title: Estimation of treatment time for microbial preprocessing of biomass.
abstract: Biochemical conversion of lignocellulosic biomass to ethanol involves size reduction, preprocessing, pretreatment, enzyme hydrolysis, and fermentation. In recent years, microbial preprocessing has been gaining attention as a means to produce labile biomass for lessening the requirement of pretreatment severity. However, loss of sugars due to microbial consumption is a major consequence, suggesting its minimization through optimization of nutrients, temperature, and preprocessing time. In this work, we emphasized estimation of fungal preprocessing time, at which higher sugar yields can be achieved after preprocessing and enzyme hydrolysis. The estimation is based on the enzymatic activity profile obtained by treating switchgrass with Phanerochaete chrysosporium for 28 days. Enzyme assays were conducted once in every 7 days for 28 days, for activities of phenol oxidase, peroxidase, beta-glucosidase, beta-xylosidase, and cellobiohydrolase. We found no activity for phenol oxidase and peroxidase, but the greatest activities for cellulases on the seventh day. We then treated switchgrass for 7 days with P. chrysosporium and observed that the preprocessed switchgrass had higher glucan (39%), xylan (17.5%), and total sugar yields (25.5%) than the unpreprocessed switchgrass (34%, 37.5%, and 20.5%, respectively, p < 0.05). This verifies the utility of using enzyme assays for initial estimation of preprocessing time to enhance sugar yields.
authors: Department of Chemical Engineering, University of Mississippi, University, MS 38655, USA. swetha.mahalaxmi@gmail.com
authors: Swetha
authors: S
authors: Mahalaxmi
authors: Colin R
authors: CR
authors: Jackson
authors: Clint
authors: C
authors: Williford
authors: Charles L
authors: CL
authors: Burandt
mesh_terms: D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D005947:Glucose / Q000032:analysis; D020075:Phanerochaete / Q000201:enzymology / Q000378:metabolism*; D006109:Poaceae / Q000378:metabolism; D013997:Time Factors
chemical_list: D005947:Glucose