THE EFFECT OF ANTIBIOTICS, FUNGICIDES AND ULTRAVIOLET RADIATION ON CULTURES OF MICROALGAE AND CYANOBACTERIA ISOLATED FROM THE SOIL OF RICE FIELDS

Abstract

The effect of broad-spectrum antibiotics (ampicillin, tetracycline, ceftriaxone) and fungicides (fluconazole, nystatin), as well as ultraviolet radiation on microalgae cultures Chlorella vulgaris sp BB-5, Chlamydomonas sp Sh-2 and cyanobacteria Oscillatoria pseudogeminate sp BB-11, Spirulina sp Sh-8, Phormidium sp Sh-4 and concomitant microorganisms isolated from the soil of the sown fields of Birlik village (Almaty region) and Shieli village (Kyzylorda region) was studied. The concentrations of the studied antibiotics ampicillin, tetracycline, 200 μg/ml and ceftriaxone 100 μg/ml suppressed the vital activity of all cyanobacteria and concomitant bacteria. Concomitant micromycetes were suppressed by both studied fungicides at a concentration of 40 μg/ml, most bacteria were suppressed by a combined preparation (tetracycline + fungicide).  The studied strains of cyanobacteria were more sensitive to antibiotics than to fungicides. Perhaps this is caused by the physiological similarity of bacteria and cyanobacteria, as well as their symbiotic relationship. Irradiation of cultures with ultraviolet radiation showed the greatest sensitivity of microalgae, so when irradiating a suspension of microalgae and cyanobacteria with UV rays for 10-20 minutes, all microorganism cells died, whereas 10-15 minuteirradiation allows us to get rid of only some non-spore-bearing bacteria.