Assessment of cultivation parameters influencing the growth, pigment production and anti-MRSA activity of Pseudoalteromonas rubra BF1A IBRL isolated from Malaysian marine environment

Abstract

Aims: Pigments are coloured substances that exhibit important characteristics to many industries including food, textile, cosmetics, food, pharmaceutical and also aquaculture industry. Naturally derived pigments from marine bacteria do not only exhibit the tinctorial property but are also known to possess broad range of antimicrobial activities. From the industrial point of view, the necessity to obtain suitable culture conditions for maximum yield of cell growth and pigment production is of utmost importance. Methodology and results: The effect of cultural conditions, including light, pH, temperature, agitation speed and size of inoculum on bioactivity of an epiphytic marine bacteria, Pseudoalteromonas rubra BF1A IBRL was studied using shake flask technology. The antimicrobial activity was determined using the Lorian method. As a result, prodigiosin pigment extract obtained from P. rubra BF1A IBRL showed inhibitory activity against the MRSA strain. Pseudoalteromonas rubra BF1A IBRL produced the highest level of prodigiosin and anti-MRSA activity (P<0.05) in Marine broth at initial pH of 7.6 incubated at dark condition at temperature of 26 °C, agitation speed of 120 rpm and 2% (v/v) (1 × 106 CFU/mL) of inoculums size. Conclusion, significance and impact of study: A high correlation between pigmentation and antibacterial activity were observed anticipating that the pigment has its own antibacterial properties. The above findings supported the fact that epiphytic marine bacteria were fruitful source for pigmented bioactive compounds, and the physical parameters had significantly influence of the pigment production.