Effect of pH on Different Strains of Phytase Producing Bacteria from Malaysia’s Hot Spring

Abstract

In the recent research, the optimisation of culture condition for phytase production rarely done for Acetinobacter baumanii. The optimisation of the phytase production from the bacterial strains largely contributed by Bacillus sp. The study on the phytase originated from hot spring are limited and the species that identified from the hot spring samples are not in the same species from the previous study and mainly the species isolated from Bacillus sp. In this study, four potential strains of bacteria producing phytase isolated from hot spring in several regions in Malaysia. For enrichment of the bacterial, Nutrient Agar was used, meanwhile for batch culture optimisation, the bacteria producing phytase grown in modified liquid Phytase Screening Media with soy extract as agro residual substrate as a replacement for sodium phytate, the chemical substrate. The bacteria were screened for their ability to produce clear zone in solid PSM with sodium phytate as substrate. Optimisation of media through its physical factor that is pH of the media carried out using shake flask scale in laboratory. The growth of the bacterial strains and phytase activity measured quantitatively through the two different pH of media at pH 5.5 and pH 7. The analysis of colony-forming unit and pH determination after fermentation was carried out in this study. From the study, bacterial strain L3 from Labis, Johor has the highest phytase activity in the two parameters studied where the inorganic phosphate released at pH 5.5 (0.21953 U/mL) and pH 7 (0.2047 U/mL). Optimisation carried out through manipulating the culture condition that is pH of the media to determine at which condition has the highest phytase production. Several effects on enzyme activity caused by culture conditions identified. The optimisation of the fermentation medium able to contribute to the less cost production of the industrial enzyme as phytase has potential production for feed additives for poultry feeding. In the future research, molecular identification of the bacterial strains from the better-quality bacteria producing phytase grown in optimised culture media to investigate the molecular identity of the bacterial.