Molecular Ecology Analysis Of Microbe In Tibetan Kefir And Microcapsulized Starter

Present, it is favorable for civilian in some areas to dunk Tibetan Kefir grains in milk and drink until the milk acidified. It is said that drinking such milk for long term can strengthen body immunity, supply vitamins, slow senescence, eliminate tiredness, especially suitable to patients with stomach, kidney, liver and gall diseases. Tibetan Kefir grains is a milky and colloidal block, with a shape of rice, on which a various of microorganisms inhabit. Cultured in milk for long time, it can increase much in bulk, like a blooming white lotus, so called Tibetan lotus. Tibetan Kefir grains has good fermentative characteristics, but unlike those made of pure-cultured lactic acid bacteria (LAB), the most remarkable speciality is that there is a slight alcohol fermentation caused by yeast, as well as lactic acid fermentation. So Tibetan Kefir is a novel fermented diary with both sourness and alcohol, and if developed, it will have good market prosperity. However, this kind of product is made from Tibetan Kefir grains as starter, with the processing of recuperating and cleaning the grains, and the composition of microorganisms in Tibetan Kefir grains is complex, so the production is hard to scale up through the regeneration of starter. Thus it is a pressing problem that how to use advanced biotechnology to develop a starter that can keep traditional flavor, simplify technology and stabilize production.Starting with the study on molecular ecology of microbe in Tibetan Kefir. We found out the microflora composition and distribution in Tibetan Kefir grains and the dominant microorganisms during the fermentation. With the help of traditional isolation technology, we obtained these dominant strains, and then studied on microcapsules, high-density culturing and optimization. The main results are given as follows:1. The distribution of microorganisms in Tibetan Kefir grains was observed by scanning electronic microscope. The bacterial density in the inner layer of Tibetan Kefirgrain was less than that outer, with curved long lactobacilli dominant, so(?)e ovoid yeast existed also, and interlaced fibre structure could be observed. Plenty of short lactobacilli and a little yeast existed in outer layer, and carrier material was scarely seen.2. The microbial diversity in Tibetan Kefir grains was analysised through PCR-DGGE fingerprinting technology. There existed some difference in Tibetan Kefir grains among...