A modified atmosphere of 10% CO*, 5% O2 and 85% Nz was used to determine effects on pectinase activities of vegetable spoilage bacteria. Cultures of Erwinia carotovora, Pseudomonasji'uorescens, and Xanthomonas campesti, grown at 25°C in liquid medium held under the modified atmosphere were assayed for polygalacturonase and pectate lyase activities. Erwinia and Pseudomonas exhibited higher polygalacturonase and pectate lyase activities thanXanthomonas whether grown under modified atmosphere or air. In some cases, bacteria grown under air exhibited higher pectinase activity. In general modified atmosphere did not significantly reduce pectinase activities in any of the bacteria tested.