Culture-dependent and -independent analyses of microbial flora of funazushi and search for Lactococcus garvieae, an equol-producing bacterium

鱼米发酵过程中的微生物植物群，采用SSCP技术，（单链构象多态性）分析和通过非培养DGGE微生物计数从发酵开始时的10^2cfu/g增加到10^8cfu/g。g，在7天内pH从6.5降至4.0以下。培养法测得的鱼腥藻优势菌群为葡萄球菌属。在早期阶段，植物乳杆菌从14~90天开始，之后是副开氏乳杆菌。<th><th>还检测到近平滑念珠菌、假丝酵母菌等。至于乳酸菌生长所必需的由大米淀粉形成的可发酵糖，在早期阶段出现的表现出高淀粉分解活性的芽孢杆菌菌株被认为是负责的。DGGE分析表明，葡萄球菌属（Staphylococcus spp.）在发酵早期检测到了其它种类的细菌，而在第7天后检测到了植物乳杆菌、弯曲乳杆菌、耐乙酸乳杆菌等。这是第一次发现发酵海产品中存在耐乙酸乳球菌。此外，在60份船藻样品中发现了已知生产雌马酚（前列腺癌的假定抑制因子）的加尔维乳球菌。但培养法和PCR法均未检测到L.garvieae

Microbial flora during the fermentation of funazushi, crucian carp fermented with rice, were studied both by culture-dependent method with SSCP (single strand conformation polymorphism) analysis and by culture-independent DGGE (denaturing gradient gel electrophoresis) method.Microbial count increased from 10^2cfu/g at the beginning of the fermentation to 10^8cfu/g after 3 days and pH dropped from 6.5 to below 4.0 within 7 days of fermentation. Dominant microflora of funazushi by culture method were Staphylococcus spp. at the early stage, Lactobacillus plantarum from 14^<th> to 90^<th> day, and thereafter L.parakefiri. Yeasts of Candida parapsilosis, C.versatilis, etc were also detected. As for the formation of fermentable sugars from rice-starch necessary for the growth of lactic acid bacteria, Bacillus strains, showing high amylolytic activity, appeared in the early stage were thought to be responsible. By the DGGE analysis, Staphylococcus spp. and some variety of other bacteria were detected at the early stage of fermentation, while L.plantarum, L.curvatus, L.acetotolerans, etc were detected after the day 7. This is the first description to show the existence of L.acetotolerans in fermented seafoods.Further, Lactococcus garvieae known as producer of equol, postulated inhibitory factor in prostate cancer, was searched for in 60 funazushi samples. However, L.garvieae was not detected both by culture and PCR methods