Isolation, identification and phosphorus removal optimization of a phosphorus-accumulating Bacillus amyloliquefaciens

Abstract:

[Background] Phosphorus is the main nutrient that causes eutrophication in water. Biological phosphorus removal has the characteristics of low cost, high efficiency and wide application range, and has become a hot spot in the field of water treatment research in recent years. Although some phosphorus-accumulating bacteria have been screened, their phosphorus removal efficiency is not high, the phosphorus removal conditions of the phosphorus-accumulating bacteria need to be optimized. Immobilization and recycling of the phosphorus-accumulating bacteria are urgently needed to be studied. [Objective] Isolation, screen and identify high-efficiency phosphorus-accumulating strains, optimize the environmental conditions for phosphorus removal, explore the impact of adsorbent materials on the phosphorus removal of the bacteria, and provide a theoretical basis for the development and utilization of phosphorus-accumulating bacteria. [Methods] High-efficiency strains were obtained by routine isolation and screening of bacteria, and the strains were identified through morphological observation, physiological and biochemical experiments and 16S rRNA gene sequence analysis; Combined with single-factor experiments, Box-Behnken design and response surface analysis to optimize phosphorus removal conditions; The immobilization effect of the material was evaluated by measuring the adsorption effect of sponge, non-woven fabric and polyurethane foam on phosphorus-accumulating bacteria. [Results] A high-efficiency phosphorous-accumulating bacterium P49 was isolated and screened from the wastewater of a phosphate mine in Lianyungang city, which was identified as Bacillus amyloliquefaciens; The optimal conditions after optimization were pH 6.8, temperature was 31 °C, equipment the liquid volume was 30.2%. Under this condition, the phosphorus removal rate of P49 can reach 80.43%; The application effect of polyurethane foam was better than that of sponge and non-woven fabric. [Conclusion] Bacillus amyloliquefaciens P49 had a good phosphorus removal effect and provides microbial resources for biological phosphorus removal. Adsorption with polyurethane foam can achieve the immobilization and recovery of the strain.

Key words:phosphorus-accumulating bacteria, response surface analysis, Bacillus amyloliquefaciens, adsorbent materials, immobilization