Optimization of melanin production by Brevundimonas sp. SGJ using response surface methodology

Abstract

Melanins are predominantly indolic polymers which are extensively synthesized in animals, plants and microorganisms. It has wide applications in cosmetics, agriculture and medicine. In the present study, optimization of process parameters influencing melanin 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 optimum conditions observed were pH 5.31, tryptone 1.440 g l−1, l-tyrosine 1.872 g l−1 and CuSO4 0.0366 g l−1. Statistical analysis revealed that the model is significant with model F value 29.03 and R2 value 0.9667. The optimization of process parameters using RSM resulted in a 3.05-fold increase in the yield of melanin. The intermittent addition of l-tyrosine enhanced the melanin yield to 6.811 g l−1. The highest tyrosinase activity observed was 2,471 U mg−1 at the 18th hour of the incubation period with dry cell weight of 0.711 g l−1. The melanin production was confirmed by UV–Visible spectroscopy, FTIR and EPR analysis. Thus, Brevundimonas sp. SGJ has the potential to be a new source for the production of melanin.Electronic supplementary materialThe online version of this article (doi:10.1007/s13205-012-0082-4) contains supplementary material, which is available to authorized users.

An Organic Bipolar Resistive Switching Memory Device Based on Natural Melanin Synthesized From Aeromonas sp. SNS

“…Melanin from Aeromonas sp. SNS was purified by previously described methods of Surwase et al and characterized using chemical and spectroscopic methods to confirm its identity.…”

“…Chemical characterization of melanin was carried out by testing its solubility in water, HCl, acetone, benzene, chloroform, ethanol, NaOH, and KOH. The specific chemical tests for melanin were carried out by adding the purified powder in H 2 O 2 , FeCl 3 , and KMnO 4 . The absorption spectra of extracted melanin (0.1 g L −1 ) were obtained by wavelength scanning from 200 to 800 nm by using a UV–Visible spectrophotometer (Shimadzu UV‐1800, Japan).…”

Overview on the biotechnological production of l-DOPA

“…SGJ, they conducted the response surface methodology (RSM) and determined the nutritional parameters influencing L-DOPA production: pH of 5.2, 1.55 g L −1 of tryptone, 4.21 g L −1 of L-tyrosine, and 0.037 g L −1 of CuSO 4 resulted in the highest L-DOPA production, 3.36 g L −1 . As a result, the optimized reaction media by RSM exhibited 8.36-fold increase in L-DOPA production and the highest tyrosinase activity was observed with 0.71 g L −1 of dry cell weight (Surwase et al 2012b). …”

Statistical medium optimization for the production of collagenolytic protease by Pseudomonas sp. SUK using response surface methodology

“…Shapes of the contour plots, circular or elliptical, emphasize the significant or insignificant interactions between the corresponding variables. Insignificant interactions amongst the corresponding variables were shown by circular contour plots while elliptical contour plots represent the significant interactions [14,32]. The response surface curves and contour plots rep resented in figure a 1 and b 1 show the interaction between gelatin and peptone.…”

“…Literature data showed that significant increase in product formation can be achieved by employing RSM [14][15][16]. Also some of the reports mentioned that use of more than one protein source is responsible for increase in protease yield [17,18].…”