An acidophilic sporeformer was isolated from several varieties of shelf-stable juices. The organism sporulated on potato dextrose agar (pH 3.5) at 37°C within 24 hours and grew well in fruit and berry juices. The pH range of growth in potato dextrose broth was 3.0 to 5.3. The D87.8°C' D91.1°C' and D95°C determined in berry juice were 11.0, 3.8, and 1.0 min, respectively. The ability of this organism to grow at low pH and to survive pasteurization poses a threat of economic loss by spoilage to beverage producers. The organism could not be identified based on its characteristics or the fatty acid profile comparison to those of other Bacillus species, including the acidophilic B. acidocaldarius.

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Unacidified and acidified noodles were inoculated with a composite of C. bon&rum types A and B spores. Noodles were cooked, packaged in oxygen-permeable polypropylene bags, steamed, cooled, then stored aerobically at 7 or 23°C or anaerobically at 30°C. Toxin did not develop in any aerobically stored samples at pH 14.5. Toxin developed in samples with pH s5.0, stored aerobically and anaerobically. In addition, toxin was detected in one anaerobically incubated acidified unit where pH had been increased by microbial growth. Proper acidification of product prevented toxic growth of C. botuhum.