Simultaneous production of industrially important alkaline xylanase‐pectinase enzymes by a bacterium at low cost under solid‐state fermentation conditions

Abstract

Simultaneous production of alkaline xylanase and all seven types of pectinases by a bacterial isolate, under solid-state fermentation was checked in this study. Under optimized conditions, high concurrent production of xylanase (22,800 ± 578 IU/g substrate) and pectinase (4,832 ± 189 IU/g substrate) was achieved. The different types of pectinases produced were exo-polymethylgalacturonase (782 IU/g), endo-polymethylgalacturonase (6.42 U/g), exo-polygalacturonase (2,250 IU/g), endo-polygalacturonase (11.57 U/g), polymethylgalacturonate lyase (53.99 IU/g), polygalacturonate lyase (59.78 IU/g), and pectin esterase (5.78 IU/g). Wheat bran resulted in the highest titer of both enzymes. The maximum xylanase-pectinase yield was detected after 7 days of incubation with 2 mM MgSO 4 and 1.5 g/L K 2 HPO 4 at wheat bran to moisture ratio 1:1.5 (w/v), media to flask volume ratio 1:25, pH 7.0, temperature 37 • C, and inoculum size 15%. Xylanase was most stable at pH 8.0, retained more than 75% activity up to 24 H, whereas pectinase was most stable at pH 9.0, having full activity even after 24 H. At 45 • C, the xylanase showed 82% residual activity after 6 H of incubation. The pectinase was 97% and 61% stable up to 3 H at 50 and 55 • C, respectively. This is the first report showing the production of xylanase-pectinases by bacterium along with high titer of seven types of pectinases, suitable for industries.

A novel and cost‐effective methodology for enhanced production of industrially valuable alkaline xylano‐pectinolytic enzymes cocktail in short solid‐state fermentation cycle

“…Xylano-pectinolytic enzymes were produced under SSF conditions in 250-mL Erlenmeyer flasks containing solid substrate wheat bran (10 g) as carbon source, substrate to moisture ratio 1:1.5 (wt/vol), pH 7.0, temperature 37 C, gram flour 5% (wt/wt), inoculum size 15% (vol/vol), MgSO 4 0.08% (wt/wt), and K 2 HPO 4 0.15% (w/w). 33 After 7 days of incubation interval, the enzymes were extracted twice by shaking the media contents at 200 rpm for 20 min in the presence of extraction buffer (glycine-NaOH, 0.01 M, pH 8.5). Centrifugation was done at 10,000 rpm for 15 min in order to remove the cells and debris and the clear supernatant obtained was used as source of xylanopectinolytic enzymes concoction.…”