采用分子生物学方法对腐乳发酵过程中各阶段的发酵样品微生物的群落结构进行研究和探讨，提取样品中细菌的总DNA，通过PCR的方法获得其16S rDNA扩增片段，对所得片段进行克隆、转化，得到40个转化子。通过16S rDNA-PCR方法对转化子进行验证，结果显示其中16个为假阳性，对其余24个转化子进行双向测序，分析序列同源性，将具有显著同源性的序列归为一类。同时对所得序列进行检索分析，它们中部分与GenBank中已知基因序列具有显著同源性，另一部分序列检索分析显示为目前仍不能通过人工培养得到的未知微生物。通过对复杂微生物群落的分子生物学研究，进一步认识了腐乳发酵过程中菌种以外的杂菌分布情况，找出细菌群落变化规律，以及微生物群落结构变化与发酵过程之间的关系。

The variation of bacteria population in sufu fermentation was studied by molecular biology methods. The Genome DNA was extracted from the bacteria in Sufu sample, and its 16S rDNA fragment was amplified by PCR for further cloning and translating. The achieved 40 converters were examined by 16S rDNA PCR, 10 of which were false positive. Then the rest were sequenced bidirectionally for classifying them into different groups according to their homology. Meanwhile, comparison of these sequences with those on GeneBank by using Blast software showed that some genes had significant homology with foregone sequences in the GeneBank. This study enriched the knowledge of bacteria population distribution in sufu fermentation and revealed the relationship between microbe variation and Sufu fermentation.