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Lignins are aromatic heteropolymers that arise from oxidative coupling of lignin precursors, including lignin monomers (p-coumaryl, coniferyl, and sinapyl alcohols), oligomers, and polymers. Whereas plant peroxidases have been shown to catalyze oxidative coupling of monolignols, the oxidation activity of well-studied plant peroxidases, such as horseradish peroxidase C (HRP-C) and AtPrx53, are quite low for sinapyl alcohol. This characteristic difference has led to controversy regarding the oxidation mechanism of sinapyl alcohol and lignin oligomers and polymers by plant peroxidases. The present study explored the oxidation activities of three plant peroxidases, AtPrx2, AtPrx25, and AtPrx71, which have been already shown to be involved in lignification in the Arabidopsis stem. Recombinant proteins of these peroxidases (rAtPrxs) were produced in Escherichia coli as inclusion bodies and successfully refolded to yield their active forms. rAtPrx2, rAtPrx25, and rAtPrx71 were found to oxidize two syringyl compounds (2,6-dimethoxyphenol and syringaldazine), which were employed here as model monolignol compounds, with higher specific activities than HRP-C and rAtPrx53. Interestingly, rAtPrx2 and rAtPrx71 oxidized syringyl compounds more efficiently than guaiacol. Moreover, assays with ferrocytochrome c as a substrate showed that AtPrx2, AtPrx25, and AtPrx71 possessed the ability to oxidize large molecules. This characteristic may originate in a protein radical. These results suggest that the plant peroxidases responsible for lignin polymerization are able to directly oxidize all lignin precursors.

Pseudogluconobacter saccharoketogenes produces glucaric acid from d -glucose via two pathways, i.e., through d -glucuronic acid or d -gluconic acid. These pathways are catalyzed by alcohol dehydrogenase, aldehyde dehydrogenase, and gluconate dehydrogenase. Although d -glucaraldehyde and l -guluronic acid are also theorized to be produced in pathways throsugh d -glucuronic acid and d -gluconic acid, respectively, no direct data to identify these intermediates have been reported. In this study, the intermediates were purified and identified as d -glucaraldehyde and l -guluronic acid. The substrate specificities of the three enzymes on these intermediates and their oxidation products were studied, and the roles of alcohol, aldehyde, and gluconate dehydrogenases in d -glucaric acid-producing pathways were elucidated using the intermediates. Additionally, the substrate specificities of alcohol and aldehyde dehydrogenases on some alcohols, aldehydes, and aldoses were determined. Alcohol dehydrogenase showed wide substrate specificities, whereas the substrates oxidized by aldehyde dehydrogenase were limited. A 30-L scale reaction using the resting cells of Rh47-3 revealed that d -glucaric acid was produced from d -glucose and d -gluconic acid in 60.3 mol% (7.0 g/L) and 78.6 mol% (22.5 g/L) yields, respectively.

Artificial lignin called dehydrogenative polymers (DHPs) has been used to develop models for investigating lignin characteristics and structures. However, these models are inadequate because they have lower molecular weight and less content of β- O -4 than natural lignin. The conditions required for dehydrogenative polymerization, particularly the reaction within the polysaccharide matrix, are believed to be critical for facilitating lignin polymer growth reaction. This study investigated the effects of the polysaccharide matrix on syringyl-DHPs properties following dehydrogenative polymerization reaction on artificial cell walls. Specifically, artificial cell walls were prepared by esterifying ferulic acid to xyloglucan, which was then adsorbed on nematic ordered cellulose film. Sinapyl alcohol or coniferyl alcohol was polymerized on the film using recombinant cationic cell wall peroxidase. Syringyl-DHP and guaiacyl-DHP were prepared in the buffer and served as comparative subjects. DHPs formed on artificial cell walls had lower molecular weights and less content of β- O -4 than DHPs prepared in the buffer. These results suggest that binding DHPs to a polysaccharide matrix may limit their mobility and inhibit their growth reaction.

It has been shown that CD1d expression and glycolipid-reactive, CD1d-restricted NKT cells exacerbate the development of obesity and insulin resistance in mice. However, the relevant CD1d-expressing cells that influence the effects of NKT cells on the progression of obesity remain incompletely defined. In this study, we have demonstrated that 3T3-L1 adipocytes can present endogenous ligands to NKT cells, leading to IFN-γ production, which in turn, stimulated 3T3-L1 adipocytes to enhance expression of CD1d and CCL2 and decrease expression of adiponectin. Furthermore, adipocyte-specific CD1d deletion decreased the size of the visceral adipose tissue mass and enhanced insulin sensitivity in mice fed a high-fat diet (HFD). Accordingly, NKT cells were less activated, IFN-γ production was significantly reduced and levels of adiponectin were increased in these animals as compared with control mice on HFD. Importantly, macrophage recruitment into the adipose tissue of adipocyte-specific CD1d-deficient mice was significantly blunted. These findings indicate that interactions between NKT cells and CD1d-expressing adipocytes producing endogenous NKT cell ligands play a critical role in the induction of inflammation and functional modulation of adipose tissue that leads to obesity.

The effects of Au addition on the acetone response of Cu2O-added porous SnO2 (pr-Cu2O-SnO2) powders, which were synthesized by ultrasonic spray pyrolysis employing polymethyl methacrylate microspheres as a template, were investigated in this study. The 3.0 wt% Au-added pr-Cu2O-SnO2 sensor showed the largest acetone response among all sensors. In addition, the magnitude of the acetone response was much larger than those of the ethanol and toluene responses. The catalytic activities of these gases over Au-added pr-Cu2O-SnO2 powders were also examined to clarify the key factors affecting their acetone-sensing properties. The Au addition increased the complete oxidation activity of all gases, and the complete oxidation activity of acetone was much higher than those of ethanol and toluene. These results indicate that the oxidation behavior during the gas-diffusion process in the sensitive Au-added pr-Cu2O-SnO2 layer of the sensors is quite important in enhancing the acetone-sensing properties.

Cationic cell-wall-bound peroxidase (CWPO-C) from Populus alba is the only Class III peroxidase that has been shown to be able to oxidize high molecular weight lignin polymers from sinapyl alcohol and previously, has been believed to be a lignin polymerization-specific peroxidase. However, using an Arabidopsis heterologous expression system, we showed recently that CWPO-C contributes to differentiation or early growth and is involved in auxin catabolism. In this study, to clarify the function of CWPO-C in poplar, we analyzed CWPO-C gene expression and phenotypic changes with CWPO-C overexpression and suppression. Real-time PCR and monitoring promoter activity of CWPO-C using β-glucuronidase (GUS) assay revealed that CWPO-C was strongly expressed in immature tissues, such as the upper stem, axillary buds, and young leaves, in addition to expression in developing xylem. In transgenic poplars in which the expression of CWPO-C was upregulated or suppressed, changes in stem growth, gravitropism bending time, lignin content and syringyl/guaiacyl (S/G) composition were observed. Overexpressing CWPO-C enhanced stem growth and gravitropic response (shorter bending time). With suppressed CWPO-C expression, the lignin content was reduced approximately 45% and the S/G ratio decreased by half. These results strongly suggest that CWPO-C plays a role in differentiation and early growth, as well as in lignin polymerization.

Since ancient times, Japanese cypress timber ( Chamaecyparis obtusa ; 'hinoki' in Japanese) has been highly valued in Japan. Because of its beautiful color and fragrance, this timber has been widely used as houses and furniture materials. Scientific evidence on the effect of the usage of hinokis’ timber especially from Kagawa’s area as a building material toward human psychophysiological response has yet to be reported. The current study examined participants’ psychophysiological responses to volatile organic compounds (VOCs) generated by hinoki interior walls growing in Kagawa Prefecture, Japan. This timber was reported to have a relaxing effect toward the participants, and this study discovered that inhaling air containing VOCs emitted by Kagawa hinoki interior walls increased parasympathetic nervous activity during resting periods between arithmetic tasks. When compared to a control condition, the participants' performance on a calculation test improved dramatically in the hinoki condition. These findings suggest that VOCs released by Kagawa hinoki walls influence the autonomic nervous system, emotions, and work performance. This study not only proved Kagawa hinoki fragrance’s potential to boost human working speed, but it also newly confirmed the fragrance's ability to increase parasympathetic nervous system activity while at rest. This study also discovered that the enhanced working speed is caused by a part of the neurological underpinning for heightened arousal in the brain. As a result, this study concluded that the aroma of cypress can have physiological effects that change over time, hence optimizing individuals’ behavior at work and at rest.

The electronic nose is an increasingly useful tool in many fields and applications. Our thermal electronic nose approach, based on nanostructured metal oxide chemiresistors in a thermal gradient, has the advantage of being tiny and therefore integrable in portable and wearable devices. Obviously, a wise choice of the nanomaterial is crucial for the device’s performance and should therefore be carefully considered. Here we show how the addition of different amounts of Au (between 1 and 5 wt%) on Cu2O–SnO2 nanospheres affects the thermal electronic nose performance. Interestingly, the best performance is not achieved with the material offering the highest intrinsic selectivity. This confirms the importance of specific studies, since the performance of chemoresistive gas sensors does not linearly affect the performance of the electronic nose. By optimizing the amount of Au, the device achieved a perfect classification of the tested gases (acetone, ethanol, and toluene) and a good concentration estimation (with a mean absolute percentage error around 16%). These performances, combined with potentially smaller dimensions of less than 0.5 mm2, make this thermal electronic nose an ideal candidate for numerous applications, such as in the agri-food, environmental, and biomedical sectors.

Background Most lactobacilli found in animal intestines are generally non-motile, but there are few exceptions. Our previous work showed that Lactobacillus agilis BKN88, which is a highly motile strain originating from a chicken, takes advantage of motility in gut colonization in murine models, and thus motile lactobacilli likely have unique ecological characteristics conferred by motility. However, the ecology and habitat of gut-derived motile lactobacilli are still rarely understood. In addition, the limited availability of motile Lactobacillus isolates is one of the major obstacles for further studies. To gain insight into the ecology and habitat of the motile lactobacilli, we established a routinely applicable detection method for motile lactobacilli using PCR and subsequent selective isolation in semi-solid MRS medium for the collection of additional motile lactobacilli from animal feces. Results We applied the PCR detection using motile lactobacilli-specific primers, based on the motor switch protein gene ( fliG ) of flagella, to 120 animal feces, followed by selective isolation performed using 45 animal feces. As a result, motile lactobacilli were detected in 44 animal feces. In the selective isolation, 29 isolates of L. agilis and 2 isolates of L. ruminis were obtained from 8 animal species. Conclusions These results indicated that motile lactobacilli are distributed in different animal species. Moreover, phylogenetic analysis of the L. agilis isolates suggests co-evolution with the host, and adaptation to a particular environmental niche.

Most of the known 4-coumarate:coenzyme A ligase (4CL) isoforms lack CoA-ligation activity for sinapic acid. Therefore, there is some doubt as to whether sinapic acid contributes to sinapyl alcohol biosynthesis. In this study, we characterized the enzyme activity of a protein mixture extracted from the developing xylem of Robinia pseudoacacia . The crude protein mixture contained at least two 4CLs with sinapic acid 4-CoA ligation activity. The crude enzyme preparation displayed negligible sinapaldehyde dehydrogenase activity, but showed ferulic acid 5-hydroxylation activity and 5-hydroxyferulic acid O -methyltransferase activity; these activities were retained in the presence of competitive substrates (coniferaldehyde and 5-hydroxyconiferaldehyde, respectively). 5-Hydroxyferulic acid and sinapic acid accumulated in the developing xylem of R. pseudoacacia , suggesting, in part at least, sinapic acid is a sinapyl alcohol precursor in this species.