Bacterial Primary Colonization and Early Succession on Surfaces in Marine Waters as Determined by Amplified rRNA Gene Restriction Analysis and Sequence Analysis of 16S rRNA Genes

Abstract

The nearly universal colonization of surfaces in marine waters by bacteria and the formation of biofilms and biofouling communities have important implications for ecological function and industrial processes. However, the dynamics of surface attachment and colonization in situ, particularly during the early stages of biofilm establishment, are not well understood. Experimental surfaces that differed in their degrees of hydrophilicity or hydrophobicity were incubated in a salt marsh estuary tidal creek for 24 or 72 h. The organisms colonizing these surfaces were examined by using a cultivation-independent approach, amplified ribosomal DNA restriction analysis. The goals of this study were to assess the diversity of bacterial colonists involved in early succession on a variety of surfaces and to determine the phylogenetic affiliations of the most common early colonists. Substantial differences in the representation of different cloned ribosomal DNA sequences were found when the 24-and 72-h incubations were compared, indicating that some new organisms were recruited and some other organisms were lost. Phylogenetic analyses of the most common sequences recovered showed that the colonists were related to organisms known to inhabit surfaces or particles in marine systems. A total of 22 of the 26 clones sequenced were affiliated with the Roseobacter subgroup of the ␣ subdivision of the division Proteobacteria (␣-Proteobacteria), and most of these clones were recovered at a high frequency from all surfaces after 24 or 72 h of incubation. Two clones were affiliated with the Alteromonas group of the ␥-Proteobacteria and appeared to be involved only in the very early stages of colonization (within the first 24 h). A comparison of the colonization patterns on the test surfaces indicated that the early bacterial community succession rate and/or direction may be influenced by surface physicochemical properties. However, organisms belonging to the Roseobacter subgroup are ubiquitous and rapid colonizers of surfaces in coastal environments.

16S rDNA sequence analysis of environmental Bdellovibrio-and-like organisms (BALO) reveals extensive diversity.

“…Although Bdellovibrio and Bacteriovorax were part of separate monophyletic groups, the distance between these clades was as large as those between species in different bacterial subdivisions. The diversity among prokaryotic divisions ranges from 13 to 26 % (Dang & Lovell, 2000). The large ( 17 %) genetic distances between the groups of BALO are consistent with either a very ancient origin or two independent origins.…”

Patterns and mechanisms of genetic and phenotypic differentiation in marine microbes

“…In the planktonic lifestyle, these organisms probably grow in bursts, which are locally quickly erased by predation so that overall they should have higher turnover rates than other bacterioplankton (Mourino-Perez et al 2003;Worden et al 2006). There are strong indications that both Vibrio and Roseobacter sense and respond to their surroundings by several mechanisms, including: quorum-sensing systems (Gram et al 2002;Moran et al 2004); production of antibacterial compounds (Bruhn et al 2005); chemotaxis (Miller et al 2004;McCarter 2006); association with animal or algal cells (Buchan et al 2005); and rapid surface colonization (Dang & Lovell 2000;Thompson & Polz 2006).…”

Variability and abundance of the epiphytic bacterial community associated with a green marine Ulvacean alga

“…Bacteria within this clade are known to be ubiquitous and rapid colonizers of surfaces in coastal environments (Dang and Lovell, 2000) and have been enumerated as the most abundant group within the bacterial assemblages associated with some marine algal cultures and phytoplankton blooms in nature (Gonzalez et al, 2000;Riemann et al, 2000;Alavi et al, 2001). Given that many of the DGGE sequences fell within the Roseobacter clade, this group was selected for a detailed quantification on the surface of U. australis.…”