Regulation of antibiotic production in Actinobacteria: new perspectives from the post-genomic era

The antimicrobial activity of many of their natural products has brought prominence to the Streptomycetaceae, a family of Gram-positive bacteria that inhabit both soil and aquatic sediments. In the natural environment, antimicrobial compounds are likely to limit the growth of competitors, thereby offering a selective advantage to the producer, in particular when nutrients become limited and the developmental programme leading to spores commences. The study of the control of this secondary metabolism continues to offer insights into its integration with a complex lifecycle that takes multiple cues from the environment and primary metabolism. Such information can then be harnessed to devise laboratory screening conditions to discover compounds with new or improved clinical value. Here we provide an update of the review we published in NPR in 2011. Besides providing the essential background, we focus on recent developments in our understanding of the underlying regulatory networks, ecological triggers of natural product biosynthesis, contributions from comparative genomics and approaches to awaken the biosynthesis of otherwise silent or cryptic natural products. In addition, we highlight recent discoveries on the control of antibiotic production in other Actinobacteria, which have gained considerable attention since the start of the genomics revolution. New technologies that have the potential to produce a step change in our understanding of the regulation of secondary metabolism are also described

Ten years of hydrographic variability off Central California during the upwelling season

Analysis of mean conditions and variability during the upwelling season off central California was performed on data sets of buoy and shoreline surface measurements and CTD data from ten annual NMFS surveys (1987-1996). Climatologies of the surface conditions (alongshore wind, SST, SSS) revealed that the height of the upwelling season occurred during May and June. Variability in the surface conditions was high both inter-annually and inter- seasonally with maximum equatorward wind, lowest SST, and highest SSS during the months of May and June. Ten year climatologies of hydrographic conditions from CTD data (depth and salinity on density anomaly surfaces, and temperature, salinity, density at discrete depths) indicated complex circulation patterns and water mass properties. The nearshore region contained relatively dense, upwelled water and isopycnal gradients conformed to local bathymetry. A robust upwelling filament off Pt. Reyes and three anticyclonic eddy-like features west of the shelf break appeared in the climatologies. EOF (Empirical Orthogonal Function) analysis of the subsurface variability confirmed the presence of the prominent features that appeared in the climatologies. The geophysical signals of the first three EOF-amplitude pairs represent a cross-shore mean upwelling pattern, an alongshore pattern caused by spatial variations in wind and gradients of water mass characteristics, and a filament-eddy resolving pattern, respectivelyhttp://archive.org/details/tenyearsofhydrog00baltLieutenant, NOAA CoipsApproved for public release; distribution is unlimited

The State of the California Current, 1996-1997: Mixed Signals from the Tropics

Schwing et al.: The California Current, 1996-1997, CalCOFI Rep., Vol. 38, 1997A large number of data sets from within the California Current region, and the large-scale fields that affect this region, are available for timely assessment of recent environmental conditions in this system. In addition to the long-running quarterly CalCOFI cruises, which featured the initial research cruise of RV Roger Revelle, several surveys off Baja California and central California have provided information on coastal areas adjacent to the present CalCOFI coverage. Conditions throughout the north Pacific and in the California Current are summarized and interpreted for the 1996-97 period