传统自然发酵黏豆包关键酵母的筛选鉴定

目的 筛选适宜谷物黏豆包发酵的酵母菌菌株。方法 以采集自黑龙江省不同地区的传统自然发酵黏豆包谷物发酵液为研究对象, 通过高通量测序技术, 分析发酵液中微生物多样性, 再利用传统培养法对发酵液中的酵母菌进行分离, 筛选出耐低温、耐低pH、起酵时间快和酵香风味好的酵母菌株。结果 通过高通量测序结果显示, 在真菌菌属水平上, 3个地区样品共包含5个门、30个属、30个种, 微生物群落为酿酒酵母属(Saccharomyces)、威克汉姆酵母属(Wickerhamomyces)、毕赤酵母属(Pichia)等, 其中酿酒酵母属为首要优势菌属, 次级优势菌皆为威克汉姆酵母属。在此基础上, 利用平板划线分离出21株酵母菌, 通过分子生物学鉴定, TY5、TY9和AC6为酿酒酵母, TY8和SC4为威克汉姆酵母, AC3为热带假丝酵母, SC3为季也蒙毕赤酵母, SC5为胶红酵母; TY5、TY8、TY9、AC6、SC6在pH为3、15℃条件下具有较好的生长性能, 其中菌株TY9和AC6具有较强的耐酸性及耐低温性, 且起酵时间快, 菌株TY9发酵风味最好, 呈现较强的谷物发酵风味。结论 筛选出一株耐低温、耐低pH、起酵时间快和酵香风味好的菌株, 经鉴定为酿酒酵母。本研究为东北黏豆包酸面团发酵菌剂的开发提供了理论基础。

Screening and identification of key yeast in traditional naturally fermented Niandoubao

Objective To screen the yeast strains suitable for the fermentation of cereal Niandoubao. Methods The fermentation broth of traditional natural fermented Niandoubao collected from different regions of Heilongjiang Province was used as the research object. The microbial diversity in the fermentation broth was analyzed by high-throughput sequencing technology, and the yeasts in the fermentation broth were isolated by traditional culture method. The yeast with low temperature resistance, low pH resistance, fast fermentation time and good aroma flavor were screened. Results The results of high-throughput sequencing showed that at the level of fungal genus, the samples from the 3 regions contained 5 phyla, 30 genera and 30 species. The microbial community was Saccharomyces, Wickerhamomyces, Pichia, etc.. Among them, Saccharomyces was the primary dominant genus, and the secondary dominant bacteria were all Wickhamomyces. On this basis, 21 yeast strains were isolated by plate streaking. Through molecular biology identification, TY5, TY9 and AC6 were Saccharomyces cerevisiae, TY8 and SC4 were Wickerhamomyces anomalus, AC3 was Candida tropicalis, SC3 was Pichia guilliermondii, and SC5 was Rhodotorula mucilaginosa. TY5, TY8, TY9, AC6 and SC6 had good growth performance at pH 3 and 15°C. Among them, strains TY9 and AC6 had strong acid resistance and low temperature resistance, and the fermentation time was fast. The fermentation flavor of strain TY9 was the best, showing strong grain fermentation flavor. Conclusion A strain with low temperature tolerance, low pH tolerance, fast fermentation time and good flavor is screened and identified as Saccharomyces cerevisiae. This study provides a theoretical basis for the development of northeast Niandoubao fermentation agent.