Unlocking the potential of insect and ruminant host symbionts for recycling of lignocellulosic carbon with a biorefinery approach: a review

Uprising fossil fuel depletion and deterioration of ecological reserves supply have led to the search for alternative renewable and sustainable energy sources and chemicals. Although first generation biorefinery is quite successful commercially in generating bulk of biofuels globally, the food versus fuel debate has necessitated the use of non-edible feedstocks, majorly waste biomass, for second generation production of biofuels and chemicals. A diverse class of microbes and enzymes are being exploited for biofuels production for a series of treatment process, however, the conversion efficiency of wide range of lignocellulosic biomass (LCB) and consolidated way of processing remains challenging. There were lot of research efforts in the past decade to scour for potential microbial candidate. In this context, evolution has developed the gut microbiota of several insects and ruminants that are potential LCB degraders host eco-system to overcome its host nutritional constraints, where LCB processed by microbiomes pretends to be a promising candidate. Synergistic microbial symbionts could make a significant contribution towards recycling the renewable carbon from distinctly abundant recalcitrant LCB. Several studies have assessed the bioprospection of innumerable gut symbionts and their lignocellulolytic enzymes for LCB degradation. Though, some reviews exist on molecular characterization of gut microbes, but none of them has enlightened the microbial community design coupled with various LCB valorization which intensifies the microbial diversity in biofuels application. This review provides a deep insight into the significant breakthroughs attained in enrichment strategy of gut microbial community and its molecular characterization techniques which aids in understanding the holistic microbial community dynamics. Special emphasis is placed on gut microbial role in LCB depolymerization strategies to lignocellulolytic enzymes production and its functional metagenomic data mining eventually generating the sugar platform for biofuels and renewable chemicals production

Biodiesel Production From Lignocellulosic Biomass Using Oleaginous Microbes: Prospects for Integrated Biofuel Production

Biodiesel is an eco-friendly, renewable, and potential liquid biofuel mitigating greenhouse gas emissions. Biodiesel has been produced initially from vegetable oils, non-edible oils, and waste oils. However, these feedstocks have several disadvantages such as requirement of land and labor and remain expensive. Similarly, in reference to waste oils, the feedstock content is succinct in supply and unable to meet the demand. Recent studies demonstrated utilization of lignocellulosic substrates for biodiesel production using oleaginous microorganisms. These microbes accumulate higher lipid content under stress conditions, whose lipid composition is similar to vegetable oils. In this paper, feedstocks used for biodiesel production such as vegetable oils, non-edible oils, oleaginous microalgae, fungi, yeast, and bacteria have been illustrated. Thereafter, steps enumerated in biodiesel production from lignocellulosic substrates through pretreatment, saccharification and oleaginous microbe-mediated fermentation, lipid extraction, transesterification, and purification of biodiesel are discussed. Besides, the importance of metabolic engineering in ensuring biofuels and biorefinery and a brief note on integration of liquid biofuels have been included that have significant importance in terms of circular economy aspects.Fil: Chintagunta, Anjani Devi. Vignan’s Foundation for Science, Technology and Research. Department of Biotechnology; IndiaFil: Zuccaro, Gaetano. Institut National de la Recherche Agronomique; Francia. Università degli Studi di Napoli Federico II; ItaliaFil: Kumar, Mahesh. Central Agricultural University; IndiaFil: Kumar, S. P. Jeevan. Indian Institute of Seed Science; India. Directorate of Floricultural Research; IndiaFil: Garlapati, Vijay Kumar. Jaypee University of Information Technology; IndiaFil: Postemsky, Pablo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Kumar, N. S. Sampath. Vignan’s Foundation for Science, Technology and Research. Department of Biotechnology; IndiaFil: Chandel, Anuj K.. Universidade de Sao Paulo; BrasilFil: Simal Gandara, Jesus. Universidad de Vigo; Españ

Biological production and recovery of 2,3-butanediol using arabinose from sugar beet pulp by Enterobacter ludwigii

Sugar beet pulp (SBP) is a major byproduct from the sugar industries and consists of >20% w/w arabinose. The current work evaluated the potential of Enterobacter ludwigii assimilating pure arabinose and arabinose rich hydrolysate from SBP pellets for 2,3-butanediol (BDO) production. The hydrolysate was obtained through dilute acid pretreatment (DAP) with sulphuric acid. The process was optimized for acid and solid loading to obtain a hydrolysate free from furan derivatives. The effect of different levels of substrate (10–60 g/L) using pure arabinose was conducted in shake flask experiments, followed by co-fermentation with small amounts of glucose and SBP hydrolysate. After flask cultivations, BDO fermentations were carried-out in a bench-top bioreactor in batch and fed-batch modes using pure arabinose as well as SBP hydrolysate. The fed-batch culture led to BDO production of 42.9 and 35.5 g/L from pure arabinose and SBP hydrolysate with conversion yields of 0.31 and 0.29 g/g, respectively. Finally, BDO accumulated on pure arabinose and SBP hydrolysate were recovered using an aqueous two-phase extraction system. The recovery yield of BDO accumulated on arabinose and hydrolysate was ∼97%. The work demonstrated the feasibility of using SBP as a suitable feedstock for manufacturing BDO

Comparative highly efficient production of β-glucan by Lasiodiplodia theobromae CCT 3966 and its multiscale characterization

Lasiodiplodan, a (1→6)-β-d-glucan, is an exopolysaccharide with high commercial value and many applications in food, pharmaceuticals, and cosmetics. Current industrial production of β-glucans from crops is mostly by chemical routes generating hazardous and toxic waste. Therefore, alternative sustainable and eco-friendly pathways are highly desirable. Here, we have studied the lasiodiplodan production from sugarcane bagasse (SCB), a major lignocellulosic agricultural residue, by Lasiodiplodia theobromae CCT 3966. Lasiodiplodan accumulated on SCB hydrolysate (carbon source) supplemented with soybean bran or rice bran (nitrogen source) was 16.2 [6.8 × 103 Da] and 22.0 [7.6 × 103 Da] g/L, respectively. Lasiodiplodan showed high purity, low solubility, pseudoplastic behavior and was composed of glucose units. Moreover, the exopolysaccharides were substantially amorphous with moderate thermal stability and similar degradation temperatures. To our knowledge, this is the first report on the highest production of SCB-based lasiodiplodan to date. L. theobromae, as a microbial cell factory, demonstrated the commercial potential for the sustainable production of lasiodiplodan from renewable biomass feedstock

Biofuels in BrazilFundamental Aspects, Recent Developments, and Future Perspectives /

XVI, 435 p. 109 illus., 56 illus. in color.onlin

D-XylitolFermentative Production, Application and Commercialization /

XVI, 348 p.online resource

Bioconversion of pentose sugars into ethanol: a review and future directions,” Biotechnology and Molecular

Hemicelluloses, the second most abundant polysaccharide in nature, are well suited for ethanol production due to their enormous availability, low cost and environmental benign process. The major fraction in hemeicelluloses is pentosans and the conversion of pentosans to ethanol is problematic. To get the process economized, the conversion of hemicellulose to ethanol with a satisfactory yield is necessary. In recent years, significant advances have been made towards the technology of pentosans to ethanol conversion. However, there are technical and economical impediments to the development of commercially viable processes utilizing hemicellulosic derived sugars. This article provides an overview of the new insights in pentose sugars conversion into ethanol, pentoses resources, microorganisms and the technology