High-level production of melanin by a novel isolate ofStreptomyces kathirae

Abstract

Forty-five bacterial strains that produced diffusive pigments were isolated from 40 soil samples. Maximum pigment production was from a Streptomyces kathirae strain designated SC-1. The diffused pigment was characterized by UV-visual and infrared spectroscopy, MS and (1) H nuclear magnetic resonance imaging, and was confirmed as melanin. This may be the first report of melanin production by S. kathirae. To enhance melanin production, the culture medium was optimized by conducting a series of batch fermentations in a defined medium, and the results were analysed statistically using a response surface method. The optimal culture medium comprised 3.3 g L(-1) amylodextrine, 37 g L(-1) yeast extract, 5 g L(-1) NaCl, 0.1 g L(-1) CaCl2 and 54.4 μM CuSO4 . The pH of this medium was 6.0. Under optimal conditions, the melanin concentration was maximized at 13.7 g L(-1) , c. 8.6-fold higher than obtained in suboptimal medium. To our knowledge, the results provide novel data on melanin fermentation, and identify an excellent candidate for industrial-scale microbial fermentation of melanin.

Partial purification and characterisation of two actinomycete tyrosinases and their application in cross-linking reactions

“…ISP6 and ISP7 agar media used in actinomycete systematics as an indicator of melanin production) [14]. A recent study by Guo et al [22] defined a medium for optimal melanin production by Streptomyces kathirae. The optimal medium contained a high concentration of…”

Production of natural melanin by Auricularia auricula and study on its molecular structure

“…In the upfield of 1 H NMR spectrum at d H 0.5 ppm to d H 2.5 ppm the peaks can be assigned to CH 3 , CH 2 groups of alkyl fragments with corresponding to d c 15 ppm to d c 40 ppm in the 13 C NMR spectrum. Those aliphatic carbons were due to proteinaceous material (Guo, Chen, et al, 2014;Guo, Rao, et al, 2014). Peaks from d H 3.5 ppm to d H 4.5 ppm in the 1 H NMR spectrum can be assigned to protons on carbons attached to oxygen or nitrogen atoms.…”

“…Furthermore, the extraction is a very complicated and time-consuming process, which severely limits the application of natural pigments on a large scale. Microbial submerged fermentation is considered a promising alternative for the efficient production of natural pigments (Guo, Chen, et al, 2014;Guo, Rao, et al, 2014;Vinarov, Robucheva, Sidorenko, & Dirina, 2003) because it is prone to industrialization.…”

“…many researchers now explore melanin production by bacteria, mycete, or fungi, but these microorganisms often secrete many toxic secondary metabolites. The latter make the produced melanins following these routes difficult to use in food, cosmetics, pharmacology and medicines (Figueiredo-Carvalho, dos Santos, Nosanchuk, Zancope-Oliveira, & Almeida-Paes, 2014;Goncalves, Lisboa, & Pombeiro-Sponchiado, 2012;Guo, Chen, et al, 2014;Guo, Rao, et al, 2014;Wan et al, 2007). Over the last 50 years, the study of melanin structure has been attracting scientific interest and has become a key research focus in the field of natural pigments.…”

Production and Characterization of Melanin from Streptomyces Cavourensis Strain RD8 Using Response Surface Optimization

“…The conventional 'one-factor-at-a-time' (OFAT) method of optimization is laborious, time-consuming and unsuitable for understanding the underlying interactions (Box and Draper, 1987). Due to the economic viability of the melanin production; the optimization of the parameters are a pre-requisite (Guo et al, 2014). The chemometrics are the most promising tools for the proces and product optimization, finding pervasive applications (Karthikeyan et al, 2014;Vidhyadevi et al, 2014;Kumar et al, 2012).The present study describes melanin production from actinomycete isolated from Gulf of Khambhat (GoK) and also focuses on screening of macronutrients and quantifying operational parameters using chemometrics.…”