The Enzyme Immobilization: Carriers and immobilization methods

Strategies based on the enzyme application are increasingly replacing the conventional chemical procedures because of their efficiency, quicker performance and environmental protection. However, natural enzymes can rarely be used in industry since their beneficial features can not endure the industrial conditions. Additional drawbacks of natural enzymes are their inhibition by reaction products and difficulty to be removed from the reaction mixture. The most promising technique to substantially improve the enzyme properties, such as activity, pH, thermal and organic-solvent stability, reusability and storage stability, in non-natural environments is by the enzyme immobilization. In this review we summarized different techniques used to immobilize enzymes to inert carriers. A wide variety of materials of both the organic and inorganic origin was used as carriers for the enzyme immobilization. We also summarized a class of new materials where the enzyme performance was enhanced by combining different classical materials and shaping in specific forms

Lipase production by Yarrowia lipolytica using olive oil processing wastes as substrates

In this study, the solid and liquid wastes from the olive oil processing industry were evaluated as substrates for Yarrowia lipolytica growth with the aim of lipase production. Olive mill wastewater and olive oil cake seemed to provide the necessary nutrients and physical support for yeast growth and enzyme production. The highest lipolytic activity of 850 IU dm(3) was achieved after 4 days of submerged cultivation in supplemented olive mill wastewater. In addition, olive oil cake appeared to be a convenient substrate for lipase production under a solid-state fermentation mode. Lipase production was further improved by media supplementation and/or change in the physical settings of the experiment. However, the most significant improvement of lipase production under solid-state fermentation was achieved by an alkaline treatment of the substrate (more than 10-fold), when the amount of produced lipase reached up to approximate to 40 IU g(-1) of substrate

Global prevalence of hepatitis B or hepatitis C infection among patients with tuberculosis disease: systematic review and meta-analysisResearch in context

Summary: Background: There is a substantial overlap in the epidemiology of chronic hepatitis B (HBV), hepatitis C (HCV) and tuberculosis (TB) due to overlapping risk factors. Testing for viral hepatitis is not widely recommended for patients with TB. The aim of this systematic review was to evaluate the global prevalence of chronic viral hepatitis infection among patients with TB. Methods: MEDLINE, EMBASE, Web of Science, Cochrane Library, African Journals Online, LILACS, and country TB reports were searched for studies published between January 1st, 2011 and June 17th 2021. Random-effects meta-analyses for proportions were conducted to obtain pooled prevalences. The prevalence of chronic HBV/HCV infection among patients with TB was also compared to that in the general population. The protocol was registered on PROSPERO (CRD42021276468). Findings: This analysis included 127 studies (83 for both HBV and HCV, 28 for HBV only, and 25 for HCV only) and data from 94,936 patients. The global pooled seroprevalence was 5.8% (95% CI 5.0–6.8) for HBs-antigen and 10.3% (95% CI 8.4–12.3) for HCV-antibodies. Pooled prevalence was highest in the WHO African Region for HBV at 7.8% (95% CI 5.2–10.9) and in the WHO European Region at 17.5% (95% CI 12.2–23.5) for HCV. In studies among TB patients who inject drugs, HCV prevalence was 92.5% (95% CI 80.8–99.0). Pooled HCV-antibody seroprevalence among patients with TB was higher than in the general population in all six WHO regions while HBs-antigen seroprevalence was higher in 3/6 regions. Interpretation: This review highlights the syndemicity of chronic viral hepatitis and TB and suggests that routine testing for hepatitis upon TB diagnosis may be justified. The prevalence of chronic HBV and HCV infections was higher among patients with TB than in the general population. Funding: This study was study was funded by the Global Tuberculosis Programme, World Health Organization