Molecular Identification of Pseudomonas Strains with Polyethylene Degradation Ability from Soil and Cloning of alkB Gene

Today, high-density plastics such as polyethylene are recognized as one of the major pollutants of the environment by the Global Environment Organization. This study has been designed to isolate bacterial strains of Pseudomonas with polyethylene degradation power and to clone the alk-B gene to be used in the future to expedite the biological degradation of plastic waste. To isolate the polyethylene degrading bacteria, two culture methods were used, direct culture and pre-enriched medium. Bacteria were cultured in MSM medium, and the best strains that could decrease the plastic weight were selected for PCR of the alk-B gene. After phylogenetic analysis of PCR sequences and TA cloning, the alk-B gene was introduced into the E. coli XL1-Blue by PTG19-T vector. After confirming the presence of the gene in the cloning vector by colony PCR, the samples with recombinant plasmids were sequenced. The percentage of polyethylene degradation by Pseudomonas strains was 7.2% at most and 4.5% on average. All the polyethylene-degrading strains were isolated and all had the alk-B gene. Also, the data showed that with TA cloning can colon alk-B in the vector. The data of the present study show that by optimizing the polyethylene-degrading bacteria isolated from the soil could greatly accelerate the process of biodegradation of polyethylene. It seems by developing genetic methods based on the genomes of bacteria, especially the strain of Pseudomonas aeruginosa, it is possible to devise methods by which all types of polyethylene to be degraded at a shorter time.