The purpose of this study was to characterize precipitates formed in anaerobic, H2S-producing cultures of two Tissierella isolates and Desulfosporosinus strain DB. The cultures were grown in Cu-containing media as part of a larger study of Cu resistance in anaerobic sulfidogens. The Tissierella strains produced H2S from peptone. Desulfosporosinus formed H2S from peptone or through dissimilatory sulfate reduction with lactate. Tissierella cultures precipitated iron phosphate, vivianite, but no crystalline phases or Cu sulfides were detected. Multiple Cu sulfides, including chalcopyrite and covellite, were detected in Desulfosporosinus cultures but vivianite was not formed. Ion microprobe spectra and electron microscopic examination showed major variation in the elemental composition and morphological differences depending on incubation conditions. Extended incubation time for at least 1-2 months increased the crystallinity of the precipitates. The results highlight biogeochemical differences in sulfide and phosphate precipitates between the two major groups of Firmicutes although they may share the same habitat including the human intestinal tract.

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Pure cultures of lipophilic microorganisms of different phylogenetic groups were isolated from fat-containing industrial wastewaters. The strains of the genera Pseudomonas and Bacillus were the most active lipolytic microorganisms.

Analysis of fatty acid composition in liquid culture media after lipophilic bacterial strains cultivation was carried out. Pure cultures were earlierisolated from fat-containing wastes and cultivated on media with diverse fat sources. It was shown that microorganisms hydrolyze animal and milk fats to free fatty acids.

Pilot tests of the composting of waste activated sludge in an urban wastewater treatment plant with a consortium of thermophilic and thermotolerant bacteria has been carried out. The most effective was the bioconversion of activated sludge together with pine sawdust in a ratio of 1:1 or 1:2 using forced aeration of the mixture (0.35 m3/min).