Eco-applicable pectinase from Bacillus infantis (SA2): enzyme production, optimization, protein profiling, and...

Microorganisms and their derivative by-products are among the renewable energy sources in ecologically sustainable systems. In this study, four pectin-degrading bacterial strains were isolated from oil-contaminated agricultural soil. Strain SA2 produced the maximum enzyme index, measuring of 20 mm, and exhibited extracellular pectinase enzyme activity of 119.67 U/mL. The strain was identified as Bacillus infantis through 16S rRNA gene sequencing. Using a one-factor-at-a-time approach, B. infantis (SA2) demonstrated the highest enzyme activity (U/mL) at 180 at 40 °C, 172 at pH 8.0, 187 with 1.5% glucose, and 174 with 1% ammonium sulfate. RSM optimized with five variables, viz., temperature 37.5 °C, pH 8.5, glucose 0.5%, ammonium sulfate 1.5%, and incubation time 24 h, predicted a pectinase yield of 268 U/mL. Under such optimized conditions, the partially optimized protein was characterized through SDS-PAGE, which revealed a characterization by molecular weight of 40 kDa. Nine major peptide peaks from pectinase protein were identified through mass fingerprinting. Of these, the peptide IAIDPIQGVDEAKAR, with a mass-to-charge ratio of 595 and a peak area of 6321, exhibited a maximum error (ppm) of 6321 of - 68.46. We made a homology modeling structure of the pectinase-producing enzyme, and molecular studies demonstrated its ability to degrade agricultural pesticides with a binding affinity of - 6.3 kcal/mol. Overall, B. infantis (SA2) is a good source of pectinase-producing strain and represents a valuable resource for industrial purposes, promising biotechnological biofertilizer applications, including in the agricultural sector.