Production of saturated acyl L-ascorbate by immobilized lipase using a continuous stirred tank reactor

6-O-decanoyl, 6-O-dodecanoyl, or 6-O-tetradecanoyl L-ascorbate was continuously produced at 50 degrees C using a continuous stirred tank reactor (CSTR) with an immobilized lipase, Chirazyme L-2 C2, from Candida antarctica. Acetone was used as the reaction medium. For each saturated acyl L-ascorbate, the productivity of ca. 60 g/L reactor/day was achieved for at least 11 days. The solubility of the saturated acyl L-ascorbate in the soybean oil or water was measured at various temperatures. The solubilities in both the soybean oil and the water were higher for L-ascorbate with a shorter acyl chain. The acyl chain dependence of the solubility in water was stronger than that of the solubility in soybean oil. The temperature dependences of the solubility in both soybean oil and water could be expressed by the van't Hoff equation, and the dissolution enthalpy (DeltaH) values for the soybean oil and water were about 20 and 90 kJ/mol, respectively, irrespective of the acyl chain length. The radical scavenging activities of L-ascorbic acid and the saturated acyl L-ascorbates against 1,1-diphenyl-2-picrylhydrazyl free radical were ca. 95% for all of the compounds, and the introduction of a saturated acyl group to the L-ascorbic acid did not affect the activity.     

培养基对尖孢镰刀菌非致病力菌株281产孢量的影响

选择8种培养基，采用液体培养法，研究培养基质对尖孢镰刀菌(Fusarium oxysporum Schl.)281菌株小孢子产生量的影响，结果表明，在PDA培养基上培养144h得到最大小孢子产量1.283×109cfu/ml，与其它培养基产孢量差异显著（P=0.05）。培养至192h时，ATCC培养基的小孢子数量达到1.325×109cfu/ml，与PDA培养基之间无显著差异（P=0.05），与其它6种培养基之间差异显著（P=0.05）。综合比较8种培养基，PDA培养基培养时间短，配制简单，是较为理想的产小孢子培养基。     

Immunobiotic lactic acid bacteria beneficially regulate immune response triggered by poly(I:C) in porcine intestinal epithelial cells

ABSTRACT: This study analyzed the functional expression of TLR3 in various gastrointestinal tissues from adult swine and shows that TLR3 is expressed preferentially in intestinal epithelial cells (IEC), CD172a+CD11R1high and CD4+ cells from ileal Peyer's patches. We characterized the inflammatory immune response triggered by TLR3 activation in a clonal porcine intestinal epitheliocyte cell line (PIE cells) and in PIE-immune cell co-cultures, and demonstrated that these systems are valuable tools to study in vitro the immune response triggered by TLR3 on IEC and the interaction between IEC and immune cells. In addition, we selected an immunobiotic lactic acid bacteria strain, Lactobacillus casei MEP221106, able to beneficially regulate the anti-viral immune response triggered by poly(I:C) stimulation in PIE cells. Moreover, we deepened our understanding of the possible mechanisms of immunobiotic action by demonstrating that L. casei MEP221106 modulates the interaction between IEC and immune cells during the generation of a TLR3-mediated immune response.     

Stopped-flow kinetic study of the aroxyl radical-scavenging action of catechins and vitamin C in ethanol and micellar solutions

Kinetic study of the aroxyl radical-scavenging action of catechins (epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), and epigallocatechin gallate (EGCG)) and related compounds (methyl gallate (MG), 4-methylcatechol (MC), and 5-methoxyresorcinol (MR)) has been performed. The second-order rate constant ( k s) for the reaction of these antioxidants with aroxyl radical has been measured in ethanol and aqueous Triton X-100 micellar solution (5.0 wt %). The k s values decreased in the order of EGCG > EGC > MC > ECG > EC > MG > MR in ethanol, indicating that the reactivity of the OH groups in catechins decreased in the order of pyrogallol B-ring > catechol B-ring > gallate G-ring > resorcinol A-ring. The structure-activity relationship in the free radical-scavenging reaction by catechins has been clarified by the detailed analyses of the pH dependence of k s values. From the results, the p K a values have been determined for catechins. The monoanion form at catechol B- and resorcinol A-rings and dianion form at pyrogallol B- and gallate G-rings show the highest activity for free radical scavenging. It was found that the free radical-scavenging activities of catechins are 3.2-13 times larger than that of vitamin C at pH 7.0.     

Weak northern and strong tropical land carbon uptake from vertical profiles of atmospheric CO2

Measurements of midday vertical atmospheric CO2 distributions reveal annual-mean vertical CO2 gradients that are inconsistent with atmospheric models that estimate a large transfer of terrestrial carbon from tropical to northern latitudes. The three models that most closely reproduce the observed annual-mean vertical CO2 gradients estimate weaker northern uptake of -1.5 petagrams of carbon per year (Pg C year(-1)) and weaker tropical emission of +0.1 Pg C year(-1) compared with previous consensus estimates of -2.4 and +1.8 Pg C year(-1), respectively. This suggests that northern terrestrial uptake of industrial CO2 emissions plays a smaller role than previously thought and that, after subtracting land-use emissions, tropical ecosystems may currently be strong sinks for CO2.     

Development of winter wheat with excellent resistance to pre-harvest sprouting and rain damage

Pre-harvest sprouting and high alpha-amylase activity are the most serious problems for the wheat production in Hokkaido, the northern most part of Japan. It has become more frequent for wheats to be exposed to continuous rain for several days in harvest time. In addition, low temperature below 15 ^°C, combined with rainfall, accelerates the damage of pre-harvest sprouting. Therefore, we started a breeding program in 1998 to develop wheat varieties with excellent resistant to sprouting damage in Hokkaido.Selection and evaluation of pre-harvest sprouting of resistant lines were conducted by two tests. One test was artificial rain treatment of intact spikes and the other was a germination test of hand-threshed grains at 10, 15 and 20 ^°C. The spikes of each line and variety were collected at physiological maturity and at one week after the first sampling date. Falling number was also measured.We have succeeded in breeding a deeply dormant breeding line, Kitakei 1802, from 1,923 doubled haploid lines raised by anther culture from the cross between Kitakei 1616 and Nishikazekomugi. Kitakei 1802 hardly sprouted through 10 days” continuous rainfall treatment at low temperature (15 ^°C) and maintained high falling number (> 300 s) in 2002 and 2003.     

Structural differences between myofibrillar protein,paratropomyosin, and tropomyosin as revealed by high‐performance liquid chromatography

Paratropomyosin (PTM) composes myofibril functions to weaken the rigor linkages formed between actin and myosin during postmortem aging of muscles. PTM has the similar physico‐chemical properties as tropomyosin (TM) that is a regulatory protein of myofibrils. So far, it is unclear whether PTM is definitely different from TM, because the primary structure of PTM has not been determined yet. The aim of this study was to clarify structural difference of PTM from TM. PTM was prepared by column chromatography immediately after slaughter from broiler breast muscle, and purified by high‐performance liquid chromatography (HPLC). Purified PTM was successfully separated from TM, and the recovered PTM molecule was reduced with dithiothreitol to separate again by HPLC. Two subunits were obtained and peptides from each digested subunit by V8 protease were recovered by HPLC, and then amino acid sequences of the peptides were analyzed by protein sequencing. As a result, some amino acid residues were replaced from that of TMα1 isoform which is the major isoform of TM, and also was different between the two subunits. Therefore, it is concluded that PTM clearly differs from TM and it is suggested that functional difference in PTM from TM is attributed to amino acid replacements in subunits composing PTM.     

Evaluation of changes in left ventricular myocardial function observed in canine myocardial dysfunction model using a two-dimensional tissue tracking technique

This study was conducted to assess the ability of two-dimensional tissue tracking (2DTT) to evaluate changes in left ventricular (LV) myocardial function associated with sustained high electrical pacing. Pacemakers were implanted at the right ventricular (RV) apex of five female Beagles, and sustained high electrical pacing of 250 beats per minute (bpm) was performed for three consecutive weeks. Conventional echocardiography and 2DTT were performed at baseline, and at every week for three weeks with pacing. The baseline parameters were then compared to those of weeks 1, 2, and 3. Three weeks of pacing resulted in significant reduction of radial and circumferential global strains (p < 0.001). Regional analysis revealed reduction of segmental strains in both radial and circumferential directions, as well as increased dyssynchrony after three weeks of pacing in the radial direction (p = 0.0007). The results of this study revealed the ability of 2DTT to measure radial and circumferential strains in dogs with sustained high-electrical pacing, and allowed assessment of global and regional myocardial function and the degree of dyssynchrony.     

Distribution of type VI collagen in the cartilaginous tissue of the proximal tibia in the domestic cat

To investigate the distribution of the early stage chondrocytes during the formation and closure of epiphyseal growth plate (EGP) of the domestic cat, we examined the EGP of proximal tibiae by immunohistochemistry for type VI collagen. In the epiphyseal cartilage without the secondary ossification center (SOC) and EGP in newborn cats aged 1 and 10 days, type VI collagen-positive chondrocytes were located around the cartilage canals and articular surface. In the epiphyseal cartilage with the SOC and EGP in young cats aged 1 to 3 months, type VI collagen-positive chondrocytes were located in the upper resting zone of the EGP, and then increased throughout the resting zone along with maturation. In the adult cats with the partially closed EGP, type VI collagen-positive chondrocytes were distributed throughout the remaining EGP. These findings indicate that the early stage chondrocytes characterized with type VI collagen are continuously located in the EGP during maturation. In addition, the increase of the early stage chondrocytes and the decrease of the reserve chondrocytes in the EGP along with maturation may cause the cessation of the longitudinal growth of the EGP, and finally bring about the EGP closure.