The new Leavening Bacteria in dough of Wheat flour

据报道，野生酵母和其他微生物参与了中国的配方。(1)用发酵剂和酵母制作的馒头的感官测试结果显示，样品之间的偏好相同，特别是用发酵剂制作的馒头口感较好，而酵母风味较差。(2)对几种微生物进行了纯分离鉴定。微生物鉴定为阴沟肠杆菌GAO。(3)测定了阴沟肠杆菌GAO和ATCC 13047的原料药生物型，两者的原料药生物型均为3305573。热稳定型肠毒素的API生物型为3305763，与分离的阴沟肠杆菌GAO和ATCC 13047不同。(4) BALB株裸鼠经浓缩混悬液经腹腔注射或经探针给药均未见脏器重量变化。脏器未见异常，未见腹泻等。因此，一般认为正常动物和人类的非毒性微生物感染对裸鼠是致命的。考虑到这些事实，阴沟芽孢杆菌GAO似乎没有传染性。此外，肠毒素样物质的产生是不可能的。综上所述，我们认为阴沟肠杆菌GAO及其培养基不具有感染性，而从其器官重量和器官检查结果来看，没有形成肠毒素样物质产生的观点。目前正在对这种细菌和使用这种细菌作为发酵食品的馒头进行慢性毒性试验。

It has been reported the wild yeasts and other microorganisms are involved in the Chinese recipe.(1)The results for the sensory test of Mantou prepared with starter and yeasts showed as same preference among samples,especially Mantou with starter have favorable taste not yeast flavor.(2)Several species of microorganisms were identified when they were purely isolated. The microorganisms was identified as Enterobacter cloacae GAO.(3)The API biotype was determined for E. cloacae GAO and ATCC 13047, both of them were found be 3305573. The API biotype of the heat-stable enterotoxin was 3305763, which was different from that of the isolated E. cloacae GAO and ATCC 13047, respectively.(4)The results upon administration of the concentrated suspension to nude mice of the BALB strain shows no changes in organ weights were observed after intraperitone injection or oral administration with a probe. No abnormal finding was observed on organs, and diarrhea, etc., were not noted either. Therefore,it is generally assumed that infections of non-virulent microorganisms for normal animals and humans are fatal for nude mice. Considering these facts, it seems likely that E. cloacae GAO has no infectivity.Moreover, the production of an enterotoxin-like substance is out of the question. From these facts, E. cloacae GAO and its culture medium were considered not to have infectivity, and in view of the organ weights and the findings on organs, an opinion as to the production of an enterotoxin-like substance was not formed. The chronic toxicity testing of this bacterium and of mantou as a fermented food using this bacteium is now in progress.