Microbiological and Mathematical Modeling Studies on the Production of Quinone Compound by some Streptomyces spp.

Abstract

Abstract During the screening program for isolation of Streptomyces sp. from Egyptian soil samples that have the ability to produce tacrolimus compound, Streptomyces isolate was found to produce a compound that interfere with HPLC analysis of tacrolimus compound, The producer organism was identified by phenotypic and genotypic methods. These methods confirmed that the strain name was Streptomyces pilosus SBG-NRC-216.The produced compound was purified and identified by spectroscopic analysis as Piloquinone. A series of experiments were conducted to investigate efficacy of the compound. Piloquinone showed a potent anticancer activity exhibiting IC50 µg/ml: 17.04, 41.07, 52.12, 87.82 and 177.67 against five different human tumor cell lines; breast cancer cell line MCF-7, human liver cancer cell line HepG2, human lung cancer cell line A549 and human colon cancer cell line Caco2 and HCT-116 respectively. However, the results proved that Piloquinone doesn’t have any antioxidant activity and antimicrobial activity against the tested pathogenic strains, the results also indicated that Piloquinone has a weak antiviral activity against the H5N1 virus. The study was extended to include maximizing Piloquinone production; the results revealed that the medium described in protocol No. 3 has a significant effect on Piloquinone production and 144 hrs is the best incubation period for Piloquinone production. The technique of Biostatistical experimental design was also conducted. Two stages were involved, by applying Plackett-Burman design; more than two fold increase was achieved when compared with the basal medium composition. In addition, the second stage of optimization (Taguchi design) was also conducted and more than fourfold increment was achieved.