Availability of the Molecular Switch XylR Controls Phenotypic Heterogeneity and Lag Duration during Escherichia coli Adaptation from Glucose to Xylose.

The glucose-xylose metabolic transition is of growing interest as a model to explore cellular adaption since these molecules are the main substrates resulting from the deconstruction of lignocellulosic biomass. Here, we investigated the role of the XylR transcription factor in the length of the lag phases when the bacterium needs to adapt from glucose- to xylose-based growth. First, a variety of lag times were observed when different strains of were switched from glucose to xylose.

A Promoter Variant Confers Constitutive Noisy Bimodal Expression That Increases Oxidative Stress Resistance in Yeast.

Higher noise in the expression of stress-related genes was previously shown to confer better resistance in selective conditions. Thus, evolving the promoter of such genes toward higher transcriptional noise appears to be an attractive strategy to engineer microbial strains with enhanced stress resistance. Here we generated hundreds of promoter variants of the gene involved in oxidative stress resistance in and created a yeast library by replacing the native promoter by these variants at the native locus.

Multiple Parameters Drive the Efficiency of CRISPR/Cas9-Induced Gene Modifications in Yarrowia lipolytica.

Yarrowia lipolytica is an oleaginous yeast of growing industrial interest for biotechnological applications. In the last few years, genome edition has become an easier and more accessible prospect with the world wild spread development of CRISPR/Cas9 technology. In this study, we focused our attention on the production of the two key elements of the CRISPR-Cas9 ribonucleic acid protein complex in this non-conventional yeast.

Use of photoswitchable fluorescent proteins for droplet-based microfluidic screening.

Application of droplet-based microfluidics for the screening of microbial libraries is one of the important ongoing developments in functional genomics/metagenomics. In this article, we propose a new method that can be employed for high-throughput profiling of cell growth. It consists of light-driven labelling droplets that contain growing cells directly in a microfluidics observation chamber, followed by recovery of the labelled cells.