| Abstract [eng] |
Analysis of bioactive compound synthesis gene transcription in Krubera – Voronja Cave bacterial Because of increasing emergence of antibiotic resistant bacteria, scientists are constantly trying to discover for new bioactive compounds. A promising environment for such a search - caves. A limited resource of available energy in such habitats, forces organisms to compete through production of antimicrobial agents. Many bacteria that show biological activities have already been isolated, although the bioactive compound production genes remain unexplored. Four bacterial strains isolated from Kruber-Voronja cave samples were analyzed during the work. In the genomes of these microorganisms, genes for the production of bioactive substances have been identified: Streptomyces sp. - Type I and Type II PKS genes and NRPS gene; Pseudarthrobacter sp. - one NRPS gene; Pseudomonas sp. - two different NRPS genes; Planomicrobium sp. - one gene coding for Type I PKS. Growth curves were constructed for all four strains by growing microorganisms nutrient rich and nutrient poor enviroments. Total RNA were extracted from the cells in the exponential growth phase, in the transition to stationary growth and in the stationary growth phase. In case of Pseudarthrobacter sp. strain NRPS expression was observed only in nutrient poor medium, during all growth phases. For Streptomyces sp. Type I PKS expression was observed only during exponential growth in rich media, and Type II PKS at all growth stages, both in rich and poor media. Streptomyces sp. expression of the NRPS gene, similar to Pseudarthrobacter sp. strain, observed only in nutrient poor media, during all growth stages.For Pseudomonas sp. the expression of one NRPS gene was not observed and the other NRPS gene expression was observed under all conditions tested. The quantitative expression analysis using specific quantitative PCR primers showed that in case of Streptomyces sp. strain PKS genes D_18_PKS_1 and D_18_PKS_2 expression levels were completely different depending on the composition of the nutrient amountin growth media, and the expression of the gene L_5_PKS_1 was higher in nutrient poor media and independent of the growth phase. In case of Pseudomonas sp. strain expression of L_3_NRPS_3 gene increased over all growth phases but was not dependent on the composition of the culture medium. The expression of the gene I_13_NRPS_1 was significantly higher during exponential growth in nutrient poor media, and the expression of the gene A_16_NRPS_ depended on both the composition of growth media and growth phase. |
