Ecology and Molecular Genetic Studies of Marine Bacteria

摘要

Sequencing of the chitinase operon of V. vulnificus is complete. In vitro transcription/translation analyses indicate the synthesis of a structural protein 100kD in size. Analyses with deletion mutants of the original 'chitinase' clone are being used to determine translation initiation and termination sites. Results indicate that chitin hydrolysis by V. vulnificus is accomplished via a glucosaminidase rather than, or in addition to, the classical two enzyme (chitinase and chitobiase) system. The rapid isolation method of prokaryotic DNA from aquatic habitats has been successfully used to recover plasmids DNA's, stable RNA's and DNA samples from hydrothermal vent fluids. The inclusion of a glass fiber prefiltration step has facillitated sampling of increased volumes of water. Optimization of the sensitivity of DNA probes to detect low copy number number genes in bacteria from environmental samples has been accomplished. Purified 'black smoker DNA' was ligated with vector DNA and eight clones have been isolated. DNA sequencing of the cloned DNA is proceeding in order to compare these sequences with known archaebacterial DNA sequences. Preliminary DNA/DNA homology data suggest that V. ordallii and V. anuillarum; V. fluvialis and V furnissii; and V. harveyi and V. carchariae may represent only three species. The relative binding ratios obtained indicate that some species may be more correctly assigned to a genus other than Vibrio. (aw)