Relationship Between The Biological Characteristics Of Marine Habitats Bacillus, Pharmaceutically Active And Cyclic Peptides

Cyclic peptides are important substances produced by microbes, with a wide range of physiological activity and research value. Many of them are derived from bacillus. In this paper, bacillus producing cyclic peptide compounds derived from marine and this strains may be screened by cyclic peptide production.These strains can be mutagenic ultraviolet and nitrite to get the strains producing high cyclic peptide,and strain fermentation conditions were optimized by orthogonal experiment.(1)Bacillus is important pesticide formulations of viable resource bacteria, antibacterial activity at its plant in addition to the performance itself inhibitory effect related, and produce a variety of activity also have some relevance, and its metabolic activity is often closely related activity and yield was found that the activity of strains of the target compound is positively correlated。Got three strains(BL10-02、BS10-15 and BS10-19)have high activity and antibacterial activity.(2)The experimental strains were isolated and purified from the ocean to obtain single colonies of strain, fermentation liquid was tested in cyclic peptide production and antibacterial activity to get two strains(BL10-02 and BM10-01)having high cyclic peptide production and high antibacterial activity.The strain of BL10-02 was mutagenized by UV and nitrous acid treatment to get 17 high activated strains.Among them 7 strians bacteria Alternaria solani fungus spore germination inhibiting effect by the 7 strains from the 17 high activated increased four-fold.BM10-01 same after UV mutagenesis and nitrous acid mutagenesis, get 5 inhibitory activity was increased 2-fold strain.Select BL10-02 high activity strain cyclic peptide production tests, cyclic peptide production by up to more than the original strain is BL10-02-7 production increased 49%。(3)After the culture conditions were optimized,the results showed that the mutant strain BL10-02-7was stable and the cyclic peptide yield of which increased by 57% than the original strain. Preliminary optimization of culture conditions of the mutant showed that the optimal fermentation medium included peptone(7g/L), yeast extract(4g/L), glucose(0.5 g/L), Na Cl(30g/L), Mg Cl2·6H2O(2.3g/L), KCl(0.3g/L), Fe PO4(0.02g/L), the appropriate p H was 7.0, the optimal incubation temperature was 25 ℃.(4)In this study, four different forms colonies are gathered to study the relationship between morphological and physiological characteristics and yield of cyclic peptides.The results showed that dispersed smooth strains subculture in stability and cyclic peptide production aspects obvious advantage and havea higher antibacterial activity, for future breeding strains provide some help.