Rapid degradation of the triazinone herbicide metamitron by a Rhodococcus sp. isolated from treated soil

N.R. PAREKH, A. WALKER, S.J. ROBERTS AND S.J. WELCH. 1994. Seven bacterial isolates which degraded the herbicide metamitron (3-methyl-4-amino-6-phenyl-1,2,4-triazin-5-one) were obtained from field-enhanced soil by liquid enrichment culture. All isolates appeared to be identical and a representative, 0246b, was identified as a Rhodococcus sp. by cell wall and fatty acid analyses. This isolate degraded metamitron as the sole source of carbon within 24 h at 25C and this is the first report of a bacterium capable of growing with metamitron as the sole source of carbon. Metamitron was degraded less rapidly when it was the sole source of both carbon and nitrogen. The rate and extent of degradation was affected by the presence and type of additional sources of carbon and nitrogen in the culture medium. In studies with [¹⁴C]-phenyl-labelled metamitron Rhodococcus sp. 0246b partly mineralized the phenyl ring.     

Purification and properties of alpha-galactosidase from Klebsiella Sp. No. PG-2

alpha-Galactosidase has been purified from Klebsiella Sp. No. PG-2, a bacterium isolated from rat small intestine, using calcium phosphate gel, DEAE-cellulose column chromatography and gel filtration technique. About 130-fold increase in specific activity was observed, the pH optimum of 6.5-7.0 characterizes the enzyme as neutral alpha-galactosidase. The optimum temperature was 37 degrees C and the energy of activation was 11,856 cal/mole. Km values obtained for raffinose, mellibose, stachyose and p-nitrophenyl-alpha-D-galactopyranoside were 20.0, 6.6 33.3 and 4.0 mM respectively. The activity was inhibited by p-CMB; iodoacetate, Ag2+, Hg2+, Cu2+, Pb2+ and galactose. Examination of the enzyme activity indicated that the enzyme is cytosolic and is inducible in nature.     

Steroid interference in iron-cholesterol reactions: A comparative study

Interference from various physiological and non-physiological steroids in the spectrophotometric determination of cholesterol by the Zak method (ferric chloride) and the method of Parekh and Jung (ferric acetate) was quantitatively measured. Contribution of the steroids at the specific absorption maxima of the cholesterol assays was determined by employing the steroids (40 mg/dl) alone, or added to a serum pool of known cholesterol content. The results show that the method of Parekh and Jung is less influenced by the presence of steroids than the Zak method. Observations on the structural specificity of the iron-cholesterol reaction are discussed.     

Comparing the glycosylation patterns of recombinant glycoproteins.

The glycosylation profile of a recombinant glycoprotein can not only significantly affect its therapeutic profile, but is also extremely sensitive to cell-culture and purification conditions. To define glycosylation patterns and to ensure consistency of recombinant glycoproteins among different preparations requires highly sensitive and reproducible analytical methods that can be used routinely. New strategies and instrumentation are being developed which should allow such analysis to be largely automated.