Formation of the spore clumps during heat treatment increases the heat resistance of bacterial spores.
Effects of the clumping of bacterial spores on their heat resistance as a result of heat treatment were investigated. Spore suspensions of Bacillus cereus, Bacillus coagulans and Bacillus licheniformis were heated at 85 degrees C. Survivor curves of the three strains showed tailing in all treatments after 30 min. As the treatment time increased, the formation of spore clumps increased in all strains after 20 min. Relative hydrophobicity of the spore surface increased as a result of heat treatment. The effect of spore concentration on the inactivation of the B. licheniformis spores was investigated, and surviving curves showed no tailing below a concentration of 4.9 log CFU/ml.
Furukawa
Soichi
S
Laboratory of Food Microbiology, Department of Food Science and Technology, College of Bioresource Sciences, Nihon University, 1866, Kameino, Fujisawa-shi 252-8510, Japan. furukawa@brs.nihon-u.ac.jp
Narisawa
Naoki
N
Watanabe
Taisuke
T
Kawarai
Taketo
T
Myozen
Keiko
K
Okazaki
Sachiko
S
Ogihara
Hirokazu
H
Yamasaki
Makari
M
D001407:Bacillus / Q000502:physiology*; D001422:Bacterial Adhesion; D005516:Food Microbiology; D006358:Hot Temperature; D057927:Hydrophobic and Hydrophilic Interactions; D008858:Microscopy, Phase-Contrast; D013171:Spores, Bacterial / Q000502:physiology*; D013234:Stem Cells; D013997:Time Factors