Affects Of Several Organic Matters On Growth Of Acidithiobacillus Ferrooxidans ATCC 23270 And Study Of Its Cbb Gene Expression Difference

Leaching bacillus,which is chemoautotroph,acidophilic and aerobic, is such a special bacillus that can use the iron and sulfur as the substances from mine.Acidithiobacillus ferrooxidans(abbreviation is A.f)the most used leaching bacillus,can the iron and sulfur as the substances from mine.It is chemoautotrophic,acidophilic,aerobic and Gram-negative.Because of its wide range of applications in industrial and agricultural production, the relationship between A.f and the organic matters aroused widespread attention from the day A.f was found.In this paper,we studied affects of three typical organic matters on the growth of A.f ATCC 23270.Acidithiobacillus ferrooxidans ATCC 23270 is an important model organism for bioleaching and bioremediation studies because of its diverse metabolic capabilities,and lix984n is a most widely used extrantant.Little is known about response of cbb genes in A.ferrooxidans to lix984n shock.To define the organism's response of the CO₂ fixation genes to lix984n addition,gene expression of cbb genes were examined by using Real-time PCR.There may be a natural increase or decrease in expression of most cbb genes under 5-min shock by 3%(v/v)lix984n, while sdhC and cbbR had quick responses to the shock.10-min shock had some effect on cbb gene expression,and 15-min shock affected the Calvin cycle greatly in A.ferrooxidans ATCC 23270,as all cbb gene expression was at a very high level.Therefore,after short-time lix984n shock,the solution of A.ferrooxidans can also be re-used to do bioleaching.Meanwhile,we did further study on cbb genes by bioinformation. From the comparison of the deduced amino acid sequences of the putative regulatory proteins of the cbbR in A.f ATCC 23270,C.vinosum(C.v),A. eutrophus(A.e),and X.flavus(X.f),and of CbbP in A.f ATCC 23270,R. capsulatus and R.sphaeroides,we knew more about the two genes. Moreover,we used BDGP website to search for potential upstream promoters of cbb genes.The results showed that some cbb genes shared one promoter.The expression of cbb genes with one promoter was of much similarity.Based on a comparison of these promoters,we can't find a similarity region.It is thus apparent that the overall regulation of the CO₂ fixation genes in A.f ATCC 23270 may be quite complex and remains to be resolved.