Chicken Manure Methanogenesis.

Abstract

A thermophilic (55 C) acetate-enriched methanogenic culture was obtained in order to study the differential inhibition phenomena observed in chicken manure methane fermentation. The substrate range, temperature optima, and morphology of the culture, which was apparently dominated by Methanosarcina species, were recorded. Effects were reported of different concentrations of the carboxylic ionophores monensin and lasalocid on methane formation by the growing culture from acetate and from H 2 /C0 2 . Significantly (P<.01) greater sensitivity was observed for methanogenesis from acetate compared with that from H 2 /C0 2 in a specified ionophore concentration range. In order to establish the validity of this experimental model system in reflecting the inhibition observed for broiler litter, the effects of a manure water extract and its subfractions also were examined using 2-[ l4 C]acetate or H 2 /C0 2 as the methanogenic substrate. The existence of selective inhibition of methanogenesis from acetate clearly (P<.001) was shown by the water extract and by its organic solvent soluble subfractions, as well as by the pure ionophores. Furthermore, chromatographic fractionation gave strong indication that broiler litter extracts contained monensin at levels which proved to be inhibitory. A decrease of Na + concentration in the medium also was found to be detrimental to acetate decarboxylation, but did not interfere with H 2 oxidation to methane. The combination of low Na + concentrations and subinhibitory concentration of monensin inhibited both methanogenic activities. (

Anaerobic digestion and horticultural value of solid waste from manufacture of instant coffee

“…Volatile fatty acids (VFA) and biogas composition were analyzed every 10 days by gas chromatography (15,18). Samples of slurry were prepared and analyzed by GC (Varían 6000, USA), equipped with a flame ionization detector, as described by Dosoretz et al (19). Biogas samples were analyzed by GC (Model GOW MAC, Series 150, USA), equipped with a thermal conductivity detector.…”

Chicken Manure Methanogenesis.

“…In addition, studies with acetate enriched methanogenic cultures originating from our inoculum (Dosoretz et al, 1987) indicate that the growth of the culture on either H 2 /C0 2 or acetate is not inhibited by an NH 3 /NH 4 + concentration of 5000 mg/L. Similar levels can also be tolerated by cow manure digesters.…”