Corynebacterium glutamicum pyruvate:quinone oxidoreductase: an enigmatic metabolic enzyme with unusual structural features.

Pyruvate:quinone oxidoreductase (PQO) is a flavin-containing peripheral membrane enzyme catalyzing the decarboxylation of pyruvate to acetate and CO with quinone as an electron acceptor. Here, we investigate PQO activity in Corynebacterium glutamicum, examine purified PQO, and describe the crystal structure of the native enzyme and a truncated version. The specific PQO activity was highest in stationary phase cells grown in complex medium, lower in cells grown in complex medium containing glucose or acetate, and lowest in cells grown in minimal acetate-medium.

Recombinant Production of Rhamnolipids in KT2440 on Cultures Grown Chemo-Autotrophically with Carbon Dioxide and Hydrogen.

The establishment of sustainable processes for the production of commodity chemicals is one of today's central challenges for biotechnological industries. The chemo-autotrophic fixation of CO and the subsequent production of acetate by acetogenic bacteria via anaerobic gas fermentation represents a promising platform for the ecologically sustainable production of high-value biocommodities via sequential fermentation processes. In this study, the applicability of acetate-containing cell-free spent medium of the gas-fermenting acetogenic bacterium WP1 as the feeder strain for growth and the recombinant production of PAO1 mono-rhamnolipids in the well-established nonpathogenic producer strain KT2440 were investigated.

Optimized recombinant production of the bacteriocin garvicin Q by .

Bacteriocins are antimicrobial peptides applied in food preservation and are interesting candidates as alternatives to conventional antibiotics or as microbiome modulators. Recently, we established as a suitable production host for various bacteriocins including garvicin Q (GarQ). Here, we establish secretion of GarQ by via the Sec translocon achieving GarQ titers of about 7 mg L in initial fermentations.

C-di-AMP Is a Second Messenger in That Regulates Expression of a Cell Wall-Related Peptidase via a Riboswitch.

Cyclic di-adenosine monophosphate (c-di-AMP) is a bacterial second messenger discovered in and involved in potassium homeostasis, cell wall maintenance and/or DNA stress response. As the role of c-di-AMP has been mostly studied in Firmicutes, we sought to increase the understanding of its role in Actinobacteria, namely in . This organism is a well-known industrial production host and a model organism for pathogens, such as or .

The Superiority of over as a Recombinant Bacterial Host for Hyaluronic Acid Production.

(1) Background: Hyaluronic acid (HA) is a polyanionic mucopolysaccharide extensively used in biomedical and cosmetic industries due to its unique rheological properties. Recombinant HA production using other microbial platforms has received increasing interest to avoid potential toxin contamination associated with its production by streptococcal fermentation. In this study, the Gram-negative strains Escherichia coli (pLysY/Iq), E.