Impeding Bacillus spore germination in vitro and in milk by soy glycinin during long cold storage.
This paper presents a study of the magnitude and mechanism of impeding the emergent spore germination of Bacillus subtilis (non-hemolytic strain) and Bacillus licheniformis (hemolytic strain) under the action of soybean glycinin and its basic subunit (BS). Incubating B. licheniformis spores with 100 μg/ml of glycinin or BS at 35°C for 24 h totally prevented the hemolytic activity associated with the emergent vegetative cells on blood agar during 3-5 days of incubation at 35°C in contrast to the control. Glycinin and BS (100 μg/ml) also resulted in the leakage of 70 and 73% of the initially germinating spore contents of A260 absorbing materials of the two bacterial species after 2 h of incubation at 35°C, respectively. Increasing the concentration of glycinin and BS up to 400 μg/ml increased the germinating spore leakage to 83 and 88%, respectively. Spore germination in Muller Hinton Broth containing glycinin and BS (100 μg/ml) was practically nil after 4 days of incubation at 35°C. Supplementing milk preheated at 80°C/5 min with both glycinin and BS kept the final vegetative cell counts down to about 30 and 20% of the corresponding control, respectively, after 50 days of storage at 4°C. Both light, and transmission electron, microscopy images revealed significant morphological and structural distorting changes in BS-treated spores of B. licheniformis.
Microbiology Department, Faculty of Agriculture, Zagazig University.
Samir A
SA
Mahgoub
Ali O
AO
Osman
Mahmoud Z
MZ
Sitohy
D000818:Animals; D000069976:Bacillus licheniformis / Q000187:drug effects* / Q000502:physiology; D001412:Bacillus subtilis / Q000187:drug effects* / Q000502:physiology; D003080:Cold Temperature; D061353:Food Storage; D005916:Globulins / Q000737:chemistry / Q000494:pharmacology*; D046529:Microscopy, Electron, Transmission; D008892:Milk / Q000737:chemistry / Q000382:microbiology*; D030262:Soybean Proteins / Q000737:chemistry / Q000494:pharmacology*; D013025:Glycine max / Q000737:chemistry; D013171:Spores, Bacterial / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure
D005916:Globulins; D030262:Soybean Proteins; C011474:glycinin