Mao Ping, Hu Yuanliang, Liao Tingting, Wang Zhaoting, Zhao Shumiao, Liang Yunxiang, Hu Yongmei
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P.R. China.
Hubei Collaborative Innovation Center for Industrial Fermentation, Wuhan 430068, P.R. China.
J Microbiol Biotechnol. 2017 Apr 28;27(4):678-684. doi: 10.4014/jmb.1605.05011.
The aim of this study was to elucidate the changes in the microbial community and biochemical properties of a traditional sweet paste during fermentation. PCR-denaturing gradient gel electrophoresis (DGGE) analysis showed that was the predominant species in the koji (the fungal mixture), and the majority of the fungi isolated belonged to two species in the mash. The bacterial DGGE profiles revealed the presence of during fermentation, and sp., and several uncultured bacteria were also detected in the mash after 14 days of main fermentation. Additionally, during main fermentation, amino-type nitrogen and total acid increased gradually to a maximum of 6.77 ± 0.25 g/kg and 19.10 ± 0.58 g/kg (30 days) respectively, and the concentration of reducing sugar increased to 337.41 ± 3.99 g/kg (7 days). The 180-day fermented sweet paste contained 261.46 ± 19.49 g/kg reducing sugar and its pH value remained at around 4.65. This study has used the PCR-DGGE technique to demonstrate the microbial community (including bacteria and fungi) in sweet paste and provides useful information (biochemical properties) about the assessment of the quality of sweet paste throughout fermentation.
本研究的目的是阐明传统甜酱发酵过程中微生物群落和生化特性的变化。PCR-变性梯度凝胶电泳（DGGE）分析表明，米曲霉是曲（真菌混合物）中的优势菌种，且分离出的大多数真菌属于醪液中的两个米曲霉种类。细菌DGGE图谱显示发酵过程中有嗜热栖热菌存在，主发酵14天后在醪液中还检测到嗜热栖热菌、嗜热栖热放线菌和几种未培养细菌。此外，在主发酵过程中，氨基态氮和总酸分别逐渐增加至最大值6.77±0.25 g/kg和19.10±0.58 g/kg（30天），还原糖浓度增加至337.41±3.99 g/kg（7天）。180天发酵的甜酱含有261.46±19.49 g/kg还原糖，其pH值保持在4.65左右。本研究利用PCR-DGGE技术展示了甜酱中的微生物群落（包括细菌和真菌），并提供了有关整个发酵过程中甜酱质量评估的有用信息（生化特性）。
