Study On The Relationship Between Cholesterol Oxidase And The Red Pigment Of Red High-yield Bacteria

With the aim of the exploitation and application of the Cholesterol oxidase (EC1.1.3.6 COD), the research mainly focused on the relationship between the COD enzyme activity and the red pigment. produced from a red bacteria DGCCN-R. The coupling effect can be used for establishing a screen method to select high producer from mutagenesis.The genetic stability experiments showed that the red strain DGCCN-R was still maintaining its high-yield activity and red color after 8 run of propagation. It was clear the red strain showed genetic stabilization in its color and enzyme-yield activity, and spontaneous reverse mutation had be no found. The red strain was initial identified by physiological and biochemical method and 16S rDNA sequencing, and named red Brevibacterium.Studied on the relationships between enzyme production and the red pigment, between the red pigment and cholesterol residual in fermentation liquid, between the red pigment and cholesterol-4-en-3 from catalysis of cholesterol, A positive correlation between COD activity and the red pigment producing by DGCCN-R was found. The red strain DGCCN-R was treated with NTG(1mg/mL) under ultrasonicztion(200W,50KHz), two mutants were obtained.One showed white color named DGCCN-W, the other one showed pink color named DGCCN-P. The enzyme activity of two mutants was obvious decrease. The positive correlation between COD activity and the red pigment was proved in the other angle. Analyzed the relationship between COD activity and the red pigment producing by DGCCN-R through studying on the carbon,nitrogen,metal ions in the fermentation medium, and conditions for culture such as temperature and ventilation. The results indicated that there were the some impact on enzyme-yield and red-pigment-producing by these factors, and proved the positive correlation between COD activity and the red pigment from fermentation.Isolated the red pigment and analyzed the relationship between COD activity and the pigment from metabolites. Analyzed he red pigment by HPLC, UV, MS means and inhibitor experiment, the results showed the pigment is a type of carotenoid.