Isolation And Characterization of Pigment Producing Bacteria from Air and Water and Its Various Applications

Microbial pigments are bioactive secondary metabolites produced by diverse microorganisms including bacteria, fungi, and actinomycetes. In recent years, increasing environmental and health concerns associated with synthetic dyes have led to a growing interest in natural pigments derived from microorganisms. The present study focuses on the isolation and characterization of pigment-producing bacteria from air and water samples and evaluates their potential applications in pharmaceutical and industrial sectors. Air samples were collected using the settle plate method, while water samples were collected from ponds, lakes, and tap water sources under sterile conditions. Samples were cultured on nutrient agar and incubated at 30–37°C for 24–48 hours. Pigmented colonies were selected based on distinct coloration and purified through repeated streaking. Morphological characterization included colony morphology, Gram staining, and motility testing. Biochemical identification involved catalase, oxidase, indole, MR-VP, citrate utilization, urease, and carbohydrate fermentation tests. Pigments were extracted using organic solvents such as methanol and acetone, followed by spectrophotometric analysis to determine absorbance maxima. Antimicrobial activity of extracted pigments was evaluated using the agar well diffusion method against test pathogens. The study successfully isolated multiple pigment-producing bacterial strains exhibiting red, yellow, violet, and blue-green pigments. Spectrophotometric analysis confirmed characteristic absorption peaks corresponding to known microbial pigments. Several isolates demonstrated significant antimicrobial activity. The findings suggest that air and water are rich reservoirs of pigment-producing bacteria with promising pharmaceutical, agricultural, cosmetic, and textile applications. Microbial pigments represent sustainable and eco-friendly alternatives to synthetic dyes.