Isolation and Identification of a Sexual Hormone in Yeast

5-Fluorotryptophan (5FT), indolmycin (IM), 4-fluorotryptophan and 7-azatryptophan were found on screening to be tryptophan antagonists among various chemically synthesized and naturally occurring tryptophan analogues for the isolation of l-tryptophan (l-Trp) producing mutants of Bacillus subtilis K.

From among 5FT resistant mutants, potent l-Trp producers were obtained using an improved isolation medium. Growth of the isolated 5FT-resistant l-Trp producer, AJ 11709, was inhibited by IM. From among 5FT and IM resistant mutants, the best strain, AJ 11979, which produced 9.0 g/liter of l-Trp from 13% glucose on 120hr cultivation, was selected.     

A New Basic Triple Salt Containing Magnesium Hydroxide

The quinary system KCl-K₂SO₄-MgCl₂-MgSO₄-Mg(OH)₂-H₂O and associated eight systems K₂SO₄-MgSO₄-Mg(OH)₂-H₂O, MgCl₂-MgSO₄-Mg(OH)₂-H₂O, KCl-MgCl₂-Mg(OH)₂-H₂O, KCl-K₂SO₄-Mg(OH)₂-H₂O, MgSO₄-Mg(OH)₂-H₂O, MgCl₂-Mg(OH)₂-H₂O, K₂SO₄-Mg(OH)₂-H₂O and KCl-Mg(OH)₂-H₂O were investigated at 50° The solid phases of these systems were the new basic triple salt (NS salt B), MgCl₂ · 3Mg(OH)₂ · 8H₂O, MgSO₄ · 5Mg(OH)₂ · 3H₂O, carnallite, leonite, kieserite, hexahydrite, bischofite, potassium chloride, potassium sulfate and magnesium hydroxide and the crystallization fields of these salts in nine systems were determined.     

Mechanism of Action of Bacillus thuringiensis Insecticidal Delta-endotoxin on Insect Cells in Vitro

Cultured insect cells, TN-368 from the cabbage looper, swelled and burst upon treatment with the enzyme-digested delta-endotoxin of Bacillus thuringiensis var. aizawai. The cytotoxic sweelling was depended upon the amount of the delta-endotoxin added and the concentration of NaCl or KC1 in the isotonic solution. The concentration of Na⁺ in the swollen cells approximately doubled in isotonic NaCl, while that of K⁺ decreased to 10% of the original cellular concentration. The cell swelling was inhibited by tetrodotoxin and also by ouabain in only KC1 isotonic solution. On the other hand, 4-aminopyridine stimulated the swelling in the isotonic KC1 solution, These results indicate that the delta-endotoxin induces the stimulation of Na+ influx and K+ efflux in the isotonic NaCl solution, and also stimulates the Na⁺, K⁺-ATPase in the isotonic KC1 solution. The cytotoxic swelling was also blocked by cAMP, AMP, ATP, GTP, and NAD, but not by adenosine and GMP. These results suggest the participation of nucleotide derivatives in the action of delta-endotoxin.     

A Root Growth-promoting Factor,Capillarol, from Artemisia capillaris Thunb

A root growth-promoting factor was isolated from Artemisia capillaris Thunb. The chemical structure of this compound was elucidated as methyl 3-(3-methylbut-2-enoyl)-4-hydroxycinnamate (capillarol) on the basis of its spectroscopic analysis. At 5×10^–4m this compound promoted rice root growth to 180% of the control value.     

Environmental DNA as a ‘Snapshot’ of Fish Distribution: A Case Study of Japanese Jack Mackerel in Maizuru Bay,Sea of Japan

Recent studies in streams and ponds have demonstrated that the distribution and biomass of aquatic organisms can be estimated by detection and quantification of environmental DNA (eDNA). In more open systems such as seas, it is not evident whether eDNA can represent the distribution and biomass of aquatic organisms because various environmental factors (e.g., water flow) are expected to affect eDNA distribution and concentration. To test the relationships between the distribution of fish and eDNA, we conducted a grid survey in Maizuru Bay, Sea of Japan, and sampled surface and bottom waters while monitoring biomass of the Japanese jack mackerel (Trachurus japonicus) using echo sounder technology. A linear model showed a high R² value (0.665) without outlier data points, and the association between estimated eDNA concentrations from the surface water samples and echo intensity was significantly positive, suggesting that the estimated spatial variation in eDNA concentration can reflect the local biomass of the jack mackerel. We also found that a best-fit model included echo intensity obtained within 10–150 m from water sampling sites, indicating that the estimated eDNA concentration most likely reflects fish biomass within 150 m in the bay. Although eDNA from a wholesale fish market partially affected eDNA concentration, we conclude that eDNA generally provides a ‘snapshot’ of fish distribution and biomass in a large area. Further studies in which dynamics of eDNA under field conditions (e.g., patterns of release, degradation, and diffusion of eDNA) are taken into account will provide a better estimate of fish distribution and biomass based on eDNA.     

Advances in purine and pyrimidine metabolism in health and diseases

ABSTRACT

In June, 2015, the Purine and Pyrimidine Society organized the 16th biennial symposium on Purine and Pyrimidine metabolism at the Faculty House of Columbia University, New York City. This exciting meeting focused on these important molecules, new developments in inborn errors of metabolism; therapeutic analogs. In addition, the biochemistry of mammalian and non-mammalian systems were discussed. Due to significant advances in molecular medicine, the boundaries between clinical and basic sciences have merged into exciting translational research, of which a small portion was highlighted in the presymposium.