Submitted to: Applied and Environmental Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 11, 2000
Publication Date: N/A
Interpretive Summary: Biological organisms do not live in isolation. Instead, they interact with one another in a variety of ways. Groups of organisms living near each other are called communities. In analyzing communities, one can identify the different species, which is structural analysis, or one can measure the different functions carried out by the community, which is functional analysis. Both functional and structural analysis are very difficult for microorganisms, because they are too small to directly identify and because the vast majority of microorganisms cannot be grown in the laboratory. We have developed a new method for characterizing communities of fungi. Fungi and fungal spores from soil, plant leaves, and compost are suspended in water, diluted with a mixture of antibiotics to prevent growth of bacteria, and transferred into plates with 96 different wells. Each well contains a different compound that fungi can grow on. The pattern of growth among the different wells reveals differences in the fungal community. The method differentiated fungal communities from soil, leaf, and compost samples. Within the group of soil samples, the method differentiated fungal communities from different soil types and from the soil around different plant species. This method, which is very easy to carry out, provides a mixture of structural and functional information, and may be useful to microbiologists, mycologists, and ecologists studying the role of fungi in agriculture.
Technical Abstract: A simple method for characterization of fungal communities was developed. Dilute suspensions of environmental samples in 0.2 % agar containing three different antibiotics were pipetted into 96-well plates (Biolog SF-N) containing a diverse collection of 95 different carbon sources. The plates were incubated for four to twelve days at 22 deg C and the absorbance measured at 650 nm. Canonical variates analysis was used to analyze the multivariate data. The method effectively separated fungal communities in compost and phylloplane samples from fungal communities in soil. Fungal communities in soil taken from the root zone of corn and soybean could be distinguished according to soil and plant type. Data taken at a single time-point were dominated by the total absorbance of the plate and separated samples primarily by soil type. When multiple time-points were combined to keep the total absorbance constant, differences in substrate utilization patterns due to different plant types could be distinguished. This method may be useful for community analysis in a variety of agricultural and ecological studies.