Micrococcus yunnanensis and Psychrobacter sp. as Potential Producers of Polymers from Hot Spring

Abstract

Polyhydroxyalkanoates (PHAs) and exopolysaccharides (EPSs) are biopolymers bacteria under nutrient-limiting conditions. In this study, bacterial strains were isolated from hot springs. Soil samples were collected from Tatta Pani, Azad Kashmir, Pakistan. Bacterial strains AJ2 and AJ3 were selected due to their ability to produce PHAs and EPSs. Phylogenetic analysis showed that strain AJ2 was Micrococcus yunnanensis and AJ3 was Psychrobacter sp. Three carbon sources (glucose, glycerol, and molasses) were used for polymer production. The effect of high pH (8) and high temperature (55 °C) was checked on PHAs and EPSs production. The highest yield of PHAs was given by strain AJ3 (89.43%) with molasses. When grown at 55 °C for 24 hours, strain AJ3 showed the highest PHAs accumulation, 79% with glucose. At alkaline pH 8, strain AJ3 gave 34% PHAs with molasses. The highest EPSs production was observed for strain AJ3. AJ3 gave 70g/L of EPSs with both glucose and glycerol. The amplification of the phaC gene was done to confirm the genetic basis of PHAs production. FTIR analysis showed clear bands at 1722 cm-1 and 2925 cm-1 representing the carbonyl and alkyl groups of PHAs, respectively.