OPTIMIZATION OF LACTOBACILLUS PLANTARUM ACTIVITIES IN THE BIOSINTHESIS OF LIPASE ENZYMES

Objective: Lipase was protein compounds that can be used for many human activities. Its main function was to degrade fat including 'wrapping' cholesterol which make easily flowed in the blood. The presence lipase was important because can help the digestive healthy. These enzyme can catalyze a variety of reactions including hydrolysis, alcoholysis, esterification and aminolysis. Lipase was utilized in various sectors, such as fat, oil, milk and pharmaceutical industries. This enzyme biosynthesis can be carried out by Pseudomonas aeruginosa, Lactobacillus plantarum and Aspergillus niger. Methods: The process through fermentation techniques in lipid containing substrates under optimal conditions required by microorganisms. The fermentation products produced were tested for the presence of lipase enzymes qualitatively and quantitatively. The biosynthesis process can be influence by changes in pH, temperature and the presence of glucose. This study aimed to determine the ability of L. plantarum to produce lipases with vegetables oil substrates. The research used L. plantarum carried out at 37 °C for 24-48 h and pH 6-8 in the vegetable oil substrates. Results: The fermentation products showed hydrolysis reaction to the test media containing oil lipid with lipase levels of 2.708-3.3000 U/ml Conclusion: The results showed that Lactobacillus plantarum can synthesize the lipase enzyme in palm oil and corn oil as substrates.

Basal Glutathionylation of Na,K-ATPaseα-Subunit Depends on Redox Status of Cells during the Enzyme Biosynthesis

Many viruses induce oxidative stress and cause S-glutathionylation of Cys residues of the host and viral proteins. Changes in cell functioning during viral infection may be associated with glutathionylation of a number of key proteins including Na,K-ATPase which creates a gradient of sodium and potassium ions. It was found that Na,K-ATPaseα-subunit has a basal glutathionylation which is not abrogated by reducing agent. We have shown that acute hypoxia leads to increase of total glutathionylation level of Na,K-ATPaseα-subunit; however, basal glutathionylation ofα-subunit increases under prolonged hypoxia only. The role of basal glutathionylation in Na,K-ATPase function remains unclear. Understanding significance of basal glutathionylation is complicated by the fact that there are no X-ray structures of Na,K-ATPase with the identified glutathione molecules. We have analyzed all X-ray structures of the Na,K-ATPaseα-subunit from pig kidney and found that there are a number of isolated cavities with unresolved electron density close to the relevant cysteine residues. Analysis of the structures showed that this unresolved density in the structure can be occupied by glutathione associated with cysteine residues. Here, we discuss the role of basal glutathionylation of Na,K-ATPaseα-subunit and provide evidence supporting the view that this modification is cotranslational.