Investigations of 16S rRNA gene sequences hallmark modern microbiology. These sequences provide culture-independent insight into the abundance and distribution of microbiota and serve as a principle resource through which microbial community diversity is measured. Consequently, researchers rely on 16S gene sequences to test hypotheses rooted in ecology, evolution, and disease....
The bioavailability of chemical compounds in the marine environment fundamentally influences the growth and physiology of microorganisms. Organic and inorganic chemicals that are produced by some marine plankton can be consumed by other plankton for energy production, growth, or to initiate essential physiological processes. Cultures of the diatom Thalassiosira pseudonana,...
Cell-cell communication in bacteria is understood to facilitate the coordination of population-wide cooperative behavior in the form of concerted gene expression. The opportunistic pathogen Pseudomonas aeruginosa uses such a communication mechanism to regulate a large group of genes important to virulence strategies in this bacterium. This general mechanism of communication...
Agrobacterium species transform plant cells by targeting a portion of plasmid-encoded bacterial DNA to the host nucleus. Genetic transformation by A. tumefaciens and A. rhizogenes requires secreted effector proteins. The tumor-inducing (Ti) plasmid from virulent A. tumefaciens encodes VirE2, a secreted single-stranded DNA-binding protein required for efficient transformation of hosts....
Isothiocyanates (ITCs) are produced by roots in a variety of agricultural plants, such as those within the Brassicaceae family. ITCs act as fumigants, and are used to control microbial plant pathogens by adding brassica-origin seed meal to soil prior to replanting. However, there is suggestion that the presence of residual...
Pseudomonas aeruginosa is an opportunistic human pathogen that infects immunocompromised individuals such as those suffering from burns or the genetic disorder cystic fibrosis. This organism utilizes a cell-cell communication mechanism known as quorum sensing (QS) to coordinate virulence gene expression and biofilm formation. It has three interconnected QS systems, namely...
Pseudomonas aeruginosa is an environmental bacterium as well as an opportunistic pathogen that primarily infects immunocompromised individuals, including those suffering from cystic fibrosis. The density-dependent regulation of gene expression via cell-to-cell communication, also termed quorum sensing (QS), is an important virulence determinant in this organism. Generally, P. aeruginosa uses three...
Cooperative behaviors in bacteria are increasingly appreciated for their relevance to microbial ecology and utility as model systems for social evolution. One example is the secretion of siderophores, a structurally diverse group of compounds that chelate extracellular iron. Siderophore production is considered cooperative because the benefits can be shared with...
On coral reefs, disturbances rarely occur in isolation. Global stressors such as increasing seawater temperature often coincide with local stressors like nutrient pollution. In the face of increasing anthropogenic stress, corals can function as environmental sentinels, although little is known about how multiple stressors interact to disrupt their associated bacterial...
T cells are one of the key cells in the immune system. Although they are not the first line of defense against a pathogen, their functions can greatly enhance the phagocytosis and destruction of pathogens as well as the development of antibody responses. Furthermore, even when responding T cells have...