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MICROBIOLOGICAL CHARACTERISTIC OF THE ALAZANI RIVER BASIN AND ITS ICHTHYOFAUNA

euroasia

Introduction
Georgia is rich of fresh water resources although water quality in water surface media does not correspond to European regulations. The main reason for this is untreated sewage waters causing collection of large amount of biogenic materials that determines active growth (eutrophication) seaweeds. This process is accompanied by oxygen exhaustion and destruction of water ecosystem. [5-10]. Such wastes as domestic consuming, industrial and rain waste waters, pesticides , that occur in water due to irrigation of agricultural lands, influence chemical as well as bacteriological contents of the water.[1.7.8] Chemical substances, accumulated in basins, might cause negative ecological changes. Micro flora and in particular eukaryotic as well as prokaryotic microorganisms sensitively reacts to such ecological changes. Thus, the microbiological characteristic of the river Alazani and its Ichthyofauna is very topical. [9]

Material and Methods
Research sample was taken within the period of July-August. The research object were the river Alazani water and gills and skin of one of the dominant representative fish “barbel”. Sample collection, preparation and analysis were performed by microbiological methods, that are accepted in ichthyopathology and sanitary microbiology. Organs and tissues were inoculated in selective growth medium [4] for qualitative and quantitative analysis. Quantitative measurement of fish microbial contamination (bacterial fib ration) was performed by the combination of mesophilic aerobic and facultative anaerobic bacteria by MAFAB R method. [2] . Total bacteriological pollution was measured by the amount of grown colonies, the formation unit of which was (gce) per 1 gr organ. [3-6-11]

Discussion of the obtained results
Obtained data proved that fish micro flora studied by us reacts to the river abiotic, biotic and anthropogenic processes. According to the obtained data 24 families of microorganisms were isolated: Aeromonas, Acidovarax, Acinetobacter, Alcaligenes, Bacillus, Edwardsiella, Enterobacter, Enterococcus, Escherichia, Candida, Citrobacter, Clostridium, Flavobacterium, Klebsiella, Micrococcus, Moraxella, Proteus, Pseudomonas, Rhodotorula,

Roseomonas, Serratia, Staphylococcus, Vibrio, Yersinia.
Ichthyofauna micro flora is closely related to water bacterial pollution, and their amounf in fish could be changed even when reservoir micro biocenosis content is stabile. Although, in the barbell micro flora the following aerobic gram negative microorganisms were always stably observed: Acinetobacter, Aeromonas, Alcaligenes, Clostridium, Micrococcus

As it is known, temperature factor activates and decreases the growth of micro flora that determines seasonal dynamics in bacterial population. E.G. In autumn in Alazani barbell gills and on the skin the following microorganisms Aeromonas, Bacillus, Clostridium, Pseudomonas, were identified. However it mostly was contaminated by Aeromonas hydrophila and A.caviae- species. Seasonal dynamics of enterobacterial contamination increased in summer months and reached 23%. The presence of enterobacteria in Alazani water is determined by anthropogenic contamination of the water: household sewage and wastewater, whilst seasonal increase is related to water warming in summer period. As a result of regional study, Alazani water was mostly contaminated by sulfitreducing clostridia that is an indicator of fecal contamination. On the oplural gills and skin of the caught fish contamination was mostly observed in Shakriani and Gurjaani app. 103-104 gke/g in 2014, rather than at Akhmeta and Artana. The increase of fseudomonadas was also observed in winter, that could be explained by the stability of temperature mode. In winter the following species of psykhrophilic microorganisms: Bacillus, Flavobacterium, Microccocus, Pseudomonas were identified.

The main criterion for fish flash quality indicator is total amount of mesophilic aerobic and facultative microorganisms. Obtained results proved seasonal changes for no more 5-104 gce/g of these microorganisms in fish skin and gills, that is an indicator not only of seasonality but ecological condition of the water as well.

According to the observation was have established that the contamination on barbell skin and gills in Alazani water at Shakriani and Gurjaani in July-August period reached respectively 2,6-104, და 3,7-104 gce/g (norm 5.0×104) whilst at Akhmeta and Arthana it was 1.7-104, და 3,5-104 gce/g. The difference between them was nearly 1.5-2 fold more that must be explained by the increase of fecal masses at Shakriani and Gurjaani.

As it is known fish gills have essential barrier function for fish organism. Through them the relation between water and fish internal organs is possible. [8]. As a result of toxic damage of gills, these substances as well as other various microorganisms are able to penetrate into fish internal organs. In healthy fish gills microorganisms have protection function. They clean the water in fish organism from these microorganisms.

Thus, sanitary-hygienic norms of the river Alazani are not respected, non-normative inflow of fecal masses and sewage in Alazani is present, that deteriorates water ecological condition and causes its pollution by microorganisms. The studies proved that opportunistic species of bacteria dominants in water: Acinetobacter, Aeromonas, Alcaligenes, Citrobacter, Clostridium, Pseudomonas.

The fact is that the bacteria of this species are able to survive in water and in hydrobionts for a long time. According to the indices microorganism contamination has undulating character. From Autumn the contamination is close to norm, that cannot be said about summer period. Regional changes were also observed, e.g. it is quite High at Shakriani than at Akhmeta and Artana, that was likely encouraged by anthropogenic influence and water high temperature in summer.

Bibliography

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