Biology subjects

Kurian, N. K.

Publications and source records attributed to Kurian, N. K..

3 recordsLinked to original sources

bioRxiv2026

Noncytotoxic bacterial nano-melanin with immense cosmetic potential produced by Bacillus infantis isolated from salt pans of Marakkanam, Tamil Nadu, India

Melanin is a high molecular weight pigment derived from the oxidation of phenols, followed by the polymerization of phenols and the quinones they produce. Usually, they appear in dark brown or black color. Bacillus infantis was isolated from saltpans of Marakkanam, Tamilnadu. This strain was utilized for melanin production by screening using tyrosine basal broth, and the extracted pigment was characterized by UV-visible spectrometer and FT-IR. Notably, melanin was found to be nano size and it is confirmed by DLS analysis. The nano-sized melanin-producing strain Bacillus infantis was confirmed as non-pathogenic by testing with different antibiotics. This study also explores the sun protection factor of melanin, and this melanin shows successful outcomes. The antioxidant activity of melanin shows a wide range of radical scavenging activity by DPPH, ABTS and FRAP assays. The melanin has shown modest anti-ageing activity at the higher concentration tested. Nano melanin was found to be non-cytotoxic even in higher concentrations tested. This is the first report on melanin production by Bacillus infantis, and there is limited information available to date about melanin-producing bacteria from salt pan sediments.

microbiology↗

bioRxiv2026

NANO DOPA MELANIN PIGMENT WITH COSMETIC POTENTIAL PRODUCED BY HALOTOLERANT MARINE CORYNEBACTERIUM AMYCOLATUM

Bacterial melanin are macromolecules found in nature that provide a wide range of biological functions, including pigmentation, resistance to radiation, scavenging of free radicals, thermoregulation and protected from oxidative stress and harmful heavy metals. The melanin is crucial for pathogenesis and bacterial survival in a variety of circumstances, and they can also influence how bacteria interact with other organisms. Usually, bacteria produce the melanin is either black or brown colour. The produced melanin has excellent properties like antimicrobial, antioxidant, photoprotective and antibiofilm. This is a report on Corynebacterium amycolatum melanin-producing bacteria isolated from the marine sediment of Thiruvanmiyur beach in Tamil Nadu, India. Corynebacterium amycolatum was screened using tyrosine basal broth (TBB), and UV-visible spectroscopy, FTIR, and SEM were used to analyse the extracted melanin. The non-pathogenic nature of the Cornynebacterium amycolatum strain was verified through antibiotic sensitivity profiling. The cosmetic potential was evaluated using antioxidant and SPF assays. Corynebacterium amycolatum predominantly uses the DOPA pathway for melanin production, was confirmed using kojic acid inhibitor study. The in vitro studies on mouse fibroblast cell line (L929) and in vivo studies on zebra fish embryos shows non-cytotoxicity using this melanin, even in lower concentration confirms its potential to use in cosmetic formulation. This research aims to demonstrate that bacterial melanin is safe for the environment and has qualities that make it safer and more effective in cosmetics.

microbiology↗

bioRxiv2022

Halophilic bacteria Bacillus altitudinis MIM2 producing melanin isolated from Mundra port, Kutch, Gujarat, India

Melanins are ubiquitous black or brown color pigments exhibiting a wide variety of bioactivities. They are stable and insoluble in nature. Melanin are industrially important pigment currently used in cosmetics, medicine and pharmaceuticals, industries. Bacteria mainly produce three types of melanin namely, Eumelanin, pheomelanin and pyomelanin which is usually extracellularly secreted. This makes the downstream processing of bacterial melanin easier. Stress conditions like salt stress, radiation stress etc. triggers the bacteria to produce melanin and several bacterial species were found to produce melanin under different stress induced conditions. In this present study we had isolated melanin producing bacteria from saline sediment sample of Mundra port, Kutch region of Gujarat state of India. The melanin producing bacteria was characterized using staining, biochemical and molecular methods. The melanin produced was extracted and analyzed using physicochemical techniques. The extracted melanin had shown good anti-bacterial and radical scavenging activity. To our knowledge, this is the first report on Bacillus altitudinis producing melanin.

microbiology↗