Casein Hydrolysate Solution Research Articles

Evaluation of different nitrogen sources in high-calorie parenteral therapy

Five infants and two children who required prolonged high-calorie parenteral therapy were placed on nitrogen-balance studies while receiving alternate courses of two nitrogen sources; i.e., a casein hydrolysate and a synthetic amino acid solution. Quantitative analyses of plasma and urine amino acid levels were carried out during the administration of both solutions. Administration of either synthetic amino acid or casein hydrolysate solutions in concentrations of 2.125% and 4.25% resulted in positive nitrogen balance and consistent apparently equal weight gain in both concentrations. The infusion of 6.7% synthetic amino acid solutions, in conjunction with a somewhat lower caloric intake than previously employed, resulted in a more positive nitrogen balance but a diminished rate of weight gain. Methionine was the only plasma amino acid component that was consistently elevated during these infusions. The solution of 2.125% synthetic amino acids produced the same rate of weight gain as the other solutions studied, with a constant significant positive nitrogen balance. When this nitrogen source is employed, potential complications in therapy appear to be minimal.

The Effect of Kinetin on Protein Level of Brassica Leaf Disks

AbstractThe senescent leaf disks from Brassica rapa L. were floated on a medium containing 14C‐L.‐leucine in the presence or absence of kinetin. The increase in radioactivity in protein fraction of kinetin‐treated disks was almost linear with time, while the increase in untreated disks incubated for 3 days started to slow down. The leaf disks were first incubated on the solution of 14C‐L‐leucine and then transferred to either kinetin solution or water in order to study whether the slower incorporation is due to the decreased rate of protein synthesis or that of protein retention. The decrease in radioactivity of disks floated on kinetin was slower than that of disks floated on water. The slower decrease in radioactivity caused by kinetin was not due to an increased turnover rate, since the same phenomena were observed in the presence of cold leucine or casein hydrolysate solution. These results suggest that kinetin retards the decomposition of protein in leaf disks and does not stimulate the synthesis of the bulk of protein.

Development of competence in cultures of Bacillus subtilis inoculated with different numbers of bacteria.

SUMMARY: The influence of casein hydrolysate, tryptophan, glucose, magnesium sulphate and different buffer solutions on the rate of multiplication of Bacillus subtilis strain 168 was determined. Inoculum size was shown to influence the generation time and the increase in the mass of bacteria was found to be inversely proportional to the size of the inoculum. Bacillus subtilis 168 forms chains especially in minimal media. In complete media chains are formed by only a small proportion of the bacteria and sometimes not at all.A simple transformation method was used to follow the development of competence in cultures of Bacillus subtilis 168 in media inoculated with different numbers of bacteria. The estimation of the number of transformants was subject to greater error than estimation of the viable count. This error in the estimation of the number of transformants is due mainly to the thread-like character of DNA, which is difficult to dilute accurately. The smaller the inoculum of bacteria, the shorter the time for the rise phase of competence. Optimal competence is reached when about 106 bacteria/ml. are inoculated into the medium. The rise phase of competence takes a shorter time than the decline phase.An equation was developed from which it is easy to calculate approximately the onset of the peak of competence. Precise determination of this peak can be achieved by controlling the density of the bacterial suspension.

Studies on protein hydrolysis. VII.—anaphylaxis in guinea Piǵs produced by some fractions of antiǵenic casein hydrolysates

AbstractThe removal of the stable foam from an antigenic enzymic casein hydrolysate solution, reduced the anaphylactoid reaction produced by the hydrolysate and also reduced its anti‐genicity. Solutions of freeze‐dried foam fractions were in most instances distinctly antigenic, they cross‐reacted with milk proteins and produced strong anaphylactoid shock in guinea pigs.