Biodegradable Plastic Production by Bacillus spp. Isolated from Agricultural Wastes and Genetic Determination of PHA Synthesis

Abstract

Polyhydroxyalkanoates (PHAs) are resources that hoard by a variety of microorganisms as a nutrient source. It is an environmentally recyclable biopolymer, and totally corrupted biologically to simple molecules. A total of 38 isolates from agricultural wastes, 9 isolates exhibited optimistic outcome (dark blue particles) for PHA accumulation by Sudan black B staining method. Maximum bacterial growth was achieved at temperature 35°C, PH= 7, for 48 hr. incubation and 0.25% concentration of NaCl. Chosen the isolate (NE1MOK) recognized as Bacillus subtilis when diagnosed by traditional and molecular methods by amplification 16s rRNA gene. Bacillus subitilis had an ability to accumulate 0.26 g/l (40.625 %) of PHA, and characterized by Fourier transforms infrared (FTIR) analysis, which exhibited functional groups of PHA as (C-O, C=O, CH2, CH3, C-O-C, C-H and terminal OH). The responsible gene was detected by PCR, and the results of amplification were shown in all isolates with a length of amplicons 505 bp. The aim of this study was to detect more efficient bacterial isolate that produce PHAs from agricultural wastes in optimal conditions, and determining the genes responsible for it.