Effect of Water Content on the Glass Transition Temperature of Calcium Maltobionate and its Application to the Characterization of Non-Arrhenius Viscosity Behavior

To understand the fundamental physical properties of calcium maltobionate (MBCa), its water sorption isotherm, glass transition temperature (T _g), and viscosity (η) were investigated and compared with those of maltobionic acid (MBH) and maltose. Although amorphous maltose crystalized at water activity (a _w) higher than 0.43, MBCa and MBH maintained an amorphous state over the whole a _w range. In addition, MBCa had a higher T _g and greater resistance to water plasticizing than MBH and maltose. These properties of MBCa likely originate from the strong interaction between MBCa and water induced by electrostatic interactions. Moreover, the effects of temperature and water content on η of an aqueous MBCa solution were evaluated, and its behavior was described using a semi-empirical approach based on a combination of T _g extrapolated by the Gordon-Taylor equation and a non-Arrhenius formula known as the Vogel–Fulcher–Tammann equation. This result will be useful for understating the effect of MBCa addition on the solution’s properties.     

4-Vinylphenol production from glucose using recombinant <Emphasis Type="Italic">Streptomyces mobaraense</Emphasis> expressing a tyrosine ammonia lyase from <Emphasis Type="Italic">Rhodobacter sphaeroides</Emphasis>

Objectives

To find a novel host for the production of 4-vinylphenol (4VPh) by screening Streptomyces species.

Results

The conversion of p-coumaric acid (pHCA) to 4VPh in Streptomyces mobaraense was evaluated using a medium containing pHCA. S. mobaraense readily assimilated pHCA after 24 h of cultivation to produce 4VPh. A phenolic acid decarboxylase, derived from S. mobaraense (SmPAD), was purified following heterologous expression in Escherichia coli. SmPAD was evaluated under various conditions, and the enzyme’s k_cat/K_m value was 0.54 mM ^?1 s^?1. Using intergenetic conjugation, a gene from Rhodobacter sphaeroides encoding a tyrosine ammonia lyase, which catalyzes the conversion of l-tyrosine to p-coumaric acid, was introduced into S. mobaraense. The resulting S. mobaraense transformant produced 273 mg 4VPh l^?1 from 10 g glucose l^?1.

Conclusion

A novel strain suitable for the production of 4VPh and potentially other aromatic compounds was isolated.

     

Growth and nodulation in <Emphasis Type="Italic">Alnus sieboldiana</Emphasis> in response to <Emphasis Type="Italic">Frankia</Emphasis> inoculation and nitrogen treatments

Key message

We investigated a Frankia – Alnus sieboldiana symbiosis, including the minimum inoculum dose for constant nodulation, the period of time to nodulation after inoculation, and the effects of N on nodulation.

Abstract

Frankia is a nitrogen-fixing actinomycete that forms root nodules in some dicotyledonous plants, which are called actinorhizal. We studied nodule formation in Alnus sieboldiana, an actinorhizal plant, after inoculation with a Frankia isolate to establish techniques for Frankia inoculation and the cultivation of inoculated plants. Root nodules formed on seedlings of A. sieboldiana by 2 weeks after inoculation, and N₂ fixation measured by acetylene reduction activity started 3 weeks after inoculation. Nodulation was observed after inoculation with a Frankia isolate at 0.001 μL packed cell volume (pcv). The number of nodules formed on the seedlings inoculated with Frankia at more than 0.05 μL pcv was not significantly different. Nodule development and N₂ fixation were reduced when inoculated seedlings were treated weekly with 15 mM NH₄NO₃-N. In contrast, treatment with 3.75 or 0.9375 mM NH₄NO₃-N did not inhibit nodule development or N₂ fixation of inoculated seedlings by 15 weeks of N treatment.

     

Tinocladia sanrikuensis sp. nov. (Ectocarpales s.l., Phaeophyceae) from Japan

The new species Tinocladia sanrikuensis sp. nov. H.Kawai, K.Takeuchi & T.Hanyuda (Ectocarpales s.l., Phaeophyceae) is described from the Pacific coast of the Tohoku region, northern Japan based on morphology and DNA sequences. The species is a spring–summer annual growing on lower intertidal to upper subtidal rocks and cobbles on relatively protected sites. T. sanrikuensis has a slimy, cylindrical, multiaxial erect thallus, slightly hollow when fully developed, branching once to twice, and resembles T. crassa in gross morphology. The erect thalli are composed of a dense medullary layer, long subcortical filaments, and assimilatory filaments of 11–35 cells, up to 425 μm long and curved in the upper portion. Unilocular zoidangia are formed on the basal part of assimilatory filaments. The species is genetically most closely related to T. crassa and has the same basic thallus structures but differs in having thinner and longer assimilatory filaments. DNA sequences of the mitochondrial cox1 and cox3, chloroplast atpB, psaA, psbA and rbcL genes support the distinctness of this species.     

Differentiation of embryonic stem cells into inner ear vestibular hair cells using vestibular cell derived-conditioned medium

Vestibular hair cells (V–HCs) in the inner ear have important roles and various functions. When V–HCs are damaged, crippling symptoms, such as vertigo, visual field oscillation, and imbalance, are often seen. Recently, several studies have reported differentiation of embryonic stem (ES) cells, as pluripotent stem cells, to HCs, though a method for producing V–HCs has yet to be established. In the present study, we used vestibular cell conditioned medium (V-CM) and effectively induced ES cells to differentiate into V–HCs. Expressions of V-HC-related markers (Math1, Myosin6, Brn3c, Dnah5) were significantly increased in ES cells cultured in V-CM for 2 weeks, while those were not observed in ES cells cultured without V-CM. On the other hand, the cochlear HC-related marker Lmod3 was either not detected or detected only faintly in those cells when cultured in V-CM. Our results demonstrate that V-CM has an ability to specifically induce differentiation of ES cells into V–HCs.     

Rapid SNP diagnostics using asymmetric isothermal amplification and a new mismatch-suppression technology

We developed a rapid single nucleotide polymorphism (SNP) detection system named smart amplification process version 2 (SMAP 2). Because DNA amplification only occurred with a perfect primer match, amplification alone was sufficient to identify the target allele. To achieve the requisite fidelity to support this claim, we used two new and complementary approaches to suppress exponential background DNA amplification that resulted from mispriming events. SMAP 2 is isothermal and achieved SNP detection from whole human blood in 30 min when performed with a new DNA polymerase that was cloned and isolated from Alicyclobacillus acidocaldarius (Aac pol). Furthermore, to assist the scientific community in configuring SMAP 2 assays, we developed software specific for SMAP 2 primer design. With these new tools, a high-precision and rapid DNA amplification technology becomes available to aid in pharmacogenomic research and molecular-diagnostics applications.     

Delayed sleep/wake rhythm and excessive daytime sleepiness correlate with decreased daytime brain activity during cognitive task in university students

Insufficient sleep and irregular sleep/wake rhythm are common problems among university students. We investigated the effect of sleep/wake rhythm and excessive daytime sleepiness (EDS) on the cortical oxygenation as measured by near-infrared spectroscopy (NIRS) and cognitive performance in university students. Peak- and integral values by a word fluency task were measured with NIRS. EDS was evaluated by the Epworth sleepiness scale (ESS), and performance function was evaluated using N-back task. Peak cerebral oxygenation was significantly correlated with ESS, bedtime, wake-up time, and median time of sleep. Accuracy on 2-back task was significantly correlated with integral value. Peak- and integral values were significantly lower, and bedtime and median time of sleep were significantly delayed in the EDS group than in the non-EDS group. EDS accompanied by delayed sleep/wake rhythm and short sleep duration may play an important role in decreasing daytime brain activity and cognitive performance.     

MIG-seq is an effective method for high-throughput genotyping in wheat (Triticum spp.)

MIG-seq (Multiplexed inter-simple sequence repeats genotyping by sequencing) has been developed as a low cost genotyping technology, although the number of polymorphisms obtained is assumed to be minimal, resulting in the low application of this technique to analyses of agricultural plants. We applied MIG-seq to 12 plant species that include various crops and investigated the relationship between genome size and the number of bases that can be stably sequenced. The genome size and the number of loci, which can be sequenced by MIG-seq, are positively correlated. This is due to the linkage between genome size and the number of simple sequence repeats (SSRs) through the genome. The applicability of MIG-seq to population structure analysis, linkage mapping, and quantitative trait loci (QTL) analysis in wheat, which has a relatively large genome, was further evaluated. The results of population structure analysis for tetraploid wheat showed the differences among collection sites and subspecies, which agreed with previous findings. Additionally, in wheat biparental mapping populations, over 3,000 SNPs/indels with low deficiency were detected using MIG-seq, and the QTL analysis was able to detect recognized flowering-related genes. These results revealed the effectiveness of MIG-seq for genomic analysis of agricultural plants with large genomes, including wheat.     

Macrophage colony-stimulating factor is produced by human T lymphoblastoid cell line, CEM-ON: identification by amino-terminal amino acid sequence analysis

A subclone, designated CEM-ON, derived from an azaguanine-resistant human leukemic T cell line, CEM-AG(R), constitutively secretes a colony-stimulating factor (CSF) which stimulates the production of macrophages from murine bone marrow progenitor cells. This CSF has been purified from serum-free conditioned medium. Highly purified CEM-ON CSF with a specific activity of 4.7 X 10(7) units/mg protein was obtained. Amino-terminal sequence analysis showed that the first 27 amino acids were identical to the amino-terminal sequence of the M-CSF (CSF-1) based on the cDNAs for human M-CSF. On SDS-PAGE analysis, CEM-ON CSF had an apparent molecular weight of 33,000-43,000; following reduction with 2-mercaptoethanol, this migrated as a 20,000-24,000 subunit, suggesting a homodimer structure. These results show that a human T cell line, CEM-ON, secretes M-CSF into its medium.