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

442 SCHLEIFER AND KANDLER
L-Ala, L-Ala-L-Ala, or L-Ala. The amino acid
compositions of the interpeptide bridges of the
two subspecies of L. viridescens (170) are quite
similar but the amino acid sequences are reversed
(Fig. 21a and b). rhus the differences in
the peptidoglycan structure confirm the separation
of these two subspecies which was originally
based on physiological and morphological
evidence.
The two subspecies of L. coprophilus are
distinguished by the number of alanine residues
in the interpeptide bridge and by the ability of
one to form dextran (144). Although the peptidoglycan
type is quite similar to that of
Leuconostoc (vide infra), both subspecies belong
to the subgenus Betabacterium since they
produce D, L-lactic acid and split arginine.
L. coprophilus and L. viridescens form, in
contrast to other species of the genus Betabacterium,
irregular rods, and in particular both
subspecies of L. coprophilus, and L. viridescens
ssp. minor can easily be confused with Leuconostoc.
They may constitute an intermediary
group between the genera Leuconostoc and
Betabacterium. Williams and Sadler (422) report
the occurrence of Gly in cell walls of some
strains of heterofermentative lactobacilli.
These cell walls were reinvestigated in our
laboratory by quantitative amino acid analysis
and by determining the peptide pattern of
partial acid hydrolysates. It could be shown
BACTERIOL. REV.
that these cell walls were contaminated by
protein. The real amino acid composition of the
peptidoglycan of the strains mentioned by
Williams and Sadler (422) is in agreement with
the data given in Table 26.
Genus Leuconostoc. The genus Leuconostoc
was classified according to Garvie (104, 106)
and Whittenbury (417). The peptidoglycan
types of the different species are listed in Table
27. The majority of the strains contain a peptidoglycan
of the Lys-L-Ser-L-Ala type. The
remainder of the strains reveal di-L-Ala, L-Ser-
Ala, or L-Ser-L-Ser peptides as interpeptide
bridges. The correlation of the peptidoglycan
type with the present grouping of the strains
-G-M-G-
L- Ala
D- Glu --NH2
iYE
L- Lys +- L-Ala(L-Ser)---- L-Ser a
D-Ala
jI* e L-Ser--- L-Alas-L-Ala *--- b
E L-Ala - (L-Ala)-
c
D-Ala
L- Lys
FIG. 21. Fragments of the primary structures of
peptidoglycans of lactobacilli and leuconostocs. (a)
L-Lys- L-Ala( L-Ser)- L-Ser; (b) L-Lys- L-Ser- L-Ala,;
(C) L-Lys-L-Ala(2).
TABLE 27. Distribution of peptidoglycan types within the genus Leuconostoc
Species No. of ATCC or NCDOa no. Type Fig. Reference
strains
Leuconostoc cremoris .... 8 NCDO 828 L-Lys-L-Ser-L-Ala2 21b 169
L. lactis ................ 8 NCDO 533, 546 L-Lys-L-Ser-L-Ala2 plus 21b 169
L-Lys-L-Ala2 21c
L. paramesenteroides ssp.
ssp. paramesenteroides 2 NCDO 803, 883 L-Lys-L-Ala2 21c 169
ssp. lactophilum ...... 5 L-Lys-L-Ser-L-Ala2 21b 169
L. gracile (syn. L. oenos) 23 NCDO 1668, 1669, 1674, 1675, L-Lys-L-Ala-L-Ser plus 21a 169
1694, 1696, 1705, 1707, 1823, L-Lys-L-Ser-L-Ser 21a
1890, 1893
L. dextranicum .......1. NCDO 517 L-Lys-L-Ser-L-Ala2 21b 169
L. mesenteroides
ssp. mesenteroides .. 18 NCDO 183, 523, 538; ATCC L-Lys-L-Ser-L-Ala2 21b 169, 174
8082, 8086, 8293, 8357,
8359, 9135, 10830, 10830a,
10878, 12291, 14430, 14935
ssp. amelibiosus .... 4 ATCC 13146, 10882, 10883, L-Lys-L-Ala2 21c 169
11449
a See footnote a in Table 20.
T
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