• NARMATHA DEVI.P
• MAHALAKSHMI .A
• SUJATHA KABILAN

Microbial polymers such as Polyhydroxybutyrate (PHB) and Polyhydroxyalkanoates (PHAs) can be catabolized by a wide range of microorganisms by intracellular (i-phaZ) or extracellular Polyhydroxyalkanoate depolymerases (e-phaZ). In this study, various environmental samples (soil & effluent) were collected in and around Madurai dt., and analyzed for e-phaZ activity by clear zone method using 0.1% PHB. Among screened isolates, ND-3 was selected on the basis of zone diameter on media enriched with polymer, indicating the presence of an extracellular PHA depolymerase. The degradative ability of ND-3 was examined using other substrates like Poly (3-hydroxybutyric acid-co-3 hydroxyvaleric acid, Poly (L-lactide), Poly (1, 4-butylene succinate) and esterase specific substrates such as tributyrin and p-nitrophenyl (pNP)-alkanoates. The maximum activity (165.8 U/mg) was observed with p-nitrophenyl-butyrate at pH 7.5. The strain ND-3 could degrade 0.1% PHB in 4th day at 30oC and the degradation was further confirmed by Scanning Electron Microscopy.16S rRNA phylogeny results revealed that ND-3 has close relatedness to Streptomyces sp. (93%). The molecular mass of e-PhaZ was determined to be ~48kDa by SDS-PAGE and Zymogram. The results of this study suggest that this distinct enzyme might represent a new subgroup of scl PHA depolymerase.

Biodegradation, PHB, PHA depolymerase, Streptomyces sp. SEMBiodegradation, PHB, PHA depolymerase, Streptomyces sp. SEM

"MICROBIAL DEGRADATION OF POLYHYDROXYALKANOATES (PHAS) BY AN INDIGENOUS SOIL ISOLATE OF STREPTOMYCES SP.ND-3", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.8, Issue 11, page no.c703-c711, November-2021, Available :http://www.jetir.org/papers/JETIR2111293.pdf

"MICROBIAL DEGRADATION OF POLYHYDROXYALKANOATES (PHAS) BY AN INDIGENOUS SOIL ISOLATE OF STREPTOMYCES SP.ND-3", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.8, Issue 11, page no. ppc703-c711, November-2021, Available at : http://www.jetir.org/papers/JETIR2111293.pdf