Production and characterization of tailor-made Polyhydroxyalkanoates by bacillus cereus FC11

Polyhydroxyalkanoates (phas) are non-toxic,biocompatible,piezoelectric,and biodegradable thermoplastic. this study was designed to isolate the bacterial strains from trinitrotoluene (tnt)-contaminated soil capable of giving phas at high yields with tailor-made compositions. the isolated bacterial strain b. cereus fc11 gave pha yield at 76.40 wt% using 500 ml erlenmeyer flasks each containing 200 ml synthetic medium in the presence of glucose as a sole carbon source at ph value 7.0,30°c and 150 rpm after 48 h of incubation under submerged fermentation. furthermore,tailor-made pha compositions were synthesized by b. cereus fc11 by adding different co-substrates along with glucose in the medium. high performance liquid chromatography analysis revealed that the retention time of crotonic acid (by-product) obtained from digested pha was approximately 24.97 min which was similar to the retention time of crotonic acid (by-product) obtained from the digestion of commercially available poly-3-hydroxybutyrate and poly-3-hydroxybutyrate-co-3-hydroxyvalerate (sigma-aldrich). fourier transform infrared spectrum showed the absorption bands at 1719,1275 and 2932 cm-1,which were attributed to c=o,c-o stretching and c-h vibrations,respectively. the proton and carbon nuclear magnetic resonance analysis confirmed that this indigenously synthesized polymer was composed of 3-hydroxybutyrate (3-hb) and 3-hydroxyvalerate (3-hv) monomers. the number average molar mass (mn) of copolymer was 37.98 kda. copyright © 2015 zoological society of pakistan.