Background: Amylase catalyzes the breakdown of long-chain carbohydrates to yield maltotriose, maltose, glucose and dextrin as end products. It is present in mammalian saliva and helps in digestion. </P><P> Objective: Their applications in biotechnology include starch processing, biofuel, food, paper, textile and detergent industries, bioremediation of environmental pollutants and in clinical and medical applications. The commercial microbial strains for production of &#945;-amylase are Bacillus subtilis, B. licheniformis, B. amyloliquefaciens and Aspergillus oryzae. Industrial production of enzymes requires high productivity and cannot use wild-type strains for enzyme production. The yield of enzyme from bacteria can be increased by varying the physiological and genetic properties of strains. </P><P> Results: The genetic properties of a bacterium can be improved by enhancing the expression levels of the gene and secretion of the enzyme outside the cells, thereby improving the productivity by preventing degradation of enzymes. Overall, the strain for specific productivity should have the maximum ability for synthesis and secretion of an enzyme of interest. Genetic manipulation of &#945;-amylase can also be used for the production of enzymes with different properties, for example, by recombinant DNA technology. </P><P> Conclusion: This review summarizes different techniques in the production of recombinant &#945;- amylases along with the patents in this arena. The washing out of enzymes in reactions became a limitation in utilization of these enzymes in industries and hence immobilization of these enzymes becomes important. This paper also discusses the immobilization techniques for used α-amylases.

Highlights Concise information on origin and mechanism of corona virus transmission. Status of drugs under clinical trials for COVID-19. Strategic analysis of target proteins to screen potential inhibitors. Drug repurposing challenging opportunities. Consolidated report on target proteins from PDB to encourage Computer-aided drug discovery for COVID-19.

The knowledge of the docking sites and docking characteristics of the lipopeptide synthetases mentioned in the paper with the ligands can provide advantages of high speed and reliability, reduced costs on chemicals and experiments and the ethical issues concerned with the use of animal models for screening of drug toxicity.

The increase in antibiotic-resistant strains of pathogens has created havoc worldwide. These antibiotic-resistant pathogens require potent drugs for their inhibition. Lipopeptides, which are produced as secondary metabolites by many microorganisms, have the ability to act as potent safe drugs. Lipopeptides are amphiphilic molecules containing a lipid chain bound to the peptide. They exhibit broad-spectrum activities against both bacteria and fungi. Other than their antimicrobial properties, they have displayed anti-cancer properties as well, but their mechanism of action is not understood. In silico drug design uses computer simulation to discover and develop new drugs. This technique reduces the need of expensive and tedious lab work and clinical trials, but this method becomes a challenge due to complex structures of lipopeptides. Specific agonists (ligands) must be identified to initiate a physiological response when combined with a receptor (lipopeptide). In silico drug design and homology modeling talks about the interaction between ligands and the binding sites. This review summarizes the mechanism of selected lipopeptides, their respective ligands, and in silico drug design.

Silver nanoparticles exhibit wide dimensional antimicrobial and antifungal properties and therefore they are preferred for their applications in medical and cosmetics sector. They are synthesized by physical, chemical and biochemical methods. Biochemical methods are the best technique because of their non-toxic and energy efficient nature and hence are alternatives for the production of silver nanoparticles. One of the biochemical methods proposed in this work is the use of microbial surfactant for the synthesis of silver nanoparticles. The synthesis of surfactant was performed using Bacillus subtilis. The surfactant thus produced was analyzed by emulsification assay, oil spilling test, and hemolytic test. Silver nanoparticles synthesized from surfactant were observed by UV–Vis spectroscopy in the range of 400–600 nm. The surface plasmon resonance peak was observed at 410 nm corresponding to the peak of silver nanoparticles. The x-ray diffraction pattern showed an intense diffraction peak at with an average particle size of 14 nm. In silico drug designing of surfactin A synthetase C was performed using Schrödinger software for identification of novel drugs. All the two identified ligands, leucine and lysine, exhibited docking with the target protein which shows their potential as drug molecules.