Serratiopeptidase is a proteolytic enzyme extensively used as an anti-inflammatory and analgesic drug. Present work reports a thermoactive serratiopeptidase from Serratia marcescens AD-W2, a soil isolate from the North-Western Himalayan region of India. The extracellular metalloprotease has been purified by a simple two-step procedure resulting in a specific activity of 20,492 Units/mg protein with 5.28-fold purification. The molecular mass of the metalloprotease, as determined by SDS-PAGE was ~ 51 kDa. The purified serratiopeptidase presented optimum activity at pH 9.0, temperature 50 °C and stability in wide pH and temperature range. Critical temperature of 50 °C confirmed the thermoactivity of the purified serratiopeptidase. The kinetic studies of the purified serratiopeptidase revealed Vmax and Km of 57,256 Units/mL and 1.57 mg/mL, respectively, for casein. The purified serratiopeptidase from S. marcescens AD-W2 was found to be 100% identical to serralysin from Serratia marcescens ATCC 21074/E-15. The catalytic domain comprising of Zn coordinated with three histidine residues (His192, His196, His202), along with glutamate (Glu193) and tyrosine (Tyr232) residues, further confirmed that the purified protein is identical to serralysin.

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Background: COVID-19 pandemic has forced the human population to rethink over the lifestyle and food habits being followed by them. During the current scenario, when cases of more virulent new strain are emerging and specific treatment are still underway, we must look back to the Darvin’s theory of “Survival of the fittest” and in order to sustain the pandemic, we must follow the rule “Prevention is better than cure”. Traditional Medicinal System can bring possible solution including prevention and control of COVID-19. Humic substances have been used for antiviral activities, signifying that it has potential applications in the management and prevention of infectious diseases. Summary: Present article is focused on the assessment of the naturally occurring humic substances, which are major constituents of Shilajit, being used in traditional system of medicine and can be used against for the prevention of COVID-19. Key message: Humic substances not only improve the immune system, but also have anti-inflammatory, antioxidant and antiviral activities against human RNA viruses. Therefore, while the entire world is preparing to deal with alarming threat of community spread of COVID-19, Humic substances may play a vital role in improving the innate immunity for prevention and management of SARS-CoV-2 infection

An amendment to this paper has been published and can be accessed via the original article.

L-asparaginase, an important biopharmaceutical, has been a boon to cancer patients, especially for the therapeutic treatment of acute lymphoblastic leukemia. However, asparaginase formulations from E. coli and Erwinia species currently being used are associated with potential side effects causing hindrances towards a successful therapeutic treatment. Therefore, optimization and production of asparaginase from varied microbial sources has been the aim of several studies to overcome the hypersensitive and toxicological responses associated with presently used drug formulations. In this study, the possibility of using Enterobacter aesburiae strain R16C1/MT93543isolated from black gram rhizospheric soil sample as L-asparaginase source of industrial importance, was investigated. Different fermentation process parameters for the production of enzyme were optimized using submerged fermentation in shake flask. Box Behnken design was used to optimize and study individual as well as interactive effect of rpm, inoculum size (%) and temperature for asparaginase activity. Comparable values for enzyme activity were obtained from experimental results and software predicted values. As per interaction data obtained for the selected fermentation parameters, rpm, size of inoculum and temperature showed significant effects at interactive levels, thus, showing effect on production of enzyme. A significant improvement in enzyme activity was obtained using optimized environment. Higher enzyme activity of 40.36 U/ml was observed in M9 medium which was 4.4-fold higher than the initial activity of enzyme.