Isolation and Molecular Identification of Phenol Degrading Bacterium from Industrial Wastes, Collected from Jeddah Saudi Arabia

In the past two decades, phenolic compounds have had different applications, however their use in densification has increased considerably due to Covid 19. Discharge of these dangerous materials is highly toxic and causes risk and severe problems to the environment and health of human and animals, in addition to it being harmful to the aquatic life. Phenol degradation is very important due to high toxicity and stability. The aim of this study is to isolate phenol-degrading aerobic bacteria from hydrocarbon contaminated soil or wastewater, collected from the industrial area of Jeddah. Minimal medium containing phenol as carbon source was used to isolate different bacteria. About 30 actinomycete isolates were obtained, purified and preserved on Starch nitrate. Out of 30 isolates, eight isolates (27%) grow well in medium containing 0.1% phenol. After growing in broth medium, isolate BA4 and isolate BA8 were very active in phenol degradation. Growth and phenol degradation was measured in liquid medium for the two isolates. Morphological and physiological characters of these isolates were detected using different methods. Using molecular methods, they were belonging to a genus of actinomycetes. They were identified as Streptomyces flavabus BA4 and Streptomyces sp. BA8.The effects of some growth factors on growth and phenol degradation were determined. Growth was measured by dry weight (mg/l) while phenol degradation was detected by assaying the residual phenol concentration. The presence of electron donors such as glucose, starch, glycine, peptone, and Na acetate affect both growth and phenol degradation. It was clear that addition of 1 g/l peptone enhanced both growth and phenol degradation. The isolate use phenol and its derivatives m-cresol and o-cresol as carbon sources and addition of vitamin B complex increased the bacterial growth. In conclusion, phenol degradation was detected by actinobacteria and was affected by some physical and biochemical factors. It was noticed that optimization of growth conditions enhanced both growth and phenol degradation by the two selected Streptomyces isolate. Degradation process by isolate BA4 could be a promising solution for removal of phenol from wastewater.