title: Humic-like substances of bacterial origin. II. Fractionation of the bacterial humic-like substances by gel filtration on sephadex gels.
abstract: Humic-like substances obtained from cells of Pseudomonas acidovorans were separated on Sephadex G-25 into two groups of substances of different molecular weight. The substances of the molecular weight  greater than 5000 were successively separated on Sephadex gels G-50, G-75, G-100. Five fractions of different molecular weight were obtained, the percentage of which varied depending on the media used and time of incubation of the bacteria. Most (38%--46%) of the compounds contained in the bacterial humic acids were of approximate molecular weight of 40 000--50 000. The distribution of the fractions in the bacterial "humic-acids" was compared with those of the humic acid made by Fluka A. G. The synthetic humic acid contained most (approximately 40%) of the compounds of approximate molecular weight of 8000--10 000. In the bacterial and synthetic material the content of the compounds with the molecular weight above 100 000 was very similar (8%--12%).
mesh_terms: D002850:Chromatography, Gel; D006812:Humic Substances / Q000032:analysis*; D008970:Molecular Weight; D011549:Pseudomonas / Q000032:analysis*; D012988:Soil Microbiology
chemical_list: D006812:Humic Substances