Reconstruction And Analysis Of Metabolic Networks Of Bacillus Thuringiensis

Bacillus thuringiensis is a Gram-positive bacterium which widely spread in soil. It can form spores and insecticidal crystal protein in stationary phase of bacterial growth, the high insecticidal activity is due to its insecticidal crystal protein. At present, Bacillus thuringiensis is one of the most widely used as biological pesticides. Bacillus thuringiensis can produce so much insecticidal crystal protein, its carbohydrate metabolism、amino acid metabolism and energy metabolism should have a certain degree of specificity. This study based on the long-term research on whole-genome sequencing, protein interaction, regulation of metabolism and gene cluster and regulation of secondary metabolites about Bacillus thuringiensis, by using bioinformatics to compare and analyze carbohydrate metabolism、amino acid metabolism and energy metabolism of Bacillus thuringiensis, then verify some enzymes in important metabolic pathways using RT-PCR. The object is to find functional genes which related to form insecticidal crystal protein.1. Using bioinformatics methods to reconstruct carbohydrate metabolic networks, amino acid metabolic networks and energy metabolic networks of 6 Bacillus anthracis strains,10 Bacillus cereus strains and 3 Bacillus thuringiensis strains which genomes were sequenced, then reconstruct these three metabolic networks of strains YBT-1520、BMB 171 and CT-43 that genomes were sequenced by our laboratory.2. Compare and analyze the differences of Bacillus thuringiensis YBT-1520、BMB 171、CT-43 and Bacillus anthracis、Bacillus cereus, then predict that the similarity and specificity of the three strains. These three strains all have some necessary metabolic pathways, such as glycolysis, tricarboxylic acid cycle, cystine metabolism, arginine metabolism and energy metabolism, but they may have some specific pathways, Bacillus cereus have higher efficiency in utilizing monosaccharide, Bacillus anthracis rich in degradation and transport pathways of amino acids and there is a glutamate metabolic bypass way exist in Bacillus thuringiensis which can transform glutamate into y-aminobutanoate.3. According to predicts, there are isoenzymes exist in carbohydrate metabolic networks、amino acid metabolic networks and energy metabolic networks of Bacillus thuringiensis CT-43, study the expression of isoenzymes in log phase and stationary phase by using RT-PCR. The result shows that:isoenzymes don’t express in early log phase; malate dehydrogenase, succinate dehydrogenase flavoprotein subunit, aspartate aminotramsferase, butyryl coenzyme A dehydrogenase, aminoacylase, pyruvate dealdolase, threonine dehydratase, all express in stationary phase.