知识与财富的链接
米根霉(Rhizopus oryzae)能产生乳酸等有机酸,在许多领域有重要的应用价值.本研究从黑龙江省北大仓白酒大曲中分离一株霉菌,经形态学和内转录间隔区(ITS)分子鉴定,将其命名为米根霉WSW-LYN-001;对该菌株产乳酸的能力进行了研究,并对其产乳酸发酵条件进行了优化.结果显示:以葡萄糖为碳源,在48 h后,米根霉发酵液pH达3.2左右,发酵84 h后乳酸产量可保持在70 g/L左右;传代次数会影响菌丝团形态,出现絮状和球状菌丝团,进而影响乳酸产量;发酵60 h后,球状菌丝团发酵液中乳酸产量比絮状菌丝团的更高;球状菌丝团经pH和中和剂CaCO3优化后,在初始pH为7、发酵60 h后,乳酸产量最高达134.25 g/L.
Rhizopus oryzae produces important organic acids such as lactic acid, and has important application value in many fields. In this study, a fungus was isolated from Baijiu Daqu of Beidacang, Heilongjiang Province, and the strain was identified and named as Rhizopus oryzae WSW-LYN-001 using internal transcribed spacer(ITS) identification. The results showed that using glucose as the carbon source, after 48 hours, the pH of fermentation broth reached around 3.2. After 84 hours of fermentation, the lactate production maintained at around 70 g/L. The passage number could affect the morphology of fungal hyphae(flocculent and globular mycelium clusters appeared), which in turn affected lactate production. After 60 hours of fermentation, the lactate production in the fermentation broth of spherical mycelium was higher than that of flocculent mycelium. After pH optimization, the spherical mycelium produced the maximum lactic acid yield of 134.25 g/L after 60 hours of fermentation at an initial pH of 7.