An update on COVID-19: SARS-CoV-2 life cycle, immunopathology, and BCG vaccination.

The causative agent of novel coronavirus disease (COVID-19) is severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 possesses RNA as a genetic material with 79% of the match with the bat SARS-CoV genome, which became epidemic in 2002. The SARS-CoV-2 peripheral Spike-Fc protein binds specifically to the ACE2 receptors present on bronchial epithelial cells and alveolar pneumocytes to downmodulates its expression which leads to severe acute respiratory failure. The disease is super infectious from human to human and the symptoms are similar to flu. The old aged and immunocompromised population are severely affected, and healthcare providers globally applied various strategies for treatment including the repurposing of drugs including antimalarial drug, hydroxychloroquine and anti-viral drugs.Herein, we described the SARS-CoV-2 pandemic, immune responses, possible drug targets, vaccines under the trials and correlated the possibility of trained immunity induced by BCG vaccination over control of SARS-CoV-2 infection. The countries with constraint BCG vaccination policy are struggling badly compared to countries with BCG vaccination policy. The BCG vaccination policy supports either lowering the total number of COVID-19 cases or the increasing recovery rate.

Effect of nutritional supplements on bio-plastics (PHB) production utilizing sugar refinery waste with potential application in food packaging.

Polyhydroxyalkanoates (PHAs) are intracellular carbon and energy storage reserve material stored by gram-negative bacteria under nutrient limitation. PHAs are best alternative biodegradable plastics (bio-plastics) due to their resemblance to conventional synthetic plastic. The present study investigated the synergistic effect of nutritional supplements (amino acid and vitamin) on the PHA production by Alcaligenes sp. NCIM 5085 utilizing a sugar refinery waste (cane molasses) under submerged fermentation process. Initially, the effect of individual factor on PHA yield was studied by supplementing amino acids (cysteine, isoleucine, and methionine), vitamin (thiamin), and cane molasses at varying concentration in the production medium. Further, the cultivation medium was optimized by varying the levels of cane molasses, methionine and thiamin using response surface methodology to enhance the PHA yield. The maximum PHA yield of 70.89% was obtained under the optimized condition, which was then scaled up on 7.5 L-bioreactor. Batch cultivation in 7.5 L-bioreactor under the optimized condition gave a maximum PHA yield and productivity of 79.26% and 0.312 gL-1 h-1, respectively. The PHA produced was subsequently characterized as PHB by FTIR. PHB extracted was of relatively high molecular weight and crystallinity index. DSC analysis gave Tg, Tm, and Xc of 4.2, 179 °C and 66%, respectively. TGA analysis showed thermal stability with maximized degradation occurring at 302 °C, which is above the melting temperature (179 °C) of the purified polymer. The extracted polymer, therefore, possessed desirable material properties to be used in food packaging.

Effect of surfactants and inducers on increased uricase production under submerged fermentations by Bacillus cereus.

Uricase is a clinical enzyme used for the oxidation of uric acid crystals in gout disease. The present study aimed to increase the suitable surfactant-mediated uricase production on induction by different concentrations of inducers. The efficiency of Bacillus cereus to produce extracellular uricase enzyme was studied in uric acid-containing agar plates. Among the studied inducers, uric acid is the potential inducer for uricase production under submerged fermentations (SMF), which induced 19.41 U/ml uricase in medium containing 2.0 g/L of uric acid, however further increase in the uric acid concentration decreased uricase production, which could be because of substrate inhibition. The physical parameters including agitation speed (rpm) and time duration (h) of uricase production were optimized and found to produce optimum uricase at 150 rpm in 26 h of SMF. Among the studied surfactants, nonionic surfactant, polyvinyl alcohol has shown a remarkable increase in the uricase production of 31.58 U/ml, which is a 61% increase under optimized conditions in SMF. The stability of produced uricase was found at pH 7.5 and temperature 30°C. Also the effects of various metal ions (1 mM) on the uricase activity were studied and observed to be inhibitory in nature in the descending order K+ > Ca2+ > Zn2+ > Fe3+ > Ni2+ > Mg2+ > Mn2+ > Cu2+.