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

Equimolar amounts of lactobionic acid and sorbitol may be obtained in a reaction catalyzed by the enzymes glucose-fructose oxidoreductase and glucono-δ-lactonase, which are found in the periplasm of Zymomonas mobilis. These reactions are generally conducted using immobilized bacterial cells, and the cell treatment and immobilization steps are costly and time-consuming. This study evaluated alternatives to simplify the preparation of calcium alginate-immobilized biocatalyst and its application in different operation modes and types of reactors. It was possible to eliminate cell permeabilization with cetyltrimethylammonium bromide, and the reticulation of Z. mobilis cells with glutaraldehyde sufficed to inhibit the fermentative metabolism of carbohydrates by the bacterium, with accumulation of bioconversion products. When the process was carried out in a mechanically stirred reactor in batch mode, 530 mmol L- 1 of products were obtained in 24 h. The process was also tested in fed-batch mode so as to use of a larger amount of lactose, since it could not be used in the batch because of its low solubility in water. Under this condition, final products concentration reached 745 mmol L- 1 within 42 h. Similar results were obtained for reactions conducted in a pneumatically stirred reactor in batch and fed-batch modes, proving the potential use of this process in several industrial settings.

Influence of the fish oil in the gut microbiota of wistar rats (Rattus norvegicus) treated with dexamethasone and amoxicillin.

The widespread use of antibiotics and anti-inflammatory has been more and more prominent. In spite of the proven pharmacological potential, its collateral effects are still being described. The fish oil is made of acids fatty polyunsaturated, as the omega 3. The aim of this paper is to check if there would be interference of this fish oil in the gut microbiota of rats when treated with dexamethasone and amoxicillin, joining with the parameter lipids and glycemic. This study was done with 42 Wistar rats, divided into 6 groups with 7 animals each: naive (CTL), amoxicillin (AMOX), dexamethasone (DEX), fish oil (OLP), associated amoxicillin and fish oil (AMOX + OLP) association dexamethasone and fish oil (DEX + OLP). The results show that the fish oil influenced in the concentration of blood glucose in the animals, keeping stable levels even after a pool of glucose. Differently, the fish oil increased the levels of LDL in the animals. The amoxicillin changed the mass of liver and spleen, changed the levels of triglyceride and changed the gut microbiota. The dexamethasone influenced the lipids parameters and mass of the spleen as well as it slightly increased the amount of cholesterol LDL. It is possible to conclude that fish oil increases the levels of LDL in the tested model and the dose tested, but is able to maintain glucose levels even after a pool of the same, and can be a preventive model with hyperglycemia.