Experimental ecological research on the relationships of pathogenic microorganisms with algae

Abstract

Aim. The ecological relationships between Leptospira interrogans spirochetes and Chlamydomonas proteus algae and the response explicitness of individual serological types of leptospires to the allelopathic effect of algae were to be investigated during the experiment. Methods. C. proteus algae monocultures were cultivated on the Fitzgerald’s medium in the Zehnder and Gorham’s modifi cation. Sterile fi ltrates of their cultures were diluted with the nutrient medium in the ratio of 1 : 10, 1 : 100, 1 : 1,000, 1 : 10,000. Leptospires were cultivated on the Terskih and Korthof’s medium with the addition of 10 % inactivated sheep blood serum. The test samples contained diluted culture fi ltrates of algae and leptospires. The control samples were the environment for algae and leptospires cultivation. Results. In the samples with the 1 : 10 – 1 : 100 dilution of algae fi ltrates, the content of leptospires in the test samples was signifi cantly lower than in the control samples, indicating their moderate and weak inhibition. There were no statistically signifi cant differences between spirochete culture densities in the test and control samples with the dilutions of 1 : 1,000–1 : 10,000 algae fi ltrates. Conclusions. In the experiment, a topical type of ecological interspecies relationships is formed between L. interrogans and green species of C. proteus algae, which is realized through the release of biologically active substances into the habitat by C. proteus. According to the increasing sensitivity to the allelopathic effect of C. proteus, serological types of leptospires formed a row: Tarassovi, Icterohaemorrhagiae, Pomona, Grippotyphosa, Australis, Sejroe, Canicola, Hebdomadis.