羽毛降解菌的筛选及其降解特性研究

本试验旨在从实验室保藏菌株中筛选出可用于羽毛降解的菌株并优化其培养条件,应用于羽毛的生物降解.以酪蛋白培养基进行菌株初筛,以羽毛为唯一有机营养源制作的羽毛培养基进行菌株复筛;通过细菌形态学观察和16S rDNA序列测定进行菌株鉴定,并对所筛菌株在羽毛培养基中的培养条件进行优化研究.结果表明:1)通过酪蛋白培养基筛选出8...

Screening of Feather-Degrading Bacteria and Its Degradation Characteristics

The purpose of this experiment was to screen out the strains which could be used for feather degradation from the strains preserved in the laboratory,and optimize the culture conditions for feather biodegradation.Casein medium was used for primary screening and feather medium used as the only organic nutrient source for secondary screening;through bacterial morphological observation and 16 S rDNA sequence identification for strain identification,and optimization of the culture conditions of the screened strains in feather medium. The results showed as follows:1)8 strains that could produce casein degradation circles and had high transparency were screened out through casein medium. 2)A strain NLG1 that can degrade feather and produce soluble protein in 3 days was re-screened by the combined method of single feather culture medium and feather degradation liquid index determination. 3)It was identified and named as Bacillus velezensis NLG1. 4)The optimization of the culture conditions in the feather medium of the strain NLG1 was carried out,and the results were that feather substrate concentration was 2.5%(m/v),initial pH was 10,inoculated viable bacteria number was109 CFU/mL,temperature was 27 ℃,additional carbon source was soluble starch,fermentation time was 3 days. 5)After the optimization of feather degradation conditions,the soluble protein content in the fermentation broth was measured to be(32.76±0.07) μg/mL;there were 17 types of amino acids in the supernatant,and the total content of amino acids after fermentation increased from 27. 41 to 112. 18 mg/g. At the same time,the types of free amino acids and metabolites increased from 26 to 31,and the content of most free amino acids and metabolites increased. In conclusion,a natural bacterial strain,Bacillus velezensis NLG1,which can degrade feathers,is screened out in this experiment,and the optimal conditions for feather degradation are defined. Under these conditions,total contents of hydrolyzed amino acids,free amino acids and derivatives in fermentation broth are increased,improving the nutritional value of feather.Chinese Journal of Animal Nutrition,2022,34(2):1313-1324]