Study on the Boundary Growth Model of Burkholderia gladioli pv. cocovenenans

Burkholderia gladioli pv. cocovenenans (B. cocovenenans) is a pathogenic microorganism frequently isolated from food and environmental samples. It produces the mitochondrial toxin bongkrekic acid (BA), which leads to severe gastrointestinal and nervous system symptoms and can be fatal. This study aimed to investigate and model the probability of B. cocovenenans growth in broth under the influence of the environmental factors, including pH, NaCl concentration, and temperature. The growth data of B. cocovenenans in LB broth were obtained with pH values of 1.0-13.0, NaCl concentration of 0.5%-1.5%, and incubation temperatures of 15, 20, 25, 30, 37, 40, and 45 ℃ for 120 h. The resulting growth/no-growth data were fitted into logistic regression to develop a probabilistic model describing the combined effects of pH-NaCl-temperature combinations on bacterial growth. Among the 203 tested combinations, bacterial growth was observed in 71. The logistic regression model showed good predictive performance, with a concordance index of 0.944 and a concordance rate of 94.22%. The developed model provides reliable predictions of B. cocovenenans growth probability and has practical implications for food safety and public health.