Microscale quantitative analysis of polyhydroxybutyrate in prokaryotes using IDMS

Poly(3-hydroxybutyrate) (PHB) is an interesting biopolymer for replacing petroleum-based plastics, its biological production is performed in natural and engineered microorganisms. Current metabolic engineering approaches rely on high-throughput strain construction and screening. Analytical procedures have to be compatible with the small scale...

Accurate Measurement of the in vivo  Ammonium Concentration in Saccharomyces cerevisiae

Ammonium (NH4+) is the most common N-source for yeast fermentations, and N-limitation is frequently applied to reduce growth and increase product yields. While there is significant molecular knowledge on NH4 + transport and assimilation, there have been few attempts to measure the in vivo concentration of this metabolite. In this article, we...

Effective Estimation of Dynamic Metabolic Fluxes Using 13C Labeling and Piecewise Affine Approximation: From Theory to Practical Applicability

The design of microbial production processes relies on rational choices for metabolic engineering of the production host and the process conditions. These require a systematic and quantitative understanding of cellular regulation. Therefore, a novel method for dynamic flux identification using quantitative metabolomics and 13C labeling to...

Fast “Feast/Famine” Cycles for Studying Microbial Physiology Under Dynamic Conditions: A Case Study with Saccharomyces cerevisiae

Microorganisms are constantly exposed to rapidly changing conditions, under natural as well as industrial production scale environments, especially due to large-scale substrate mixing limitations. In this work, we present an experimental approach based on a dynamic feast/famine regime (400 s) that leads to repetitive cycles with moderate changes...

Resolving Phenylalanine Metabolism Sheds Light on Natural Synthesis of Penicillin G in Penicillium chrysogenum

The industrial production of penicillin G by Penicillium chrysogenum requires the supplementation of the growth medium with the side chain precursor phenylacetate. The growth of P. chrysogenum with phenylalanine as the sole nitrogen source resulted in the extracellular production of phenylacetate and penicillin G. To analyze this natural pathway...