Ultrasonic ‑assisted molten salt hydrates pretreated Eucheuma cottonii residues as a greener precursor for third-generation L-lactic acid production

This study aims to establish an efficient pretreatment method that facilitates the conversion of sugars from macroalgae wastes, Eucheuma cottonii residues (ECRs) during hydrolysis and subsequently enhances L-lactic acid (L-LA) production. Hence, ultrasonic-assisted molten salt hydrates (UMSHs) pretreatment was proposed to enhance the accessibility of ECRs to hydrolyze into glucose through dilute acid hydrolysis (DAH). The obtained hydrolysates were employed as the substrate in producing L-LA by separate hydrolysis and fermentation (SHF). The maximum glucose yield (97.75%) was achieved using UMSHs pretreated ECRs with 40wt% ZnCl2 at 80 °C for 2 h and followed with DAH. The optimum glucose to L-LA yield obtained for SHF was 90.08% using 5% (w/w) inoculum cell densities of B. coagulans ATCC 7050 with yeast extract (YE). A comparable performance (89.65%) was obtained using a nutrient combination (lipid-extracted Chlorella vulgaris residues (CVRs), vitamin B3, and vitamin B5) as a partial alternative for YE.PMID:36257523 | DOI:10.1016/j.biortech.2022.128136

Source: Bioresource Technology - October 18, 2022 Category: Biotechnology Authors: Soo Ling Chong Inn Shi Tan Henry Chee Yew Foo Yen San Chan Man Kee Lam Keat Teong Lee Source Type: research