Lactobacilli growth requirements

Gyorgy P, Norris RF, Rose CS. A variant of Lactobacillus bifidus requiring a special growth factor. Arch Biochem Biophys 1954 48 193-201. 

Laland SG, Serck-Hanssen G (1964) Synthesis of pyrimidin-2-one deoxyribosides and their ability to support die growth of the deoxyriboside-requiring organism lactobacillus acidophilus r26. Biochem J 90 76-81... 

The solution to the assay problem came from the fortunate finding by Mary Schorb, then working in the poultry industry, of a microorganism, Lactobacillus lactis dorner, which required vitamin B]2 for growth. With much quicker and more reliable assays the vitamin was isolated in 1948 in both the Merck and Glaxo laboratories. Its structure was determined by X-ray crystallography by Lenhert and Hodgkin (1961). 

Microbial growth studies also gave an important clue to the intracellular role of vitamin B12 when it was observed that the presence of thymidine overcame the need for B12 in the culture medium of Lactobacillus lactis dorner, suggesting B12 was required for the biosynthesis of thymidine. 

Studies on growth factors required by certain microorganisms, for example Streptococcus faecalis and Lactobacillus casei, and of their relevance in animal nutrition, led to the isolation and characterization of folic acid, pteroylglutamic acid (104), the structure of which was determined in 1946. It is an essential vitamin for man and together with vitamin B12 it is involved in the development of blood cells. Deficiency causes macrocytic anaemia. Many microorganisms do not use exogenous folic acid, but synthesize their own, and some... 

The isolation of lipoic acid in 1951 followed an earlier discovery that the ciliate protozoan Tetrahymena geleii required an unknown factor for growth. In independent experiments acetic acid was observed to promote rapid growth of Lactobacillus casei, but it could be replaced by an unknown "acetate replacing factor." Another lactic acid bacterium Streptococcus faecalis was unable to oxidize pyruvate without addition of "pyruvate oxidation factor." By 1949, all three unknown substances were recognized as identical.291 2913 After working up the equivalent of 10 tons of water-soluble residue from liver, Lester Reed and his collaborators isolated 30 mg of a fat-soluble acidic material which was named lipoic acid (or 6-thioctic acid).292 294... 

A number of reviews have now appeared on the subject. It has been known since 1900 that differences exist between the intestinal flora of breast-fed babies and those fed on cows milk, the flora of the former being composed almost exclusively of L. bifidus. In 1926, it was shown that a growth factor for L. bifidus occurs, associated with the lactose fraction in whey, in human milk, but it was not found in cream, in the proteins, or in the inorganic material. Later the nutritional requirements of L. bifidus were reinvestigated and, in the course of this work, there was isolated, from the feces of infants, a variant of L. bifidus which gave only a scanty growth on the normal media, but which responded to the addition of human milk. This variant was named Lactobacillus bifidus var. pennsyl-... 

Pyridoxal phosphate or related metabolites are required growth factors for Lactobacillus species (Morishita et ah, J. Bacteriol. 148[ 1981] 64-71). For example, when amino acids such as alanine or glutamate are used as the sole source of nutrition, these bacilli do not grow nor do they generate metabolic energy unless pyridoxal phosphate or its metabolites are supplied. Explain these observations. 

As reviewed in detail by Rosenberg and Godwin (R18), folate absorption has been measured by three basically different methods (1) measurement of rises in blood folate after an oral dose, (2) measurement of folate compounds in urine after an oral dose, and (3) administration of isotopically labeled folate by mouth followed by measurement of isotope appearing in plasma and excreted in urine and feees. Folate in plasma and urine is assayed with bacteria, usually strains of Lactobacillus casei or Streptococcus faecalis, which require folate for growth. They differ somewhat in the forms of folate they can utilize, but in general these microbiological assays measure unconjugated folate in either their reduced or unreduced forms. 

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