Hydrostatic Pressure Resistance of 14 Genera of Microbes under Controlled Room Temperature

Abstract

The pressure resistance of microbes (14 genera) was investigated at pressures ranging from 300 MPa to 500 MPa at 20°C for 20 min using a compact pressure vessel. Acinetobacter sp., Pseudomonas fluorescens and Vibrio parahaemolyticus, all of which are gram negative bacteria, and Saccharomyces cerevisiae were dead at 300 MPa, although gram positive bacteria were all alive at that pressure. At 400 MPa, Salmonella Typhimurium, Morganella morganii, Leuconostoc mesenteroides, and Candida parapsilosis were dead. At 500 MPa, Escherichia coli and Lactobacillus plantarum were dead. However, Staphylococcus aureus, Enterococcus faecalis, Corynebacterium sp., and Neosartorya hiratsukae (ascospores) survived even at 500 MPa, and the organisms except for N. hiratsukae were all gram positive bacteria.