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...

Citation:
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.
http://dx.doi.org/10.12665/J123.RaoPrakasham.

Posted online September 30, 2013.