Responses of bacteria from urban and desert soil for bioplastic accumulation

Abstract

Bacteria retain the ability to produce certain compounds to survive in unfavorable conditions; bioplastics is one of them. Th aim of this study was to evaluate various environments for bioplastic producing bacteria. Bacterial strains were isolated from the desert and urban soil samples. A total of 39 strains isolated from Cholistan near Bahawalpur and 24 strains were isolated from various areas of Lahore. Bacterial strains were screened for the production and accumulation of bio-plastic. Only three strains from urban soil sample were able to produce polyhydroxyalkanoates (PHA). Strain Acinetobacter seohaensis produced 40.6% bio-plastic when supplemented with coconut oil. Ths percentage is even higher than the glucose, which was 16.6 % after 24 h of incubation. Th other competent strains i.e. Exiguobacterium indicum, Bacillus acidiceler were not able to utilize the coconut oil but produced 5 and 22% bio-plastic when supplemented with 2% glucose after 24 h of incubation, respectively. Th percentage of the bioplastic produced when grown in nutrient broth was very low. Th Fourier-transform infrared spectroscopy (FTIR) analysis of the extracted bio-plastic indicated the presence of the C=O functional group specifi for the presence of polyhydroxyalkanoates, the absorbance peaks were specifially at 1600 cm-1. Ribo-typing of all the six strains were carried out, strains identifid as Exiguobacterium indicum, Bacillus acidiceler, Acinetobacter seohaensis, Serratia proteamaculans, Trabulsiella guamensis and Serratia grimesii and showed 98 to 100% similarity with sequences available in public domains.