Localization of quantitation of the ornithine lipid of Thiobacillus thiooxidans.

The ornithine lipid of Thiobacillus thiooxidans was found to be 1.9% of the total polar lipids. Approximately 80% of this lipid was found to be localized in the outer membrane.

The interpretation of the mass spectrum of an ornithine-containing lipid from Thiobacillus thiooxidans.

The electron impact mass spectrum of a previously identified ornithine-containing lipid from Thiobacillus thiooxidans has been interpreted using exact mass measurements, low and high energy ionization, and defocused metastable studies. The spectrum, which did not contain a molecular ion for the intact lipid, was consistent with cyclization of the ornithine zwitterionic moiety with elimination of water to give 3[3'-(11,12-methylene-2-hydroxyoctadecanoxy)hexadecanylamine]-2-piperidone. Production of this sufficiently volatile species for mass spectral analysis was accomplished by gentle pyrolysis in the mass spectrometer source. The spectrum can be understood to arise by three primary decompositions which serve to separate the two fatty acid constituents. The remainder of the spectrum is consistent with the expected fragmentations of these constituents.

Physical and chemical studies of Thiobacillus ferroxidans lipopolysaccharides.

The lipopolysaccharides (LPS) of the obligate acidophile Thiobacillus ferroxidans grown on iron, sulfur, and glucose as energy sources were examined for various physical and chemical properties. Both qualitative and quantitative variation were found among the three preparations. The LPS extracted from iron-grown cells (Fe-LPS) contained less than 3% protein compared to 18 to 25% in LPS extracted from either sulfur-grown cells (S-LPS) or glucose-grown cells (G-LPS). S-LPS showed two distinct sedimentable species, 61S and 9.3S, which could be fractionated on a column of Sepharose 4B. The relative densities of both S-LPS and G-LPS were found to be significantly greater than that of Fe-LPS. Spectral differences were noted when each LPS was reacted with a carbocyanine dye. Fe-LPS showed a single absorbance maximum at 472 nm, S-LPS displayed its maximum at 650 nm, and G-LPS showed two maxima, the first at 468 nm and the other at 655 nm. Analysis of the methyl ester derivatives of the LPS fatty aicds using gas chromatography-mass spectrometry revealed the presence of a very stable species, tentatively identified as a methoxy methyl ester with a formula of CH3-3-C10H10-COOCH3, as the major component from each LPS. beta-Hydroxymyristic acid was found only in Fe-LPS.

Purification and some properties of cytochrome c-552 from a sulfur-oxidizing bacterium, Thiobacillus thiooxidans.

A soluble cytochrome c-552 from Thiobacillus thiooxidans was highly purified and its physico-chemical properteis were studied. The absorption maxima were at 552,523,418 nm in the reduced from and at 412 nm in the oxidized form. The pyridine hemochrome spectrum was the same as that of other cytochromes c. The molecular weight, estimated by the gel filtration method, was found to be 12,600. The isoelectric point was determined to be 9.2-9.3 by the electrofocusing technique. The standard oxidation-reduction potential of this cytochrome was +0.247 V.

Fatty acids of Thiobacillus thiooxidans.

Fatty acid spectra were made on Thiobacillus thiooxidans cultures both in the presence and absence of organic compounds. Small additions of glucose or acetate had no significant effect either on growth or fatty acid content. The addition of biotin had no stimulatory effect but did result in slight quantitative changes in the fatty acid spectrum. The predominant fatty acid was a C(19) cyclopropane acid.