Weedy lignocellulosic feedstock and microbial metabolic engineering: advancing the generation of ‘Biofuel’

Abstract

Lignocellulosic materials are the most abundant renewable organic resources (~200 billion tons annually) on earth that are readily available for conversion to ethanol and other value-added products, but they have not yet been tapped for the commercial production of fuel ethanol. The lignocellulosic substrates include woody substrates such as hardwood (birch and aspen, etc.) and softwood (spruce and pine, etc.), agro residues (wheat straw, sugarcane bagasse, corn stover, etc.), dedicated energy crops (switch grass, and Miscanthus etc.), weedy materials (Eicchornia crassipes, Lantana camara etc.), and municipal solid waste (food and kitchen waste, etc.). Despite the success achieved in the laboratory, there are limitations to success with lignocellulosic substrates on a commercial scale. The future of lignocellulosics is expected to lie in improvements of plant biomass, metabolic engineering of ethanol, and cellulolytic enzyme-producing microorganisms, fullest exploitation of weed materials, and process integration of the individual steps involved in bioethanol production. Issues related to the chemical composition of various weedy raw substrates for bioethanol formation, including chemical composition-based structural hydrolysis of the substrate, need special attention. This area could be opened up further by exploring genetically modified metabolic engineering routes in weedy materials and in biocatalysts that would make the production of bioethanol more efficient.

Effective saccharification of kraft pulp by using a cellulase cocktail prepared from genetically engineered Aspergillus oryzae

“…SF2). The ethanol yield from kraft pulp was relatively high as compared with that reported in previous studies that used other lignocellulosic biomass as feedstock, 12,13) which can be attributed to low lignin component and crystallinity of kraft pulp. Such description about ethanol yield in SSF from lignocellulosic feedstocks was summarized in the review.…”

Evolutionary Adaptation of Kluyveromyces marxianus NIRE-K3 for Enhanced Xylose Utilization

“…Therefore, both these sugars needed to be fermented for economical process development. Conventional yeast Saccharomyces cerevisiae can only ferment glucose, but unable to ferment xylose due to lack of xylose metabolic genes (Kumar et al, 2010;Chandel and Singh, 2011;Kuhad et al, 2011;Sharma et al, 2016).…”

Crop Management Effects on the Energy and Carbon Balances of Maize Stover-Based Ethanol Production

“…Lignocellulosic ethanol, on the other hand, can displace more non-renewable energy and reduce environmental risks more efficiently than can starch-or sugar-based ethanol [10,11]. Also, lignocellulosic feedstocks are abundant, relatively cheap, and widely available [7,[12][13][14]. The United States has an annual potential of producing about 189 million m 3 of biofuels from lignocellulosic feedstocks [12].…”