Biotransformation and toxicity of aniline and aniline derivatives in cyanobacteria

Agmenellum quadruplicatum strain PR-6 and Oscillatoria sp. strain JCM grown photoautotrophically in the presence of aniline metabolized the aromatic amine to formanilide, acetanilide and p-aminophenol. The metabolites were isolated by either thin-layer, gas-liquid or high pressure liquid chromatography and identified by comparison of their chromatographic, ultraviolet absorbance and mass spectral properties with those of authentic compounds. The toxicity of aniline derivatives towards Agmenellum quadruplicatum strain PR-6 indicated that the cyanobacterium was extremely sensitive to o-, m- and p-aminophenols, and phenylhydroxylamine.Abbreviations TLC thin layer chromatography - HPLC high pressure liquid chromatography - GC/MS gas chromatography/mass spectrometry - m/e mass to charge ratio     

A dynamic kinetic model of the activated sludge process

A kinetic model has been developed which describes the dynamic response of activated sludge to changes in substrate concentration. The well known phenomenon of “growth-rate hysteresis” can be explained by the simple yet biologically reasonable hypotheses of the model. Experimental results have verified the model quantitatively.     

Viscoelastic behavior of mammalian DNA.

The viscoelastic behavior of rat 9L cellular DNA was studied as a function of the detergent used for lysis, the pH and duration of lysis, and gamma ray dose. For nondenaturing lysis conditions, a model of the DNA was proposed to account for the effects of these agents on the viscoelastic retardation time. It was concluded that these agents affect the hydrodynamic radius of the DNA rather than its molecular weight. For denaturing lysis conditions, molecular weights calculated from the relaxation time were consistent with those calculated from alkaline sucrose sedimentation profiles.     

New evidence for taurine biosynthesis in man obtained from 18O2 inhalation studies

The ability of adult humans to synthesize taurine was assessed by measurement of the 18O content of urinary taurine in eight subjects following 60 minutes inhalation of 18O2 (97% 18O). All subjects had at least one 3-hour urine collection in which the mole ratio of 18O-taurine to taurine was at least three times greater than the standard deviation of the stable isotope measurement. The peak mole ratios of 18O-taurine/16O-taurine ranged from 0.0075 to 0.015. These data indicated that adult human subjects have a significant ability to synthesize taurine.