2013 Publications

// anaerobic growth // dinoroseobacter shibae // transposon mutagenesis // Anaerobic growth and survival are integral parts of the life cycle of many marine bacteria. To identify genes essential for the anoxic life of Dinoroseobacter shibae, a transposon library was screened for strains impaired in anaerobic denitrifying growth. A novel type of anaerobic adaptation strategy was deduced

A library of 36 strains that varied both transcriptional and translational aspects of GFP Expression was constructed, tested in a micro-reactor and monitored during expression to capture biomass and fluorescence over time.

Strains with reduced citrate synthase activity were further investigated. Proline supplementation partly reversed the growth rate reduction, and simultaneously increased l-lysine accumulation leading to an increase in l-lysine productivity.

Three transfection reagents, Lipofectamine® 2000, TransIT-PRO® and linear 25 kDa polyethylenimine were evaluated for transient expression of enhanced GFP in CHO cells.

Characterization of IpsA, a LacI-type transcriptional regulator conserved among Mycobacteria and Corynebacteria. Myo-inositol was identified as an effector of IpsA, causing the dissociation of the IpsA-DNA complex in vitro.

IolR binding sites were identified in the promoter regions of iolC, iolT1 and iolR. A consensus DNA-binding motif was identified (5’ -KGWCHTRACA-3’ ) which corresponds well to those of other GntR-type regulators of the HutC family.

A C. glutamicum strain was used as a cellular chassis to establish a microbial cell factory for the production of ectoines. The genome of the basic C. glutamicum strain was further engineered.

Genetically encoded sensors which transmit elevated cytosolic concentrations of O-acetyl serine (OAS) and O-acetyl homoserine were described into an optical output.

The construction of MB001, a prophage-free variant of C. glutamicum ATCC 13032 with a 6% reduced genome is presented, a novel platform strain for metabolic engineering.

A robust fermentation process for the efficient production of active rPTH 1-34 based on a calnexin super-transformed H. polymorpha clone was developed.

Current methodologies in genetics and microbiology enable researchers to influence metabolic pathways of microbial cells in many directions.

A platform strain overproducing ornithine with deletions of argR and argF (ORN1) has been employed for production of derived compounds such as putrescine. The product spectrum was expanded to include L-proline.

A new xylose isomerase from Prevotella ruminicola TC2-24 was identified, that has one of the highest affinities and specific activities compared to other bacterial and fungal D-xylose isomerases expressed in yeast.

The recombineering for C. glutamicum using RecT of prophage Rac was established and combined with nanosensor technology to enable the detection and isolation of productive mutants at the single-cell level.

SsrA-mediated peptide tagging was used for the construction of unstable variants of the GFP derivative eYFP and applied those for transient gene expression analysis in C. glutamicum.

The growth of C. glutamicum with glucose as substrate at different scales covering batch cultivations in the liter range down to single cell cultivations in the picoliter range were compared.