Summary• Spatial distribution and biomass of genets of sporocarps and ectomycorrhizas of Suillus pictus were studied in a plot of 20 × 24 m established in a Pinus pentaphylla var. himekomatsu plantation.• The biomass of S. pictus ectomycorrhizas was evaluated based on morphotypes, and genets were identified based on the inter-simple sequence repeat (ISSR) polymorphism analysis.• Suillus pictus was one of the dominant ectomycorrhizal fungal species in both the sporocarp and ectomycorrhizal communities in the study plot. Four genets were identified from sporocarps and these coincided with those identified from ectomycorrhizas. Sporocarps of each S. pictus genet occurred separately from those of other genets. Spatial distributions of ectomycorrhizas of each genet were wider than those of sporocarps. The largest genet occupied c . 54% of the plot, and the area of each genet differed considerably.• Vegetative growth of mycelia is assumed to play a more important role in the propagation of S. pictus than colonization from spores because expansions of all the four genets ranged from 25 to 30 m and no small genets were found in this plot.

A bacterial strain capable of rapidly degrading di-2-ethylhexyl phthalate (DEHP) was isolated from soil and identified as Bacillus subtilis. The organism also utilized di-butyl phthalate, di-ethyl phthalate, di-pentyl phthalate, di-propyl phthalate, and phthalic acid as sole carbon sources; and their biodegradation ratio was over 99%, when the incubation was performed for 5 days at 30 degrees C. The microorganism degraded di-2-ethylhexyl phthalate and di-butyl phthalate through the intermediate formation of mono-2-ethylhexyl phthalate and mono-butyl phthalate, which were then metabolized to phthalic acid and further by a protocatechuate pathway, as evidenced by oxygen uptake studies and GC-MS analysis. The decontamination of soil polluted with di-2-ethylhexyl phthalate by B. subtilis was investigated. Experimental results showed that the strain could degrade about 80% of 5 mM DEHP simply by adding 8% culture medium to soil, indicating that the degradation can occur even when other organisms are present.

The fungus Tricholoma matsutake forms an ectomycorrhizal relationship with pine trees. Its sporocarps often develop in a circle, which is commonly known as a fairy ring. The fungus produces a solid, compact, white aggregate of mycelia and mycorrhizae beneath the fairy ring, which in Japanese is called a 'shiro'. In the present study, we used soil dilution plating and molecular techniques to analyze the bacterial communities within, beneath, and outside the T. matsutake fairy ring. Soil dilution plating confirmed previous reports that bacteria and actinomycetes are seldom present in the soil of the active mycorrhizal zone of the T. matsutake shiro. In addition, the results showed that the absence of bacteria was strongly correlated with the presence of T. matsutake mycorrhizae. The results demonstrate that bacteria, especially aerobic and heterotrophic forms, and actinomycetes, are strongly inhibited by T. matsutake. Indeed, neither bacteria nor actinomycetes were detected in 11.3% of 213 soil samples from the entire shiro area by culture-dependent methods. However, molecular techniques demonstrated that some bacteria, such as individual genera of Sphingomonas and Acidobacterium, were present in the active mycorrhizal zone, even though they were not detected in soil assays using the dilution plating technique.

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