Phytochemical and antibacterial insights into crude pigment of endophytic fungi Corynespora torulosa (Syd.) Crous for its preliminary application for dyeing

Abstract

The present work aimed to isolate pigment-producing endophytic fungi from the medicinal plant Hygrophila erecta. Sterilized plant tissue (leaf) was cultured on Potato Dextrose Agar media to isolate endophytic fungi. Morphological identification was complemented by molecular characterization using ITS region sequencing and it was identified as Corynespora torulosa (Syd.) Crous. Pigmentation was checked in different media and maximum production was noted in Czapek Dox Broth at pH 9.0 and 67.04 ± 1.38 mg of crude extract was quantified. Qualitative detection of secondary metabolites in crude pigment extract was carried out by standard procedures, interestingly which disclosed the presence of flavonoids, phenols, terpenoids, sterols and saponins. The antibacterial efficacy of the pigment was evaluated against a panel of pathogenic bacteria, including Escherichia coli ATCC 2592, Salmonella typhimurium ATCC 25241 and Bacillus subtilis ATCC 11774 using the agar well diffusion method giving inhibition zones of 12.31 ± 0.78 mm, 16.80 ± 0.54 mm and 23.88 ± 0.39 mm respectively. GC-MS analysis revealed several compounds with potent anti-microbial, anti-inflammatory and analgesic activities. Textile dyeing treatments of color fastness to washing were tested, and crude extracts of C. torulusa have provided promising results for dyeing and mordanting. © 2025 Har Krishan Bhalla & Sons.