title: Bioethanol production from leafy biomass of mango (Mangifera indica) involving naturally isolated and recombinant enzymes.
abstract: The present study describes the usage of dried leafy biomass of mango (Mangifera indica) containing 26.3% (w/w) cellulose, 54.4% (w/w) hemicellulose, and 16.9% (w/w) lignin, as a substrate for bioethanol production from Zymomonas mobilis and Candida shehatae. The substrate was subjected to two different pretreatment strategies, namely, wet oxidation and an organosolv process. An ethanol concentration (1.21 g/L) was obtained with Z. mobilis in a shake-flask simultaneous saccharification and fermentation (SSF) trial using 1% (w/v) wet oxidation pretreated mango leaves along with mixed enzymatic consortium of Bacillus subtilis cellulase and recombinant hemicellulase (GH43), whereas C. shehatae gave a slightly higher (8%) ethanol titer of 1.31 g/L. Employing 1% (w/v) organosolv pretreated mango leaves and using Z. mobilis and C. shehatae separately in the SSF, the ethanol titers of 1.33 g/L and 1.52 g/L, respectively, were obtained. The SSF experiments performed with 5% (w/v) organosolv-pretreated substrate along with C. shehatae as fermentative organism gave a significantly enhanced ethanol titer value of 8.11 g/L using the shake flask and 12.33 g/L at the bioreactor level. From the bioreactor, 94.4% (v/v) ethanol was recovered by rotary evaporator with 21% purification efficiency.
authors.affiliation: Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam, India.
authors.forename: Saprativ P
authors.initials: SP
authors.lastname: Das
authors.forename: Rajeev
authors.initials: R
authors.lastname: Ravindran
authors.forename: Deepmoni
authors.initials: D
authors.lastname: Deka
authors.forename: Mohammad
authors.initials: M
authors.lastname: Jawed
authors.forename: Debasish
authors.initials: D
authors.lastname: Das
authors.forename: Arun
authors.initials: A
authors.lastname: Goyal
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology; D018533:Biomass; D019149:Bioreactors; D002480:Cellulase / Q000737:chemistry*; D000431:Ethanol / Q000138:chemical synthesis* / Q000737:chemistry; D005285:Fermentation; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry; D031022:Mangifera / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry / Q000494:pharmacology; D017355:Zymomonas
chemical_list: D011134:Polysaccharides; D011994:Recombinant Proteins; D000431:Ethanol; C007916:hemicellulose; D008031:Lignin; D002480:Cellulase