浓香型白酒窖泥放线菌的群落结构及其多样性

以泸州老窖1、50、100和400年窖泥为研究对象,采用变性梯度凝胶电泳(DGGE)研究浓香型白酒窖泥放线菌的群落结构及其多样性。DGGE图谱显示,除1年样品外,其余窖底泥多样性指数(H)均低于同窖龄窖壁泥,但均匀度指数(EH)较高。不同窖池相同部位窖泥的群落结构变化趋势为:随窖龄的延长,窖壁泥H值逐渐上升,为1.74—2.28;窖底泥下降,为1.73—2.07。EH值均为波动下降,分别在0.986—0.991和0.971—0.994之间。窖底泥相似性系数(SC)逐渐上升,为0.46—0.82;窖壁泥为0.31—0.62。DGGE条带测序结果显示,窖泥放线菌归于Olsenella、Atopobium、Streptomyces和Corynebacterium 4个属。Olsenella和Atopobium属为共有的优势属,且在窖壁泥中的优势度(di)均随窖龄延长而降低,在窖底泥中升高。实验结果表明,浓香型白酒窖泥蕴藏着丰富的放线菌资源,群落结构和多样性存在差异,菌群演替呈现一定规律性。

Analysis of actinobacteria community and diversity in the pit mud of chinese luzhou-flavour liquor

In this study, the pit mud of Luzhou-flavour liquor which was used for 1, 50, 100 and 400 years were taken from a factory affiliated to the Luzhou Laojiao Group. Eight mixed samples were sampled from the wall and bottom layers of the pit mud in the cellars. Denaturing gradient gel electrophoresis (DGGE) was employed to analyse actinobacteria community structure and diversity from the samples.For the analysis, 16S rRNA fragments about 400 bp amplified from DNA extracted from the eight mixed pit mud samples. Among all samples, ten stronger bands and few number of less intense bands were detected, only three stronger bands can be amplified from each sample, differences between the DGGE patterns of the different position of pit mud were also detected. On the whole, however, the community of the samples taken from the same position was comparatively similar, and a regular pattern was observed during the community succession. In the same cellar, except the sample used for about 1 year, the diversity index (H) of the wall-layer sample was much higher than the bottom -layer samples'', while the evenness index (EH) is opposite. In addition, with the increase of pit age, the H values of the wall-layer sample gradually increased from 1.74 to 2.28, and decreased from 2.07 to 1.73 in the bottom-layer sample. Meanwhile all samples showed a linear trend toward decrease in the EH values, and the variation of EH values of the wall and the bottom layers were between 0.986 to 0.991 and 0.971 to 0.994, respectively. Moreover, the similarity coefficient (S_C) between the bottom layer enhanced with the increasing pit age, ranging from 0.46 to 0.82, and the S_C values of the bottom layer ranged from 0.31 to 0.62. The recovery of DGGE strip series showed the 16S rRNA gene sequence similarity between the ten stronger bands and the typical strains published in Genbank was 90% to 100%, and those sequences belonged to four genera (Olsenella, Atopobium, Streptomyces and Corynebacterium).The three stronger bands that can be amplified from each sample belonged to Olsenella and Atopobium. With the increasing pit age, the dominant degree (d_i) of the three stronger bands in the wall-layer generally decreased, but increased in the bottom-layer. This result revealed the abundant diversity of actinobacteria in the pit mud of Chinese Luzhou-flavour liquor. The actinobacteria community structure and diversity were different among different samples, whereas the community succession is regular. To our knowledge, this was the first time the community and diversity of acinobacteria in pit mud were reported.