Vertical structure of bacterial communities in peats of the Yakhroma river floodplain
The abundance and taxonomic structure of soil bacterial communities have been studied in different geomorphological parts of the Yakhroma floodplain. It has been found that the numbers of bacteria reach a peak in calcareous peat soil under forest near the floodplain terrace, decreasing to a minimum in soddy alluvial soil near the riverbed. All soils are characterized by the presence of different ecological-trophic bacterial groups capable of peat destruction. Seasonal dynamics of the structure of bacterial communities and, in some soil types, its spatial dynamics accounted for by changes in the botanical structure of peat across its profile have been revealed. All peat soils in the floodplain have high contents of organic matter and neutral pH and, therefore, are favorable biotopes for the development of saprotrophic bacteria. This, in turn, largely accounts for high productivity and stability of this agroecosystem as a whole.
Actinobacteria may influence white truffle (Tuber magnatum Pico) nutrition, ascocarp degradation and interactions with other soil fungi
Abstract To test the hypothesis that truffle-associated bacteria may improve truffle nutrition, we isolated bacteria from white truffle ascocarps and tested Actinobacteria for their ability to solubilise phosphate and iron, nutrients that have limited availability in white truffle grounds. Two isolates with sequence similarities to Curtobacterium flaccumfaciens and Rhodococcus sp. were characterized in detail. Both solubilised Ca 3 (PO 4 ) 2 in a way that was dependent on the nitrogen and carbon sources present. Neither strain broke down phytate, but both produced chelating compounds, performed ammonification, and broke down β-glucan. Additionally, C. flaccumfaciens decomposed chitin, pectin, lipids and proteins, while Rhodococcus sp. exhibited urease activity. Three potentially fungicolous fungi were isolated from diseased white truffle ascocarps and bioassayed against the isolated Actinobacteria. The Rhodococcus isolate inhibited Verticillium leptobactrum , neither bacterium affected Clonostachys rosea , while both isolates promoted growth of Trichoderma sp. The results suggest that Actinobacteria might be involved in improving truffle nutrition, ascocarp degradation and establishing relationships with other soil fungi.
The incidence of dead and dying fish in the Moray Firth, September 1963
Dead and dying fish were reported from the Moray Firth during a period of 15 days in September 1963. The initial mortalities were in the inner Firth, but they later spread outwards, especially eastwards along the southern shores of the Firth. Mass mortalities of the lugworm (Arenicola marina) also occurred in Scottish waters in 1962 and 1963, and at Balintorein Easter Ross fish and lugworm mortalities were contemporary.