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A procedure for fractional determination of soybean sterols is presented. Sterols in lipid extracts were fractionated into four classes, fatty acid esters, the free form, acylated glucosides and non-acylated glucosides, by Florisil column chromatography. Sterol contents in the four classes were determined colorimetrically with ferric chloride-perchloric acid reagent. Before the colorimetry, the fatty acid ester fraction was hydrolyzed with ethanolic KOH, and the sterol was isolated as tomatinide. The free sterol fraction was directly treated with tomatine solution. The tomatinides were dissociated with dimethyl sulfoxide. To avoid the contamination of pigments from the acylated glucoside fraction, the second Florisil column was rinsed with diethyl ether between the elution with the first solvent (0 to 50% diethyl ether in n-heхane) and that with the second solvent (0 to 30% methanol in diethyl ether).

Riboflavin(RF)-productivity of reseoflavin(RoF)-resistant strains of Staphylococcus aureus, Bacillus pumilus and Bacillus subtilis was studied. Two of three types of resistant strains of S. aureus were shown to produce more RF than the parent strains. Resistant strains of B. pumilus were also RF-producing, and one type (fp) of the resistant strains from B. subtilis HW produced a large amount of RF in the culture medium. The hereditary stability of RF-producing properties of the fp type was also shown.