The Distribution Of Bacteria And Actionmyces And The Metabolism Of Bacteria In Sediments Of Dianchi Lake

Dianchi lake a altiplano lake in Chinese southwest has been eutrophiced ,usually measures to remedy it haven't got any ideal result .the mainly reason comes from lacking understanding of Eco-environment in the lake .Dianchi lake is a special lake which sits on the Yunnan-Guizhou plateau,the temperature there is stable ,every season algae can grow in the lake.Sediments in the lake usually be considered as one source of lake water pollution ,but the microbiology which be a very important role to the releasing of nutrition in it seldom be studied .The thesis tries to have a research to the microbiology in sediments of Dianchi lake.The content of this thesis is divided two parts : 1)distribution of bacteria and actionmyces,which mainly investigate the number and species of bacteria and actionmyces in the sediment of Dianchi lake 2)metabolizing phosphorus of bacteria,we isolated some dominated bacteria in the sediments of Dianchi lake and researched their ability of metabolizing phosphorus.When investigating the distribution of actionmyces we found the number has large differences among the different areas.The number of actionmyces in northeast of the lake where has many rivers is the greatest among the different areas,and so does the bacteria. When we arranged the content of acionmyces or bacteria according their latitude and longitude we found their number rise from southwest to northeast fluctuately .The number of actionmyces and bacteria both decline dramatically in vertical .The number of Bacillus is the greatest among bacteria and the number of Micromonospora is greatest among actionmyces.When we studied the relation between phosphorus and bacteria or actionmyces ,we found the number of bacteria or actionmyces has a positive correlation with content of phosphorus ,so the content of phosphorus in the sediments of Dianchi is still a limiting factor to the biomass of bacteria or actionmyces.We isolated the dominant bacteria from six typical areas of Dianchi lake then studied their ability of transforming phosphorus.The results show that most bacteria have the preference in transforming organic and inorganic phosphorus,at the same time,the changing range of transforming ability of organic phosphorus is more than that of inorganic phosphorus,the traditional method of isolating bacteria which have strong ability of transforming phosphorus from solid medium is questionable,when some bacteria are mixed,their ability of transforming phosphorus may change,and the ability of transforming phosphorus isn't correlative with single nutrient directly such as the total phosphorus nitrogen or organic matters.The ability of assimilate soluble phosphorus is also different,espacilly in short time.When sediments was inoculated bacteria into,which is the dominant bacteria of six typical areas of Dianchi lake. The results show that the blooming of bacteria shall reduce the quantity of soluble phosphorus in the water in some time, but as time goes on, some bacteria which ordinarily come from the areas where phosphorus is abundance can increase the quantity of soluble phosphorus releasing from the sediments. At the some time , the constitute of bacteria is also an important element to the releasing of phosphorus in the sediments .