Page 159 - The Biochemistry of Inorganic Polyphosphates

March 9, 2004
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WU095-08
WU095/Kulaev
Propionibacteria 143
RNA
pentose cycle

Fr−1,6−dip G−6−P
Fr−6−P

Glycolysis P ortho Polyphosphates ATP activation
ATP, ADP
reaction

oligo−P

Krebs cycle and oxidative
phosphorylation

Figure 8.11 Possible pathways of PolyP metabolism in Mycobacteria (Szymona, 1964).

growth stages, using lactate as a carbon source. The remaining 20–30 % of the PolyP was
evenly distributed between the salt-soluble and alkali-soluble fractions. Low-molecular-
weight acid-soluble PolyP in the propionic bacteria at all growth stages on lactate was not
found. The total amount of PolyP increases during the culture growth (Figure 8.12). The
PolyP content increased sixfold under logarithmic growth whereas it remained at the same
level during the stationary growth phase (Kulaev et al., 1973a).
It was shown that the accumulation of PolyP fractions in P. shermanii was strongly in-
hibited by adding 50 µgml −1 of the antibiotic polymyxin M to the medium (Konovalova
and Vorob’eva, 1972). The presence of this antibiotic in the culture medium substantially
retarded the accumulation of this compound (Figure 8.12). This observation is of great
interest in view of the fact that the site of attack of this antibiotic in the bacterial cell is the
cytoplasmic membrane. The close link between PolyP metabolism and the functioning of
the cytoplasmic membrane may be explained by inhibition of the P i uptake or by possible
inhibition of PolyP-synthesizing enzymes or, conversely, activation of PolyP-cleaving en-
zymes. In order to resolve this question, an attempt was made in our laboratory to determine
the activities of most of the enzymes currently known to be involved in the synthesis or
utilization of PolyPs in this microorganisms (Kulaev et al., 1973). The activities of some
PolyP-dependent enzymes were examined at different growth stages of P. shermanii (see
Figure 8.12). It can be seen that under normal growth conditions, 1,3-diphosphoglycerate–
polyphosphate phosphotransferase is more active in old culture. Polymyxin M has no