Koka Jayasimhulu

Biodegradation of carbazole by Ralstonia sp. RJGII.123 isolated from a hydrocarbon contaminated soil

The use of microorganisms for bioremediation of contaminated soils may be enhanced with an understanding of the pathways involved in their degradation of hazardous compounds. Ralstonia sp. strain RJGII.123 was isolated from soil located at a former coal gasification plant, based on its ability to mineralize carbazole, a three-ring N-heterocyclic pollutant. Experiments were carried out with strain RJGHII.123 and 14C-carbazole (2 mg/L and 500 mg/L) as the sole organic carbon source. At 15 days, 80% of the 2 mg/L carbazole was recovered as CO2, and <1% remained as undegraded carbazole, while 24% of the 500 mg/L carbazole was recovered as CO2 and approximately 70% remained as undegraded carbazole. Several stable intermediates were formed during this time. These intermediates were separated by high performance liquid chromatography (HPLC) and were characterized using high resolution mass spectroscopy (HR-MS) and gas chromatography - mass spectroscopy (GC-MS). At least 10 ring cleavage products of carbazole degradation were identified; four of these were confirmed as anthranilic acid, indole-2-carboxylic acid, indole-3-carboxylic acid, and (1H)-4-quinolinone by comparison with standards. These data indicate that strain RJGII.123 shares aspects of carbazole degradation with previously described Pseudomonas spp., and may be useful in facilitating the bioremediation of NHA from contaminated soils.

The free amino acid pool in Leishmania tropica promastigotes

The principal constituents of the free amino acid pool in Leishmania tropica promastigotes include alanine, glycine, serine, threonine, alpha-aminobutyric acid and ethanolamine. Changes in levels of the pool constituents during starvation, nutrient supplementation and treatment with a metabolic inhibitor (sodium fluoride) were followed. Several enzymes capable of converting amino acids to Krebs cycle intermediates were identified. It is suggested that during prolonged starvation which is accompanied by enhanced proteolysis, these enzymes enable the cells to utilize endogenous amino acids as carbon and energy sources. This is compatible with previous reports that Leishmania promastigotes in culture could grow on amino acids as growth substrates when carbohydrates are totally lacking.

Neutral Lipids, their Fatty Acids, and the Sterols of the Marine Ciliated Protozoon, Parauronema acutum

Abstract The neutral lipids and their fatty acids and the sterol fractions of the marine ciliated protozoon, Parauronema acutum, were characterized. The neutral lipids consisted of triglycerides (30%), sterols (29%), free fatty acids (24%), steryl esters (9%), and diglycerides (8%) and small amounts of fatty alcohols. The fatty acid profiles of these lipids were very similar although quantitative differences were detected. Saturated fatty acids, primarily 14:0, 16:0, and 18:0 constituted 20–30% of the total. Unsaturated fatty acids containing one to three double bonds, primarily 18:1(9), 18:2 (9,12), 18:3 (9, 12, 15) and 20:3 (11, 14, 17), constituted 35–50% of the total. Highly unsaturated fatty acids, 18:4 (6, 9, 12, 15), 20:5 (5, 8, 11, 14, 17) and 22:6 (4, 7, 10, 16, 19), constituted 16–25% of the total. The fatty alcohols consisted of 14:0 (2%), 16:0 (66%), 18:0 (3%), 20:0 (8%), and 22:0 (21%). The sterols of Parauronema acutum consisted of cholesterol (53%), campesterol (32%), desmosterol (7%), and β-sitosterol (8%).

Identification of C31 and C32 Sterols in Pneumocystis carinii hominis‐Infected Human Lungs

SUMMARY Two sterols in autopsied whole lung specimens obtained from Pneumocystis carinii pneumonia patients were detected by gas‐liquid chromatography and their structures were elucidated by mass spectrometry and nuclear magnetic resonance spectrometry. Both were in the lanosterol series; the C31 sterol, with a methyl group at C‐24, was identified as euphorbol, and the more abundant C32 sterol, with an ethyl group at C‐24, is given the trivial name pnemocysterol.

Reaction of [fac-(CO)3(dppe)Mn(OH2)]BF4 with 13CO and conversion of the resulting tetracarbonyl to labeled isocyanato complexes

Abstract When 13 CO is bubbled into a CH 2 Cl 2 solution of [ fac -(CO) 3 (dppe)Mn(OH 2 )]BF 4 (dppe=Ph 2 PCH 2 CH 2 PPh 2 ), the aqua ligand is replaced by the CO to give the tetracarbonyl, [(CO) 3 ( 13 CO)(dppe)Mn]BF 4 ( 1 ) in which the labeled CO appears exclusively at the site originally occupied by the aqua ligand. Treatment of this aqua complex with NaN 3 leads to an approximate 50:50 mixture of isocyanates corresponding to attack, with equal probability, at either the labeled CO or its axial partner. Neither of the two CO groups trans to the P atoms in the tetracarbonyl are affected.