US 4,540,666 A · Methane fermentation

Abstract

A methane fermentation process wherein a strain of the genus Methanobacterium is cultivated in a fermenter containing at least a carbon source, a nitrogen source, inorganic salts and micro-flora for methane fermentation. The strain has a methanogenic activity above 8.7.times.10.sup.-8 ml/cell.day in the stationary phase of growth, exhibits the methanogenic activity even at an oxygen partial pressure of 1/30 atm. and is allowed to live under an oxygen partial pressure up to 1/5 atm. The seed of the strain is obtained by anaerobically cultivating the strain in a culture medium containing at least nitrogen sources, inorganic salts and reducing agents in a mesophilic range of 25.degree. to 45.degree. C. using a substrate such as a mixed gas of hydrogen and carbon dioxide, a formate or an acetate. The growth of the strain is facilitated when cocultured with a strain belonging to the genus Clostridium.

Claims10

Dependent claims

A fermentation process comprising:

(a) inoculating a bacteria strain of the genus Methanobacterium in a fermentation media which comprises at least inorganic salts, carbon sources, nitrogen sources and micro-flora of methane fermentation which are capable of liquifying the carbon sources and convert the carbon sources to low molecular weight materials which are utilized by the bacteria strain for methane fermentation, said bacteria strain having all the identifying characteristics of strain ST-23 (FERM BR-44),
(b) maintaining the fermentation media at a temperature of 25.degree. to 45.degree. C. whereby methane is produced, and
(c) collecting the produced methane from the fermentation media.

Dependencies are inferred from the claim text.

Methane fermentation

Life of this patent

Methane fermentation

Life of this patent

Abstract

Claims10