Peptidoglycan .Types of Bacterial Cell Walls and their Taxonomic ...

Voi- 36, 1972 PEPTIDOGLYCAN TYPES OF BACTERIAL CELL WALLS
439
TABLE 21. Distinction of strains of Streptococcus sp. (serological group K) and strains of S. salivarius
Sero- Forma-
Species Strain no. logical Peptidoglycan type tion of
group levan
Streptococcus salivarius I ............. Kiel 21372 K L-Lys-L-Ala2, +
S. salivarius II ....................... Kiel 21367 L-Lys-L-Thr-Gly +
Streptococcus sp...................... Kiel 226, 13272 K L-Lys-direct
Streptococcus sp...................... NCTC 10232 K L-Lys-L-Ala(L-Ser)-L-Ala
TABLE 22. Grouping of strains of streptococci according to their peptidoglycan types
Peptidoglycan type Species or serological groups
L-Lys-L-Ala,-2 ................... Streptococcus sp. (groups F, G, and P)
L-Lys-L-Ala2,3 . .................. S. pyogenes (group A), S. equisimilis, S. zooepidemicus, S. equi, S. dysgalactiae
(all group C), S. faecalis (group D), S. sanguis (group H),
S. salivarius (group K), Streptococcus sp. (groups F, L. M and U),
S. thermophilus
L-Lys-L-Ala3 ..................... S. uberis (group E), Streptococcus sp. (group P)
L-Lys-L-Ala-L-Ala(L-Ser) ........ S. agalactiae (group B), Streptococcus sp. (group K)
L-Lys-L-Ala2-L-Ala(L-Ser) ....... Streptococcus sp. (group G)
L-Lys-L-Ala-Gly ................ Streptococcus sp. (group L), S. viridans IV
L-Lys-L-Thr-L-Ala .............. S. equinus (group D), S. mutans
L-Lys-L-Thr-L-Ala(L-Ser) ........ S. bovis, S. equinus (both group D), S. milleri
L-Lys-L-Thr-Gly ................ S. equinus (group D), S. salivarius II
L-Lys-D-Asp .................... S. faecium, S. faecium var. durans (both group D), S. avium (group Q);
S. lactis and S. cremoris (both group N)
L-Lys-direct .. . ... Streptococcus sp. (group R), S. viridans I, S. sp. (groups K and 0),
S. sanguis II, S. viridans II and IV
TABLE 23. Amino acid composition of the cell walls of Peptostreptococcus
Molar ratio of amino acids
Species Suggested peptidoglycan Fig. Reference
Glu Lys Ala Asp Gly
P. putridus ....... 1.0 0.8 1.6 0.8 L-Lys-D-Asp 9 30
P. intermedius .... 1.0 1.1 4.0 L-Lys-L-Ala2 19a 30
P. evolutus ....... 1.0 1.1 2.8 1.0 L-Lys-L-Ala-Gly 19d 339
peptide (Fig. 20) as in some streptococci (vide
supra). These few data indicate a diversity of
peptidoglycan types similar to that found
within the genus Streptococcus.
Genus Lactobacillus. The genus Lactobacillus
is divided into four subgenera by using the
grouping of Orla-Jensen (277) but using his
genera as subgenera.
(i) All the strains of the subgenus Thermobacterium
contain the Lys-D-Asp type of
peptidoglycan (Table 24, Fig. 9) as described by
Kandler (168, 169). The structure of the cell
wall of one strain of L. acidophilus has been
studied in greater detail (65). Besides peptidoglycan,
a neutral and an anionic polysaccharide
are the main structural components of these
cell walls. The peptide subunits of the peptidoglycan
are cross-linked, as in the other
thermobacteria, by single D-isoasparaginyl res-
idues. All the muramic acid residues are peptide
substituted, and about 60 to 70% of them
carry 0-acetyl substituents on C6. The neutral
polysaccharide is composed of equimolar
amounts of glucose, galactose, and rhamnose
and is linked by phosphodiester groups to
muramic acid residues. The anionic polysaccharide
is a glycerophosphate-polyglucose. The
backbone is composed of a (a or f3) 1,6-linked
polyglucose polymer. Monomeric a-glycerol
phosphate side chains are attached to the
glucose residues on C2 or C4 position.
(ii) The subgenus Streptobacterium can be
subdivided into two groups based on the occurrence
of the L-Lys-D-Asp and the direct crosslinked
m-Dpm type as shown in Table 25. The
latter type was found in L. plantarum and L.
inulinus and was described in detail by Weiss et
al. (406) and by Matsuda et al. (241, 242). With
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