Engineered Chimeras Unveil Swappable Modular Features of Fatty Acid and Polyketide Synthase Acyl Carrier Proteins.

The strategic redesign of microbial biosynthetic pathways is a compelling route to access molecules of diverse structure and function in a potentially environmentally sustainable fashion. The promise of this approach hinges on an improved understanding of acyl carrier proteins (ACPs), which serve as central hubs in biosynthetic pathways. These small, flexible proteins mediate the transport of molecular building blocks and intermediates to enzymatic partners that extend and tailor the growing natural products.

Development of a Kribbella-specific isolation medium and description of Kribbella capetownensis sp. nov. and Kribbella speibonae sp. nov., isolated from soil.

Two actinobacterial strains were isolated from samples collected from the University of Cape Town, South Africa. A third actinobacterial strain was isolated from soil collected in the town of Stellenbosch, South Africa, using a newly-developed Kribbella-selective medium. Analysis of the 16S rRNA genes showed that the three strains belonged to the genus Kribbella.

Kribbella podocarpi sp. nov., isolated from the leaves of a yellowwood tree (Podocarpus latifolius).

An endophytic actinobacterial strain was isolated from a yellowwood tree growing on the slope of Devil's Peak, Cape Town, South Africa. Analysis of the 16S rRNA gene showed that the strain belongs to the genus Kribbella. Phylogenetic analyses using the 16S rRNA gene and multilocus sequence analysis using the concatenated gene sequences of the gyrB, rpoB, relA, recA and atpD genes showed that strain YPL1 is closely related to the type strains of Kribbella karoonensis and Kribbella shirazensis.

Description of Kribbella italica sp. nov., isolated from a Roman catacomb.

A novel actinobacterium, strain BC637(T), was isolated from a biodeteriogenic biofilm sample collected in 2009 in the Saint Callixstus Roman catacomb. The strain was found to belong to the genus Kribbella by analysis of the 16S rRNA gene. Phylogenetic analysis using the 16S rRNA gene and the gyrB, rpoB, relA, recA and atpD concatenated gene sequences showed that strain BC637(T) was most closely related to the type strains of Kribbella lupini and Kribbella endophytica.

Kribbella albertanoniae sp. nov., isolated from a Roman catacomb, and emended description of the genus Kribbella.

A novel actinobacterium, strain BC640(T), was isolated from a biofilm sample collected in 2009 in the Saint Callistus Roman catacombs. Analysis of the 16S rRNA gene sequence showed that the strain belonged to the genus Kribbella. Phylogenetic analysis using the 16S rRNA gene and concatenated gyrB, rpoB, relA, recA and atpD gene sequences showed that strain BC640(T) was most closely related to the type strains of Kribbella yunnanensis and Kribbella sandramycini.

Multilocus sequence analysis of the actinobacterial genus Kribbella.

Multilocus sequence analysis (MLSA) was used to refine the phylogenetic analysis of the genus Kribbella, which currently contains 17 species with validly-published names. Sequences were obtained for the 16S rRNA, gyrB, rpoB, recA, relA and atpD genes for 16 of the 17 type strains of the genus plus seven non-type strains. A five-gene concatenated sequence of 4099 nt was used to examine the phylogenetic relationships between the species of the genus Kribbella.