Screening Of The Extracellularly Enzymes Producing Bacteria And Its Transform Efficiency Of Organic N And P In The Ponds

With the rapid development of aquaculture, the deterioration of water environment became a limit factor of development. In order to find a new method to improve the water quality, in this experiment, we aimed to screen some extracellularly enzymes-producing bacteria form nature, which could reduce the contents of organic subtance in the pond water.Different bacteria were separated from the soil and sullage in the compond system. Select the target bacteria which have the ability to produce alkaline phosphatase by using the tiny board coloration, or protease by using protease differential medium. Select again by measure their ability of enzymes producing. The method of measuring alkline phosphatase activity is using disodium phenyl phosphate, while using Lowry method to measure the activity of protease.Liquid medium which contained these extarcellular enzymes were put into the eutrophic water respectively. Check the contents of organic subtance, and do research on their influence to N and P in the water.The result is that:(1) Four kinds of bacteria with strong ability to produce alkaline phosphatase were chosen (R1, R3, R4 and P3). Compare with the contrast, all of these bacteria had the ability to transform onganic phosphor, and the efficiency was 55.09%,36.36%,52.62% and 54.23%, respectively.(2) Two kinds of bacteria with strong ability to produce protease were chosen (PRO1 and PRO9) their protease could catalyze the reaction of ammoniation, to reduce the content of organic nitrogen.In this experiment, we got bacteria R1(PR09), which can produce both alkaline phosphatase and protease. Some experiment was doing on, to get the suitable condition of R1 to produce these extracellularly enzymes. The result was that:(1)In the process of cultivation, the extracellular alkaline phosphatase activity of R1(PR09) was growing when the quantity of bacteria was increasing. But 36 hour after inoculation, the activity of proease reach the top, and then, the activity was decreased, no longer with the increasing of bacteria quantity.(2)The most suitable tempreture of R1(PRO9) for alkaline phosphatase producing was 37-47℃, and for protease was 67℃.(3) The most suitable pH of R1(PR09) for alkaline phosphatase producing was 8-10, and for protease was 7.In this experiment, we got some kinds of bacterias with the research prospect which had strong production capacity of extracellular enzymes, and could be used to transform organic subtance to improve the water quality of pound.