Periodicity of bud bursting in willow (Salix viminalis) as affected by growth regulators

Saunders, P. F. and Barros, R. S. 1987. Periodicity of bud bursting in willow ( Salix viminalis ) as affected by growth regulators.
Lateral vegetative buds of willow ( Salix viminalis L.) were only innately dormant for 3–5 weeks in October; during this time their apices were correlatively inhibited by the bud leaflets. Exogenous gibberellins stimulated the opening of cultured buds when the plants were dormant or entering dormancy. As dormancy was being released, however, cultured buds became more responsive to exogenous cytokinins. Thus the demand for gibberellins and cytokinins for bud opening seemed to be sequential rather than simultaneous. Dormant buds cultured in the presence of abscisic acid remained unopened, but they opened after a chilling treatment. Subsequent growth of such buds as measured by dry matter accumulation, was observed only if a cytokinin was added to the medium.     

Cloning and expression in Escherichia coli of a cellulase gene from Ruminococcus flavefaciens.

An endoglucanase gene of Ruminococcus flavefaciens FD1 was cloned on the vector pEcoR251 to form the recombinant plasmid pMEB200. The cloned endoglucanase gene showed carboxymethylcellulase enzyme activity but no degradation of Avicel (FMC Corp., Philadelphia, Pa.) or filter paper. Carboxymethylcellulase activity was found during the late-exponential-growth phase and accumulated in the periplasmic fraction. Enzyme production was not subject to catabolite repression by glucose.     

Production of ethanol by immobilized Saccharomyces bayanus in an extractive fermentation system

An extractive fermentation system using immobilized yeast cells was developed to study the ethanol production at high sugar concentrations. Organic acids were used as extracting solvents of ethanol and their toxicity was tested in free and k-carrageenan entrapped cell preparations. Immobilization seems to protect cells against solvent toxicity, when long-chain organic acids, e.g., oleic acid, were used, probably due to steric and diffusional limitations, the free cells not being viable at high oleic acid concentrations. The entrapped cells also present a higher metabolic activity than their free counterparts at high glucose concentrations. A solution of 300 g/L of glucose was totally fermented by the immobilized yeast cells, which when free cannot normally convert more than 200 g/L. In situ recovery of ethanol by oleic acid in a batch immobilized cell system led to higher ethanol productivities and to the fermentation of 400 g/L, when an oleic acid/medium ratio of 5 was used.     

A complex balanced chromosomal rearrangement in repeated abortions

Summary A double balanced reciprocal translocation involving four chromosomes, t(1;19;6;14) (1p11; 19p11; 6q25; 14q21), was found in the phenotypically normal husband in a couple referred because of repeated abortions. Reciprocal translocations, t(6;14), had been transmitted by his mother, his father being apparently homozygous for a translocation comprising pairs 1 and 19-t(1;19)(1;19). The genetic consequences of this complex chromosomal rearrangement are analyzed.     

Protein kinase C from small intestine epithelial cells

Protein kinase C activity has been identified in cytosolic and membrane fractions from rat and rabbit small intestine epithelial cells. The cytosolic fraction comprised about the 75% of total activity. Protein kinase C activity was resolved from other protein kinase activities by ion exchange chromatography. Phosphatidylserine or phosphatidylinositol were required for protein kinase C to be active. In addition, the activity was enhanced by the presence of a diacylglycerol. Diolein and dimyristin were the most effective (13-14 fold activation). In the presence of phosphatidylserine and diolein, the Ka for activation by Ca2+ was 10(-7)M. The phorbol ester TPA substituted for diacylglycerol in activating protein kinase C. Brush border and basolateral membranes contained protein kinase C activity, although the specific activity of the basal lateral membranes was four-fold higher than the specific activity of the brush border membranes. The presence of PKC in small intestine epithelial cells might have important implications in the Ca2+ mediated control of ionic transport in this tissue.     

Production and Regeneration of Thiobacillus ferrooxidans Spheroplasts

We have isolated a metabolite of territrem, designated territrem B', from the chloroform extract of a rice culture of Aspergillus terreus 23-1 by using the same isolation procedure as that for territrems A, B, and C. The present isolation procedure gave about 10 mg of territrem B' from 4 kg of rice culture per batch. Analysis of the high-resolution mass spectrum showed that the molecular composition of territrem B' is C29H34O10 (found, 542.2167; required, 542.200). Some results of physicochemical and acute tests are presented in this paper. Single-crystal X-ray diffractometry of territrem B' indicated that the three-dimensional structure of territrem B' has not changed significantly from that of territrem B except for the insertion of one oxygen atom into territrem B to make an additional pyron ring in the E ring. The tremorgenic activity of territrem B' is greatly reduced as tested by intraperitoneal injection in mice.     

Reaction of ethyl 2-amino-4,6-O-benzylidene-2-deoxy-d-gluconate with acetylenic esters

Ethyl 2-amino-4,6-O-benzylidene-2-deoxy-d-gluconate adds to acetylenic esters to give sugar enaminones. The following acetylene derivatives have been employed: methyl propiolate, ethyl phenylpropiolate, and dimethyl acetylenedicarboxylate (6). With compound 6, the reaction leads to a mixture of the expected enaminone and the isomeric oxazolidine derivative. The structures and configurations of the new compounds were studied by spectroscopic and chemical methods.