基于原位培养和传统培养分析比较不同储存期酱香大曲的细菌群落

Comparative analysis of bacterial community of high temperature Daqu with different storage periods based on in situ cultivation and traditional cultivation

该研究首次利用原位培养法分离筛选5个储存期的酱香型大曲细菌。对比分析原位培养和传统培养法分离筛选出的细菌群落多样性和组成。结果显示,5个储存期酱香大曲基于原位培养法总共分离筛选到15个属下的36种细菌,而传统培养法只分离筛选到5个属下的17种细菌。每个储存期的酱香大曲基于原位培养分离筛选到的细菌数量和种类都比传统培养更丰富。原位培养获得的独有菌属在白酒发酵环境中大多只是基于免培养技术发现,利用原位培养能将这些菌属分离培养出。原位培养获得的Bacillus paramycoides、Bacillus vallismortis、Staphylococcus xylosus、Alcaligenes sp.、Alcaligenes faecalis、Alcaligenes aquatilis、Brevibacillus borstelensis等功能细菌在白酒发酵环境中鲜有报道。另外,研究发现储藏3~8个月的陈曲样品,细菌菌群结构组成中主要优势菌群相似且稳定,但6~8个月陈曲中绝对优势属的分离频率最高。因此,可选用6个月及以上储存期的陈曲酿酒。该研究突出显示了原位培养的优势,为进一步解析酱香型大曲功能细菌,筛选优良酿造细菌提供新的方法和思路。

The present study was the first to isolate and screen bacteria in high temperature Daqu with five different storage periods based on in situ cultivation approach.The bacterial community composition cultured with in situ cultivation and traditional cultivation were compared and analyzed.The results showed that 15 genera and 36 species were isolated by in situ cultivation while only 5 genera and 17 species were obtained by traditional cultivation.In each Daqu with a different storage period,the diversity and richness of bacteria isolated by in situ cultivation were more abundant than those of traditional cultivation.Interestingly,the unique bacteria previously reported in Baijiu fermentation environment based on the culture-independent method were successfully isolated by in situ cultivation.Functional bacteria including Bacillus paramycoides,Bacillus vallismortis,Staphylococcus xylosus,Alcaligenes sp.,Alcaligenes faecalis,Alcaligenes aquatilis,and Brevibacillus borstelensis obtained by in situ cultivation were rarely reported in Baijiu fermentation environment.In addition,although the dominant bacteria in high temperature Daqu with a 3-8 months storage period were similar and stable,the isolation frequency of the dominant genus was the highest in Daqu samples with six and eight months.Therefore,high temperature Daqu with six months or more storage period is suitable and applied in the subsequent brewing process.This study highlights the advantages of in situ cultivation and provides a new method and a novel pathway to screen functional microorganisms inhabiting the whole liquor brewing environment.