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J R Gohlke

Publications and source records attributed to J R Gohlke.

6 recordsLinked to original sources
PubMed1981

Rapid identification of Enterobacteriaceae with microbial enzyme activity profiles.

A total of 539 clinical isolates belonging to 10 species of the Enterobacteriaceae family were identified by enzyme activity profiles within 30 min of test inoculation. Each isolate was grown at 37 degrees C for 18 h on Mueller-Hinton agar and suspended to an optical density of 200 Klett units on 0.85% saline. Enzyme activity profiles were obtained by inoculating 18 fluorogenic substrates with the standardized bacterial suspension and monitoring initial rates of hydrolysis over the first 30 min of analysis. Individual enzyme activity profiles were entered into a coded data bank, and identifications were based on the Bayesian theory of probabilities. At a confidence level of 95%, five species were identified with a greater than 90% efficiency, three species were identified between 83 and 88% efficiency, and two species demonstrated a 72 and 75% efficiency of identification. The enzyme activity profile method of bacterial identification is rapid, easily automated, and reproducible.

Aminopeptidases↗
PubMed1975

Levels and rates of synthesis of ribosomal ribonucleic acid, transfer ribonucleic acid, and protein in Neurospora crassa in different steady states of growth.

The levels of ribosomes, tRNA molecules, and total protein per genome in Neurospora mycelia have been determined in eight different conditions of exponential growth. By increasing the rate of growth the number of ribosomes per genome increases dramatically while the level of total protein remains almost unchanged and the level of tRNA increases only slightly. The rates of synthesis of each of the macromolecules have been estimated. Increasing the rate of growth (mu) up to 0.5, the ratio between the rates of synthesis of tRNA and rRNA decreases reaching a constant value. The equations that best describe the dependence of the rate of synthesis of the macromolecules on the rate of growth (mu) have been determined. The rate of rRNA synthesis (rr), expressed as nucleotides polymerized, min- minus 1 per genome, is given by the equation: rr equals 6.51 times 10-7 mu-2-19. The rate of protein synthesis (rp), expressed as amino acids polymerized, min- minus 1 per genome is given by the following relationship: rp equals -1.43 times 10-7 + 3.43 times 10-8 mu. The equation describing the tRNA synthesis (rt) expressed as nucleotides, min- minus 1 per genome is rt equals 6.45 times 10-5 times exp 2.30 mu; however, more accurate determinations appear to be required for a firmer assignment of this latter equation. The significance of these equations for the studies on the regulation of rRNA and protein synthesis is discussed. For instance the rate of rRNA synthesis may set the limit for the maximal growth rate attainable by a cell, as the maximal rate of rRNA synthesis that may take place in a given cell is limited by the degree of redundancy of the rRNA genes.

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