Bacterial whole-cell biosensor for glutamine with applications for quantifying and visualizing glutamine in plants.

A whole-cell biosensor for glutamine (GlnLux) was constructed by transforming an Escherichia coli glutamine (Gln) auxotroph with a constitutive lux reporter gene. Measurements of Gln in plant extracts using GlnLux correlated with quantification using high-performance liquid chromatography (Spearman's r = 0.95). GlnLux permitted charge-coupled-device (CCD) imaging of Gln from whole plant organs.

Survival mechanisms and culturability of Campylobacter jejuni under stress conditions.

Culture-based isolation and enumeration of bacterial human pathogens from environmental and human food samples has significant limitations.Many pathogens enter a viable but non-culturable(VBNC) state in response to stress, and cannot be detected via culturing methods. Favourable growth conditions with a source of energy and an ideal stoichiometric ratio of carbon to inorganic elements can reverse this VBNC state. This review will focus on the bacterium Campylobacter jejuni which is a leading cause of food borne illness in the developed world. C. jejuni can enter a VBNC state in response to extremes in: pH, moisture content, temperature,nutrient content and salinity. Once in a VBNC state,the organism must maintain an energy balance from substrate oxidation through respiration to grow,divide and remain viable. The goal of this review isa greater understanding of how abiotic stress and thermodynamics influence the viability of C. jejuni.