Propagation of microbial cells on single carbon products

DETAILED DESCRIPTION It is an object of the present invention is to provide an anaerobic process for propagation of microbial cells with high vitamin and protein value on single carbon products to provide microbial cells and valuable fermentation products.
It is a further object to disclose our discovery that anaerobic, acidogenic microorganisms can be grown on single carbon products to produce higher carbon products such as acetic acid and butyric acid.
In the method of the present invention an acidogenic microorganism, such as Butyribacterium methylotrophicum, is anaerobically grown in a medium containing a single carbon product such as methanol, CO or synthesis gas to obtain microbial cells, and acids such as acetic and butyric acids.
The preferred acidogenic microorganism is Butyribacterium methylotrophicum which is a methylotrophic, acidogenic, anaerobic bacterium that was first isolated from a sewage digestor in Marburg, Federal Republic of Germany.
The neotype strain of the species is a pure culture of the Marburg strain which has been deposited in the American Type Culture Collection (Rockville, Md) accession number ATCC 33266.
It is a mesophilic, Gram-positive, nonmotile, pleomorphic rod that perfoms homoacetic, homobutyric, or heteroacidic fermentations.
Cell morphology varies from single or paired straight rods to rudimentarily branched rods, club-shaped cells, or oval refractile cells.
Cell heat resistance correlated with the presence of a few refractile cells.
Electron micrographs of thin sections revealed a thick monolayered cell wall and an atypical spore structure.
The DNA base composition was 48.
8.
+-.
0.
2 mol% guanosine plus cytosine.
Corrinoid levels varied from 0.
35.
+-.
0.
16 to 7.
9.
+-.
1.
6 .
mu.
g/mg cell dry weight when cells were grown on glucose or methanol/acetate/CO.
sub.
2 respectively.
Batch growth in a mineral medium that contained 0.
1% yeast extract, N.
sub.
2 /CO.
sub.
2, 100 mM methanol, and 50 mM Na acetate displayed a 20 h doubling time, final A.
sub.
540 of 0.
9, butyric acid yield of 25 mM, and