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Effects of wet heat treatment on the germination of individual spores of C lostridium perfringens
Author(s) -
Wang G.,
ParedesSabja D.,
Sarker M.R.,
Green C.,
Setlow P.,
Li Yq.
Publication year - 2012
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.2012.05387.x
Subject(s) - library science , computer science
Aim To analyse the effect of wet heat treatment on nutrient and non‐nutrient germination of individual spores of C lostridium perfringens . Methods and Results Raman spectroscopy and differential interference contrast ( DIC ) microscopy were used to monitor the dynamic germination of individual untreated and wet heat‐treated spores of Cl. perfringens with various germinants. When incubated in water at 90–100°C for 10–30 min, more than 90% of spores were inactivated but 50–80% retained their Ca 2+ ‐dipicolinic acid (Ca DPA ). The wet heat‐treated spores that lost Ca DPA exhibited extensive protein denaturation as seen in the 1640–1680 cm −1 (amide I) and 1230–1340 cm −1 (amide III ) regions of R aman spectra, while spores that retained Ca DPA showed partial protein denaturation. Wet heat‐treated spores that retained Ca DPA germinated with KC l or l ‐asparagine, but wet heat treatment increased values of T lag , Δ T release and Δ T lys , during which spores initiated release of the majority of their Ca DPA after mixing with germinant, released >90% of their Ca DPA and completed the decrease in their DIC intensity because of cortex hydrolysis, respectively. Untreated Cl. perfringens spores lacking the essential cortex‐lytic enzyme ( CLE ), SleC, exhibited longer T lag and Δ T release values during KC l germination than wild‐type spores and germinated poorly with Ca DPA . Wet heat‐treated wild‐type spores germinating with Ca DPA or dodecylamine exhibited increased T lag , Δ T release and Δ T lys values, as did wet heat‐treated sleC spores germinating with dodecylamine. Conclusions (i) Some proteins important in C l. perfringens spore germination are damaged by wet heat treatment; (ii) the CLE SleC or the serine protease CspB that activates SleC might be germination proteins damaged by wet heat; and (iii) the Ca DPA release process seems likely to be damaged by wet heat. Significance and Impact of the Study This study provides information on the germination of individual Cl. perfringens spores and improves the understanding of effects of wet heat treatment on spores.