Low intensity ultrasound increases the fermentation efficiency of Lactobacillus casei subsp.casei ATTC 39392
Low intensity ultrasound increases the fermentation efficiency of Lactobacillus casei subsp.casei ATTC 39392
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DOI：
10.1016/j.ijbiomac.2016.01.103
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发表时间：
2016-05-01
影响因子：
8.2
通讯作者：
Kafil, Hossein Samadi
中科院分区：
文献类型：
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作者：
Dahroud, Behnaz Dahri;Mokarram, Reza Rezai;Kafil, Hossein Samadi
l -乳酸（L-LA）是应用广泛的微生物产品之一，其生产效率具有重要意义。在本研究中，我们一直在探索应用低强度超声技术来提高干酪乳杆菌在不同培养基中产生l -乳酸的代谢活性。以L-LA、生物质产量和底物（蛋白质）消耗量为发酵产量参数。L-LA和蛋白质含量分别用可滴定酸度法和双缩脲法测定。采用分光光度法（OD600(nm)）测定细胞生长情况。以l - la、生物量产量和蛋白质消耗为因变量，以波幅（20%、40%和60%）、波幅持续时间（15、30、45 s）和蛋白胨添加量（2、6和10 g/l）为自变量。结果表明：L-LA、生物量产量和底物消耗量显著增加（约25%）；生物量产量的最佳条件为振幅60%、暴露时间15s和10 g/l蛋白胨，乳酸产量和底物消耗分别为40%、30s和6 g/l蛋白胨。流式细胞术分析也显示超声使细胞膜通透性增加。这一观察结果表明，低强度超声是改善干酪乳杆菌代谢活性的一个潜在参数。(C) 2016 Elsevier B.V.版权所有
L-Lactic acid (L-LA) is one of the microbial products with several applications and its production efficiency is so important. In the present study, we have been exploring application of low intensity ultrasound technology to improve the metabolic activity for L-lactic acid production by Lactobacillus casei in different mediums. L-LA, biomass production and substrate (protein) consumption were measured as parameters of fermentation yield. L-LA and protein contents were determined using the titratable acidity and the biuret method respectively. Spectrophotometry (OD600(nm)) was used for measuring cell growths. L-LA, biomass production and protein consumption considered as dependent variables, but the amplitude of waves (20%, 40% and 60%), waves duration (15,30, 45 s) and add of peptone (2, 6 and 10 g/l) as independent variables. The results showed that L-LA, biomass production and substrate consumption significantly increased (approximate to 25%). Optimum conditions for biomass production was amplitude of 60%, 15 s exposure time and 10 g/l peptone, while for acid lactic production and substrate consumption was 40%, 30s and 6 g/l peptone, respectively. Flowcytometry analysis also showed that sonication led to increasing cell membrane permeability. This observation shows low intensity ultrasound as a potential parameter in the improvement of metabolic activity of L. casei. (C) 2016 Elsevier B.V. All rights reserved.