Study of the microbial biodiversity of the Lake La Izvor, Chisinau municipality

Abstract

The microbial biodiversity of the lake "La Izvor" in Chisinau municipality was studied. Samples were taken from water, silt, and biofilm. The taxonomic groups of microorganisms were isolated from the samples: microalgae, cyanobacteria, actinobacteria, bacteria, yeasts, and micromycetes. Agarized nutrients specific to each taxonomic group were used to isolate microorganisms.
As a result of the research, 26 genera of microalgae and cyanobacteria from the phylum Cyanophyta, Chlorophyta, and Bacillariophyta were detected and studied. Most genera (21) were detected in water and 5 genera in biofilm. 8 genera of actinobacteria were also detected (Actinomadura, Actinoplanes, Frankia, Geodermatophilus, Micromonospora, Nocardia, Rhodococcus, Streptomyces). Representatives of the genus Micromonospora, Actinoplanes, Geodermatophilus, and Streptomyces are spread in the silt, and Streptomyces predominates in water and biofilm.
Out of 213 strains of bacteria isolated from water, silt, and biofilm, 148 strains were found to be pathogenic (Escherichia, Klebsiella, Salmonella, Sarcina, Shigella, Staphylococcus), and 65 strains (representatives of the genera Bacillus, Brevibacillus, Micrococcus, Pseudomonas) non-pathogenic. Most were isolated from water (120 strains), then from silt (54), and biofilm (39). 7 yeast strains were isolated in pure culture, 3 from water and 4 from silt (representatives of the genera Saccharomyces, Schizosaccharomyces, Candida).
As a result of the study of the fungal community in the water system "La Izvor", representatives of 18 genera were found: Alternaria, Aspergillus, Acremonium, Ambrosiela, Arthrinium, Botrytis, Cladosporium, Chaetomium, Penicillium, Trichoderma, Fusarium, Monilinia, Mucor, Rhizopus, Trichocladium, Phoma, Stachybotris, Ulocladium, Talaromyces. Also, fungi were detected, which could not be determined, because for this it is necessary to carry out more extensive research (biochemical, genetic). Representatives of the genera Aspergillus and Penicillium predominated in all samples.