Abstract

Fusarium is a diverse genus known for its hyaline, cotton-like colonies, with many species acting as pathogens in plants, animals, and humans. However, specific species such as Fusarium oxysporum, Fusarium moniliforme (now Gibberella fujikuroi), and Fusarium solani produce carotenoid pigments valuable to the food, textile, and cosmetic industries. This study reports, probably for the first time, the isolation of pink-pigmented Fusarium foetens CBS 110286 from Punjab, India, optimizes its pigment production via response surface methodology, and evaluates its antimicrobial activity. The Design-Expert® software (version 13, Stat-Ease, USA) was used to ascertain the effects of five independent variables: temperature (25°C–45°C), incubation time (7 days), peptone (0.1–0.3 g/l), fructose (0.1–0.3 g/l), and initial pH (4–8) were analyzed. In addition, high performance liquid chromatography and gas chromatography mass spectrophotometer characterization was carried out to identify and quantify the major metabolites. The optimized conditions yielded significant pigment production, exhibiting a broad-spectrum effect in peptone and fructose, as well as a zone of inhibition (11 mm) against the Gram-positive bacterium Staphylococcus aureus, and approximately 8 mm against Escherichia coli. This result may have potential applications in the textile, pharmaceutical, and biotechnological industries upon complete characterization.

Key words: Antimicrobial activity, Fusarium foetens, Response Surface methodology, Optimization