Lertsriwong Supattra, Khaosaart Phatcharaphong, Boonvitthya Nassapat, Chulalaksananukul Warawut, Glinwong Chompunuch
Program in Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
Biofuels By Biocatalysts Research Unit, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
Synth Syst Biotechnol. 2025 Jun 1;10(4):1077-1086. doi: 10.1016/j.synbio.2025.05.011. eCollection 2025 Dec.
Rice straw and sugar cane industrial waste are a plentiful source of lignocellulosic biomass with a high polysaccharide content, that is hydrolyzed into sugar for microbial growth and their metabolites. 3-Hydroxypropionic acid (3-HP) is a promising chemical building block that can be produced from renewable resources. The malonyl-CoA pathway is one of the biosynthetic routes for 3-HP production by expressing the malonyl-CoA reductase gene (). However, the problem of the activity imbalance between the C and N-terminal causes a low conversion rate of malonyl-CoA to 3-hydroxypropionic acid. This study aimed to balance the bi-functional MCR enzyme by dissecting MCR into two fragments and enhancing the supply of intermediates to increase the production of 3-HP. The recombinant strain harboring the dissected gene showed a 21-fold increase in 3-HP titer compared to the strain carrying the full-length gene. The addition of cerulenin and acetate to the fermented medium enhanced 3-HP yield by 8 times, in which recombinant yeast produced 3-HP up to 10 g/L (0.201 g/g). The results of using rice straw hydrolysate as a carbon source indicated that S2 produced 3-HP of 4.02 g/L, which was 0.074 g/g in the diluted hydrolysate. These findings provide an alternative and sustainable strategy for utilizing lignocellulosic biomass for future 3-HP production at an industrial scale.
稻草和甘蔗工业废料是富含木质纤维素生物质的丰富来源,其多糖含量高,可水解为糖以供微生物生长及其代谢产物生成。3-羟基丙酸(3-HP)是一种有前景的化学构件,可从可再生资源中生产。丙二酰辅酶A途径是通过表达丙二酰辅酶A还原酶基因生产3-HP的生物合成途径之一。然而,C端和N端之间活性失衡的问题导致丙二酰辅酶A向3-羟基丙酸的转化率较低。本研究旨在通过将丙二酰辅酶A还原酶(MCR)分解为两个片段并增强中间体供应来平衡双功能MCR酶,以提高3-HP的产量。与携带全长MCR基因的菌株相比,携带分解后的MCR基因的重组菌株的3-HP滴度提高了21倍。向发酵培养基中添加浅蓝菌素和乙酸盐可使3-HP产量提高8倍,其中重组酵母产生的3-HP高达10 g/L(0.201 g/g)。使用稻草水解物作为碳源的结果表明,S2产生了4.02 g/L的3-HP,在稀释水解物中为0.074 g/g。这些发现为未来工业规模利用木质纤维素生物质生产3-HP提供了一种替代且可持续的策略。