摘要：Mixed cultures of Wolinella recta, an asaccharolytic formate-oxidising bacterium, and Streptococcus sanguis, a saccharolytic formate-producing bacterium, were studied in cheniostats with glucose as the limiting nutrient and fumarate and/or oxygen as an electron acceptor. Steady-state cultures were established at different levels of fumarate and air supply. Two different types of relationships between both species were recognised in such cultures. A commensal relationship, with W. recta growing at the expense of formate produced by S. sanguis, was observed in strictly anaerobic cultures with fumarate as the sole electron acceptor. A distinctly mutualistic relationship was established in aerated cultures. In these cultures W. recta scavenged oxygen (or possibly H2O2 produced by S. sanguis) whereas S. sanguis provided W. recta with formate through the fermentation of glucose. The ecological consequences for the role of W. recta in the changeover from a healthy to a diseased subgingival microflora is discussed.Keywords: Wolinella recta; Streptococcus sanguis; Periodontal disease; Commensalism; Mutualism.
