The distribution of cadmium between cellular subfractions in cadmium-sensitive and cadmium-resistant Staphyloccus aureus.

The accumulation and distribution of cadmium (Cd) between cellular subfractions were studied in Cd-resistant Staphylococcus 3719 + and its plasmid-negative Cd-sensitive variant 3719–, grown in media containing 0.01, 0.1 or 50 mg of Cd/litre. In the media containing 0.01 and 0.1 mg of Cd/1 the uptake of Cd by the Gd-resistant S. aureus was significantly less than that by Cd-sensitive S. aureus, both in toto and in terms of the cell wall fractions. Only variant 3719 + grew in the medium containing 50 mg of Cd/1. The finding of a lag phase in the growth of both variants is interpreted to suggest that the resistance is of inducible character, even in the sensitive S. aureus. The mechanism of resistance to Cd could consist of both barrier and clearance functions.     

The Effect of Catalase on The Toxicity of Cadmium in Cadmium-Sensitive and Cadmium-Resistant Staphylococcus Aureus

The effect of catalase on the toxicity of cadmium (Cd) in Cd-resistant Staphylococcus aureus 3719+ and its plasmid-negative Cd-sensitive variant 3719– was studied. Catalase on a solid medium increased the recovery of Gd-stressed S. aureus 3719– cells, and the addition of catalase into a liquid growth medium resulted in a shortened lag phase of growth especially in S. aureus 3719–. The catalase activity of S. aureus 3719+ cell suspensions was greater than the corresponding activity of S. aureus 3719– cell suspensions. Cd did not influence the activity of beef liver catalase or the catalase production of the bacterial cells.Catalase reduced the toxicity of Cd especially for S. aureus 3719–. The greater catalase production of S. aureus 3719+ might be one factor in its resistance against the toxic effects of Cd. It is suggested that Cd together with hydrogen peroxide may induce oxidative damage to cells if there is not sufficient catalase available to decompose all the hydrogen peroxide formed.     

Dehydrated mink manure as a protein source for growing pigs

The use of dehydrated mink manure as a protein source for growing pigs was studied by substituting 7.5 and 15 % (w/w) of the complete feed with manure and a corresponding amount of barley. The manure used had a poor feed value as compared to the values obtained earlier in digestibility tests in minks. The crude protein content was 21.3 %. The addition of mink manure to the feed did not adversely affect the feed consumption, nor were any effects on the health of the pigs observed. The differences in daily gain and feed efficiency recorded between the experimental groups were not statistically significant. The number of experimental animals was small, and a large variation occurred within the groups. The addition of mink manure to the diet resulted in lower weight gain, apparently due to a lower energy supply. The groups given mink manure received less feed units than the controls. No harmful effects of the manure feeding on carcase quality was observed and organoleptic tests revealed no changes in the smell or taste of the meat. No changes were found in the digestive tracts, livers or kidneys of the pigs.     

Oat Bran Fermentation by Rye Sourdough

Hydration of oat bran including fermentation by rye sourdough was studied. Three types of oat bran suspensions were prepared (a control, one with whole meal rye flour added, and one with rye starter added). The suspensions were incubated for 1, 2, 3 and 4 hr. β‐Glucan content and solubilities of protein and β‐glucan were analyzed. Viscosity of the supernatants of oat bran suspensions was determined. Neither the rye sourdough nor the rye flour alone had a significant effect on the total β‐glucan content of oat bran suspensions. However, the addition of rye, either as whole meal rye flour or as sourdough starter, markedly increased the solubility of β‐glucan and proteins and simultaneously decreased the viscosity of the water‐soluble fraction of oat bran suspension. This suggests that a hydrolysis of β‐glucan had occurred that could change the rheological properties of oat bran in baking and the physiological potential of oat bran in nutrition.