However, the acid phosphatases of ectomycorrhizal fungi could not function in
alkaline soils, and an alternate surface enzyme would be needed. Moreover, aquatic
and terrestrial fungi typically produce alkaline phosphatase (Nagasaki 1968; Wilson
1972; Davis and Less 1972, 1973; Hochberg and Sargent 1973; Cohen 1985).
Bae and Barton (1989) studied phosphatase activities at pH 4.5–11 and revealed
that the cell extract of C. geophilum possessed alkaline phosphatase activity only in
the alkaline range (pH 9.5). Thus, C. geophilum is the ectomycorrhizal fungi that has
been reported to possess an alkaline phosphatase, it would provide a mechanism
whereby the fungi could utilize the phosphate in organic phosphates in alkaline soils.
Although the above in vitro studies using fungal spores and beads of A. niger and
Penicillium spp. are significantly different from sclerotia grains, we hypothesize that
mycelium of C. geophilum is likely to uptake Cu from alkaline soil and that its
sclerotia grains become enriched in Cu when these Cu-rich hyphae form sclerotia.
Further studies on the activity of hydrolytic enzymes such as alkaline phosphatase
in both mycelium and sclerotia grains of C. geophilum may help to elucidate the
mechanism by which heavy metals such as Cu are transferred from soil to sclerotia
grains in semi-arid weak alkaline soil.
11.4 Conclusion
Melanized sclerotia, thought to be C. geophilum, were found in Dark Kastanozem
soil in a semi-arid region of steppe forest in northern Mongolia. The soil was
calcareous, high pH (7.1), and the sclerotia had higher Ca concentrations and higher
TFs of Cu than sclerotia from Japanese Fulvic Andosols or Andic Cambisols with
low pH (4.5). The sclerotia collected from Japanese soils had both higher concentrations and higher TFs of Al. The enrichment of Cu in Mongolia sclerotia grains
appears to be a result of a biotic mechanism in high-pH soil conditions.
Acknowledgement This study was supported by the financial support of the Grant-in-Aid for
Scientific Research from Japan Society for the Promotion of Science, JSPS Project No. 17K07700.
References
Bae KS, Barton LL (1989) Alkaline phosphatase and other hydrolyases produced by Cenococcum
grainforme, an ectomycorrhizal fungus. Appl Environ Microbiol 55:2511–2516
Bahram M, Polme S, Koljalg U, Tedersoo L (2011) A single European aspen (Populus tremula) tree
individual may potentially harbour dozens of Cenococcum geophilum ITS genotypes and
hundreds of species of ectomycorrhizal fungi. FEMS Microbiol Ecol 75:313–320
Bruenger FW, Stover BJ, Atherton DR (1967) The incorporation of various metal ions into in vivoand in vitro-produced melanin. Radiat Res 32:1–21
Cabuk A, Ilhan S, Filik C, Caliskan F (2004) Pb
2+ biosorption by pretreated fungal biomass. Turk J
Biol 29:23–28
206
K. Nyamsanjaa et al.
alkaline soils, and an alternate surface enzyme would be needed. Moreover, aquatic
and terrestrial fungi typically produce alkaline phosphatase (Nagasaki 1968; Wilson
1972; Davis and Less 1972, 1973; Hochberg and Sargent 1973; Cohen 1985).
Bae and Barton (1989) studied phosphatase activities at pH 4.5–11 and revealed
that the cell extract of C. geophilum possessed alkaline phosphatase activity only in
the alkaline range (pH 9.5). Thus, C. geophilum is the ectomycorrhizal fungi that has
been reported to possess an alkaline phosphatase, it would provide a mechanism
whereby the fungi could utilize the phosphate in organic phosphates in alkaline soils.
Although the above in vitro studies using fungal spores and beads of A. niger and
Penicillium spp. are significantly different from sclerotia grains, we hypothesize that
mycelium of C. geophilum is likely to uptake Cu from alkaline soil and that its
sclerotia grains become enriched in Cu when these Cu-rich hyphae form sclerotia.
Further studies on the activity of hydrolytic enzymes such as alkaline phosphatase
in both mycelium and sclerotia grains of C. geophilum may help to elucidate the
mechanism by which heavy metals such as Cu are transferred from soil to sclerotia
grains in semi-arid weak alkaline soil.
11.4 Conclusion
Melanized sclerotia, thought to be C. geophilum, were found in Dark Kastanozem
soil in a semi-arid region of steppe forest in northern Mongolia. The soil was
calcareous, high pH (7.1), and the sclerotia had higher Ca concentrations and higher
TFs of Cu than sclerotia from Japanese Fulvic Andosols or Andic Cambisols with
low pH (4.5). The sclerotia collected from Japanese soils had both higher concentrations and higher TFs of Al. The enrichment of Cu in Mongolia sclerotia grains
appears to be a result of a biotic mechanism in high-pH soil conditions.
Acknowledgement This study was supported by the financial support of the Grant-in-Aid for
Scientific Research from Japan Society for the Promotion of Science, JSPS Project No. 17K07700.
References
Bae KS, Barton LL (1989) Alkaline phosphatase and other hydrolyases produced by Cenococcum
grainforme, an ectomycorrhizal fungus. Appl Environ Microbiol 55:2511–2516
Bahram M, Polme S, Koljalg U, Tedersoo L (2011) A single European aspen (Populus tremula) tree
individual may potentially harbour dozens of Cenococcum geophilum ITS genotypes and
hundreds of species of ectomycorrhizal fungi. FEMS Microbiol Ecol 75:313–320
Bruenger FW, Stover BJ, Atherton DR (1967) The incorporation of various metal ions into in vivoand in vitro-produced melanin. Radiat Res 32:1–21
Cabuk A, Ilhan S, Filik C, Caliskan F (2004) Pb
2+ biosorption by pretreated fungal biomass. Turk J
Biol 29:23–28
206
K. Nyamsanjaa et al.