Enzymes of carbohydrate metabolism in the developing rice grain

The levels of reducing and nonreducing sugars, starch, soluble protein, and selected enzymes involved in the metabolism of sucrose, glucose-1-P, and glucose nucleotides were assayed in dehulled developing rice grains (Oryza sativa L. line IR1541-76-3) during the first 3 weeks after flowering. The level of reducing sugars in the grain was highest 5 to 6 days after flowering. The level of nonreducing sugars and the rate of starch accumulation were maximum 11 to 12 days after flowering, when the level of soluble protein was also the highest. The activities of bound and free invertase, sucrose-UDP and sucrose-ADP glucosyltransferases, hexokinase, phosphoglucomutase, nucleoside diphosphokinase, and UDP-glucose and ADP-glucose pyrophosphorylases were high throughout starch deposition, and were maximum, except for nucleoside diphosphokinase which did not increase in activity, between 8 and 18 days after flowering. Soluble primed phosphorylase and ADP glucose-α-glucosyltransferase (starch synthetase) were both present during starch accumulation. Phosphorylase activity was at least 2-fold that of soluble starch synthetase but the synthetase followed more closely the rate of starch accumulation in the grain. The activity of starch synthetase bound to the starch granule also increased progressively with increased starch content of the grain.     

Ontogenetic changes in haemoglobins in roach, Rutilus rutilus (L.) and rudd, Scardinius erythrophthalmus (L.)

The haemoglobins and globins of the roach, Rutilus rutilus (L.) and the rudd, Scardinius erythrophthalmus (L.) have been studied by starch gel electrophoresis. At all stages of development studied, the roach and rudd haemoglobins give a similar electrophoretic pattern, the young fish of about 2 cm standard length possessing three separate haemoglobins, of which two bands only persist in the adult. The evolutionary significance of multiple haemoglobins in fishes is briefly discussed.     

Rapid Methods for Biochemical Testing of Anaerobic Bacteria

Rapid biochemical tests for nitrate, indole, gelatin, starch, esculin, and o-nitrophenyl-beta-D-galactopyranoside were performed on 112 strains of anaerobic bacteria. All tests were incubated under aerobic conditions, and results were recorded within 4 h. The tests for nitrate, indole, and starch showed a 95% or greater correlation when compared to the standard biochemical tests. Tests for esculin and gelatin showed an agreement of 86 and 77%, respectively. PathoTec test strips for nitrate, indole, esculin, o-nitrophenyl-beta-D-galactopyranoside, Voges-Proskauer, and urease were also tested and showed encouraging results.     

Epidemiological Tracing of Pseudomonas aeruginosa: Antibiogram and Serotyping

The spread of a particular strain of Pseudomonas aeruginosa through a pediatric burn unit was monitored using serological typing and antibiotic susceptibility data.     

Comparison of Macroscopic Examination, Routine Gram Stains, and Routine Subcultures in the Initial Detection of Positive Blood Cultures

Blood was cultured in two vaccum bottles containing Columbia broth with sodium polyanethol sulfonate and CO₂. Filtered air was admitted to one bottle, and the bottles were incubated at 35 C until growth was detected or for a maximum of 7 days. Bottles were examined daily for macroscopic growth. Gram stains were made routinely on the 1st, 4th, and 7th days, and samples were routinely subcultured to sheep blood agar (incubated in GasPak jar) and chocolate agar (incubated in CO₂) on the 1st and 4th days of incubation. Of 1,127 positive blood cultures, 65% were first detected by macroscopic examination, 23% were first detected by Gram stain, and 12% were first detected only by subculture.     

Evaluation of a New Incubation-Type Indole Strip Test

A total of 189 of Enterobacteriaceae and three strains of Clostridium perfringens were tested with a new incubation-type indole paper strip. This 4-hr incubation test gave the same results as a standard 48-hr indole test, except with some strains of Proteus rettgeri. Results with P. rettgeri varied somewhat according to the medium upon which the organisms had been grown.     

Physiology of the Yellow-Green 6 Gene in Tomato: A Possible Interrelationship between the Phenotypic Expressions of the Yellow-Green 6 Gene Mutation and the Gibberellins

The yellow-green 6 (yg(6)) mutation in tomato (Lycopersicon esculentum Mill.) is controlled by a single recessive gene with pleiotropic effects. The syndrome of characters associated with the mutation are enhanced stem elongation, reduced chlorophyll content and absence of detectable anthocyanins. We now have shown that the mutant also has fewer lateral roots than the wild type and higher l-phenylalanine ammonia-lyase (E.C. 4.3.1.5) activity than the normal tomato. These traits of the mutant closely resemble those induced in many plants by the application of gibberellic acid which suggests that the phenotypic expressions of the mutation might in some manner be related to the endogenous level or activity of the gibberellins. In support of this premise, data are presented which show that the characters of the mutant can be induced in the wild type tomato by application of gibberellic acid. Conversely, several traits of the wild type can be induced in the mutant by an inhibitor of gibberellin hiosynthesis, Phosfon. In addition, an embryoless barley half-seed bioassay for the gibberellins and gas-liquid chromatography indicated that the mutant contained at least three times as much total gibberellin as the wild type plant.     

Transport of Vitamin B12 in Escherichia coli: Common Receptor Sites for Vitamin B12 and the E Colicins on the Outer Membrane of the Cell Envelope

The first step in the transport of cyanocobalamin (CN-B(12)) by cells of Escherichia coli was shown previously to consist of binding of the B(12) to specific receptor sites located on the outer membrane of the cell envelope. In this paper, evidence is presented that these B(12) receptor sites also function as the receptors for the E colicins, and that there is competition between B(12) and the E colicins for occupancy of these sites. The cell strains used were E. coli KBT001, a methionine/B(12) auxotroph, and B(12) transport mutants derived from strain KBT001. Colicins E1 and E3 inhibited binding of B(12) to the outer membrane B(12) receptor sites, and CN-B(12) protected cells against these colicins. Half-maximal protection was given by CN-B(12) concentrations in the range of 1 to 6 nM, depending upon the colicin concentration used. Colicin E1 competitively inhibited the binding of (57)Co-labeled CN-B(12) to isolated outer membrane particles. Functional colicin E receptor sites were found in cell envelopes from cells of only those strains that possessed intact B(12) receptors. Colicin K did not inhibit the binding of B(12) to the outer membrane receptor sites, and no evidence was found for any identity between the B(12) and colicin K receptors. However, both colicin K and colicin E1 inhibited the secondary phase of B(12) transport, which is believed to consist of the energy-coupled movement of B(12) across the inner membrane.     

Organisms Encountered in Urine Cultures over a 10-Year Period

Urinary isolates from 1961 to 1970 were surveyed. Forty-four different species were encountered in urine cultures. The most frequently isolated were Escherichia coli, Klebsiella, enterococci, Pseudomonas aeruginosa, and Proteus mirabilis.