ABSTRACT
The enzymatic hydrolysis of poly- and oligosaccharides from plants seems like an advantageous approach for sugars production. Two inulinases producing fructose from plant oligosaccharides were isolated from yeast Kluyveromyces marxianus and plant Helianthus tuberosus. Both enzymes were immobilized on polymeric carriers by using the static adsorption approach. We could save 80.4% of the initial catalytic activity of plant inulinase immobilized on KU-2 cation-exchange resin and 75.5% of yeast enzyme activity adsorbed on AV-17-2P anion-exchange resin. After immobilization, the Km values increased 1.5 and 6 times for enzymes from K. marxianus and H. tuberosus, respectively. The optimal temperatures for catalysis of both enzymes were increased from 48-50⯰C up to 70⯰C. The activities of both immobilized enzymes remained unchanged after the 10â¯cycles of 20-min hydrolysis reaction at 70⯰C model batch reactor. Sorbents, native and immobilized enzymes did not exhibit any mutagenic or cytotoxic activity.
Subject(s)
Fructose/chemistry , Glycoside Hydrolases/chemistry , Glycoside Hydrolases/metabolism , Helianthus/enzymology , Kluyveromyces/enzymology , Plant Extracts/chemistry , Adsorption , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism , Enzymes, Immobilized/toxicity , Glycoside Hydrolases/toxicity , Humans , Hydrolysis , Inulin/chemistry , MCF-7 Cells , Resins, Synthetic/chemistryABSTRACT
Gram-positive bacteria cause a wide spectrum of infectious diseases, including nosocomial infections. While in the biofilm, bacteria exhibit increased resistance to antibiotics and the human immune system, causing difficulties in treatment. Thus, the development of biofilm formation inhibitors is a great challenge in pharmacology. The gram-positive bacterium Bacillus subtilis is widely used as a model organism for studying biofilm formation. Here, we report on the effect of new synthesized 2(5H)-furanones on the biofilm formation by B.subtilis cells. Among 57 compounds tested, sulfur-containing derivatives of 2(5H)-furanone (F12, F15, and F94) repressed biofilm formation at a concentration of 10 µg/ml. Derivatives F12 and F94 were found to inhibit the biosynthesis of GFP from the promoter of the eps operon encoding genes of the biofilm exopolysaccharide synthesis (EPS). Using the differential fluorescence staining of alive/dead cells, we demonstrated an increased bacterial sensitivity to antibiotics (kanamycin and chloramphenicol) in the presence of F12, F15, and F94, with F12 being the most efficient one. The derivative F15 was capable of disrupting an already formed biofilm and thereby increasing the efficiency of antibiotics.
