Influences of lactic acid bacteria on animal bodies. I. Amino acids requirement of lactic acid bacteria in culture medium
Nakamura, I.; Anzai, H.
Kitasato Archives of Experimental Medicine 44(1): 21-36
1971
ISSN/ISBN: 0023-1924 PMID: 5147360 Document Number: 40564
When Lactobacillus casei, Streptococcus lactis, L. jugurt and Str. thermophilus were cultured in a sterile skim-milk medium for 48 h at 37 deg C, max. amino acid residues/100 g hydrolysate were generally obtained after 36 h; only proline, lysine, histidine and arginine residues were highest at 48 h, and only methionine and tyrosine in skim-milk cultures of Str. lactis and L. casei respectively showed changes of >10% between values at 36 and at 48 h. When L. casei and Str. lactis were each cultured at 37 deg C in the synthetic medium of Tamura et al. [DSA 16, 761] at original, 1/3 and 1/6 concn., L. casei multiplied rapidly after a 24-h lag phase and reached the stationary phase after 48 h; viable count and titratable acidity at this point were approx. proportional to concn. of the medium. Str. lactis had a lag phase of 10 h and reached the stationary phase after 24 h in the 2 lower concn. of the synthetic medium; growth was much slower in the medium at original concn., lag phase being about 36 h. Most of the 17 amino acids in the synthetic medium were consumed to a greater or lesser extent, except for glycine, which increased in the presence of L. casei, and methionine, which increased slightly in the presence of either organism.