Serological Studies on Proteinases Produced by Aeromonas Salmonicida and Other Aeromonads

Comparison of Bacillus thuringiensis with other bacillus species based on enzymoserological examinations of their proteolytic enzymes

Investigated strains of Bacillus thuringiensis were all good producers of casein precipitating proteinases (CP-enzymes).

CP-enzymes produced by five strains of B. thuringiensis were serologically compared with enzymes produced by strains of B. cereus, B. licheniformis and B. subtilis. The technique used is a special enzymoserological procedure by which the proteolytic activity is neutralized by specific antisera. A close enzymoserological relationship was demonstrated between B. thuringiensis and B. cereus, while no interspecies cross-reactions occurred between enzymes of these species, and those of B. licheniformis and B. subtilis.

The possibility of undetected transference of B. thuringiensis from bacteriologically treated plant material to animals is discussed in relation to the high degree of similarity between B. cereus and B. thuringiensis.

Proteolytic enzymes and biological inhibitors. V. Serological relationship between bovine and swine trypsins and bovine -chymotrypsin

The serological relationship between bovine and swine trypsins, and bovine α-chymotrypsin has been studied with rabbit antisera at different stages in the immunization period. By using paper electrophoresis to distinguish between the naturally occurring inhibitors and the antienzymes in the γ-globulin fractions, combined with the casein precipitating inhibition test (electrophoretic CPI-test) it was found that at 18 days after immunization the antienzymes inhibited only the homologous enzymes. After an additional 12 and 24 days the anti- bovine trypsin also inhibited swine trypsin and α-chymotrypsin, and anti-swine trypsin inhibited bovine trypsin, while antia-chymotrypsin inhibited only the homologous enzyme. The enzyme inhibition in the heterologous systems was about 1/10 of that in the homologous systems. Similar results were obtained by applying the Kunitz test to isolated γ-globulins. The total trypsin inhibitory activity of the whole anti- bovine trypsin serum increased 50 % from the beginning to the end of the immunization period (tested on bovine trypsin).

Using the double diffusion technique, cross precipitation only occurred between anti-bovine trypsin and swine trypsin.

Acetyltrypsin (bovine) was affected by the 3 antisera in a way similar to native bovine trypsin.

The results are discussed in relation to other reports concerning the serological relationship of animal proteinases.