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The novel coronavirus (SARS-CoV-2) outbreak has started taking away the millions of lives worldwide. Identification of known and approved drugs against novel coronavirus disease (COVID-19) seems to be an urgent need for the repurposing of the existing drugs. So, here we examined a safe strategy of using approved drugs of SuperDRUG2 database against modeled membrane protein (M-protein) of SARS-CoV-2 which is essential for virus assembly by using molecular docking-based virtual screening. A total of 3639 drugs from SuperDRUG2 database and additionally 14 potential drugs reported against COVID-19 proteins were selected. Molecular docking analyses revealed that nine drugs can bind the active site of M-protein with desirable molecular interactions. We therefore applied molecular dynamics simulations and binding free energy calculation using MM-PBSA to analyze the stability of the compounds. The complexes of M-protein with the selected drugs were simulated for 50 ns and ranked according to their binding free energies. The binding mode of the drugs with M-protein was analyzed and it was observed that Colchicine, Remdesivir, Bafilomycin A1 from COVID-19 suggested drugs and Temozolomide from SuperDRUG2 database displayed desirable molecular interactions and higher binding affinity towards M-protein. Interestingly, Colchicine was found as the top most binder among tested drugs against M-protein. We therefore additionally identified four Colchicine derivatives which can bind efficiently with M-protein and have better pharmacokinetic properties. We recommend that these drugs can be tested further through in vitro studies against SARS-CoV-2 M-protein.

This study exclusively focused on the potential application of an inexpensive and sustainable waste macro-algal biomass as an adsorbent for biosorption of copper ions from aqueous medium. After extraction of agar from brown macro-marine algaeGelidiella acerosa, the residual biomass without any further treatment was used as an adsorbent for the expulsion of copper from wastewater. Physicochemical parameters of biosorption like initial pH, initial concentration of Cu(II) solution and biosorbent dosage were optimized using response surface methodology. The maximum copper biosorption potential of 96.36% was observed at optimum conditions of pH of 5.31, initial concentration of 23.87 mg/l and biosorbent dosage of 0.41 g/l. Adopting FTIR and SEM techniques, the surface morphological features of biosorbent were studied. The pseudo-second-order kinetic model was found to be a proper approach to describe biosorption kinetics. All these results confirmed that spentG.acerosacould be considered as an efficient, eco-friendly and economic alternative for Cu(II) removal from aqueous solution.

Biosurfactants are amphiphilic compounds produced by bacteria either extracellularly or as a part of the cell membrane. Biosurfactants have had a profound impact on medical and pharmaceutical biotechnology. In our previous work, we isolated a new biosurfactant produced by Acinetobacter indicus M6 which reduces the surface tension of water from 72.0 to 39.8 mN/m and which showed thermophilic, halophytic and acidophilic stability. The chemical nature was found to be a class of glycolipoprotein. Here, our research presents the extracted biosurfactant’s anti-proliferative activity against lung cancer cells (A549), and anti-microbial and anti-biofilm activity against MRSA. The anti-tumour activity of biosurfactant against lung cancer cells was evaluated in terms of cell viability at different concentrations. The results showed a decrease in the percentage of lung cancer viable cells with increasing biosurfactant concentrations and incubation time, with a significant decrease being observed at 200 µg/ml concentration leading to cell proliferation inhibition at G1 phase. Treatment of biofilms for seven days at 500 µg/ml resulted in up to 82.5% biofilm disruption. Keywords: Biosurfactant, Acinetobacter indicus M6, Cell viability, Anti-proliferative activity, Anti-biofilm activity

The immunoglobulin (Ig) binding proteins of Staphylococcus aureus namely staphylococcal protein A (SpA) and staphylococcal binder of immunoglobulin (Sbi) are responsible for false positives during immunoassays. Avian IgY antibodies were reported to have no affinity to SpA and thus are safe for use in immunoassays. However, the behaviour of Sbi with IgY was not reported. The purpose of the present study is to evaluate the interactions between IgY antibodies and Sbi protein from different S. aureus strains. Initially, heterologous cloning and expression of complete sbi gene in Escherichia coli was undertaken. Recombinant Sbi protein was utilized to generate polyclonal anti-Sbi IgY and anti-Sbi antibodies in chicken and BALB/c mice respectively. Indirect ELISA and Western blotting were performed to evaluate the reactivity of anti-Sbi antibodies. Non-reducing PAGE followed by Western blotting and double-antibody sandwich dot-ELISA were performed to analyze the reactivity of IgY antibodies with recombinant Sbi and native Sbi from S. aureus strains. To avoid the possible interference of enzyme-conjugated secondary antibodies from mammalian sources, mouse anti-Sbi revealing antibodies were labeled with biotin so that streptavidin-HRP was used as developing reagent for chromogenic reaction. Sbi was highly immunogenic in chicken and mouse with antibody titers of 1:128,000 and 1:64,000 dilutions respectively. We observed that unimmunized IgY antibodies showed no affinity to either recombinant Sbi or native Sbi from S. aureus strains in Western blotting and double antibody sandwich ELISA. In view of these observations, we recommend that IgY antibodies are safe and free from false positives due to SpA and Sbi in immunoassays involving detection of S. aureus antigens/exotoxins.

A novel approach of cellulase-based co-culture producing bioethanol using low-cost nutrient medium has been employed for the study, and docking strategies provided the information of cellobiose and cellotetraose inhibitors during cellulase production. The Acinetobacter species was isolated from termite gut and confirmed in 16s rDNA analysis. SDS-PAGE reveals the molecular weight of purified cellulose was 45 kDa. Cellulose activity was achieved maximum of 1.2 IU/mL at 48th hour of incubation, and about 80% of polysaccharides were converted into simple sugars. The enzyme activity was optimum at different physiological conditions like temperature at 37 °C, pH 7.0 and with 4% concentration of banana peduncle extract powder. Upon reaching maximum cellulolytic activity of 0.594 IU/mL, the percentage of ethanol produced from cellulosic hydrolysate using S. cerevisiae reached maximum ethanol (18.3 g/L) during 48 h of incubation. Cellulase produced by Acinetobacter indicus KTCV2 strain exhibits a short incubation period (48 h) and produces cellulase in broader pH and temperature ranges. Banana peduncle offers a cheapest raw material composed of cellulosic biomass in agricultural practices, which served as a good substrate for the production of ethanol.

Background ATP-binding cassette (ABC) transporters constitute one of the largest transporter protein families and play a role in diverse biological processes. Results In the present study, bacteriocin isolated from the Enterococcus casseliflavus MI001 strain was identified as an ABC transporter ATP-binding protein. The optimal conditions for the production of bacteriocin were found to be at 35 °C, a pH 5.5, and an incubation time of 24 h. Purification was performed using ammonium sulphate precipitation, gel filtration, and DEAE ion exchange chromatography. The bacteriocin was purified with an eightfold purification scheme resulting with a specific activity of 15,000 AU/mg. The NMR spectrum of purified bacteriocin revealed the presence of amino acids, namely lysine, methionine, cysteine, proline, threonine, tryptophan, and histidine. Further, the bacteriocin ABC transporter showed antimicrobial activity against food spoilage microorganisms. Conclusions The ABC transporter ATP-binding protein could be used as a potential alternative for food preservation, and it may be considered as a bio-preservative agent in food processing industries.