Bioconversion of novel substrate Saccharum spontaneum, a weedy material, into ethanol by Pichia stipitis NCIM3498.
Rising fuel prices and environmental issues have paved the way for the exploration of cellulosic ethanol. However, challenges involving substrate hydrolysis and cost-effectiveness still limit the efficient bioconversion and utilization of cellulosic ethanol. We aimed to evaluate a cheaper and abundantly available wild sugarcane variety, Saccharum spontaneum, as the raw substrate for bioconversion of ethanol by Pichia stipitis NCIM3498. Three different strategies for substrate hydrolysis using acid (dilute sulfuric acid) and alkali (dilute sodium hydroxide) and aqueous ammonia (AA) treatment followed by enzymatic hydrolysis were studied. A maximum of 631.5±3.25 mg/g sugars with 89.38% hydrolytic efficiency (HE) could be achieved after enzymatic hydrolysis of AA-pretreated S. spontaneum. All the substrate hydrolysates were evaluated for ethanol conversion in batches by P. stipitis. The microbial fermentation of released sugars into ethanol showed (g/g) 0.36±0.011, 0.384±0.022, 0.391±0.02, and 0.40±0.01 yield from detoxified acid hydrolysate and acid-, NaOH- and AA-pretreated substrate S. spontaneum enzymatic hydrolysates, respectively.
Chandel
Anuj K
AK
Centre for Biotechnology, Jawaharlal Nehru Technological University, Hyderabad 500 072, India. chandel_anujkumar@yahoo.com
Singh
Om V
OV
Rao
L Venkateswar
LV
Chandrasekhar
G
G
Narasu
M Lakshmi
ML
D000468:Alkalies / Q000494:pharmacology; D001230:Aspergillus / Q000187:drug effects / Q000201:enzymology; D056804:Biofuels / Q000032:analysis; D001709:Biotechnology / Q000379:methods*; D002480:Cellulase / Q000378:metabolism; D000431:Ethanol / Q000032:analysis*; D006868:Hydrolysis / Q000187:drug effects; D010843:Pichia / Q000187:drug effects / Q000378:metabolism*; D057685:Plant Weeds / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D031786:Saccharum / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D013464:Sulfuric Acids / Q000494:pharmacology; D013997:Time Factors
D000468:Alkalies; D056804:Biofuels; D013464:Sulfuric Acids; D000431:Ethanol; D002480:Cellulase; C033158:sulfuric acid