Germination of Bacterial Spores by Long-Chain Alkyl Amines

SUMMARYL-Alanine-initiated germination of spores of Bacillus cereus was potentiated by the following structural analogues of alanine : 0-carbamyh-serhe (OCDS), D-cycloserine (DCS), P-alanylhydroxamic acid (PAHA) and glycyl hydroxamic acid (GHA) ; but not by D-a-alanyl-hydroxamic acid (DAHA). Potentiation of germination resulted from inhibition of alanine racemase in the spores with consequent suppression of the formation of D-alanine, an inhibitor of L-alanine-initiated germination. OCDS was the most effective potentiator of germination and inhibitor of racemase. PAHA and GHA were more effective potentiators of germination than could be explained solely by their weak inhibition of the racemase. The extra effectiveness was associated with slow binding of the analogues to the spores, and possibly also with formation of hydroxylamine which also inhibited alanine racemase and potentiated L-alanine-initiated germination. Germination initiated by ribosides and amino acids other than L-alanine was not strongly potentiated by OCDS, arguing against a role for L-alanine as an intermediate. However, germination initiated by adenosine + D-alanine was strongly inhibited by OCDS, which argues for the role of D-alanine being to supply the L-isomer by racemization. Antibacterial activities of the analogues did not mirror their activities as potentiators of germination.

Section: Discussionmentioning

confidence: 64%

Stimulation of Germination of Bacterial Spores by Analogues of D-Alanine

Jones¹,

Gould

1968

“…Spores of C. botulinum irradiated with sublethal doses of y-radiation in cured ham did become activated (Anellis, Berkowitz, Jarboe & El-Bisi, 1967). Activation of B. cereus spores by heat and y-radiation were similar qualitatively except when n-dodecylamine was used as germinant; then Activation of Bacillus spores 83 radiation caused activation but heat did not, as noted by Rode & Foster (1961). The mode of action of n-dodecylamine as a germinant is not understood, so the different activation responses cannot yet be explained.…”

Section: Discussionmentioning

confidence: 90%

“…at 37" i n the presence of I 1 Calcium dipicolinate (CaDPA), which is a spore constituent, will germinate spores of most bacteria, probably by de-stabilizing some spore-Ca-DPA structure (Riemann & Ordal, I 961). The long chain primary alkane n-dodecylamine (laurylarnine) will also germinate many spores, probably by virtue of its surface-active properties, and has been called a 'chemical germinant' to distinguish it from germinants like amino acids and ribosides (Rode & Foster, 1961). Figure 2 shows the effect of radiation and of heat on germination of spores of Bacillus cereus PX in CaDPA.…”

Section: Activation Of Bacillus Spores 79mentioning

confidence: 99%

Activation of Spores of Bacillus cereus by -Radiation

Gould

Ordal

1968

S U M M A R YSpores of Bacillus cereus strain PX which were exposed to 0.02, 0.06, 0.18, 0.54 and 1-08 Mrad of y-radiation became progressively more activated, i.e. they germinated more rapidly in the presence of germinants (e.g. L-alanine, inosine, rt-dodecylamine, calcium dipicolinate) than did unirradiated spores. Heat-and radiation-activation differed in that irradiated spores but not heated spores germinated faster than untreated control spores in n-dodecylamine. The two methods of activation were similar in that both sorts of activated spores could be de-activated, and heated and irradiated spores both had increased contents of titratable thiol groups as compared with untreated spores. Germination-like changes still occurred rapidly in spores which had been subjected to doses of y-radiation sufficient to render them non-viable. Ionizing radiation, heat and other agents which activate spores probably do so by changing the tertiary structure of spore macromolecules and thereby exposing previously masked reactive sites which are important in germination.

“…activation reported earlier (Gould & Ordal, I 967). Radiation activation was not masked by heating the spores when n-dodecylamine was the germinant since heat does not activate spores for germination in n-dodecylamine (Rode & Foster, 1961). Exposure of spores to IAM slowed their subsequent germination in n-dodecylamine, and spores y-irradiated in IAM germinated still more slowly (Fig.…”

Section: Growth After Diferent Germinant Treatments Of Spores Y-irradmentioning

confidence: 97%

Mechanism of the Inhibition of Germination of Bacterial Spores by -radiation in the Presence of Iodoacetamide and Iodate

Gould¹

1970

SUMMARYWhereas y-radiation alone either did not affect or stimulated spore germination, spores which had been irradiated in the presence of iodoacetamide (IAM) or potassium iodate were inhibited from germinating in germinants like L-alanine, inosine or yeast glucose broth. Activity of a lytic enzyme which may be involved in germination was mostly lost in spores irradiated in TAM, and a phosphomonoesterase was about 60 % inhibited. Spore alanine racemase was partly inactivated by y-radiation alone but, with spore protease, survived irradiation in IAM without much further loss of activity. Although spores made non-germinable by y-radiation plus IAM were nonviable as measured by colony counts, viability could be partly restored by chemical treatments known to by-pass the normal germination reactions. It was concluded that spores were inactivated by y-radiation in the presence of the potentiators through inactivation of enzyme(s) essential in the degradative reactions of germination. The enzyme inactivation was caused by iodinecontaining free radicals rather than directly by the y-radiation.