There are reports on melanin production from various microorganisms, including Bacillus species which are well known for their pigment production ability in various stress environments [4] and [12]. Selection of substrate for melanin production has economic importance. For instance till date expensive substrates like NCM media [4], LB (Luria–Bertani) media [12], minimal media supplemented with L-tyrosine [13], amino acids enriched tryptone broth agar [14] and so on [15] and [16]

were used for high yield of melanin. Owing to the economy and practicability of the melanin production process; the need to use economically feasible substrates along with optimization of the key parameters is needed. In recent years, considerable interest has been developed in using agro-industrial wastes as substrates for valuable products like pigments. The abundantly available AZD2281 in vitro fruit waste in India used widely as animal feed or disposed to the soil. The effective utilization of this waste

which is rich in carbohydrates and other nutrients can address our primary objective of melanin production in a cheaper way. An optimization strategy like Taguchi method [17] is a systematic technique of design and analysis of experiments that has been employed successfully in recent years to design, improve the CYTH4 see more product quality economically [18], and a central composite design (CCD) approach has been used to fit a polynomial model. The complementary use of both the methodologies provides a great amount of information based on only a small number of experiments and to scheme a process.

In this study, a bacterium capable of producing melanin was isolated from garden soil and subsequently characterized. The strain was cultivated on the fruit waste extract (FWE) as the sole source of energy to produce significant amounts of melanin. The key parameters in melanin production were identified and optimized using simple two steps Taguchi and CCD (central composite design) approach. Upon purification and characterization, the obtained melanin was tested for In vitro sun protection effect, free radical scavenging and metal chelating activities. DPPH (2,2-diphenyl-1-picrylhydrazyl), purchased from HiMedia chemicals, Mumbai, India. Ascorbic acid was purchased from Merck, India. Ferrozine and melanin (synthetic) were purchased from Sigma–Aldrich, India. Ethanol, NaCl, NaOH, HCl are from Merck, India and all other chemicals used were of analytical reagent grade throughout the study. Ultrapure water was used for the experiments and aseptic conditions were maintained wherever necessary.