Fermentative Production of Value-Added Products from Lignocellulosic Biomass

Bioconversion of lignocellulosic biomass (agro residues, grasses, wood, weed, dedicated energy crops and others) into biofuels and other value-added products offers numerous geopolitical, environmental, and strategic benefits. Ligno-cellulosic biomass (LB) is the most abundant renewable organic resources (∼200 billion tons annually) on earth that are readily available for conversion to biofuels and other value-added products (industrial enzymes, organic acids, pharmaceuticals, commodity chemicals, and food/feed). However, they have not yet been tapped for the commercial production of these products. The last three decades witnessed the success made in research and development for the conversion of LB into biofuels and other commercially viable products. Despite the success achieved in the laboratory, there are several challenges for the successful bioconversion of lignocellulosic substrates into value-added products at commercial scale. The future of lignocellulosics conversion is expected to lie in improvement in pretreatment technologies, cellulolytic enzymes producing microorganisms, fullest exploitation of biomass components, and process integration. Further, advancement in system-biology-based " OMICS " approaches may provide new breakthroughs for the development of biocatalysts/enzyme titers for the cost effective production of commodity chemicals and fuels from biomass. This special issue presents a diverse range of experimental advancements on biomass pretreatment, enzymatic saccharification, production of cellulosic biofuels, polyhy-droxyalkanoates (PHA), polyhydroxybutyrate (PHB), and lovastatin and blends of polyacrylonitrile (PAN) and lignin. Authors here report on process variables including feed-stock types (grasses and sugarcane-based agro residues), bioprocess engineering simulations, multivisual structural analysis of lignocellulosics after pretreatment, improvements in cellulase-mediated hydrolysis, and modification in fermentation strategies for the production of a range of value-added products. Selection of suitable lignocellulosic substrates plays a key role for the economic cellulosic ethanol production. Factors such as availability of feedstock and presence of high amount of carbohydrates and lignin amounts are critical for biofuels production at large scale under the biorefinery concept. Of particular interest in this regard is the use of sugarcane residues, corn stover, and grasses as a second-generation feedstock. L. Canilha et al. comprehensively reviewed the technologies (pretreatment methods, detoxification, hydrol-ysis, fermentation, and end-product distillation) for second-generation (2G) ethanol production from sugarcane residues (sugarcane bagasse and straw). Grasses are another excellent feedstock for 2G ethanol production in countries like Thailand. J. Wongwatanapaiboon et al. collected data on composition of cellulose, hemicellulose, and lignin in 18 types of grasses followed by the alkaline peroxide mediated pretreatment. The pretreated materials were evaluated for ethanol production under simultaneous saccharification and fermentation approach employing …