BIODEGRDATION OF POLYAROMATIC HYDROCARBON USING LOCALLY PSEUDOMONAS PUTIDA H18 ISOLATED FROM PETROLEUM CONTAMINATED LOCATIONS

Ahmed Bahgat

doi:10.21608/ajps.2021.187824

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are the major sources of pollution that cause dangerous effects on human and other organisms. Biodegradation of PAHs in the contaminated area is an engaging remediation technique and its accommodation depends on the optimal condition for the PAH-degrading isolates. In the current study, four bacterial strains were isolated from polluted area with petrochemical compounds with the ability for biodegradation of phenanthrene and pyrene. Only one strain has high biodegradation ratio of phenanthrene and pyrene. The optimization process for biodegradation of phenanthrene and pyrene was executed and qualified under different conditions of shaking, static, pH, temperature, inoculum sizes, salt concentration, carbon and nitrogen sources. Phylogenetic tree based on 16S rDNA genetic analysis sequence indicates that this bacterial isolate was belonged to genus Pseudomonas and identified as Pseudomonas putida (H 18). The optimal conditions for biodegradation were observed in media containing phenanthrene and pyrene as sole carbon source, yeast extract as nitrogen source, and 4% of inoculum size, at pH 8 and 35oC under static condition for 8 days. The maximum biodegradation efficiency was reached to 92% of phenanthrene and pyrene and was confirmed by using GS-mass spectroscopy.

Highlights

Polycyclic aromatic hydrocarbons (PAHs) are aromatic compounds with two or more fused benzene rings
The isolation and characterization of bacterial isolate which has the ability for biodegradation of pheneatherene and pyrene mixture is potentially important for bioremediation
Four bacterial isolates have the ability to degrade of phenanthrene and pyrene mixture but, the highest biodegradation ratio of phenanthrene and pyrene mixture was observed by one of the which isolated from the petroleum polluted industrial area (Figure 1)

Summary

Introduction

Polycyclic aromatic hydrocarbons (PAHs) are aromatic compounds with two or more fused benzene rings. PAHs are hydrophobic compounds and their immutability in the ambience is principally due to their low solubility in water (Bukvic, 2002). The prominence of PAHs to microbial degradation has been regarded to their hydrophobic nature These compounds are orderly bounded to soil particles, resulting in low bioavailability to microorganisms (Zhao et al, 2019). This phenomenon is predominately enhanced in aged polluted soils; likewise, many biodegradation studies have focused on isolating microorganisms and study their degradative capability to high molecular weight compounds

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Conclusion