ISOLATION AND MOLECULAR CHARACTERIZATION OF BACTERIAL ISOLATES DEGRADING CRYSTALS AND LOWDENSITY POLYETHYLENE

摘要

Nine samples were collected from soil and water of three different locations in Saudi Arabia SABIC in Jubail, Sahara Petrochemicals Co. in Jubail and NATPET at Yanbu Industrial City, as well as sample from soil garbage in Jeddah. Samples were growingin the minimal medium containing PE as a sole source of carbon. Polyethylene (PE) crystal treatments of 20 isolates after 4 months showed biodegradation efficiency of isolate 41 obtained from soil of Sahara that identified by 16S rRNA gene as Paenibacillus cookii. The isolate showed a unique characteristic with 1.95%. Isolation of LMWPE degrading strains was conducted using VB medium supplemented with 0.03 gL of PE for 45 days. The highest biodegradation efficiency recorded in isolate 37 identified asBacillus circulans strain obtained from NATPET water with 2.33%. Isolate 44 identified as Paenibacillus agaridevorans was obtained from Sahara soil revealed high degradation efficiency with 0.67%. Two other isolates 33 and 27 with efficiency 0.33% were obtained from Sahara and NATPET water and identified as Gram negative Stenotrophomonas acidaminiphila strain. Isolate 33 showed 92 positional differences with base-pair substitutions either transversions interchanges in 59 nucleotides and 33 transitions,while isolate 27 revealed a total of 3 variations only.