Bioethanol: A New Synergy between Marine Chitinases from Bacillus haynesii and Ethanol Production by Mucor circinelloides

Autor: Vishnupriya Govindaraj, Arun Kumar Subramani, Ramya Gopalakrishnan, Se-Kwon Kim, Ritu Raval, Keyur Raval
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Fermentation, Vol 9, Iss 1, p 40 (2023)
Druh dokumentu: article
ISSN: 2311-5637
DOI: 10.3390/fermentation9010040
Popis: The fourth generation of bioethanol production is on a lookout for non-lignocellulosic biomass waste. One such candidate is chitin, the second most abundant biopolymer on earth. However, the crystalline nature of chitin hinders its application potential for bioethanol production. This limitation can be circumvented by hydrolysing this polymer into oligomers using chitinases. We used this hypothesis and isolated a Bacillus haynesii, a marine bacterium that utilizes colloidal chitin as a substrate and produces chitin oligosaccharides. Further, we utilized Mucor circinelloides to produce bioethanol using the chitin oligosaccharides in the shake flask. We investigated the effect of inoculum age, filling volume, different substrates, and substrate concentration on bioethanol production using Mucor circinelloides from Bacillus haynesii-produced chitin oligosaccharides. Bacillus haynesii demonstrated a maximum chitinase activity of 3.08 U/mL with specific activity of 96 U/mg at the 90th h. Chitin oligosaccharides produced by Bacillus haynesii were confirmed using mass spectrometry. Bioethanol concentration was determined using dichromate oxidation assay as well as gas chromatography. The research resulted in 7.4 g/L of ethanol from 30 g/L of chitin oligosaccharides, with a maximum ethanol yield of 0.25 g of ethanol/g substrate at the 55th h with 48 h inoculum in 80 mL of fermentation medium. Results suggest that chitin oligosaccharides from Bacillus haynesii are an effective and renewable substrate for bioethanol production.
Databáze: Directory of Open Access Journals