Intra- and intraspecific variation of Juniperus virginiana and J. scopulorum seedling based on volatile oil composition

Comparisons of volatile oil constituents were made among samples of juvenile foliage collected from 78 Juniperus virginiana and 28 J. scopulorum seedling sources growing in a “common garden” environment. A canonical variate analysis, a principal coordinates analysis and hybrid distance diagrams of 30 chemical characters indicate both taxa are good species and that they exhibit clinical patterns in the Great Plains. In addition, a possible evoluitonary link between present-day J. virginiana populations in southern Texas and ancient J. scopulorum populations is indicated.     

Isolation and characterization of nuclear genes coding for subunits of the yeast ubiquinol-cytochrome c reductase complex

Nuclear genes coding for the M_r 17000, 14000 and 11000 subunits of the ubiquinol-cytochrome c reductase complex (complex III) in yeast have been isolated from a clone bank of yeast nuclear DNA by use of a mRNA hybridization-competition assay. This is based on our observations that levels of mRNAs for these subunits are much reduced during glucose repression and in cytoplasmic petite mutants and the procedure should be of general application for the isolation of other inducible or repressible genes coding for mRNAs present at low levels in the cell. A first characterization of the clones is presented. The genes are not closely linked in the genome and those coding for M_r 14000 and 11000 subunits are present in unique genomic environments, which suggests that there are only single copies of each in the nuclear genome.     

Reverse-phase high-pressure liquid chromatography of uridine diphosphate N-acetylmuramyl peptide precursors of bacterial cell wall peptidoglycan

A series of seven different UDP-N-acetylmuramyl peptide precursors of bacterial cell wall peptidoglycan was examined by reverse-phase high-pressure liquid chromatography. Mixtures of these compounds were successfully and rapidly analyzed by using a Waters μBondapak C₁₈ column as a stationary phase and isocratic elutions with 0.05 m ammonium phosphate or formate buffers of appopriate pH. Furthermore, their accurate quantitation could also be readily achieved by reverse-phase high-pressure liquid chromatography. All these techniques should be extremely useful for the purification of these compounds and for a wide range of biochemical studies concerning the cytoplasmic steps of the biosynthesis of peptidoglycan.     

Virulence ofEscherichia coli strains isolated from urine of patients with acute cystitis and from faeces of healthy women

E. coli strains were isolated from the urine of patients with acute cystitis in general practice and from the faeces of a comparable reference group of healthy individuals. These strains were serotyped and tested for virulence in an experimental mouse model. Of 30 cystitis-strains 18 were virulent, and of 30 faeces-strains 15 were virulent. It is concluded that the cystitis-strains were not more often virulent than the faeces-strains. O antigens commonly found among urinaryE. coli isolates were present in 60% of the cystitis-strains and in 37% of the faeces-strains. K antigens commonly found in urinaryE. coli strains were present in 33% of the cystitis-strains and in 12% of the faeces-strains. Neither the presence of common urinary O-antigens, nor the presence of common urinary K antigens could be associated with virulence of the isolated strains. However, it is suggested that certain O and K antigens (O2, O6, K23) may be associated with virulence for the urinary tract.     

Trehalase activity in extracts of Phycomyces blakesleeanus spores following the induction of germination by heat activation

The heat activation of trehalase in extracts of sporangiospores of Phycomyces blakesleeanus, following the induction of germination by heat activation and the gelatinization of potato starch granules were studied under different conditions in order to discriminate between several phenomena as possible triggers in the activation of trehalase.Short-chain alcohols (from methanol to pentanol) lower the activation temperature of trehalase while long-chain alcohols (from heptanol to nonanol) raise it. Short-chain alcohols also lower the gelatinization temperature of potato starch granules, while long-chain alcohols, hexanol and heptanol have hardly any influence on the gelatinization temperature. Octanol raises the gelatinization temperature. More polar phenols lower the activation temperature of trehalase, while more apolar phenols will raise it. The gelatinization temperature of starch granules is more lowered by the polar polyphenols than by the more apolar phenols.The effect of high pressure on starch gelatinization was investigated in order to compare data from such a model system with the data on trehalase activation.The gelatinization temperature of starch granules is shifted upwards with about 3–5 K/1000 atm (1.013×10⁵ kPa). Pressures higher than 1500 atm do not further increase the gelatinization temperature. However, no reversal of the effect, as occurs with protein conformational changes, is seen with pressure up to 2500 atm. Also for trehalase activation we find a continuous upward shift of the activation temperature with about 5–9 K/1000 atm. These data are in agreement with a thermal transition in a polysaccharide matrix, being the trigger in the heat activation of trehalase.     

Survival of microorganisms after drying and storage

Bacteria, yeasts and fungi suspended in a dextran solution were added to ampoules containing strips of filter paper which were dried without vacuum conditions. The ampoules were sealed and stored in the dark at room temperature. Viability counts were made of the original suspension immediately after drying and after storage periods of 3–48 months. Although bacterial cultures of many genera did not show much resistance against dry conditions, bacteria of 13 other genera had survived well or moderately after 4 years of storage. Most of the dried yeast cultures had survived after this period. Of the 16 fungal genera tested, species of 6 genera exhibited growth after 4 years. Results of this study were compared with those of two other preservation methods by which the same microorganisms were used.     

Fermentative Conversion of Cellulose to Acetic Acid and Cellulolytic Enzyme Production by a Bacterial Mixed Culture Obtained from Sewage Sludge

A simple procedure that uses a cellulose-enriched culture started from sewage sludge was developed for producing cellulolytic enzymes and converting cellulose to acetic acid rather than CH₄ and CO₂. In this procedure, the culture which converts cellulose to CH₄ and CO₂ was mixed with a synthetic medium and cellulose and heated to 80°C for 15 min before incubation. The end products formed were acetic acid, propionic acid, CO₂, and traces of ethanol and H₂. Supernatants from 6- to 10-day-old cultures contained 16 to 36 mM acetic acid. Cellulolytic enzymes in the supernatant were stable at 2°C under aerobic conditions for up to 4 weeks and had the ability to hydrolyze carboxymethyl cellulose, a microcystalline cellulose, cellobiose, xylan, and filter paper to reducing sugars.