Development of strategy for simultaneous enhanced production of alkaline xylanase-pectinase enzymes by a bacterial isolate in short submerged fermentation cycle

Abstract

The aim of this study is to enhance the production of industrially valuable xylanase and pectinase enzymes in short duration, using agrowaste extracted substrates. Conventional cum statistical multifactor analysis approaches were used in order to evaluate the effect of crude extracted substrates, supplemented for the production of xylanase-pectinase enzymes. Incorporation of crude extracted xylan (1.2 mg/ml of inoculum) and pectin (4.8 mg/ml of inoculum) substrates in inoculum resulted in maximal xylanase (320 ± 15) and pectinase titre (90 ± 8) after 48 h, using 2% wheat bran and 2% citrus peel in production medium with 48 h of fermentation time, with one variable factor at a time approach. The best condition obtained after performing statistical multifactor interaction analysis includes 5.50 mg/ml of pectin in inoculum,1.50 mg/ml of xylan in inoculum, wheat bran 3%, temperature 37.5 °C, time 48 h, 7 mg/ml of pectin in production medium, peptone 1.05%, inoculum size 2% and inoculum age of 20 h, with alkaline xylanase activity of 415.22 ± 18.50 IU/ml and alkaline pectinase activity of 109.10 ± 8.80 IU/ml. Activity of different pectinolytic enzymes per ml was also calculated, with 18.98 IU of exo-polymethylgalacturonase, 0.14 IU of endo-polymethylgalacturonase, 80 IU of exo-polygalacturonase, 0.28 IU of endo-polygalacturonase, 1.42 IU of polymethylgalacturonate lyase, 1.47 IU of polygalacturonate lyase, 0.15 IU of pectin esterase. This is the first report mentioning the utilization of crude extracted xylan and extracted pectin in inoculum to get the increment in the activity of both alkaline xylanase-pectinase enzymes simultaneously under short submerged fermentation cycle.

Keywords: Agro-wastes; Alkaline xylanase-pectinase; Extracted pectin; Extracted xylan; Response surface methodology.