Classification And Identification Of Bacilli From Chinese Traditional Medicine And Food And Antagonistic Characterization Of Bacillus Subtilis H110

Studies on taxonomy and resource of bacilli isolated from cheese, oral drugs, extreme environments and soil have been carried out in the two last decades, but reports of bacilli from Chinese traditional medicine haven't been published. Biodiversity and phylogenic status of bacilli by performing taxonomy, is significant for finding, conserving, utilizing of the bacilli resources. This thesis reviewed the historical development, the current taxonomic status and the phylogeny of bacilli.Bacilli, isolated from Chinese traditional medicine and food, were studied by numerical taxonomy and 16S rDNA full lenth sequencing. Based on the phenotypic and genetic characteristics, a bacilli strains Bank was formed.preliminarily. Many strains possessed high levels of antagonistic properties. Among them, five strains (H110, H184, H216, V316 and V382) showed higher antibacterial activity. Compounds produced by 5 strains had characteristics of protein.A numerical taxonomic study has been preformed with 836 strains on 104 phenotypic characteristics. All isolates could be classificated into 7 groups based on results from unweighted average linkage cluster analysis of a similarity matrix, derived from the simple matching coefficient, which were defined at the 75% similarity level.To determine the phylogenetic position of these new groups, the full length of 16S rDNA of chosen strains were sequenced and analyzed with the sequences of type strains of recognized species of bacilli. The results revealed that our strains belonged to the genus bacillus. Strains H285 , H24, H53, H128, V362 and V382 fell to the genetic rRNA group 1 of the genus Bacillus, and H84 exhibited a close phylogenetic relationship to strains of rRNA group 2. The 16S rDNA sequencing show that strain H285 and H24 have similarity values of 93% and 92% to the recognized species Bacillus cereus, respectively. H53 and H128 are closely related to Bacillus vallismortis and Bacillus amyloliquefaciens (91-95% sequence similarity). Strains H382 and H362 formed a coherent clustering with Bacillus subtilis, exhibited levels of 16S rRNA similarity of 93-96% with Bacillus subtilis. H84, falling within Group 2, were clustered within Bacillus fusiformis and Sporosarcina globispora, sharing 90-97% 16S rRNA sequence similarity.Moreover, Twenty-nine Bacillus strains inhibit the growth of 7 plant fungi. And H110 was evaluated for its effectiveness in postharvest control of blue mold and black spot caused by Penicillium expansum and Alternaria alternata on apple-pear (Pyrus bretschneideri Rehd.) fruits. Four treatments (culture, cell-free filtrate, cell suspension and crude protein) of H110 all could significantly reduce incidence and severity at 25℃. Studies in vitro showed that these treatments also had great effects on spore germination. Crude extract was most effective for controlling the two diseases in these treatments. The mechanism by which H110 inhibit pathogens may be related to its ability to produce antagonistic protein and compete for nutrients and space.One component of antifungal proteins from H110 was separated by gel filtration on SephadexG-75 column, which was named H110-I. SDS-PAGE showed that H110-I included two protein ingradients, the molecular weight of which were 50kD and 29kD.