Abstract
The authors have studied so called “lactic acid value” of various protein such as egg albumin, casein, gelatin, glutenine, etc. using Lact. arabinosus, Leuc, mesenteroides, Lact. casei, Lact. fermenti, and Str. faecalis, as test organisms. The lactic acid value were measured according to ordinary bio-assay method(1) with acid and pancreatin-hydrlysates of the above proteins, the basal medium being shown in Table 1, and expressed by maximal acid production and tan θ=V/C, where V indicates number of c. c. of 0.05 N NaOH at the half maximum point and C the concentration of the protein in per cent. The results are shown in Table 2. It is clear from these results that under the conditions so far investigated the lactic acid values of various proteins vary according to the species of the testorganisms and this fact shows not only the complicated relationships in the amino acid requirements of individual lactic acid bacteria, but also the fact that such method as adopted by the authors may properly be used in determining the nutritive values of raw materials for organisms used in the fermentation industries. If we can find either a complete parallelism between the lactic acid value and the ordinary biological value or nutritive equivalence between various proteins through proper selection of the test orgamism, it may be possible to determine the nutritive values of proteins for animals through a microbiological way. The comparison between the “lactic acid values” and the biological values is shown in Table 3 where Str. faecalis is proved to be comparatively fit for the purpose. The authors are deeply indebted to Dr. Raper and Dr. Smith of the N. R. R. L. for granting us the test organisms.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the agricultural chemical society of Japan
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
