Variation in microbial communities colonizing horticultural slow sand filter beds: implications for filter function

Bellerophon is a program for detecting chimeric sequences in multiple sequence datasets by an adaption of partial treeing analysis. Bellerophon was specifically developed to detect 16S rRNA gene chimeras in PCR-clone libraries of environmental samples but can be applied to other nucleotide sequence alignments. Bellerophon is available as an interactive web server at http://foo.maths.uq.edu.au/~huber/bellerophon.pl

To determine the significance of differences between clonal libraries of environmental rRNA gene sequences, differences between homologous coverage curves, CX(D), and heterologous coverage curves, CXY(D), were calculated by a Cramér-von Mises-type statistic and compared by a Monte Carlo test procedure. This method successfully distinguished rRNA gene sequence libraries from soil and bioreactors and correctly failed to find differences between libraries of the same composition.

Significant portions of grain produced for livestock consumption are convened into ensiled forage. Silage producers have long recognized the positive effects of using an inoculant to insure the proper transformation of forage into a palatable and digestible feedstuff. When silage is fed from a storage structure, exposure to air stimulates the growth of epiphytic aerobes that may result in the loss of up to 50% of the dry matter. Moreover, fungi have been found to be associated with ensiled forage, but their growth is normally suppressed by the anaerobic conditions. However, the introduction of oxygen results in a fungal bloom, and the fungi and the associated metabolites may result in lost productivity in the livestock consuming the contaminated forage. In this study, we report on the diversity of the fungal community associated with whole plant corn silage during the ensiling process, and the effect of two different bacterial inoculants as compared with the uninoculated natural epiphytic fermentation on the distribution of the fungi associated with the silage. The fungal community from duplicate mini-silo packages of the same treatment was analyzed by denaturing gradient gel electrophoresis and direct sequencing of the resulting operational taxonomic units. This method proved useful in analyzing the complex microbial communities associated with the forage in that it was possible to determine that one inoculant dramatically influenced the fungal community associated with whole plant corn silage.