Investigation of poly(γ-glutamic acid) production via online determination of viscosity and oxygen transfer rate in shake flasks.

Background: Poly(γ-glutamic acid) (γ-PGA) is a biopolymer with many useful properties making it applicable for instance in food and skin care industries, in wastewater treatment, in biodegradable plastics or in the pharmaceutical industry. γ-PGA is usually produced microbially by different spp. The produced γ-PGA increases the viscosity of the fermentation broth.

Definition of culture conditions for Arxula adeninivorans, a rational basis for studying heterologous gene expression in this dimorphic yeast.

The yeast Arxula adeninivorans is considered to be a promising producer of recombinant proteins. However, growth characteristics are poorly investigated and no industrial process has been established yet. Though of vital interest for strain screening and production processes, rationally defined culture conditions remain to be developed.

Physiological relation between respiration activity and heterologous expression of selected benzoylformate decarboxylase variants in Escherichia coli.

Background: The benzoylformate decarboxylase (BFD) from Pseudomonas putida is a biotechnologically interesting biocatalyst. It catalyses the formation of chiral 2-hydroxy ketones, which are important building blocks for stereoselective syntheses. To optimise the enzyme function often the amino acid composition is modified to improve the performance of the enzyme.

Replication methods and tools in high-throughput cultivation processes - recognizing potential variations of growth and product formation by on-line monitoring.

Background: High-throughput cultivations in microtiter plates are the method of choice to express proteins from recombinant clone libraries. Such processes typically include several steps, whereby some of them are linked by replication steps: transformation, plating, colony picking, preculture, main culture and induction. In this study, the effects of conventional replication methods and replication tools (8-channel pipette, 96-pin replicators: steel replicator with fixed or spring-loaded pins, plastic replicator with fixed pins) on growth kinetics of Escherichia coli SCS1 pQE-30 pSE111 were observed.