Studies on microorganisms in fermented seafoods

点击翻译按钮获取中文摘要

Microbiological characteristics of several traditional fermented fish products in Japan were studied. The results are as follows;(1) A detailed investigation of the phenotypic, chemotaxonomic and phylogenetic characteristics of the helical bacteria isolated from kusaya gravy revealed that they should belong to a new genus, with enough phylogenetic distance from each of the known species. So we proposed the name Marinospirillum megaterium sp.nov. for the isolates, with a creation of a new genus.(2) Microbial poulation in kusaya garavy was analyzed by grouping of genetic identification from 16SrRNA gene. Sequence analysis of cloned partial 16SrDNA indicated that the major bacteria in the gravy were Bacteroides-Cytophaga group, wall less spirohaeta-like bacteria, etc. The results indicated that there are diverse organisms which are unknown and unculturable in the gravy.(3) Accumulation of organic acids such as lactic acid, acetic acid, etc., which might contribute to the preservability and taste of shiokara, during the ripening of shiokara was studied and it was found that the dominant microoraganisms could form organic acids in shiokara. We also made clear that some inoculated strains into shiokara of Vibrio parahaemolyticus, Clostridium botulinum, Staphylococcus aureus did not grow in it.(4) Three culture methods for the differentiation of Staphylococcus and Micrococcus were evaluated. The results confirmed that OF test of glucose (Baird-Parker's method) is misleading method, while simultaneous use of FP & SK agar was suggested to be useful in routine identification system.(5)A strain of strictly anaerobic and moderately halophilic bacteria isolated from salted fish ovaries was considered to be a new species. We proposed for it the name Haloanaerobium fermentans sp. nov. Both Tetragenococcus halophilus and T. muriaticus were isolated during the fermentation process of fermented fish ovaries with rice-bran.