category: Research

Dynamic changes in microbial community structure and function in phenol-degrading microcosms inoculated with cells from a contaminated aquifer

Contamination of aquifers by organic pollutants threatens groundwater supplies and the environment. In situ biodegradation of organic pollutants by microbial communities is important for the remediation of contaminated sites, but our understanding of the relationship between microbial development and pollutant biodegradation is poor. A particular challenge is understanding the in …

Quantification of biofilm and planktonic communities

Biofilms are difficult to quantify especially when microscopic observations are impractical. However it is important to quantify attached cell numbers to complement planktonic cell counts in order to achieve a holistic understanding of microbial processes. Traditional counting methods, including microscopic techniques and serial dilution plating, generally require biofilms to be …

Aggregative behaviour of bacteria isolated from canine dental plaque

Interbacterial adhesion of bacteria isolated from canine dental plaque was assessed by performing a visual coaggregation assay. Using conditions mimicking those likely to be encountered in vivo, the entire cultivable plaque microbiota from a single dog was assessed, and eight (6.7%) unique coaggregation interactions were detected for 120 crosses. Transmission …

Cultivable Oral Microbiota of Domestic Dogs

Abstract Bacteria were isolated from the dental plaques of nine dogs and a sample of pooled saliva from five other dogs and were then identified by comparative 16S rRNA gene sequencing. Among 339 isolates, 84 different phylotypes belonging to 37 genera were identified. Approximately half of the phylotypes were identified …

Bacterial Biofilm Development on Hydroxyapatite-Coated Glass

Glass plates are frequently used as the substratum in flow cell experiments to allow continuous non-destructive observations of biofilm development via microscopy. The aim of this study was to evaluate hydroxyapatite-coated glass as a substratum for flow cell experiments, in comparison to plain glass, for modelling primary colonization of the …

Prevalence of Csh-like fibrillar surface proteins among mitis group oral streptococci

The prevalence of Csh-like fibrillar surface proteins among oral streptococci was investigated by ELISA and by immunoelectron microscopy using antiserum raised to recombinant fragments of CshA of Streptococcus gordonii DL1. The majority of S. gordonii, Streptococcus sanguis and Streptococcus oralis strains tested elaborated short (ca. 50-80 nm long) surface fibrils …

Distribution of CshA Fibrils amongst Mitis Group Oral Streptococci

Many oral streptococci express large surface structures (fibrils and fimbriae) that have been implicated in adhesion of bacteria to oral surfaces. Streptococcus gordonii DL1 short peritrichous fibrils (61 nm long) are composed of cell-wall-anchored CshA adhesin (259 kDa). ELISA studies have previously shown that proteins immunologically related to CshA are …