Development of Cultivation Media for Polyhydroxyalkanoates Accumulation in Bacterial Cells Isolated from Cassava Pulp

Polyhydroxyalkanoates (PHAs) are biopolymers efficiently used as biodegradable plastics to replace environmentally unfriendly petroleum-derived plastics. The polymers can be synthesized by a wide range of microorganisms. Bacteria accumulate PHAs under conditions of nutrient stress particularly nitrogen or phosphorus limitations. In this study, cultivation media were developed for detecting a number of bacteria isolated from cassava pulp for their PHA production capability by modifying media described by potential references. Both complex and minimal media were developed when cultured at 35°C for 48 h. The isolates were tested for the presence of PHA accumulation by straining with 1% Nile blue A and observed under the fluorescence microscope at excitation wave length of 650 nm. Transmission Electron Microscope (TEM) was used for comfirmation of PHA granules accumulation in bacterial cells. Alcaligenes eutrophus (TISTR 1095) and E. coli (TISTR 527) were used as the positive and negative control of PHAs-producing strain, respectively. This is the first report for the suitable media for detecting of PHAs-producing bacteria isolated from cassava pulp.