Improved Production of Laccase and Peroxidase-Free Tyrosinase in Streptomyces antibioticus

by Krothapalli Raja Surya Sambasiva Rao, Niraj Kant Tripathy, Yadla Mahalaxmi, Reddy Shetty Prakasham, and Devarakonda Srinivasa Rao
Volume 12, Issue 3 (Fall 2013)

The impact of individual and interactive behaviors of various fermentation process parameters on laccase and peroxidase-free tyrosinase production were investigated by isolated Streptomyces antibioticus RSP-T1. Six key bioprocess factors (medium pH, rpm, incubation time, sodium chloride concentration, complex nitrogen [yeast extract + peptone], and carbon source [maltose]) were selected based on using a one variable at a time methodology. All selected parameters had an impact at individual and interactive levels on tyrosinase production. Only 25% of the improved tyrosinase production was attributed to the optimized fermentation parameters selected. Regarding the nutritional parameters, the complex nitrogen/carbon source concentration (maltose and yeast extract + peptone) was found to have the most significance impact on overall tyrosinase enzyme production. Physiological growth factors (pH, rpm, and incubation time) played key roles at an interactive level. A maximum yield of 12.60 IU/mL tyrosinase production was achieved with optimized medium, adjusted to 7.5 pH, consisting of 0.75% maltose (w/v), 0.2% yeast extract (w/v), 0.2% peptone (w/v), and 1.25% sodium chloride (w/v) at 160 rpm in 24 hours. This study identified the optimum medium component concentrations for improved tyrosinase production by S. antibioticus RSP-T1. This strain requires complex nitrogen sources (yeast extract and peptone) for increased product yield. Overall, a greater than 250% increase in tyrosinase production was achieved using this optimization approach, as compared to conventional methods...

Rao KRSS, Tripathy NK, Mahalaxmi Y, Prakasham RS, Rao DS. Improved Production of Laccase and Peroxidase-Free Tyrosinase in Streptomyces antibioticus. BioProcess J, 2013; 12(3): 46-54.

Posted online September 30, 2013.