“Exploration and Optimization of Colletorichum lini Isolate KUMBASBT-16 for Pigment Synthesis and Appraisal of its Pigment Metabolites and their Bio-Efficacy”

Abstract Researchers have been exploring the use of natural colorants, particularly from filamentous fungi, to combat the carcinogenicity of synthetic dyes. The current research focused on the isolation, screening, characterization, and optimization of Colletorichum lini isolate KUMBASBT-16 for pigment production and evaluating its antimicrobial, antioxidant, and anticancer potential. The C. lini isolate KUMBASBT-16 was deposited at GenBank, NCBI (Accession No. MT994640). The desirable physico-chemical parameters for the fungus C. lini to produce maximum biomass and pigment were recorded as temperature 25°C, pH 7, carbon source: sucrose (2% W/V), nitrogen source: yeast extract (1% W/V), mineral salt: potassium phosphate (0.05% W/V) and amino acid: asparagine (0.5% W/V). The UV-Vis analysis exhibited the λmax at 390nm, FT-IR analysis transmits the frequency of different functional groups and OHR-LC/MS analysis divulges the presence of yellow-colored endogenous metabolites comprises L-pyroglutamacin, methyl-1,4-benzoquinone, and 2,2,6,6-Tetramethyl-1-piperidinol. C. lini pigment exhibited significant antimicrobial activity by inhibiting all test bacterial pathogens. Enterococcus faecalis, with an inhibition zone of 20.96 ± 0.15mm being the most susceptible. The MIC value ranged from 0.75×10³ to 1.25×10³µg/mL. The pigment of C. lini displayed remarkable antioxidant efficacy, i.e., DPPH⁺ (IC₅₀ 338.46µg/mL), ABTS•+ (IC₅₀ 117.67µg/mL), FRAP ranging from 0.251 to 2.985 and total antioxidant potential ranging from 0.078 to 1.64. C. lini pigment affects the viability of HepG2 (IC₅₀ 136.41µg/mL) and A498 (IC₅₀ Value 138.71µg/mL) and is non-toxic to HEK-293 normal cells. The findings suggest that C. lini isolate KUMBASBT-16 can be exploited for industrial applications, potentially benefiting the pharmaceutical, food, and textile industries in the future.