PANKAJ JANGID, REEMA NINGTHOUJAM AND HARISH KUMAR DHINGRA*
Department of Biosciences, Mody University of Science and Technology, Lakshmangarh, Sikar-332 311 (Rajasthan), India
*(e-mail: harishdhingra2000@gmail.com; Mobile: 94615 36233)
(Received: June 14, 2025; Accepted: July 23, 2025)
ABSTRACT
The declining oil and gas reserves globally underscore the urgency for expanded research into alternative energy sources. Bio-ethanol emerges as a prominent renewable fuel in transportation. Utilizing microorganisms to convert sugar containing waste into ethanol presents a promising avenue due to its speed and cost-effectiveness. This study aimed at isolating and identifing ethanol producing yeasts from over ripened fruits from the local market of Lakshmangarh, Rajasthan. Various biochemical tests were conducted for microbial identification of potential yeast strains isolated from over ripened plums, oranges, and grapes as substrates. The study explored the use of lignocellulosic waste, specifically rice straw avoiding competition with first generation alternatives. Chemical pre-treatment with 4% NaOH (1:10) was employed to reduce recalcitrant nature of lignin. Enzymatic hydrolysis using cellulase alpha- amylase and amyloglucosidase in 2:1:1 yielded 0.65 g/l of sugar, which was then fermented by isolates at 27°C for seven days. This process led to a significant increase in bio-ethanol production, achieving a yield of 16%.
Key words: Rice straw, renewable feed stocks, lignocellulosic biomass, fermentation, bio-ethanol