Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) belongs to the family coronaviridae. It is spherical and possesses proteins called spikes, which can clamp onto the human cells. Once in close interaction with the human cells, these viruses undergo structural change and can fuse with the cell membrane. The virus enters the host and starts the process of translation and transcription in the cells and uncoated genome, respectively. Due to the rapid transmittable nature of the virus, extant actions should be taken. The fatty acids administrated orally, or intravenously, could help us gear things up in providing resistance and preventing infection. Hence, the multiplication of the virus could be hindered by arachidonic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). In that context, the current review highlights the role of these unsaturated fatty acids and their derivatives such as lipoxins and resolvins in the inactivation of the enveloped coronavirus disease 2019 (COVID-19).
Racemize 2-hydroxybutyric acid is usually synthesized by organic methods and needs additional deracemization to obtain optically pure enantiomers for industrial application. Here we present a cascade biocatalysis system in Escherichia coli BL21 which employed L-threonine deaminase (TD), NAD-dependent L-lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH) for producing optically pure (S)-2-hydroxybutyric acid ((S)-2-HBA) from bulk chemical L-threonine. To solve the mismatch in the conversion rate and the consumption rate of intermediate 2-oxobutyric acid (2-OBA) formed in the multi-enzyme catalysis reaction, ribosome binding site regulation strategy was explored to control TD expression levels, achieving an eightfold alteration in the conversion rate of 2-OBA. With the optimized activity ratio of the three enzymes and using ADH for NADH regeneration, the recombinant strain ADH-r53 showed increased production of (S)-2-HBA with the highest titer of 129 g/L and molar yield of 93% within 24 h, which is approximately 1.65 times that of the highest yield reported so far. Moreover, (S)-2-HBA could easily be purified by distillation, making it have great potential for industrial application. Additionally, our results indicated that constructing a tunable multi-enzyme-coordinate expression system in single cell had great significance in biocatalysis of hydroxyl acids.