Metabolic Engineering for Biocatalyst Robustness to Organic Inhibitors

Microbial production of biorenewable fuels and chemicals is often limited by inhibition of the biocatalyst, either by increasing concentrations of the product compound or by contaminant compounds in the biomass‐derived sugars. This inhibition can interfere with economically viable production. Here we discuss typical mechanisms of inhibition and methods for improving biocatalyst robustness. Inhibition often takes the form of inhibition of enzyme activity, depletion of cofactor pools, and membrane damage; methods are discussed for mitigating each of these types of inhibition. Various evolutionary schemes have been developed and implemented on a variety of inhibitory compounds, including butanol, acetic acid, furfural, and ethanol. Reverse engineering of these improved strains can provide insight into new metabolic engineering strategies

COVID-19 Infection: Strategies on When to Discontinue Isolation, a Retrospective Study

Objective: Add to available understanding of COVID-19 to help decrease further spread of SARS-CoV-2 by providing protocol providers can consider when giving patients recommendations to retest as well as length of time for self-isolation. Methods: We retrospectively collected data from the electronic medical record of patients in the Mayo Clinic Florida\u27s COVID Virtual Clinic. Hundred and eighteen patients with detectable results for the virus were followed. Data reviewed in this study included (1) length of time from detectable to undetectable results; (2) length of time from onset of symptoms to undetectable result; (3) length of time from resolution of fever to undetectable result. Results: Fifty-three percent of studied patients eligible for discontinuation of self-isolation had detectable viral RNA, and therefore, underwent repeat testing. In these patients, the mean from the date of their first detectable result to attaining an undetectable result was 14.89 days. The mean time for onset of symptoms to undetectable testing was 21.5 days. Conclusions: Hundred and eighteen patients with detectable results for SARS-CoV-2 were followed in the Mayo Clinic Florida COVID Virtual Clinic; 53% of patients still showed detectable viral RNA despite meeting CDC guidelines for discontinuation of self-isolation, prompting us to propose following a more cautious guideline that other providers could consider as a strategy to discontinue self-isolation, including increasing length of days since symptom onset