One Strain Of Bacillus Thuringiensis Biological Activity

Bacillus thuringiensis (Bt) can kill Lepidoptera, Diptera, Hymenoptera, Homoptera, Coleoptera and other insect pests. To this end, human beings will be artificially cultured this organism, but also large numbers into the natural world, the world’s largest output, the most widespread of a microbial pesticide. Currently, the study focused primarily on bacteria killing effect and insecticidal gene in molecular biology, but in addition to Bacillus thuringiensis insecticidal activity, but it also has other biological activity and the value of the study can be used no relevant reports.Given the large number of bacteria used will have some impact on the ecological environment, the activated sludge from paper to screen out of one pair of heavy metals and organic phosphorus pesticides have a certain resistance to Bacillus thuringiensis (Bacillus thuringiensis) to the molecular identification, culture conditions, sewage and waste water purification, enzyme properties and other biological activity of Bt. Aims to identify Bacillus thuringiensis on the ecological environment, on the effectiveness of sewage waste water purification, to enhance further understanding of the species provide valuable theoretical basis, the results are as follows:In this paper, the automatic micro-analyzer automatically detects and bacteria16SrDNA sequence of the PCR amplification and sequencing of the isolates were identified. Identification results show that:the strain of Bacillus thuringiensis (Bacillus thuringiensis), and diamondback moth and corn borer have toxic effect.Microbiological culture method with Bacillus thuringiensis for the screening of cultu re conditions, the optimal incubation temperature for the strain is about37℃, the opt imum pH value of7, the optimum incubation time of12hours, the best medium com position and content to:Glucose, sucrose, yeast extract, KH2PO4contents were2.0,1.0,2.0,0.5. The strains of Bacillus thuringiensis on sewage and waste water purification w ith good results, can reduce the sewage BOD5, suspended solids, turbidity, protein, am monia nitrogen and orthophosphate concentration, removal rates were40%,76.47%,42.32%,19.38%,40.66%and61.92%, compared with the control increased by40%,42.08%,24.44%,6.93%,21.2%and47.58%. Of sewage waste water has good flocculation,2days after inoculation, the flocculation rate of69.62%, was increased by57.9%, th e flocculation effect is equivalent to the effect of chitosan treatment. The strains of B acillus thuringiensis can produce amylase, lipase, protease and nitrate reductase, but do es not produce cellulase and pectinase. The strain of organophosphorus pesticides-di methoate and heavy metals-cadmium all have a certain resistance, the maximum tole rance of dimethoate concentration of10mg/ml, dimethoate minimum inhibitory concent ration of2.0mg/ml. The highest concentration of cadmium tolerance of1.0g/L, the minimum inhibitory concentration of cadmium is0.4g/L.