The worldwide interest of the current era is to increase tendency towards the use of natural substances instead of synthetic ones. So, alternative and effective environment friendly sustainable technologies are highly needed. Due to a broad range of biological activities, fungi are considered as a significant source of pigments. Among the fungal species in the soil, the genera of Aspergillus, Fusarium, Penicillium, Paecilomyces, and Trichoderma are dominant. The pigments commonly produced by fungi belong to aromatic polyketide groups such as melanins, quinones, flavins, ankaflavin, anthraquinone, and naphthoquinone. The use of fungal pigments has benefits which comprise easy and fast growth in the cheap culture medium and different color shades being independent of weather conditions and would be useful in various industrial applications. In relation to the toxic effects of the synthetic dyes, the natural dyes are easily degradable since they cause no detrimental effects. Thus, the study of pigments produced by soil fungi has tremendous use in medical, textile coloring, food coloring, and cosmetics.

Objective: The present study was aimed to identify the fungal isolate from soil and to understand the different optimized parameters better to facilitate the pigment production that has high yield and stability.Methods: Aspergillus sp. was isolated from Western Ghats soil by the conventional serial dilution technique and assessed as a potential pigment producer. Different broth medium such as potato dextrose broth (PDB), czapek-dox broth (CDB), malt extract broth (MEB), rose bengal broth (RBB), sabouraud dextrose broth (SDB), yeast malt extract broth (YEMB), pH (3-9), temperature (24, 27, 30, 33, 37 and 40 °C), carbon (lactose,glucose,sucrose, maltose, galactose and fructose) and nitrogen source (peptone, yeast extract, urea and inorganic nitrogen sources like potassium nitrate, ammonium chloride and sodium nitrate), mineral salts such as sodium dihydrogen phosphate (Na2H2Po4), magnesium sulphate (Mg2So4), calcium chloride (CaCl2), copper sulphate (Cu2So4), potassium dihydrogen phosphate (KH2Po4) and manganese sulphate (Mn2So4) and inoculum age (2-7 d) of the medium related to high pigment production were analysed.Results: Aspergillus terreus KMBF1501 was identified by ribosomal DNA sequencing showing 99% similarity with other Aspergillus terreus and the accession number (KX113516) was assigned. The optimum culture conditions for pigment production by Aspergillus terreus KMBF1501 was achieved at pH 5 (0.563±0.012 nm), temperature of 27 °C (0.382±0.001 nm) with glucose (0.501±0.002 nm) as carbon source, peptone (2.147±0.004 nm) as nitrogen source, Mg2SO4 (0.401±0.001 nm) as mineral salt and 4 d (0.324±0.001 nm) of inoculum age in PDB (0.761±0.006 nm). Conclusion:Aspergillus terreus KMBF1501 produced maximum pigment when cultured in modified PDB than in common PDB medium. The high concentration of the pigment can be used for various industrial purposes.

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