ISSUES IN BIOTECHNOLOGY TEACHING - Teaching of Biotechnology in the Biochemistry Course

Biotechnology is taught in the Biochemistry course of the Faculty of Science of the Lisbon University during the last year of the course divide into two semesters. These two disciplines are optional with other disciplines that the students may choose in order to complete their knowledge in Biochemistry. Both disciplines have two credits, one for theory and the other for laboratory: Applied Biochemistry, comes in the first semester and Immobilized Biocatalysts in the second. Each discipline is taught during 13 weeks. The main goal of these two disciplines in the Biochemistry course is to give the students an applied vision, devoted to the industry, of the Biochemistry they have been taught during the previous three years

Purification, crystallization and preliminary X-ray diffraction analysis of the glyoxalase II from Leishmania infantum

A glyoxalase II from L. infantum was cloned, purified and crystallized and its structure was solved by X-ray crystallography

Metabolism of biodiesel-derived glycerol in probiotic Lactobacillus strains

Three probiotic Lactobacillus strains, Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus delbrueckii, were tested for their ability to assimilate and metabolize glycerol. Biodiesel-derived glycerol was used as the main carbon and energy source in batch microaerobic growth. Here, we show that the tested strains were able to assimilate glycerol, consuming between 38 and 48 % in approximately 24 h. L. acidophilus and L. delbrueckii showed a similar growth, higher than L. plantarum. The highest biomass reached was 2.11 g L−1 for L. acidophilus, with a cell mass yield (Y X/S) of 0.37 g g−1. L. delbrueckii and L. plantarum reached a biomass of 2.06 and 1.36 g L−1. All strains catabolize glycerol mainly through glycerol kinase (EC 2.7.1.30). For these lactobacillus species, kinetic parameters for glycerol kinase showed Michaelis–Menten constant (K m) ranging from 1.2 to 3.8 mM. The specific activities for glycerol kinase in these strains were in the range of 0.18 to 0.58 U mg protein−1, with L. acidophilus ATCC 4356 showing the maximum specific activity after 24 h of cultivation. Glycerol dehydrogenase activity was also detected in all strains studied but only for the reduction of glyceraldehyde with NADPH (K m for DL-glyceraldehyde ranging from 12.8 to 32.3 mM). This enzyme shows a very low oxidative activity with glycerol and NADP+ and, most likely, under physiological conditions, the oxidative reaction does not occur, supporting the assumption that the main metabolic flux concerning glycerol metabolism is through the glycerol kinase pathway