BIODEGRADATION OF PHENOL AT HIGH CONCENTRATION BY A NEWLY ISOLATED ADAPTED AND IDENTIFIED BACTERIA LECLERCIA ADECARBOXYLATA.

Wastewater treatment has become very important due to insufficient water resources. For wastewater treatment, Physical, Biological, and Chemical methods have been developed. Bioremediation is the most efficient and environmentally sustainable process among them. This article presents the continuous decomposition of phenolenriched refinery effluent by stimulated, activated, and adapted granules of bacteria and yeast cultures. A novel Leclercia adecarboxylata has been revealed to be capable of degrading phenol at high concentrations as well as its potential for bioremediation of phenolic wastewaters. Water samples were collected from the first and second biobased basin of the refinery in the Republic of North Macedonia to observe microbial growth. Microorganisms were extracted from refinery and synthetic wastewater. The whole procedure was performed in laboratory bioreactors under defined parameters. Several colonies of bacteria and yeast capable of degrading petroleum wastewater and phenol were isolated and adapted from active sludge originating from the treatment system of oil refinery. Phenol concentration was gradually increased from 100 to 2000 mg/L^-1 under laboratory conditions. All isolates were incubated with refinery wastewater for 20 days at 35°C and phenol degradation was monitored. 4-aminoantipyrine in the colourimetric assay method according to standard methods reported by the United States Environmental Protection Agency (EPA) was used for measuring the changes in phenol concentration. Final Strains were grown in batch cultures in 250-ml flasks containing 50 ml of MSM supplemented with phenol (1500 mg/liter utilized phenol as the sole carbon source and energy. Totally 9 isolates of 5 bacteria (BF), and 4 yeasts (KvF) were identified as; Leclercia adecarboxylata, Bacillus subtilis, Citrobacter sp., Raoultella sp. In conclusion, it was identified that BG BF-1 was the most resistant and durable bacterial strain which can degrade and adapt at high phenol concentration. Phenotypic profiling and sequence analysis identified the strain as Leclercia adecarboxylata. The resistance and viability of Leclercia adecarboxylata at high level of phenol concentrations indicates that this would be used for phenol biodegradation. Cultivation of phenol degrading Granulated forms of Leclercia adecarboxylata with other bacteria and yeast cultures can be an alternative to phenol bioremediation treatment strategy. [ABSTRACT FROM AUTHOR]