Analysis of the diversity of polyhydroxyalkanoate-synthases (PhaCs) in Bradyrhizobium diazoefficiens USDA 110

QUELAS JI; PÉREZ-GIMÉNEZ, J; MONGIARDINI EJ; CARRIÑO, J; PARISI G; LODEIRO AR

Sevilla

Congreso; XIV National Meeting of the Spanish Society of Nitrogen Fixation, XXVI Latin American Meeting on Rhizobiology and III Spanish-Portuguese Congress on Nitrogen Fixation; 2013

Sociedad Española de Fijación de Nitrógeno (SEFIN)

Polyhydroxyalkanoate (PHA) is a carbon an energy reserve that accumulates in bacterial citoplasmatic granules. PHA is of great interest due to its potential use as a biodegradable plastic. The key enzyme implicated in their synthesis is PHA-synthase (PhaC), that catalizes the polymerization of hydroxyacyl-CoA into PHA. Although most sequenced rhizobia have one or two phaC homologs in their genomes, five putative phaC open reading frames (ORFs) have been detected in Bradyrhizobium japonicum USDA 110: bll4360 (phaC1), bll6073 (phaC2), blr3732 (phaC3), blr2885 (phaC4) y blr4548 (phaC5). All these proteins possess the catalytic triad and conserved amino acid residues of polyester synthases and are distributed into four different PhaC classes. We carried studies with these proteins in silico and obtained B. japonicum mutants in each of these paralogs as well as double mutants that were analyzed phaC gene expression, PHA production in liquid cultures and their requirements in survival in media without C-source.