Phylogenetic Analysis Of The Symbiotic Bacteria Associated With Protists In The Gut Of Reticulitermes Chinese Snyder

As one of the world important pests, termites cause a tremendous amount of economic damages every year. In China, more than 100 termite species distribute in 28 provinces and cities (autonomous regions or areas), especially in south part of Huaihe River area. The main harm of the termites is to the forest trees, the orchard, the field-crops, the wood construction and the rivers and stream dikes, especially serious to the wood construction and the stream dikes. It has been shown that the symbiotic gut microbiota in wooding-feeding termites plays an important role in the digestion of different plant component. Although many studies have been made in termite's research, till recently, very little was known about how the gut microbiota involve in digestion. Previous studies show that one termite intestinal tract habors 10⁹～10¹¹ microbial cells. The microbiota may be important to the efficient digestion of cellulose, the recycle of nitrogen, the metabolism of acetate produced during microbial fermentation of carbohydrate. To obtain a better understanding of the diversity of the bacterial community inhabiting the intestinal tract of wood-feeding termite, Reticulitermes Chinese (Snyder) was used as a model system. All of the results were form the basis for further studies on the metabolic mechanisms of the gut microbiota, and for the new strategies to control wood-feeding lower termites by moving out the symbiotic microorganisms. The main results of this study are as follows:1. To understand the mechanisms of digestion of different plant components in wood-feeding lower termites, the symbiotic bacteria associated with the flagellate, Pyrsonympha grandis inhabiting the intestinal tract of R. chinensis. were studied using micromanipulation techniques. A clone library of the 16S rRNA genes of the bacteria associated with P. grandis was established. Clones were sorted based on the restriction fragment length polymorphism (RFLP) analysis and almost complete 16S rRNA genes of four clones were sequenced. The four clones were affiliated with the Cytophaga-Flavobacterium-Bacteroides (CFB) phylum, "Termite group 1 (TG-1) phylum", Gamma-Proteobacteria, and Beta-Proteobacteria, respectively.2. Eight different ribotypes of bacteria were sorted from the 16S rRNA gene library established for symbiotic bacteria associated with the flagellate, P. modesta. Phylogenetic analysis showed that all the eight clones were affiliated with Spirochaeta.3. Ten different ribotypes of bacteria were sorted from the 16S rRNA gene library established for symbiotic bacteria associated with the flagellate, Dinenympha exilis. Phylogenetic analysis showed that four of these ten ribotypes were affiliated with Spirochaeta, two were affiliated with Beta-Proteobacteria, one was affiliated with α-Proteobacteria, and the other three were affiliated with the Chryseobacterium, Pseudomonas, Delftia sp., respectively.4. Six different ribotypes of bacteria were sorted from the 16S rRNA gene library established for symbiotic bacteria associated with the flagellate, D. porteri. Phylogenetic analysis, showed that two of them were affiliated with Spirochaeta. While the other one was affiliated with Pseudomonas.5. Five different ribotypes of bacteria were sorted from the 16S rRNA gene library established for symbiotic bacteria associated with the flagellate, Holomastigotes elongatum. Phylogenetic analysis showed that two of ribotypes were affiliated with Spirochaeta. The other one was Beta-Proteobacteria.