Candidatus Pelagibacter ubique is the first cultured representative of the SAR11 clade, a clade that is found throughout the oceans and accounts for approximately 25% of all bacterial cells [1]. It has a streamlined genome that is the smallest of any known free-living organism. In this study the complete genome...
Different strains of Vibrio parahaemolyticus (Vp) in broth cultures and Vp-inoculated live Pacific oysters (Crassostrea gigas) were subjected to high pressure processing (HPP) at 241, 276, 310, and 345 MPa. Results showed Vp numbers were reduced by HPP in both pure culture and whole oysters. Vp inactivation was dependent on...
A new high-throughput culturing (HTC) method using a low nutrient
heterotrophic medium (LNHM) has led to the isolation of many novel strains of
oligotrophic bacteria from marine ecosystems. Four strains belonging to a single
dade, HTCC2151, HTCC218OT, HTCC2178T and HTCC2188T, were isolated
from the coast of Oregon by the HTC...
Symbiotic relationships of bacteria with higher organisms are
commonly observed in nature; however, the functional role of these
relationships is only rarely understood. This is particularly evident in
epibiotic bacterial associations in the marine environment where the bacteria
are often a diverse ensemble of microorganisms, thus complicating the
identification of...
The objective of this project was to use ribosomal RNA genes, cloned
from natural populations of Sargasso Sea bacterioplankton, as markers for
picoplankton diversity. It is widely recognised that a majority of
microorganisms have yet to be cultivated, and therefore much of extant
microbial diversity remains unknown (50). The method...
Biological di-nitrogen (N₂) fixation is a key process in open-ocean ecosystems, where the new nitrogen (N) provided by marine diazotrophs can support a large fraction of primary productivity and carbon (C) drawdown. Recent laboratory studies have shown that elevated pCO₂ enhances the rate of N₂ fixation by select laboratory isolates...
The physiological responses of populations of a marine
Pseudomonas sp. to nutrient starvation were observed for a period
of 40 days. During the first 25 days of starvation the viability
of the population decreased by 99.9 percent, but thereafter the
cultures maintained approximately 5 x 10⁵ viable cells per ml...
The transport response of four marine psychrophilic bacteria
to a variety of substrates was determined and related to environmental
conditions. Studies on pressure and temperature effects on glutamic
acid transport and utilization indicated that high pressures and
low temperatures inhibit glutamate transport, while permitting glutamate
respiration. Similar results were obtained...
Over 100 monthly bacterioplankton DNA samples, from each of the surface and 200 m depths at the Bermuda Atlantic Time-series Study (BATS) site, were analyzed for community assembly processes. Correlation networks, filtered for potential autocorrelation artifacts, were constructed for each depth. Network characteristics for the two depths were remarkably similar...