Screening And Identification Of Cadmium Tolerant Microorganism From Sludge

All the people pay attention to the problem that heavy-metal has polluted in our environment. It is a focus at present that microorganism is very important to deal with the heavy-metal pollution.Especially,the microorganism of endurance is used to dealing with the heavy-metal in the sludge, which is superior to the traditional way of physical and chemic.The microorganism that possess endurance to the heavy metals is rich in natural resources. For example,it exist in the the contaminated water and sludge that comes from factory, which is used to deal with liquid waste.The way not only reduce the cost of operation, but also possess excellent benefit of economy and environment,and establish base in microorganism dealing with cadmium sludge in Cadmium.The main purpose of this experiment is screening and identification of Cadmium tolerant microorganism from sludge that comes from a factory of making medicine.The study measuresed the growth curve of Cadmium, Cadmium and Zinc under different concentration,pH, absorbed capacity of Cadmium and Zinc,and infrared spectrogram.Besides,we researched the feature and mechanism of microorganism. Results are carried out as follows:Two kinds of strain are separate from the sludge that is from medicine factory. Assign is A|, B2. From identification, A₁ is F.Meningosepticum, B₂ is escherichia coli.Al can grow in the culture media contained Cadmium reached 43.80mg/L. and B2 can grow in the culture media contained Cadmium between 43.80mg/L～87.60mg/L.In this density, the growth trend of B2 is more more obvious than A1.The pH of culture medium is lower after going up first when the content Cadmium of culture medium is between 4.38mg/L and 87.60mg/L.When the content Cadmium of culture medium is 0mg/L, culture medium of A1 strain is acidity.Meanwhile, in others concentration of Cadmium, the pH of culture medium is debase with increase concentration of Cadmium.When the content Cadmium of culture medium is 0.00mg/L, the pH of culture medium of B2 strain is debase. When the content Cadmium of culture medium is between 4.38mg/L and 21.90mg/L,the pH of culture medium of B2 strain is increase.When the content Cadmium of culture medium is between 4.38mg/L and 219.00mg/L, the pH of culture medium of B2 strain is debase then increase. In this concentration, the pH of culture medium is debase with increase concentration of Cadmium except the content Cadmium of culture medium is 0.00mg/L.The content Cadmium of A1 and B2 strains is higher between 4.38mg/L and 43.80mg/L.The Cadmium content in the A1 and B2 strains has a process which becomes big first to diminish with change of time.When the content Cadmium of culture medium is 4.38mg/L, the absorption ability of A1 in Cadmium has raised which add Zinc to culture media. When the content Cadmium of culture medium is between 4.38mg/L and 8.76mg/L,the absorption ability of B2 in Cadmium has raised which add Zinc to culture media. Accompany with the increasing of content Cadmium of culture medium, the absorption ability of A1 and B2 in Zinc has raised which add Zinc to culture media.Through IR spectrum analysis,the way of endurance for heavy metals is main adsorption outside the cell wall.This experiment is just initial to describe the endurance scope of A1 and B2 to Cadmium.it also need have a better certaining of the biggest endurance for Cadmium in order to possess more comprehensive data direction that applied for getting rid of Cadmium. In the experiment ,we fixed the absorption condition of A1 and B2 to Cadmium only by the records just from the surface and simple data.It have not gone deep into the specific mechanism of endurance for Cadmium.For the larger function in cadmium pollution.we should continue to research the endurance for Cadmium mechanism deeply.