Response of Bdellovibrio and Like Organisms (BALOs) to the Migration of Naturally Occurring Bacteria to Chemoattractants |
| |
Authors: | Ashvini Chauhan Henry N Williams |
| |
Institution: | (1) Marine Microbial Ecology Laboratory, Environmental Sciences Institute, 1515 South Martin Luther King Boulevard, Florida A & M University, Tallahassee, FL 32307, USA |
| |
Abstract: | A dual culture-based and non–culture-based approach was applied to characterize predator bacterial groups in surface water
samples collected from Apalachicola Bay, Florida. Chemotaxis drop assays were performed on concentrated samples in an effort
to isolate predator bacteria by their chemotactic ability. Yeast extract (YE) and casamino acids (CA) proved to be strong
chemoattractants and resulted in three visibly distinct bands; however, dextrose, succinate, pyruvate, and concentrated cells
of Vibrio parahaemolyticus P5 as prey did not elicit any response. The three distinct bands from YE and CA were separately collected to identify the
chemotactic microbial assemblages. Plaque-forming unit assays from different chemotaxis bands with P5 as prey indicated 5-
(CA) to 10-fold (YE) higher numbers of predator bacteria in the outermost chemotactic bands. Polymerase chain reaction–restriction
fragment length polymorphism and 16S rDNA sequencing of clones from different chemotaxis bands resulted in identification
of Pseudoalteromonas spp., Marinomonas spp., and Vibrio spp., with their numbers inversely proportional to the numbers of predators—i.e., Bdellovibrio spp. and Bacteriovorax spp—in the chemotaxis bands. This study indicates that predatorial bacteria potentially respond to high densities of microbial
biomass in aquatic ecosystems and that chemotaxis drop assay may be an alternate culture-independent method to characterize
predatorial bacterial guilds from the environment. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|