Nutrient movement and mycelial reorganization in established systems of Phanerochaete velutina, following arrival of colonized wood resources.

Harris MJ, Boddy L.

Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3TL, UK.


The effect of arrival of wood resources, pre-colonized by Coriolus versicolor, Phlebia radiata, Stereum hirsutum, and Vuilleminia comedens, on mycelial systems of Phanerochaete velutina was studied in trays of nonsterile soil in the laboratory over 5 months. Morphological responses were quantified non-destructively using image analysis. In a parallel series of experiments, nutrient movement was also quantified non-destructively using (32)P monitoring with a scintillation probe and subsequently by destructively harvesting after 155 days. The presence of a fungus occupying a newly arriving resource had major effects on deployment of biomass and on the uptake and allocation of phosphorus in the established Pha. velutina system. The effects varied depending on the species occupying the new resource. Hyphal coverage was greater in the half of the system to which new resources were added. Following addition of new resources, there was massive redeployment of biomass away from regions with no new resource when the new resource was (1) uncolonized, (2) colonized by V. comedens, or (3) colonized by S. hirsutum (although to a lesser extent with the latter), but not with others. (32)P was taken up by Pha. velutina both in the vicinity of the inoculum and the new resource and was translocated to the new resource from both sites of uptake; however, the local supply contributed most. Bidirectional translocation also occurred. The results are discussed in relation to mycelial foraging strategies, nutrient translocation, and partitioning within mycelial cord systems.

PMID: 16211328 [PubMed – indexed for MEDLINE]

Decolorization of bleach plant effluent by mucoralean and white-rot fungi in a rotating biological contactor reactor.

Driessel BV, Christov L.

Sappi Biotechnology Laboratory, Department of Microbiology and Biochemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa.


Bleach plant effluents from the pulp and paper industry generated during bleaching with chlorine-containing chemicals are highly colored and also partly toxic due to the presence of chloro-organics, hence the need for pretreatment prior to discharge. In a rotating biological contactor (RBC) reactor effluent decolorization was studied using Coriolus versicolor, a white-rot fungus and Rhizomucor pusillus strain RM7, a mucoralean fungus. Decolorization by both fungi was directly proportional to initial color intensities. It was found that the extent of decolorization was not adversely affected by color intensity, except at the lowest level tested. It was shown that decolorization of 53 to 73% could be attained using a hydraulic retention time of 23 h. With R. pusillus, 55% of AOX were removed compared to 40% by C. versicolor. Fungal treatment with both R. pusillus and C. versicolor rendered the effluent essentially nontoxic. Addition of glucose to decolorization media stimulated color removal by C. versicolor, but not with R. pusillus. Ligninolytic enzymes (manganese peroxidase and laccase) were only detected in effluent treated by C. versicolor. It seems that there are definite differences in the decoloring mechanisms between the white-rot fungus (adsorption + biodegradation) and the mucoralean fungus (adsorption). This aspect needs to be investigated in greater detail to verify the mode responsible for the decolorization activity in both types of fungi.

PMID: 16233095 [PubMed]Free Article