Role of the fungal mycelium in the retention of radiocaesium in forest soils

Availability and immobilization of 137Cs in subtropical high mountain forest and grassland soils

“…Being aware of the importance of the availability of 137 Cs retained by fungi, some investigators tried to determine the fraction of nuclear fallout 137 Cs in fungal hyphae in soil (Brückmann and Wolters, 1994;Baumann et al, 1996). Recent study indicates that a critical part of fungal mycelia and fruit bodies of mycorrhizal fungi are water soluble (Vinichuk et al, 2005), which contributes to the mobility of 137 Cs in the forest soils.…”

“…In addition, many studies suggest that microflora contain a critical pool of 137 Cs in organically rich soils (Dighton et al, 1991;Simkiss et al, 1993;Sanchez et al, 2000). Microflora actively transport 137 Cs from organic horizons to fresh litter, a key function in the recycling and persistence of 137 Cs in forest soils (Brückmann and Wolters, 1994;Rafferty et al, 1997;Vinichuk et al, 2005). Fukuyama and Takenaka (2004) found that microbial activity plays a critical role in upward migration of 137 Cs from soil to litter and might induce the removal of 137 Cs with litter from the forest through runoff.…”

Mushrooms: Radioactive Contamination of Widespread Mushrooms in Japan

“…Forest soil is abundant in organic compounds; therefore, less radiocesium should be adsorbed. However, considerable proportion of 137 Cs in forest soil is retained by the fungal hyphae, and fungi are considered to prevent the elimination of cesium from ecosystems (Brückmann and Wolters 1994 ;Guillitte et al 1994 ;Vinichuk and Johanson 2003 ;Vinichuk et al 2005 ). Thus, fungal activity is likely to contribute substantially to the long-term retention of radiocesium in the organic layers of forest soil by recycling and retaining radiocesium between fungal mycelia and soil (Muramatsu and Yoshida 1997 ;Steiner et al 2002 ;Muramatsu 1994 , 1996 ).…”

Soil microorganisms determine the sorption of radionuclides within organic soil systems

“…Soil microflora, especially fungal mycelium, are strong retainers of Cs and may contribute significantly to the long-term retention of radionuclides in organic layers of forest soils Guillitte et al, 1994;Steiner et al, 2002;Vinichuk et al, 2005). The uptake of radionuclides by organic soils has been measured but the role of soil microorganisms may have been masked by the presence of even small amounts of clay minerals occurring in these soils (Avery, 1996).…”

“…The majority of previous studies on the microbial retention of radionuclides have been done with Cs and two approaches have been used: (1) measurement of the amount of radionuclide stored in fungal fruit bodies or fungal hyphae (Olsen et al, 1990;Dighton et al, 1991;Vinichuk et al, 2005) or (2) the use of partial sterilisation techniques, such as chloroform fumigation or irradiation, to measure microbially associated radionuclides within a soil matrix (Bunzl and Schimmack, 1988;Brückmann and Wolters, 1994;Stemmer et al, 2005). To determine the contribution of microbial activity to the sorption of radionuclides in organic material, it is necessary to compare non-sterile systems with sterile systems.…”