Prospection of microorganisms producing polyhydroxyalkanoates (PHAs) with emphasis on mutant strains of Bradyrhizobium elkanii and Rhizobium tropici

Abstract

Polyhydroxyalkanoates (PHAs) are homopolymers afilática hydroxyalkanoates source, being produced and accumulated intracellularly by various bacterial species as an energy source for survival. Typically, the accumulation of these polymers occurs under limiting conditions for bacterial growth, or poor nutritional limit as N, P, S, O or Mg and excess carbon. Many microorganisms can synthesize and accumulate PHAs. Among these polymers of bacterial origin are the polihidroxibutiratos (PHB), the best known of biodegradable polymers called polyhydroxyalkanoates bacterial. These polymers have similar properties to poliprepileno and PHB can be used to manufacture biodegradable plastic. Studies have revealed that there is a plasticity as capacity and accumulation of PHB in Rhizobium bacteria type in different life forms, however, some species lack the ability to synthesize and accumulate PHB as is the case of Rhizobium meliloti or capable of producing and accumulate PHB under these conditions, as is the case of Rhizobium tropici, Bradyrhizobium japonicum and Bradyrhizobium elkanii. Thus, this work aims at assessing the biotechnological potential of wild and mutant strains of Bradyrhizobium and Rhizobium tropici elkanii as biopolymer production on different carbon sources, and the emulsifying properties of the bodies of inclusions of PHB granules and cultures bacterial with possible biotechnological application in the production of biosurfactants and production of biopolymer.