Achromobacter A43 produced a compound inhibitory to the outgrowth of Clostridium botulinum type E spores. The inhibitor could be produced in various laboratory media and the outgrowth of germinated spores was completely inhibited by 1/10th dilution of the A43 spent medium. Germination was not affected. The spores lost refractility in the presence of the inhibitor and were darkly stained by crystal violet. The germinated spores showed little outgrowth, no elongation, and no lysis. The A43 inhibitor was dialysable and could be concentrated by lyophilizing the dialysate. The inhibitor was stable at 37°C, 25°C, and 5°C, but was partly inactivated when heated at 65°C for 10 min. The inhibitor was not volatile and could not be vacuum distilled at 40°C. Solutions of acids of pH below 2.0 destroyed the activity. Molecular weight of the inhibitor was estimated at 800 ~ 1,000 Daltons by PSAC Millipore Pellican ultrafiltration and by elution time on a column of Bio-Gel P-2. The inhibitor could be separated into fractions containing peptides and lipids on a Bio-Rex 70 X ion exchange column. The presence of phosphatidic amino acids was also suggested by Rhodamine 6G reaction. The A43 inhibitor was similar, in molecular weight and inhibition characteristics, to tylosin, but appeared to be more heat labile than tylosin. Achromobacter species were shown to be selectively inactivated by the smoking process. The smoked fish, therefore, may lack the added safety factor that the inhibitor similar to that of A43 might provide in other seafoods. / Graduation date: 1974

Thesis (Ph. D.)--University of Wisconsin--Madison, 1961. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

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After establishing that, like types B and E toxins, type A botulinus toxin contains only one residue of cysteine per molecule, chemical modification studies were carried out showing that sulfhydryl-specific reagents like p-chloromercuribenzoate (PCMB) and N-(4-dimethyl-amino-3,5-dinitrophenyl) maleimide (DDPM) cause a marked decrease in toxicity. Types A, B and E toxins were reacted with DDPM and a labelled peptide was obtained from the tryptic digest of each of the toxins. The quantitative amino acid analyses of these three peptides were remarkably similar. Sequence analyses showed that a sequence ala-glu-ser-cys-ser-asp-ser is common to all three DDPS-peptides. Type B botulinus toxin does not enzymatically alter acetylcholine in order to cause flaccid paralysis. It is postulated that the three thiol-containing peptides isolated contain all or part of a postulated active site common to each of types A, B and E botulinus toxins. / Science, Faculty of / Microbiology and Immunology, Department of / Graduate

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No description available.

Thesis (M.S.)--University of Wisconsin--Madison, 1966. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 84-88.

Thesis (M.S.)--University of Wisconsin--Madison, 1968. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.