Designing a cellulolytic enzyme cocktail for the efficient and economical conversion of lignocellulosic biomass to biofuels

• Published in: Enzyme and microbial technology Vol. 133; p. 109442
• Main Authors: Adsul, Mukund, Sandhu, Simranjeet Kaur, Singhania, Reeta Rani, Gupta, Ravi, Puri, Suresh K., Mathur, Anshu
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2020
• Subjects: Accessory enzymes; Auxiliary activity; bioethanol; Biofuel; Biofuels; Biomass; cellulases; Cellulolytic cocktail; Cellulose - metabolism; environmental impact; Enzymatic hydrolysis; Enzymes - metabolism; ethanol production; feedstocks; financial economics; fossil fuels; Hydrolysis; Lignin - metabolism; lignocellulose; Lignocellulosic biomass; proteins; Auxiliary activity; Accessory enzymes; Biofuel; Lignocellulosic biomass; Cellulolytic cocktail; Enzymatic hydrolysis
• ISSN: 0141-0229; 1879-0909; 1879-0909
• DOI: 10.1016/j.enzmictec.2019.109442

[Display omitted] •Cellulolytic enzyme cocktail is necessary for efficient and economical conversion of biomass to biofuels.•Microbial strain producing basic three cellulolytic enzyme is important to build a cocktail.•Accessory enzymes, noncellulolytic proteins and some chemicals are required to build efficient cocktail.•Sequential addition, blending, statistical optimization and protein expression are ways of making cellulolytic cocktail. Concerns about dwindling fossil fuels and their unfavorable environmental impacts shifted the global focus towards the development of biofuels from lignocellulosic feedstocks. The structure of this biomass is very complex due to which variety of enzymes (cellulolytic, hemicellulolytic, auxiliary/AA9) and proteins (e.g. swollenin) required for efficient deconstruction. Major impediments in large-scale commercial production of cellulosic ethanol are the cost of cellulases and inability of any single microorganism to produce all cellulolytic components in sufficient titers. In the recent past, various methods for reducing the enzyme cost during cellulosic ethanol production have been attempted. These include designing optimal synergistic enzyme blends/cocktail, having certain ratios of enzymes from different microbial sources, for efficient hydrolysis of pretreated biomass. However, the mechanisms underlying the development, strategies for production and evaluation of optimal cellulolytic cocktails still remain unclear. This article aims to explore the technical and economic benefits of using cellulolytic enzyme cocktail, basic enzymatic and non-enzymatic components required for its development and various strategies employed for efficient cellulolytic cocktail preparation. Consideration was also given to the ways of evaluation of commercially available and in-house developed cocktails. Discussion about commercially available cellulolytic cocktails, current challenges and possible avenues in the development of cellulolytic cocktails included.