传统泡菜腐败过程中膜醭和盐卤的 微生物区系分析

目的研究以Lactobacillus plantarum为菌剂发酵的传统泡菜在腐败过程中微生物的区系变化。方法通过提取腐败前、中、后期3个阶段腐败膜醭及盐卤中微生物总基因组并构建16S r RNA基因文库,分析其细菌群落构成和动态变化,并通过丰富度指数SChao1和SACE、覆盖率及多样性指数H等揭示其群落多样性。结果从不同阶段膜醭和盐卤样品中共检测到Lactobacillus等15个属,盐卤及膜醭不同腐败阶段的微生物区系差异较大。其中L.plantarum为腐败前期膜醭及盐卤样品中的优势菌。腐败中期膜醭中的优势菌群为L.plantarum、Propionbacterium acidipropionici,腐败中期盐卤中的优势菌为L.plantarum、Enterococcus malodoratus、P.acidipropionici。而腐败后期样品中,膜醭的优势菌为E.malodoratus、Providencia rettgeri和Shewanella algae,盐卤的优势菌为Morganella morganii、S.algae、E.malodoratus和Proteus mirabilis。结论盐卤及膜醭中的微生物区系在腐败前、中、后期都以细菌为主并细菌种类有差异较大。腐败前期以革兰氏阳性为主,腐败后期以革兰氏阴性为主。

Microbial communities in biofilm and brine samples during the spoilage process of traditional pickle

Objective To study the dynamic change of microbial flora in the traditional pickle brine during the deteriorating process which was fermented by starter culture Lactobacillus plantarum. Methods The total genomes of microbes in the biofilm and brine samples were extracted during the early, middle and later spoilage stage. 16S rRNA gene libraries were constructed to analyze the microbial floras. The microbial varieties were revealed by SChao1, SACE, the index of richness, coverage and H (the index of diversity). Results Lactobacillus and other 14 genera were identified. The microbial floras of different biofilm and brine samples from different spoilage periods were diverse. L. plantarum was the dominant organism in both biofilm and brine samples in early spoilage stage. L. plantarum and Propionbacterium acidipropionici were the major agents in biofilm sample in middle spoilage stage, while L. plantarum, Enterococcus malodoratus, and P. acidipropionici dominated in the brine. E. malodoratus, Providencia rettgeri and Shewanella algae were the dominant ones in biofilm samples of late spoilage stage. Morganella morganii, S. algae, E. malodoratus and Proteus mirabilis were the dominant ones in brine samples of late spoilage stage. Conclusion Bacteria were the dominant microorganism in all biofilm and brine samples. But the bacterial floras were diverse among different spoilage stages. In the early deteriorated stage, the major agents were gram-positive strains, while in the later-deteriorated stage, gram-negative strains were the domi-nant ones.