Project description:Aiming to reduce food spoilage, the present study developed novel highly active food-grade preservatives affecting a wide range of bacteria. For this purpose, storage proteins were extracted from food plants. After enzymatic hydrolysis by the digestive protease chymotrypsin, the peptide profiles were analyzed by ultrahigh-performance micro-liquid chromatography–triple quadrupole time-of-flight tandem mass spectrometry. Virtual screening identified 21 potential antimicrobial peptides in chickpea legumin. Among those, the peptides Leg1 (RIKTVTSFDLPALRFLKL) and Leg2 (RIKTVTSFDLPALRWLKL) exhibited antimicrobial activity against 16 different bacteria, including pathogens, spoilage-causing bacteria and two antibiotic-resistant strains. Minimum inhibitory concentrations (MIC) down to 15.6 µM indicated 10–1,000-fold higher activity of the novel antimicrobial peptides compared to conventional food preservatives. Moreover, Leg1 and Leg2 showed bactericidal activity in bacterial suspension and during the storage of raw pork meat.
Project description:The bacterial pathogen, Acinetobacter baumannii, is a leading cause of drug-resistant infections. Here, we investigated the potential of developing nanobodies that specifically recognize A. baumannii over other Gram-negative bacteria. Through generation and panning of a synthetic nanobody library, we identified several potential lead candidates. We demonstrate how incorporation of next generation sequencing analysis can aid in selection of lead candidates for further characterization. Using monoclonal phage display, we validated the binding of several lead nanobodies to A. baumannii. Subsequent purification and biochemical characterization revealed one particularly robust nanobody that broadly and specifically bound A. baumannii compared to other common drug resistant pathogens. These findings support the potentially for nanobodies to selectively target A. baumannii and the identification of lead candidates for possible future diagnostic and therapeutic development.
Project description:Diet can have a strong impact on development, to test this effect the strains N2, CB4856, three strains from Orsay (JU1581, JU1944, and JU1949), and three strains from Santeuil (JU1921, JU1930, and JU1932) were grown on two different food-sources. These sources were the standard lab food, Escherichia coli OP50, and the Gram-negative plant pathogen Erwinia rhapontici. The effect of these bacteria on development could also be measured by the start of reproduction, which was delayed while feeding on E. coli. To measure the transcriptional effects, age-synchronized strains were grown for 48 hours at 20 degrees Celsius. The impact of food-source on gene expression was determined by a transcriptional ruler based on the strain N2 (E-MTAB-7019).