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The preparation of biologically active oligosaccharides from the stem residues of the mallow plant (Corchorus olitorius) was evaluated by the enzymatic hydrolysis method. The isolated strain Aspergillus flavus B2 (accession number OL655454) was selected as a potential producer of the enzymes mixture. The factors affecting the hydrolysis of Mallow stems (MS) by enzyme mixture were tested using Plackett-Burman and Central Composite statistical designs. Different production conditions yielded 13 bioactive oligosaccharides (MSOS) that differed in their yield, components, monosaccharides constitution, percentage, and degree of polymerization. The optimized conditions yielded 525 milligrams of oligosaccharide per gram of dry MS using enzymes- mixture containing cellulase 4.9 U/mL, xylanase 6.8 U/mL, and pectinase 12.9 U/mL. Oligosaccharide no. 4 showed higher fibrinolytic activity than Hemoclar. All tested oligosaccharides (1 %) improved the growth of both the probiotics Bifidobacterium lactis and Lactobacillus plantarum. The antioxidant activity of the produced oligosaccharides varies depending on their characteristics and method of evaluation. Of all the samples tested, MSOS no. 11 showed the highest level of DPPH, reducing power, ABTS, and FRAP activity. Moreover, the highest reduction in tumor cell viability and the inhibited ascites were obtained by MSOS no. 11 (37.24±0.31 %). [ABSTRACT FROM AUTHOR]

Pectinase produced by a honey derived from the fungus Aspergillus awamori KX943614 was covalently immobilized onto gel beads made of alginate and agar. Polyethyleneimine, glutaraldehyde, loading time and enzyme's units were optimized by 2 4 full factorial central composite design (CCD). The immobilization process increased the optimal working pH for the free pectinase from 5 to a broader range of pH4.5-5.5 and the optimum operational temperature from 55°C to a higher temperature, of 60°C, which is favored to reduce the enzyme's microbial contamination. The thermodynamics studies showed a thermal stability enhancement against high temperature for the immobilized formula. Moreover, an increase in half-lives and D-values was achieved. The thermodynamic studies proved that immobilization of pectinase made a remarkable increase in enthalpy and free energy because of enzyme stability enhancement. The reusability test revealed that 60% of pectinase's original activity was retained after 8 successive cycles. This gel formula may be convenient for immobilization of other industrial enzymes., (Copyright © 2018 Elsevier B.V. All rights reserved.)