as squalene accumulation, the presence of terbinafine further increased the triacylglycerol content. The level of prenyl lipid carotenoid and chlorophyll was also more significant than that of the wild type. Growth and photosynthesis were not compromised in this mutant. This is the first study that has demonstrated amutant screening method to improve the co-production of TAG and isoprenoid lipids in a green microalga.Alpha Creation EnterpriseBiofuel Research Journal2292-87827420201201Simulation study of deep eutectic solvent-based biogas upgrading process integrated with single mixed refrigerant biomethane liquefaction1245125511982010.18331/BRJ2020.7.4.3ENJunaid HaiderSchool of Chemical Engineering, Yeungnam University, Gyeongsan 712–749, Republic of Korea.Muhammad Abdul QyyumSchool of Chemical Engineering, Yeungnam University, Gyeongsan 712–749, Republic of Korea.0000-0001-5052-5209Bilal KazmiDepartment of applied Chemistry and Chemical Technology, University of Karachi, Pakistan.0000-0003-1069-2920Imran AliDepartment of applied Chemistry and Chemical Technology, University of Karachi, Pakistan.Abdul-Sattar NizamiSustainable Development Study Center, Government College University, Lahore 54000, Pakistan.Moonyong LeeSchool of Chemical Engineering, Yeungnam University, Gyeongsan 712–749, Republic of Korea.Journal Article20200904Deep eutectic solvents (DESs) comprise ChCl/urea, in combination with water, have been considered in removing acid gases (CO<sub>2</sub> and H<sub>2</sub>S) from biogas. The evaluation of DES for biogas upgrading at relatively high pressure (i.e., >8.0 bar) has not been reported before. The aqueous DES performance has also not been analyzed compared to conventional amines-based solvent (MEA) and ionic liquid (IL). To the best of our knowledge, this is the first study that presents the integration of DES-based biogas upgrading with a mixed refrigerant liquefaction process to facilitate the safe and economical transportation of biomethane over long distances. The biogas considered in this study consisted of 60% CH<sub>4</sub>, 39% CO<sub>2</sub>, and 1% H<sub>2</sub>S. The aqueous ChCl/urea (70 wt%) results in biomethane with ≥99.0 wt% purity and ≥97.0 wt% recovery. Then, this biomethane was liquefied with ≥90% liquefaction rate. Based on the results obtained herein, overall capital, operating, and total annualized cost savings of 2.8%, 25.82%, and 14.26% were achieved using the 70% DES-based integrated process in comparison with the MEA-based integrated process. Whereas 1.41%, 16.85%, and 8.71% capital, operating, and total annualized costs could be saved in comparison with the IL (i.e., [Bmim][PF<sub>6</sub>])-based integrated process. It could be deduced that the overall cost of the biomethane value chain can be reduced using the proposed approach. Alpha Creation EnterpriseBiofuel Research Journal2292-87827420201201Recent innovations for reviving the ABE fermentation for production of butanol as a drop-in liquid biofuel1256126611982210.18331/BRJ2020.7.4.4ENHamid AmiriDepartment of Biotechnology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan 81746-73441, Iran.Environmental Research Institute, University of Isfahan, Isfahan 81746-73441, Iran.Journal Article20200915Butanol is a key microbial product that provides a route from renewable carbohydrate resources to a "drop-in" liquid biofuel, broadening its market in the near future. The acceptable performance of butanol as a neat or a blended fuel in different engines both from the technical and environmental points of view has attracted a wide range of research for reviving the old acetone-butanol-ethanol (ABE) fermentation. In this review, recent findings on fuel characteristics of butanol, different generations of substrate for large scale butanol production, and alternative process designs for upstream, mainstream, and downstream operations have been critically reviewed and discussed. In the upstream, studies devoted to designing and optimization of pretreatments based on prerequisites of butanol production, e.g., maximizing cellulose and hemicellulose recovery and minimizing lignin degradation, are presented. In the mainstream, different microbial systems and process integrations developed for facilitating ABE production (e.g., <em>in-situ</em> butanol removal) are scrutinized. Finally, innovations in ABE recovery and purification as "Achilles Heel" of butanol production processes which directly controls the energy return on investment (EROI), are reviewed and discussed.Alpha Creation EnterpriseBiofuel Research Journal2292-87827420201201Recent advances in bioethanol production from lignocelluloses: a comprehensive review with a focus on enzyme engineering and designer biocatalysts1267129511982410.18331/BRJ2020.7.4.5ENYogita LuganiDepartment of Biotechnology, Punjabi University, Patiala-147002, Punjab, India.Rohit RaiFaculty of Applied Medical Sciences, Lovely Professional University, Phagwara-144411, Punjab, India.Ashish A.PrabhuSchool of Water, Energy and Environment, Cranfield University, Cranfield MK43 0AL, UK.Poonam MaanSardar Vallabhbhai Patel University of Agriculture and Technology, Meerut, India.Meenu HansBiochemical Conversion Division, Sardar Swaran Singh National Institute of Bio-Energy, Kapurthala-144601, India.Vinod KumarSchool of Water, Energy and Environment, Cranfield University, Cranfield MK43 0AL, UK.0000-0001-8967-6119Sachin KumarBiochemical Conversion Division, Sardar Swaran Singh National Institute of Bio-Energy, Kapurthala-144601, India.Anuj K.ChandelDepartment of Biotechnology, Engineering School of Lorena (EEL), University of São Paulo, Lorena-SP- 12606452, Brazil.R.S. SengarSardar Vallabhbhai Patel University of Agriculture and Technology, Meerut, India.Journal Article20200628Many countries have their biofuel policy programs in place as part of their overall strategy to achieve sustainable development. Among biofuels, bioethanol as a promising alternative to gasoline is of substantial interest. However, there is limited availability of a sufficient quantity of bioethanol to meet demands due to bottlenecks in the present technologies to convert non-edible feedstocks, including lignocelluloses. This review article presents and critically discusses the recent advances in the pretreatment of lignocellulosic biomass, with a focus on the use of green solvents, including ionic liquids and deep eutectic solvents, followed by enzymatic saccharification using auxiliary proteins for the efficient saccharification of pretreated biomass. Different techniques used in strain improvement strategies to develop hyper-producing deregulated lignocellulolytic strains are also compared and discussed. The advanced techniques employed for fermentation of mixed sugars contained in lignocellulosic hydrolysates for maximizing bioethanol production are summarized with an emphasis on pathway and transporters engineering for xylose assimilation. Further, the integration of different steps is suggested and discussed for efficient biomass utilization and improved ethanol yields and productivity.