Detection and Identification of a Putative Ade- nylosuccinate Synthetase Gene Responsible for Tellurium Tolerance In Streptomyces Annu- latus Isolated From an Egyptian Contaminated Site in Hellwan

Mohamed HF, El-meleigy MA, Salem MS Abstract— Tellurium-tolerant actinomycete was isolated from the soil sample collected from an Egyptian contaminated site in Hellwan City near to a cement factory. Isolate identification was done using morphological, physiological and biochemical characterization, chemical analysis of the cell wall, cultural characteristics using the recommended media of the international Streptomyces project (for actinomycetes) and with help of 16S rRNA sequencing.which revealed high identity 98 %, with Streptomyces anulatus strain MG 001 (GenBank accession number GU569951.1). The isolate showed high tellurite tolerance up to 0.6 % (w/v). Tellurite exerts a deleterious effect on a number of small molecules containing sulfur moieties that have a recognized role in cellular oxidative stress. Because cysteine is involved in the biosynthesis of glutathione and other sulfur-containing compounds, and because cysteine desulfurase (IscS), involved in cysteine metabolism, confers tellurite resistance in E. Coli, and other bacterial species, specific PCR was done to isolate this gene from the isolated tellurium resistant streptomyces annulatus. Sequencing analysis of the PCR product which should different size from that expected lead to another putative gene, adenylosuccinate synthetase also responsible for tellirium resistance in Streptomyces species. Further molecular and bioinformatic studies were done here to confirm the sequence of the gene.