| In order to solve the problem of environmental pollution and effective utilization of waste blood in slaughterhouses, the samples were collected from waste blood accumulation soil of slaughterhouses in Shigatse area, and the samples were diluted and coated on blood agar plate for separation. The colonies with large hemolytic rings were selected for purification, and then the strains were preserved. Morphology, physiology and biochemistry, 16S rRNA gene sequence identification, drug sensitivity test and growth conditions of the preserved strains were studied. The protease activity of preserved strains was determined by Folin phenol method, and the blood culture medium conditions were preliminarily optimized to improve the blood degradation efficiency of the preserved strains. The results showed that a strain with high efficiency in degrading blood protein was obtained, and numbered as NWMCC0047. After morphological identification, physiological and biochemical identification, and 16S rRNA gene sequence identification, the strain was identified as Exiguobacterium acetylicum. Its protease activity reached up to 19.00 U/mL. The optimum growth conditions were as follows: glucose as carbon source, beef extract as nitrogen source, disodium hydrogen phosphate as inorganic salt, pH 7, and temperature 20 ℃. Through the preliminary optimization of the degradation conditions of bovine blood protein, the degradation rate reached 21.97% when the amount of blood was 10%, wheat bran was 20 g/L, inorganic salt was not added, and cultured at 37 ℃ for 85 h. The experiment provides a simple and referable operation method for the degradation of waste blood pollution and provides candidate strains for the production of organic amino acid fertilizer. |
