Isolation and Identification of PolyHydroxyButyrate (PHB) Producing Bacteria from Sewage Sample

Plastics and synthetic polymers are synthesized from nonrenewable resources like petrochemicals and persist in the environment long after intended use, resulting into problems of solid waste management and global environmental pollution. Hence, an alternative source such as Polyhydroxyalkanoates that are biodegradable, linear polyesters produced primarily by bacteria which can be used as an effective thermoplastic, and has many characteristics similar to those of standard commercial plastics like polypropylene. Aliphatic polyester ,poly3- hydroxy butyrate was discovered and identified as a granular component in bacterial cells.PHB can grow in a wide variety of natural environments and is the reserve polymer found in many species of bacteria found in nature, e.g. in soil, sea water, sewage waste or compost. In this present study high PHB producing strains were isolated from sewage sample. Five strains were showing PHB granules with Sudan Black B staining. The five strains were labeled as strain 2, 4, 5, 9 and 11. Further, they were morphologically and biochemically characterized. Growth profiles were studied for all these strains and were found that the PHB was produced maximum after 48 hrs at 37°C of incubation. Strain 2 showed high PHB production among the five strains isolated. The sugarcane molasses used in the medium for PHB production accounted for the least production cost.