Structure/function/properties relationships and application of a GH11 xylanase

Xylanases are hemicellulolytic enzymes, which are responsible for the degradation of the heteroxylans constituting the lignocellulosic plant cell wall. Due to their variety, xylanases have been classified in glycoside hydrolase families GH5, GH8, GH10, GH11, GH30 and GH43 in the CAZy database. In this work, we focus on GH11 family, which is one of the best characterized GH families with bacterial and fungal members. GH11 xylanases have for a long time been used as biotechnological tools in various industrial applications and represent in addition promising candidates for future other uses

Biochemical and molecular characterization of a recombinant \u3b1-amylase from Bacillus subtilis

Alpha amylase (EC3.2.1.1), one of more widespread enzymes in the industrial world, is a glycoside hydrolase. It hydrolyzes the \u3b1- (1,4) glucoside linkage between the glucose units of a polysaccharide. Microbial amylases, particularly those from Bacillus genus are more in demand than those from other sources. Alpha-amylases have potential application in wide number of industrial applications such as textile, paper, detergent, food, fermentation and pharmaceutical industries. Recombinant DNA technology for amylase production involves the selection of an efficient amylase gene, its insertion into an appropriate vector system, transformation in an efficient bacterial system to produce high amount of recombinant protein. In this context, the aim of this work is the overexpression of an\u3b1amylase gene from Bacillus subtilisUS572in E. coli strain and the characterization of the recombinant amylase which is an interesting candidate for biotechnological applications

Enzyme Storage and Recycling: Nanoassemblies of \u3b1-Amylase and Xylanase Immobilized on Biomimetic Magnetic Nanoparticles

Immobilization of enzymes has been extensively required in a wide variety of industrial applications, as a way to ensure functionality and the potential of enzyme recycling after used. In particular, enzyme immobilization on magnetic nanoparticles (MNPs) could offer reusability by means of magnetic recovery and concentration, along with increased stability and robust activity of enzyme at different physicochemical conditions. In the present work, microbial \u3b1-amylase (AmyKS) and xylanase (XAn11) were both immobilized on different types of magnetic nanoparticles [MamC mediated biomimetic magnetic nanoparticles (BMNPs) and inorganic magnetic nanoparticles (MNPs)] by using two different strategies (electrostatic interaction and covalent bond). AmyKS immobilization was successful using electrostatic interaction with BMNPs. Instead the best strategy to immobilize XAn11 was using MNPs through the hetero-crosslinker 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The immobilization protocols were optimized by varying glutaraldehyde (GA) concentration, enzyme quantity and reaction time. Under optimal conditions, 92% of AmyKS and 87% of XAn11 were immobilized on BMNPs and MNPs-E/N respectively (here referred as AmyKS-BMNPs and XAn11-MNPs nanoassemblies). The results show that the immobilization of the enzymes did not extensively alter their functionality and that increased enzyme stability compared to that of the free enzyme following upon storage at 4 \ub0C and 20 \ub0C. Interestingly, the immobilized amylase and xylanase were reused for 15 and 8 cycles respectively without signi\ufb01cant loss of activity upon magnetic recovering of the nanoassemblies. Results suggest the great potential of these nanoassemblies in bio-industry applications