Acidovorax
Acidovorax is a genus of bacteria which lies within the phylum Proteobacteria. The species we are investigating is called Acidovorax temperans strain CB2. This organism was isolated from an activated sludge wastewater treatment plant in northern New Zealand.
Why study Acidovorax temperans strain CB2?
Acidovorax is consistently present in activated sludge, suggesting it is an important component of activated sludge treatment systems. Our culture-independent studies of bacterial DNA in activated sludge have found that it comprises from 1 % to 12 % of the total bacterial diversity found.
We have found that there are two different varieties (morphotypes) of Acidovorax temperans strain CB2. These differ in their ability to form flocs (clumps of material) and biofilms (slimy, surface-attached layers of bacteria and other material) when grown on low-nutrient media.
- The smooth colony morphotype forms dense flocs, which readily settle out of the water column, but does not form biofilms.
- The rough colony morphotype forms loose flocs that settle poorly, but is very good at forming biofilms.
These two types therefore provide an ideal model system for investigating processes involved in floc and biofilm formation—processes which are important in activated sludge wastewater treatment systems. A better understanding of these processes and the ecological interactions of Acidovorax temperans strain CB2 in activated sludge may lead to new strategies for manipulating operation and efficiency of activated sludge treatment processes.
Acidovorax temperans strain CB2 also accumulates polyhydroxyalkanoate (PHA) storage granules when grown on rich media. This is an important property for organisms involved in biological phosphrus removal, and is a potential source reagent for the production of bioplastics.
Other members of the Acidovorax genus
Other species within the Acidovorax genus have useful metabolic pathways for degradation of biodegradable plastics and other organic contaminants, including nitrobenzene and nitrophenols, halobenzoates, PCBs, PAHs, and for removal of nutrients by denitrification.
Complete genome sequences are available on the NCBI genome database for two other Acidovorax species:
- Acidovorax avenae citrulli AAC00-1, which is a plant pathogen.
- Acidovorax sp. JS42, which is capable of degrading toxic nitroaromatic compounds.