Microbes methane producers

When carbon isotopic values fall below —40 per mil, the involvement of methane producing and consuming microbes is suspected. In modem environments the isotopic composition... 

Cappenberg, T.E., 1975. A study of mixed continuous cultures of sulfate-reducing and methane-producing bacteria. Microb. Ecol., 2 60—72. 

Anaerobic microbes in the presence of water in the landfill will consume these natural products and produce methane, CO2 and humus. One study reported the average composition of 20 year old refuse to be 33 % paper, 22% ash and 12% wood [18]. Thirty core samples revealed a wide range of degradation and microbial activity that were directly attributed to sample moisture content. Recovered polyethylene degradation was evaluated and determined to be as high as 54 %. 

That source appears to be quite small. While methane is certainly produced by microbes in oxygen-poor and anaerobic regions of the ocean, in order for the methane to escape to the atmosphere it must first pass through an overlying layer in the ocean with abundant oxygen. Probably the methane is oxidized by aerobic microbes in these layers before it can escape. 

Nutrition has important effects on the environment as a consequence of the processes of digestion (methane and phosphorus) or a combination of digestion and metabolism (nitrogen). Methane is produced by the fermentation of foods in the gut by microbes, particularly in ruminants, and the decomposition of carbon compoimds in faeces stored as manure. Undigested phosphorus compoimds are excreted in the faeces. Undigested and waste products of the metabohsm of nitrogen compounds are excreted in the faeces and urine and the decomposition of these produces nitrous oxide (N2O). Ammonia in animal wastes is responsible for soil acidification and nutrient enrichment. 

The methanogens used the Wood-Ljungdahl pathway to turn the air into sugars and carbon chains, making methane waste. Other microbes ate the methane, cracking its bonds open to get at the electrons inside, producing carbon dioxide and... 

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