Genetic control of bacterial adhesion

Adhesive substances represent a solution to the problem of colonizing varied surfaces in the bacterial habitat. A given species may have genetic information for a large repertoire of adhesive substances, and the outcome of an encounter between a population of these bacteria and a particular surface may depend on how the bacteria regulate the expression of the adhesive substances which they encode. Synthesis of adhesive substances appears to be regulated to match the demands of the environmental circumstances, and we discuss several genetic strategies which bacteria could use to control expression of these functions

Genetic control of bacterial adhesion

Adhesive substances represent a solution to the problem of colonizing varied surfaces in the bacterial habitat. A given species may have genetic information for a large repertoire of adhesive substances, and the outcome of an encounter between a population of these bacteria and a particular surface may depend on how the bacteria regulate the expression of the adhesive substances which they encode. Synthesis of adhesive substances appears to be regulated to match the demands of the environmental circumstances, and we discuss several genetic strategies which bacteria could use to control expression of these functions

Expanding ester biosynthesis in Escherichia coli

To expand the capabilities of whole-cell biocatalysis, we have engineered Escherichia coli to produce various esters. The alcohol O-acyltransferase (ATF) class of enzyme uses acyl-CoA units for ester formation. The release of free CoA upon esterification with an alcohol provides the free energy to facilitate ester formation. The diversity of CoA molecules found in nature in combination with various alcohol biosynthetic pathways allows for the biosynthesis of a multitude of esters. Small to medium volatile esters have extensive applications in the flavor, fragrance, cosmetic, solvent, paint and coating industries. The present work enables the production of these compounds by designing several ester pathways in E. coli. The engineered pathways generated acetate esters of ethyl, propyl, isobutyl, 2-methyl-1-butyl, 3-methyl-1-butyl and 2-phenylethyl alcohols. In particular, we achieved high-level production of isobutyl acetate from glucose (17.2 g l(−1)). This strategy was expanded to realize pathways for tetradecyl acetate and several isobutyrate esters

Microbial structuring of marine ecosystems

Despite the impressive advances that have been made in assessing the diversity of marine microorganisms, the mechanisms that underlie the participation of microorganisms in marine food webs and biogeochemical cycles are poorly understood. Here, we stress the need to examine the biochemical interactions of microorganisms with ocean systems at the nanometre to millimetre scale - a scale that is relevant to microbial activities. The local impact of microorganisms on biogeochemical cycles must then be scaled up to make useful predictions of how marine ecosystems in the whole ocean might respond to global change. This approach to microbial oceanography is not only helpful, but is in fact indispensable