Delftia acidovorans SPH-1
   
   
 

Microbial consortia play a fundamental role in environmental biodegradation processes, especially when complex compounds, or complex mixtures of compounds, are to be mineralized. Degradation processes carried out through the cooperation of assemblages of microorganisms can accomplish the complete biodegradation of a vast array of natural and chemical compounds, for example in sewage treatment plants. Our understanding of these complex, coordinated degradation processes, of the consortia’s organization, and of functions of the individual members and their interaction, is very rudimentary

A large bacterial consortium is needed to completely degrade commercial linear alkylbenzenesulfonate (LAS), the major laundry surfactant in world-wide use. Commercial LAS is a complex mixture of isomers. A representative model system for this cooperative environmental biodegradation process is now available for laboratory studies, a defined three-member bacterial consortium, which mineralizes individual isomers of commercial LAS. The three organisms grow in a biofilm and in two tiers with LAS, whereby the first species supplies LAS degradation intermediates, a range of sulfophenylcarboxylates (SPC), which are necessary for the growth of species within the second tier. The formation of a biofilm is dependent on the presence of LAS surfactant as stress agent, and is necessary for effective LAS degradation. The representative organisms, Parvibaculum lavamentivorans (first tier), and Comamonas testosteroni and Delftia acidovorans (second tier), can be grown individually and as a consortium in the laboratory, and are available for genetic manipulation. Furthermore, the second-tier organisms belong to genera of environmental bacteria which are frequently isolated and characterized for their ability to accomplish specialized biodegradative traits. No representatives of these genera have yet been analyzed by genome sequencing.