Kluyveromyces marxianus: a potential biocatalyst of renewable chemicals and lignocellulosic ethanol production.

Kluyveromyces marxianus is an ascomycetous yeast which has shown promising results in cellulosic ethanol and renewable chemicals production. It can survive on a variety of carbon sources under industrially favorable conditions due to its fast growth rate, thermotolerance, and acid tolerance. K. marxianus, is generally regarded as a safe (GRAS) microorganism, is widely recognized as a powerhouse for the production of heterologous proteins and is accepted by the US Food and Drug Administration (USFDA) for its pharmaceutical and food applications. Since lignocellulosic hydrolysates are comprised of diverse monomeric sugars, oligosaccharides and potential metabolism inhibiting compounds, this microorganism can play a pivotal role as it can grow on lignocellulosic hydrolysates coping with vegetal cell wall derived inhibitors. Furthermore, advancements in synthetic biology, for example CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats with Cas9)-mediated genome editing, will enable development of an engineered yeast for the production of biochemicals and biopharmaceuticals having a myriad of industrial applications. Genetic engineering companies such as Cargill, Ginkgo Bioworks, DuPont, Global Yeast, Genomatica, and several others are actively working to develop designer yeasts. Given the important traits and properties of K. marxianus, these companies may find it to be a suitable biocatalyst for renewable chemicals and fuel production on the large scale. This paper reviews the recent progress made with K. marxianus biotechnology for sustainable production of ethanol, and other products utilizing lignocellulosic sugars.

Evaluation of sorghum straw hemicellulosic hydrolysate for biotechnological production of xylitol by Candida guilliermondii

A preliminary study on xylitol production by Candida guilliermondii in sorghum straw hemicellulosic hydrolysate was performed. Hydrolysate had high xylose content and inhibitors concentrations did not exceed the commonly found values in other hemicellulosic hydrolysates. The highest xylitol yield (0.44 g/g) and productivity (0.19 g/Lh) were verified after 72 hours.

Evaluation of sorghum straw hemicellulosic hydrolysate for biotechnological production of xylitol by Candida guilliermondii.

A preliminary study on xylitol production by Candida guilliermondii in sorghum straw hemicellulosic hydrolysate was performed. Hydrolysate had high xylose content and inhibitors concentrations did not exceed the commonly found values in other hemicellulosic hydrolysates. The highest xylitol yield (0.44 g/g) and productivity (0.19 g/Lh) were verified after 72 hours.

[The first São Paulo meeting on mental health services for college students]. / O I encontro paulista dos serviços de assistência psicológica ao estudante universitário.

The authors initially describe the main psychological problems observed among medical students. After that, they write briefly about the history of the psychological support to the college student in Brazil. Next, they present a summary of the First São Paulo Meeting on Mental Health Services for College Students. Finally, they point out the main topics presented in the meeting, like the identity of the Service, its specificity, its institutional role, the ideal working setting and its ethical questions. Current working conditions for medical professionals and some characteristics of Contemporary Medicine were also discussed.

On the dose equivalence of flurazepam and triazolam.

Flurazepam (30 mg), triazolam (0.5 mg) and placebo were given in the morning to 6 normal volunteers in a double-blind crossover study. Subjects were evaluated by a large battery of psychophysiological tests before and 1 and 5 hours after drug administration. Triazolam was significantly more sedative than flurazepam and both were significantly different from placebo. Slope-ratio assay analysis of the results from the present study pooled with those from a similar previous study (C. Gorenstein and V. Gentil, Psychopharmacology, 80: 376-379, 1983) indicated that these doses are non-equivalent. We suggest that dose-equivalence studies based on the present method should be carried out early in the development of new hypnotic drugs.