Study Onthe Enrichment Culture Of Nitrifying Bacteria And The Effect Of Water Purification

With the continuous development of China's economy and the discharge of pollutants from industries such as industry,crop farming,and animal husbandry,there is a tendency for pollutants such as ammonia nitrogen and sulfides in natural waters to increase.Ammonia,sulfides,and other pollutants present in water bodies pose a certain hazard to aquaculture,which not only causes damage to aquatic animals,but also affects the quality of aquatic products,and thus affects food safety.How to degrade these substances in a green and efficient way is a research hotspot.Nitrifying bacteria are a kind of autotrophic bacteria with nitrification,including nitrifying bacteria and nitrosating bacteria.Their main characteristic is that they can convert NH₄⁺into NO₃^-through the process of NH₄⁺-NO₂^--NO₃^-.Reduce the ammonia nitrogen content.Therefore,it is of great significance for purifying water bodies and protecting the environment.In this experiment,5 strains of nitrifying bacteria were isolated from seawater using a selective medium.The isolated strains were identified by colony morphology,Gris reagent and 16S-rDNA sequencing,and were finally screened by nitrification test.A nitrifying bacteria with strong nitrification and high growth rate.Orthogonal experiments were used to optimize the culture medium,and the original mixed bacteria solution was subcultured,enriched and cultured,and then put into artificial sewage,and the water purification capacity of the strain and the high-throughput sequencing of the enrichment fluid were determined.The experimental results show that the isolated nitrifying bacteria are Arthrobacter and have strong nitrification ability.The pure nitrifying bacteria and mixed bacteria have strong effects on ammonia nitrogen,sulfides and aerobic substances in artificial sewage.The removal effect.The optimum medium composition for nitrifying bacteria is:glucose 20 g/L,ammonium sulfate 15 g/L,manganese sulfate 0.2 g/L,magnesium sulfate 0.01 g/L,peptone 5 g/L,dipotassium hydrogen phosphate 0.22 g/L,sodium bicarbonate 2.4 g/L,ferrous sulfate 0.073 g/L,seawater 1 L.The optimal culture conditions were as follows:initial pH 7,inoculum volume 5%,liquid volume 100 mL/250 mL,temperature 25°C,rotation speed 180r/min.