Molecular size fractionation of soil humic acids using preparative high performance size-exclusion chromatography.

High performance size-exclusion chromatography (HPSEC) is useful for the molecular size separation of soil humic acids (HAs), but there is no method available for various HAs with different chemical properties. In this paper the authors propose a new preparative HPSEC method for various soil HAs. Three soil HAs with different chemical properties were fractionated by a Shodex OHpak SB-2004 HQ column with 10mM sodium phosphate buffer (pH 7.

Aflatoxin non-productivity of Aspergillus oryzae caused by loss of function in the aflJ gene product.

Aspergillus oryzae, although closely related to Aspergillus flavus, does not produce aflatoxin (AF). A. oryzae RIB strains can be classified into three groups (group 1-3) based on the structure of the AF biosynthesis gene homolog cluster (AFHC).

Optimization of conditions for high-performance size-exclusion chromatography of different soil humic acids.

A method of high-performance size-exclusion chromatography (HPSEC) for a wide variety of soil humic acids (HAs) was developed. Two types of soil HAs (Cambisol and Andosol HAs), which have substantially different chemical properties, showed different effects of salt and organic solvent concentrations in the eluent on chromatograms. A Shodex OHpak SB-805 HQ column with 10 mM sodium phosphate buffer (pH 7.