Meaningful Work, Career Fit, and Professional Well-Being of Pediatric Academicians in the United States.

Objective: Examine associations between time spent in academic activities perceived as meaningful and professional well-being among academic pediatrics faculty.

Methods: The sample comprised 248 full-time pediatric faculty (76% female, 81% white, non-Hispanic, 41% instructor or assistant professor) across the United States who completed an online survey in November 2019. Survey items included sociodemographic and professional characteristics, professional well-being measures (Stanford Professional Fulfillment Index; Maslach Burnout Inventory; Intention to Leave Academic Medicine), perceived meaningfulness of academic activities and assigned time to those activities.

Strain and bioprocess improvement of a thermophilic anaerobe for the production of ethanol from wood.

Background: The thermophilic, anaerobic bacterium Thermoanaerobacterium saccharolyticum digests hemicellulose and utilizes the major sugars present in biomass. It was previously engineered to produce ethanol at yields equivalent to yeast. While saccharolytic anaerobes have been long studied as potential biomass-fermenting organisms, development efforts for commercial ethanol production have not been reported.

Anaerobic detoxification of acetic acid in a thermophilic ethanologen.

Background: The liberation of acetate from hemicellulose negatively impacts fermentations of cellulosic biomass, limiting the concentrations of substrate that can be effectively processed. Solvent-producing bacteria have the capacity to convert acetate to the less toxic product acetone, but to the best of our knowledge, this trait has not been transferred to an organism that produces ethanol at high yield.

Results: We have engineered a five-step metabolic pathway to convert acetic acid to acetone in the thermophilic anaerobe Thermoanaerobacterium saccharolyticum.

High ethanol titers from cellulose by using metabolically engineered thermophilic, anaerobic microbes.

This work describes novel genetic tools for use in Clostridium thermocellum that allow creation of unmarked mutations while using a replicating plasmid. The strategy employed counter-selections developed from the native C. thermocellum hpt gene and the Thermoanaerobacterium saccharolyticum tdk gene and was used to delete the genes for both lactate dehydrogenase (Ldh) and phosphotransacetylase (Pta).

Metabolic engineering of a thermophilic bacterium to produce ethanol at high yield.

We report engineering Thermoanaerobacterium saccharolyticum, a thermophilic anaerobic bacterium that ferments xylan and biomass-derived sugars, to produce ethanol at high yield. Knockout of genes involved in organic acid formation (acetate kinase, phosphate acetyltransferase, and L-lactate dehydrogenase) resulted in a strain able to produce ethanol as the only detectable organic product and substantial changes in electron flow relative to the wild type. Ethanol formation in the engineered strain (ALK2) utilizes pyruvate:ferredoxin oxidoreductase with electrons transferred from ferredoxin to NAD(P), a pathway different from that in previously described microbes with a homoethanol fermentation.