Valorization of a plant ß-amylase: Immobilization and dataset on the kinetic process.

The data presented in this article are related to the research article titled "Immobilization nd topochemical mechanism of a new ß-amylase extracted from Pergularia tomentosa" (Lahmar et al., 2017) [1]. This article documented information on the determination of the molecular weight of the ß-amylase, the method of its immobilization and a comparison of the kinetic mechanism between the free and the immobilized forms by a mathematical method. Fresh Pergularia tomentosa was collected from Tunisia and a special method for ß-amylase extraction was followed (Yotova et al., 2000) [2]. Public dissemination of this dataset will allow further analyses of the data.

Influence of Ni2+ on urease activity produced by biofilms of Arthrobacter oxydans 1388.

New TiO2-based hybrid materials composed of an organic polymer, cellulose acetate butyrate and copolymer of acrylonitrile acrylamide (AN + AA) were prepared. The effectiveness of immobilization of microbial strain Arthrobacter oxydans 1388 on the newly synthesized hybrid membranes was investigated by biochemical methods. The obtained results revealed that the matrix more suitable for biofilm formation was composed of organic polymers without a metal component in the membrane composition. The influence of Ni2+ on urease activity produced by biofilms was investigated. The experimental results demonstrated that 2 mg L-1 concentration of Ni2+ in the nutrient medium is more appropriate for biofilm proliferation.

Total internal reflection imaging of microorganism adhesion using an oil immersion objective.

In this paper, we report the results of total internal reflection microscopy investigations of the interaction of two types of microorganisms: Saccharomyces cerevisiae and Escherichia coli with substrates. It is shown that with this method qualitative and quantitative information about cells-substrate interaction can be obtained. One can easily make a difference between attached and non-attached as well as between dead and alive cells, and more generally can follow the dynamics of the process of cells' attachment to substrates. Quantitative information about the cell size and cell-substrate distance is obtained by using a model in which yeast cells and bacteria are approximated by ellipsoids, and multiple reflections of the evanescent waves between the cells and the substrate are neglected.

Plasmon microscopy and imaging ellipsometry of Artrobacter oxydans attached on polymer films.

The attachment of Artrobacter oxydans 1,388 on a newly synthesized biodegradable copolymer of poly-(hexanlactam)-co-block-poly-(delta-valerolactone) is investigated by optical, microscopic and biochemical methods. The potentials of surface plasmon microscopy and imaging ellipsometry for detecting microorganisms when Al films are used to excite plasmons is assessed by comparing images obtained by these methods with dark field microscopy pictures. The experimental results demonstrate that in this case imaging ellipsometry and plasmon microscopy in transmission are promising methods and can be used in optical sensors for monitoring cell adhesion.