Understanding growth and age of red tree corals (Primnoa pacifica) in the North Pacific Ocean.

Massive, long-lived deep-sea red tree corals (Primnoa pacifica) form a solid, layered axis comprised of calcite and gorgonin skeleton. They are abundant on the outer continental shelf and upper slope of the Northeast Pacific, providing habitat for fish and invertebrates. Yet, their large size and arborescent morphology makes them susceptible to disturbance from fishing activities.

Regulation of D-xylose metabolism in Caulobacter crescentus by a LacI-type repressor.

In the oligotrophic freshwater bacterium Caulobacter crescentus, D-xylose induces expression of over 50 genes, including the xyl operon, which encodes key enzymes for xylose metabolism. The promoter (P(xylX)) controlling expression of the xyl operon is widely used as a tool for inducible heterologous gene expression in C. crescentus.

Genetic analysis of a novel pathway for D-xylose metabolism in Caulobacter crescentus.

Genetic data suggest that the oligotrophic freshwater bacterium Caulobacter crescentus metabolizes D-xylose through a pathway yielding alpha-ketoglutarate, comparable to the recently described L-arabinose degradation pathway of Azospirillum brasilense. Enzymes of the C. crescentus pathway, including an NAD(+)-dependent xylose dehydrogenase, are encoded in the xylose-inducible xylXABCD operon (CC0823-CC0819).