pCold-assisted expression of a thermostable xylanase from : cloning, expression and characterization.

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The biotechnological application of bacterial xylanases requires a high thermostability, a catalytically active state for a broad pH range. The (MTCC 1270) A gene was amplified and cloned into the pCold vector and was expressed in to evaluate the expressed proteins' thermostability The pCold, compared to other similar vectors, has unique properties-including pH and temperature tolerance due to the presence of the cspA promoter. The recombinant A-pCold (rxynApC) showed the expression of A gene with a molecular weight of ~ 27 kDa, confirmed on SDS-PAGE. The rxynApC exhibits optimal activity at 70 °C and pH 8.0. The residual activity of the recombinant enzyme was 90% at pH 8.0. The thermal decomposition temperature ( ) value for the rxynApC enzyme was 93.33 °C obtained from the thermogravimetric analysis, indicating the potent stability of the cloned enzyme. The specific activity of native xylanase and rxynApC under optimal conditions was 32.35 and 105.5 U/mg, respectively. The structural model of the A gene was predicted using the in silico tool along with the active site (containing four important Tyr-166, Gly-7, Try-69 and Arg-112 amino acids). The predicted biophysical parameters of the in silico model were similar to the experimental results. The unique feature of the A promoter is that it gave a high expression of rxynApC enzyme having alkali and thermostable properties with high yield in surrogate host Thus, the recombinant A gene can potentially be applied to different industrial needs by looking at its thermostability and enhanced enzyme activity.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-022-03315-y.