Page 157 - The Biochemistry of Inorganic Polyphosphates

Char Count= 0
20:32
March 9, 2004
WU095-08
WU095/Kulaev
Mycobacteria and Corynebacteria 141
120
110
1
4 100
90
80
70
0.35
Granules per cell 1.2 3 2 PolyP ( µmol (mg N) −1 ) 0.30 60 Polyphosphatase activity (units (mg N) −1 )
1.0
50
0.25
0.8
40
0.20
0.6
0.4 0.15 30
0.10 20
0.2
0.05 10
0 0
2 4 6 8 10 12 14 16
Time (h)

Figure 8.10 Changes in the amount of PolyP, granules and exopolyphosphatase activity in
Corynebacterium xerosis (Hughes and Muhammed, 1962): (1) exopolyphosphatase activity; (2)
PolyP; (3) granules; (4) biomass.

et al., 1958), Winder and Denneny (1957) and Szymona (1964). These workers have shown
that rapidly dividing cells of Mycobacteria accumulate minimal amounts of PolyPs. When
the cells enter the stationary growth phase, the more rapid biosynthetic processes cease
and the PolyP content increases rapidly. When culture development is inhibited by nitrogen
starvation (Sall et al., 1956), antimetabolites azaserine (Mudd et al., 1958) or ethionine
(Ebel, 1952d), or deficiency of Zn 2+ in the medium, PolyP accumulates rapidly. Thus, the
accumulation of PolyPs under stress is also characteristic of this group of bacteria.
When the normal grouwth conditions are restored, PolyP is actively utilized for the
biosynthesis of nucleic acids and phospholipids as a source of phosphorus (Mudd et al.,
1958; Winder and Denneny, 1957).
PolyP metabolism under various growth conditions and at different growth stages has
also been investigated in Corynebacterium (Hughes and Muhammed 1962; Dirheimer and
Ebel, 1962, 1964b, 1965, 1968). Hughes and Muhammed (1962) showed that the PolyP
content of Corynebacterium xerosis was a function of the phase of growth (Figure 8.10).
When the cells of this bacterium were placed in a fresh medium, PolyP accumulation was
observed during the latent period. On entering the logarithmic growth phase, PolyP was
actively utilized and accumulated again in the stationary phase. As in Mycobacteria, rapid
accumulation of PolyP occurred under nitrogen starvation. In Corynebacterium diphteriae,
it was shown that acid-insoluble PolyP accumulated in the greatest amounts at a stage