State Key Laboratory of Food Science and Technology, Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China.
Institute for Chinese Jiang-Flavor Baijiu (Liquor), Renhuai, Guizhou 564500, China.
J Agric Food Chem. 2020 Apr 29;68(17):4903-4911. doi: 10.1021/acs.jafc.9b08052. Epub 2020 Mar 27.
Lactic acid is a universal metabolite, as well as a growth inhibitor of ethanol producers in Baijiu fermentation. Revealing the mechanism of lactic acid tolerance is essential for the yield of fermented foods. Here, we employed reverse transcription-quantitative polymerase chain reaction to explore the degradation mechanism of lactic acid, based on the coculture of and . Under high lactic acid stress, decreased lactic acid from 40.00 to 35.46 g L within 24 h. Then, restored its capacity to degrade lactic acid. Finally, lactic acid decreased to 26.29 g L. Coculture significantly enhanced lactic acid consumption compared to the monoculture of (90% higher) or (209% higher). We found that lactate catabolism, H extrusion, and glycerol transport were the lactic acid tolerance pathways in yeasts. This study reveals the novel acid tolerance mechanisms of microbiota and would provide new strategies for ethanol production under acid stress.
乳酸是一种普遍存在的代谢物，也是白酒发酵中乙醇生产者的生长抑制剂。揭示乳酸耐受机制对于发酵食品的产量至关重要。在这里，我们采用反转录定量聚合酶链反应（reverse transcription-quantitative polymerase chain reaction），基于 和 的共培养，探索乳酸的降解机制。在高乳酸胁迫下， 在 24 小时内将乳酸从 40.00 减少到 35.46 g/L。然后， 恢复了其降解乳酸的能力。最后，乳酸降低到 26.29 g/L。与 （90%更高）或 （209%更高）的单培养相比，共培养显著提高了乳酸的消耗。我们发现，乳酸盐分解代谢、H 排出和甘油运输是酵母的乳酸耐受途径。这项研究揭示了微生物群落的新的耐酸机制，并为酸胁迫下的乙醇生产提供了新的策略。
