The influence of regulatory elements on Mycoplasma hyopneumoniae 7448 transcriptional response during oxidative stress and heat shock

Molecular Biology Reports - The comprehension of genome organization and gene modulation is essential for understanding pathogens’ infection mechanisms. Mycoplasma hyopneumoniae 7448 genome...     

Assessment of different systems for the production of aldonic acids and sorbitol by calcium alginate-immobilized Zymomonas mobilis cells

Bioprocess and Biosystems Engineering - Equimolar amounts of lactobionic acid and sorbitol may be obtained in a reaction catalyzed by the enzymes glucose–fructose oxidoreductase and...     

Production of organic acids by periplasmic enzymes present in free and immobilized cells of Zymomonas mobilis

In this work the periplasmic enzymatic complex glucose-fructose oxidoreductase (GFOR)/glucono-δ-lactonase (GL) of permeabilized free or immobilized cells of Zymomonas mobilis was evaluated for the bioconversion of mixtures of fructose and different aldoses into organic acids. For all tested pairs of substrates with permeabilized free-cells, the best enzymatic activities were obtained in reactions with pH around 6.4 and temperatures ranging from 39 to 45 °C. Decreasing enzyme/substrate affinities were observed when fructose was in the mixture with glucose, maltose, galactose, and lactose, in this order. In bioconversion runs with 0.7 mol l^?1 of fructose and with aldose, with permeabilized free-cells of Z. mobilis, maximal concentrations of the respective aldonic acids of 0.64, 0.57, 0.51, and 0.51 mol l^?1 were achieved, with conversion yields of 95, 88, 78, and 78 %, respectively. Due to the important applications of lactobionic acid, the formation of this substance by the enzymatic GFOR/GL complex in Ca-alginate-immobilized cells was assessed. The highest GFOR/GL activities were found at pH 7.0–8.0 and temperatures of 47–50 °C. However, when a 24 h bioconversion run was carried out, it was observed that a combination of pH 6.4 and temperature of 47 °C led to the best results. In this case, despite the fact that Ca-alginate acts as a barrier for the diffusion of substrates and products, maximal lactobionic acid concentration, conversion yields and specific productivity similar to those obtained with permeabilized free-cells were achieved.     

Correction to: High lactobionic acid production by immobilized Zymomonas mobilis cells: a great step for large-scale process

Bioprocess and Biosystems Engineering - In the original publication, table captions were incorrectly published. The correct captions are given here.     

High lactobionic acid production by immobilized Zymomonas mobilis cells: a great step for large-scale process

Bioprocess and Biosystems Engineering - Lactobionic acid and sorbitol are produced from lactose and fructose in reactions catalyzed by glucose–fructose oxidoreductase and...