Calcium alginate matrix increases the stability and recycling capability of immobilized endo-β-1,4-xylanase from Geobacillus stearothermophilus KIBGE-IB29

Abstract

Exploration of microbial pool from extremely diversified ecosystem is significantly important for various industrial applications. Bacterial communities from extreme habitats including volcanic vents, hot springs, and industrial sectors are eagerly explored for the isolation of thermophiles. Geobacillus stearothermophilus KIBGE-IB29, isolated from blast furnace site of a steel processing industry, is capable of producing thermostable endo-β-1,4-xylanase. In the current study, this enzyme was immobilized within calcium alginate beads using entrapment technique. Amalgamation of sodium alginate (40.0 gL(-1)) and calcium chloride (0.4 M) was used for the formation of immobilized beads. It was observed that temperature (50 °C) and pH (7.0) optima of immobilized enzyme remained same, but enzyme-substrate reaction time increased from 5.0 to 30.0 min as compared to free enzyme. Diffusion limit of high molecular weight xylan (corncob) caused a decline in V max of immobilized enzyme from 4773 to 203.7 U min(-1), whereas K m value increased from 0.5074 to 0.5722 mg ml(-1) with reference to free enzyme. Immobilized endo-β-1,4-xylanase showed its stability even at high temperatures as compared to free enzyme and retained 18 and 9 % residual activity at 70 and 80 °C, respectively. Immobilized enzyme also exhibited sufficient recycling efficiency up to five reaction cycles which indicated that this enzyme can be a plausible candidate in paper and pulp industry.

Immobilization and Biochemical Properties of Purified Xylanase from Bacillus amyloliquefaciens SK-3 and Its Application in Kraft Pulp Biobleaching

“…It was noted that immobilized xylanase is capable to stand a wide range of temperatures for relatively longer time period in comparison with free enzyme. These results were also agreement with those earlier reports [31,32]. It is possible that elevated temperature may denature the catalytic function of an enzyme in the micro environment of the matrix used.…”

“…The smaller beads with xylanase immobilization possibly may be due to the addition xylanase enzyme. Similar observations were also reported on immobilization of xylanase on Ca-alginate beads [32,33].…”

“…After seven cycles, 30% of the initial activity was retained by immobilized enzyme. The loss of activity of entrapped enzyme is may be due to leakage of enzyme from the calcium alginate beads as results of washing of beads at the end of each cycle or conformational changes by repeated uses [30,32]. This is higher value of the operational stability as compared to that reported previously by using same support for xylanase, pectinase immobilization under same [30,31,40].…”

Enhanced elimination of non‐digestible oligosaccharides from soy milk by immobilized α‐galactosidase: A comparative analysis

“…In the present study, comparison of two different matrices namely alginate and chitosan for immobilization of α‐galactosidase from A. oryzae was performed. Alginate, a natural polysaccharide composed of 1,4 linked β ‐d mannuronic and α ‐l‐guluronic acid residues forms an insoluble gel‐like matrix in the presence of calcium ions (Bibi, Qader, & Aman, ). Chitosan, a natural polyaminosaccharide obtained by N‐deacetylation of chitin, can form macrospheres which can entrap enzymes (Nath et al, ).…”

Glycyrrhetic Acid 3‐O‐Mono‐β‐d‐glucuronide (GAMG): An Innovative High‐Potency Sweetener with Improved Biological Activities

“…Immobilization can improve the biocatalytic efficiency and reusability of an enzyme (Bibi, Qader, & Aman, ). Purified β‐GUS from Aspergillus terreus was immobilized via entrapment in alginate gel for the bioconversion of GL into GAMG.…”