Page 158 - The Biochemistry of Inorganic Polyphosphates

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Peculiarities of polyphosphate metabolism
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preceding cell division and was consumed rapidly in the process of division (Dirheimer and
Ebel, 1962, 1964b, 1965, 1968).
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Using PNMRspectroscopy,theaccumulationofsolublecytosolicPolyPunderaeration
and its breakdown under anaerobiosis have been observed in Corynebacterium glutamicum
(Lambert et al., 2002). Under 60–80 % saturation with oxygen, PolyP accumulation was
detected when P i and glucose or acetate were added to a cell suspension. This PolyP was
apparently of a high molecular weight, but at the initial stages of PolyP formation its chain
length was ∼ 40 phosphate residues. The PolyP level rose after the addition of carbon
sources and declined again when the oxygen level was recovered. Both processes, the
increase of PolyP during aeration and supply with carbon source and P i and the decrease
during anaerobiosis, occurred within minutes (Lambert et al., 2002). Thus, PolyP occurs
in Corynebacterium glutamicum not only as a granular store material, but also as a very
dynamic compound that may play a decisive role in this bacterium.
The presence of some specific PolyP-dependent enzymes is characteristic of these bacte-
ria. First, it is polyphosphate glucokinase that was found in Mycobacterium phlei (Szymona,
1957), Corynebacterium xerosis (Dirheimer and Ebel, 1962, 1964b, 1968) and Mycobac-
terium tuberculosis (Hsieh et al., 1993a,b; 1996a,b), and other representatives of this sys-
tematic group (Dirheimer and Ebel, 1962, 1964b; Kulaev and Vagabov, 1983). This enzyme,
purified from Mycobacterium phlei (Girbal et al., 1989) and cloned from Mycobacterium
tuberculosis (Hsieh, 1996; Hsieh et al., 1996a), is well described in a recent review (Phillips
et al., 1999). Secondly, in Mycobacterium tuberculosis a polyphosphate/ATP–NAD kinase
was characterized (Kawai et al., 2000). Such activity was found in Corynebacterium am-
moniagenes (Fillipovich et al., 2000).
Thirdly, in Mycobacterium phlei in media containing fructose, mannose or gluconate,
enzymatic activities were found forming fructose-6-phosphate, mannose-6-phosphate or
gluconate-6-phosphate through PolyP utilization (Szymona and Szumilo, 1966; Szymona
et al., 1969). Finally, AMP phosphotransferase activity in Corynebacterium and Mycobac-
terium was revealed (Winder and Denneny, 1957; Szymona, 1964; Dirheimer and Ebel,
1965). It is likely that the abilities to utilize PolyPs directly for the phosphorylation
of NAD, glucose and other sugars provide considerable energetic advantages for these
bacteria.
Polyphosphate kinase (Muhammed, 1961; Robinson and Wood, 1986; Robinson et al.,
1987) and exopolyphosphatase (Muhammed et al., 1959) are presented as well, while
putative genes for these activities have also been found (Zhang et al., 2002; Cardona et al.,
2002). The exopolyphosphatase of C. xerosis was studied by Muhammed et al. (1959).
This activity changes during the culture growth, in parallel with the accumulation of PolyP
and PolyP granules (see Figure 8.10), hence indicating the importance of this enzyme in
PolyP metabolism. The possible pathways of PolyP metabolism in Mycobacteria are shown
schematically in Figure 8.11 (Szymona, 1964).

8.8 Propionibacteria

PolyP metabolism has been most studied in Propionibacterium shermanii. Konovalova and
Vorob’eva (1972) have examined the PolyP content in this bacterium. In this study, 70–
80 % of the total PolyP was found in the fraction extracted by hot perchloric acid at all