Secondary Metabolites Produced By Myxobacteria

The work in this thesis was mainly related to the second metabolites produced by myxobacteria. According to the types of the second metabolites, there contains two parts in the thesis. In the first part, the volatile organized compounds (VOCs) emitted by myxobacteria were studied. We collected the VOCs from the samples by using a closed-loop stripping apparatus (CLSA) and separated and identified the VOCs with GC-MS. Then the constituted volatile compounds from different strains in different cultured conditions were compared. More than sixty kinds of the volatile compounds belonging to different classes were found. Among these compounds three kinds of terpens were identified as a-pinene (3), dl-Limonene(4) and α -Thujene (19), which were firstly reported in myxobacteria. A unique pyrazine, identified as 3-methoxy-2,5-dimethylpyrazine (11) in our studies had been reported by researchers in GBF of Germany in their study with Chondromyces crocatus. The substances with good symmetry, such as l,3,5,7cyclooctatetraene (5), belonged to several groups. It was interesting that we also found some sulfur-compounds that were reported produced by actinomycetes. During the course of the data analysis, we found a possible relationship between the occurring of volatile compounds and the morphogenesis of myxobacterial fruiting bodies.Myxococcus fulvus HW-1, a salt-tolerant strain changes its morphogenesis process in different conditions. Usually the morphogenesis was carried out together with the production of second metabolites at the same period during the life cycle of myxobacteria. In order to prove the relationships between them, we analyzed the...