Molecular structures of high- and low-methoxy water-soluble polysaccharides derived from peas and their functions for stabilizing milk proteins under acidic conditions.

The structural and functional properties of two different pea water-soluble polysaccharides, a high methyl-esterified (HM-SPPS; degree of methyl esterification (DMe): 71.0 %) and low methyl-esterified SPPS (LM-SPPS; DMe: 25.2 %) were investigated. The two extracts did not vary in composition and showed a weight average molecular mass of about 1,000 kDa, as measured by size exclusion chromatography equipped with a multi-angle light scattering detector. Both HM-SPPS and LM-SPPS had similar sugar compositions, with arabinose 42.2-47.1 %, glucose 26.6-31.0 %, and galacturonic acid 17.5-18.0 %, as their main sugars. Their charge varied as a function of pH. The molecular structure was observed by a scanning probe microscope and showed a straight chain structure with small branches. The structure was similar to that already reported for polysaccharides from kidney bean. SPPS molecules interact with acidified milk protein particles at pH < 4.4. There were differences between the two SPPS. LM-SPPS could stabilize a model acidified milk dispersion with minimal aggregation between pH 3.6-4.4, while HM-SPPS showed the presence of bridging flocculation caused by polysaccharide's entanglements. It was concluded that SPPS stabilizes acidified protein by steric and electrostatic repulsion.

Quantification of leuco-indigo in indigo-dye-fermenting suspension by normal pulse voltammetry.

Quantification of leuco-indigo is most important for Aizome, Japanese indigo-dyeing; however, there has been no convenient quantitative method. This study demonstrated that normal pulse voltammetry under quiescent conditions can be used to detect leuco-indigo. As a result of quantification of leuco-indigo in the depth direction in fermenting suspensions, the steady-state concentrations of leuco-indigo showed sigmoidal profiles in the depth direction. The steady state is caused by competitive reactions of microbial reduction of indigo and autoxidation of leuco-indigo by O2 dissolved from the air interface of the suspension. In addition, we investigated the effects of stirring the suspension and adding some nutrients to the concentration profile. The weakened activity was partially recovered by the addition of ethanol and remarkably recovered by the addition of hipolypepton or glucose. Knowledge is essential for the proper management of indigo-dye-fermenting suspensions.

Family physicians can contribute to Olympic and Paralympic Games or other sports events.

Many sports physicians are from primary care backgrounds around the world but not in Japan. However, from the view of family physicians who contributed to Tokyo 2020 Olympic and Paralympic Games as medical staff, family physicians in Japan can play an active role in sporting events.

Isolation and characterization of indigo-reducing bacteria and analysis of microbiota from indigo fermentation suspensions.

In natural indigo dyeing, the water-insoluble indigo included in the composted indigo leaves called sukumo is converted to water-soluble leuco-indigo through the reduction activities of microorganisms under alkaline conditions. To understand the relationship between indigo reduction and microorganisms in indigo-fermentation suspensions, we isolated and identified the microorganisms that reduce indigo and analyzed the microbiota in indigo-fermentation suspensions. Indigo-reducing microorganisms, which were not isolated by means of a conventional indigo carmine-reduction assay method, were isolated by using indigo as a direct substrate and further identified and characterized. We succeeded in isolating bacteria closely related to Corynebacterium glutamicum, Chryseomicrobium aureum, and Enterococcus sp. for the first time. Anthraquinone was found to be an effective mediator that facilitated the indigo-reduction activity of the isolated strains. On analysis of the microbiota in indigo-fermentation suspensions, the ratio of indigo-reducing bacteria and others was found to be important for maintaining the indigo-reduction activity.

Strigolactone biosynthesis catalyzed by cytochrome P450 and sulfotransferase in sorghum.

Root parasitic plants such as Striga, Orobanche, and Phelipanche spp. cause serious damage to crop production world-wide. Deletion of the Low Germination Stimulant 1 (LGS1) gene gives a Striga-resistance trait in sorghum (Sorghum bicolor). The LGS1 gene encodes a sulfotransferase-like protein, but its function has not been elucidated. Since the profile of strigolactones (SLs) that induce seed germination in root parasitic plants is altered in the lgs1 mutant, LGS1 is thought to be an SL biosynthetic enzyme. In order to clarify the enzymatic function of LGS1, we looked for candidate SL substrates that accumulate in the lgs1 mutants and performed in vivo and in vitro metabolism experiments. We found the SL precursor 18-hydroxycarlactonoic acid (18-OH-CLA) is a substrate for LGS1. CYP711A cytochrome P450 enzymes (SbMAX1 proteins) in sorghum produce 18-OH-CLA. When LGS1 and SbMAX1 coding sequences were co-expressed in Nicotiana benthamiana with the upstream SL biosynthesis genes from sorghum, the canonical SLs 5-deoxystrigol and 4-deoxyorobanchol were produced. This finding showed that LGS1 in sorghum uses a sulfo group to catalyze leaving of a hydroxyl group and cyclization of 18-OH-CLA. A similar SL biosynthetic pathway has not been found in other plant species.

Voltammetric in-situ monitoring of leuco-indigo in indigo-fermenting suspensions.

Cyclic voltammetry was successfully applied to in-vivo monitoring of leuco-indigo in indigo-fermenting suspensions under quiescent conditions without deoxygenation; the working and counter electrodes were kept on the surface of each suspension by a polyethylene vinyl alcohol tube holder. The anodic peak current was used as a measure of the leuco-indigo concentration. The voltammetric wave shape suggested partial solubilization of the indigo with some macromolecules in the fermenting suspensions, which lead to an in-situ method without any electrode surface pretreatment. The anodic peak current well reflected the dyeing activity of a suspensions. The results obtained for laboratory-level fermentation systems clarified the number of days required for dye fermentation, the effectiveness of addition of old suspension as an additive for preparing fresh fermenting suspensions, and the importance of addition of a nitrogen-based nutrient as well as a glucose-based one to recover the indigo-reducing activity. The method can also be applied to determine the amounts of indigo in used dye suspensions and extracts of fermented indigo leaves (sukumo) by adding a chemical reduction pretreatment.