Application of N-(9-Acridinyl)maleimide as a Fluorescent Detection Reagent of Cysteine and Related Thiols and Disulfide Compounds on Thin-layer Chromatogram

Fluctuations of pungent principles of hot pepper fruits (capsaicinoid), chlorophylls, carotenoid, and fresh fruit weight in Capsicum annuum var. annuum cv. Karayatsubusa at different growth stages after flowering were examined. Capsaicinoid was first detected 20 days after flowering, and reached maximal level around 40 days after flowering, then later decreased gradually. The capsaicinoid composition did not show any appreciable change throughout the stages after flowering. CAP and DC were the major components in all of the stages examined. By using radioisotopic technique, it was found that the main formation and accumulation sites of capsaicinoid are in the placenta of the fruits.     

Studies on Metabolism of Pyrrolidone Carboxylic Acid in Bacteria

l-Glutamic acid was formed from d-, l-, and dl-PCA with cell-free extract of Pseudomonas alcaligenes ATCC-12815 grown in the medium containing dl-PCA as a sole source of carbon and nitrogen. The enzyme(s) involved in this conversion reaction was distributed in the soluble fraction within the cell and in 0.5 saturated fraction at the fractionation procedure with the saturation of ammonium sulfate. Optimum pH of this enzyme(s) lied at pH 8.5 and optimum temperature was 30°C. Cu (5 × 10^?3 m) inhibited the reaction considerably while Ca or Fe accelerated it. PALP (1×10^?3 m) also gave an enhanced activity to some extent. The enzyme preparation converted dextro-rotatory enan-thiomorph of PCA to its laevo-rotatory one which in turn was not converted to the opposite rotation direction by this enzyme. Furthermore, the preparation did not, if any, show d-glutamic acid racemase activity. Isotopic experiments with using dl-PCA-1-¹⁴C revealed that l-glutamic acid-1-¹⁴C was formed by the cleavage of –CO–NH– bond of pyrrolidone ring of PCA. It was concluded that dl-PCA when assimilated by the present bacterium is at first transformed to l-PCA by the optically isomerizing enzyme and subsequently is cleaved to l-glutamic acid probably by the PCA hydrolysing enzyme.     

Adaptation of Hydrogenobacter thermophilus toward oxidative stress triggered by high expression of alkyl hydroperoxide reductase

Ferriperoxin is a novel peroxidase essential for aerobiosis of Hydrogenobacter thermophilus. Although the ferriperoxin-deficient mutant (Δfpx) was unable to grow aerobically, a suppressor mutant capable of aerobic growth was obtained after long aerobic cultivation. The alkyl hydroperoxide reductase gene was significantly upregulated in the suppressor mutant, indicating that the enzyme counteracts oxidative stress in the absence of ferriperoxin.     

Isolation and Characterization of a Temperature-sensitive Sporulation Mutant of Bacillus subtilis

Temperature-sensitive sporulation mutants were isolated spontaneously from Bacillus subtilis 168 TT by a sequential transfer method. A representative mutant strain, ts32, was characterized in detail. The mutant grew normally at 30°C and 42°C, but did not sporulate at 42°C. Electron microscopic observation and physiological analysis showed that the mutant was blocked at stage 0-1 of sporulation. Genetic analysis suggested that the mutation was located at the spo0B locus on the B. subtilis chromosome. Temperature-shift experiments clearly showed that the spo0B gene product functions only at the beginning of sporulation.     

Ceramide in Rice Grain

A rice lamina inclination test that is simple and specific for brassinosteroids was used as a micro-quantitative bioassay for brassinolide 1 and its 6-keto congener, castasterone 2, in the concentration range of 5 x 10^–5 /ig/ml to 5 x 10^–3μg/ml, when uniform seedlings of the rice cultivars Arborio J-l and Nihonbare were selected. A phytohormone, indole-3-acetic acid (IAA), showed similar activity in this bioassay. Its lowest effective concentration, however, was 50 /ig/μl, about five orders of magnitude greater than that of brassinolide. Other phytohormones, abscisic acid (ABA) and the cytokinins kinetin and A⁶-benzyladenine, inhibited the lamina inclination of rice seedlings. The addition of a cytokinin reduced the promoting effect of brassinolide. Thus, the rice lamina inclination test can be used both as a micro-quantitative bioassay for brassinosteroids and as a method for detecting antibrassinolide compouds.     

Production of Nucleic Acid-Related Substances by Fermentative Processes

Brevibacterium insectiphilium KY 3446 (Steinhous, Breed AHU 1401) was found to accumulate IMP from hypoxanthine and UMP from uracil, respectively. This strain is thus considered to present the fourth example in salvage-type fermentation, in addition to Micrococcus sodonensis, Arthrobacter citreus and Brevibacterium ammoniagenes reported previously.

IMP from adenine and UMP from cytosine were also produced by KY 3446, respectively. Further, the addition of inosine and adenosine instead of the bases also caused IMP accumulation.

This strain grew well on sucrose medium, and produced IMP and UMP in higher yields on sucrose than on glucose medium.

Excessive amounts of Mn²⁺ stimulated growth, but markedly inhibited IMP production. The optimal concentration of Mn²⁺ for IMP accumulation induced morphogenetic alterations from normal and small to abnormal and large cells.     

Purification and Characterization,of Rice Bran Lipase II

A species of rice bran lipase (lipase II) was purified by ammonium sulfate precipitation, followed by successive chromatographies on DEAE-cellulose, Sephadex G–75 and CH-Sephadex C–50. Both polyacrylamide disc electrophoresis and ultracentrifugation demonstrated that the enzyme protein is homogeneous. The isoelectric point of the enzyme was 9.10 by ampholine electrophoresis. The sedimentation coefficient of the enzyme was evaluated to be 2.60 S, and the molecular weight to be 33,300 according to Archbald’s method. The enzyme showed the optimum pH between 7.5 and 8.0, and the optimum temperature at about 27°C. It was stable over the pH range from 5 to 9.5 and below 30°C. In substrate specificity, the enzyme exhibited a high specificity toward triglycerides having short-carbon chain fatty acids, although it was capable of hydrolyzing the ester bonds in the rice and olive oil.     

Characterization of a Degraded Product Derived from Serratia piscatorum Polysaccharide by Ultrasonication

Acidic polysaccharide, PLS F–II, was prepared from Serratia piscatorum polysaccharide, PLS N–I, by a sequence of ultrasonication and gel filtration and was examined for chemical composition and biological activity.

The purified PLS F–II preparation was shown to be homogeneous by ultracentrifugation, zone electrophoresis and column chromatography. The molecular weight was estimated to be about 2 × 10⁴ by the Archibald method. PLS F–II was composed of l-rhamnose, d-galactose and d-galacturonic acid in the molar ratio of 2: 1: 1 and was partially acylated on the galacturonic acid residues.

PLS F–II was found to enhance the antibody formation in mice, although it showed no anti-inflammatory activity.     

Biosynthesis of Piericidins A and B by Streptomyces mobaraensis

Biosynthesis of piericidins A and B (PA and PB) has been investigated using ¹⁴C-labeled compounds. Incorporation ratios of dl-methionine(methyl-¹⁴C), propionate-1-¹⁴C and acetate-1-¹⁴C and-2-¹⁴C were 7.4, 4,5, 1.2 and 0.9%, respectively, whereas dl-mevalonic lactone- 2-¹⁴C and formate-¹⁴C were not incorporated. Degradation studies on labeled PA show that in the biosynthesis of piericidins a long branched C₂₃-chain was formed from five propionate and four acetate units and then a nitrogen atom was introduced at the terminal part of the chain, followed by cyclization to form the pyridine ring. The two methoxyl groups on the rings of PA and PB as well as the one in the side chain of PB were derived from S-methyl of methionine.     

Historical Biogeography and Diversification of Truffles in the Tuberaceae and Their Newly Identified Southern Hemisphere Sister Lineage

Truffles have evolved from epigeous (aboveground) ancestors in nearly every major lineage of fleshy fungi. Because accelerated rates of morphological evolution accompany the transition to the truffle form, closely related epigeous ancestors remain unknown for most truffle lineages. This is the case for the quintessential truffle genus Tuber, which includes species with socio-economic importance and esteemed culinary attributes. Ecologically, Tuber spp. form obligate mycorrhizal symbioses with diverse species of plant hosts including pines, oaks, poplars, orchids, and commercially important trees such as hazelnut and pecan. Unfortunately, limited geographic sampling and inconclusive phylogenetic relationships have obscured our understanding of their origin, biogeography, and diversification. To address this problem, we present a global sampling of Tuberaceae based on DNA sequence data from four loci for phylogenetic inference and molecular dating. Our well-resolved Tuberaceae phylogeny shows high levels of regional and continental endemism. We also identify a previously unknown epigeous member of the Tuberaceae – the South American cup-fungus Nothojafnea thaxteri (E.K. Cash) Gamundí. Phylogenetic resolution was further improved through the inclusion of a previously unrecognized Southern hemisphere sister group of the Tuberaceae. This morphologically diverse assemblage of species includes truffle (e.g. Gymnohydnotrya spp.) and non-truffle forms that are endemic to Australia and South America. Southern hemisphere taxa appear to have diverged more recently than the Northern hemisphere lineages. Our analysis of the Tuberaceae suggests that Tuber evolved from an epigeous ancestor. Molecular dating estimates Tuberaceae divergence in the late Jurassic (∼156 million years ago), with subsequent radiations in the Cretaceous and Paleogene. Intra-continental diversification, limited long-distance dispersal, and ecological adaptations help to explain patterns of truffle evolution and biodiversity.