Optimization of L-DOPA production by Brevundimonas sp. SGJ using response surface methodology.

L-DOPA (3,4-dihydroxyphenyl-L-alanine) is an extensively used drug for the treatment of Parkinson's disease. In the present study, optimization of nutritional parameters influencing L-DOPA production was attempted using the response surface methodology (RSM) from Brevundimonas sp. SGJ. A Plackett-Burman design was used for screening of critical components, while further optimization was carried out using the Box-Behnken design. The optimized levels of factors predicted by the model were pH 5.02, 1.549 g l(-1) tryptone, 4.207 g l(-1) L-tyrosine and 0.0369 g l(-1) CuSO(4) , which resulted in highest L-DOPA yield of 3.359 g l(-1). The optimization of medium using RSM resulted in a 8.355-fold increase in the yield of L-DOPA. The anova showed a significant R(2) value (0.9667), model F-value (29.068) and probability (0.001), with insignificant lack of fit. The highest tyrosinase activity observed was 2471 U mg(-1) at the 18th hour of the incubation period with dry cell weight of 0.711 g l(-1). L-DOPA production was confirmed by HPTLC, HPLC and GC-MS analysis. Thus, Brevundimonas sp. SGJ has the potential to be a new source for the production of L-DOPA.