title: Two-step statistical optimization for cold active β-glucosidase production from Pseudomonas lutea BG8 and its application for improving saccharification of paddy straw.
abstract: β-Glucosidase is an essential part of cellulase enzyme system for efficient and complete hydrolysis of biomass. Psychrotolerant Pseudomonas lutea BG8 produced β-glucosidase with lower temperature optima and hence can play important role in bringing down the energy requirement for bioethanol production. To enhance β-glucosidase production, two statistical tools: Taguchi and Box-Behnken designs were applied to reveal the most influential factors and their respective concentration for maximum production of β-glucosidase under submerged fermentation. The optimal medium composition for maximum β-glucosidase production were 2.99% (w/v) bagasse, 0.33% (w/v) yeast extract, 0.38% (w/v) Triton X-100, 0.39% (w/v) NaNO3, and pH 8.0 at temperature 30 °C. Under optimized conditions, β-glucosidase production increased up to 9.12-fold (17.52 ± 0.24 IU/g) in shake flask. Large-scale production in 7-L stirred tank bioreactor resulted in higher β-glucosidase production (23.29 ± 0.23 IU/g) within 80 H of incubation, which was 1.34-fold higher than shake flask studies. Commercial cellulase (Celluclast®1.5L) when supplemented with this crude β-glucosidase resulted in improved sugar release (548.4 ± 2.76 mg/gds) from paddy straw at comparatively low temperature (40 °C) of saccharification. P. lutea BG8 therefore showed great potential for cold active β-glucosidase production and can be used as accessory enzyme along with commercial cellulase to improve saccharification efficiency.
authors.affiliation: Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi, India.|Laboratory of Enzyme Technology and Protein Bioinformatics, Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India.
authors.forename: Rameshwar
authors.initials: R
authors.lastname: Tiwari
authors.affiliation: Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi, India.
authors.forename: Kumar
authors.initials: K
authors.lastname: Pranaw
authors.affiliation: Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi, India.
authors.forename: Surender
authors.initials: S
authors.lastname: Singh
authors.affiliation: School of Mechanical Engineering, Galgotias University, Greater Noida, Uttar Pradesh, India.
authors.forename: Pawan K S
authors.initials: PK
authors.lastname: Nain
authors.affiliation: Laboratory of Enzyme Technology and Protein Bioinformatics, Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, India.
authors.forename: Pratyoosh
authors.initials: P
authors.lastname: Shukla
authors.affiliation: Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi, India. latarajat@yahoo.co.in.
authors.forename: Lata
authors.initials: L
authors.lastname: Nain
mesh_terms: D019149:Bioreactors / Q000382:microbiology; D001709:Biotechnology / Q000379:methods*; D002241:Carbohydrates / Q000737:chemistry*; D003080:Cold Temperature; D005285:Fermentation; D007700:Kinetics; D010936:Plant Extracts / Q000737:chemistry*; D011549:Pseudomonas / Q000378:metabolism*; D013223:Statistics as Topic; D001617:beta-Glucosidase / Q000096:biosynthesis* / Q000378:metabolism*
chemical_list: D002241:Carbohydrates; D010936:Plant Extracts; D001617:beta-Glucosidase
keywords: Box-Behnken design; Taguchi experimental design; bioreactor; saccharification