A novel alpha-galactosidase gene (aga2) was cloned from Bifidobacterium breve 203. It contained an ORF of 2226-bp nucleotides encoding 741 amino acids with a calculated molecular mass of 81.5 kDa. The recombinant enzyme Aga2 was heterogeneously expressed, purified and characterized. Regarding substrate specificity for hydrolysis, Aga2 was highly active towards p-nitrophenyl-alpha-d-galactopyranoside (pNPG). The Km value for pNPG was estimated to be 0.27 mM and for melibiose it was estimated to be 4.3 mM. Aga2 was capable of catalyzing transglycosylation as well as hydrolysis. The enzyme synthesized a trisaccharide (Gal-alpha-1, 4-Gal-alpha-1, 6-Glc) using melibiose as a substrate. It was a new oligosaccharide produced by glycosidase and contained Gal-alpha-1,4 linkage, a novel galactosidic link formed by microbial alpha-galactosidase. In the presence of pNPG as a donor, Aga2 was able to catalyze glycosyl transfer to various acceptors including monosaccharides, disaccharides and sugar alcohols.

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A novel regularised image super-resolution algorithm is proposed, building on the emerging cosparse or analysis sparse prior models, which are important complementary alternatives to the widely used synthesis sparse counterpart. Moreover, to achieve adaptivity to the varying local structures of natural images, the patch space is partitioned into meaningful subspaces by clustering and learn analysis sub-dictionary for each cluster are partitioned, which are performed online and iteratively based solely on the current available image information, for maximum generality and flexibility. In addition, non-local feature self-similarity is incorporated for further reconstruction quality enhancement. Experimental results show that the proposed approach gives favourable results with respect to the state-of-the-art methods.

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