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The seeds of Monochoria vaginalis require light to germinate. However, they are able to germinate in darkness in the presence of rice hulls. The mechanism of this phenomenon was investigated in this study, in which only the unsterilized seeds of Monochoria were induced to germinate by the presence of a rice hull extract. The rice hull extract was able to be replaced by either a mixture of amino acids and phosphate or a yeast extract. The culture media in which germination was observed always showed turbidity, indicating the propagation of bacteria, which were identified as Bacillus sp., Pedobacter sp., Pantoea sp. and Sphingomonas sp. Treatment with the individual bacterial species or combinations of these bacteria induced Monochoria seed germination when added to the media containing the rice hull extract. It was concluded that the rice hull extract accelerates the propagation of bacteria, which in turn digest the seed coat of Monochoria, facilitating its germination.  相似文献   
94.
Immunostimulatory sequences of oligodeoxynucleotides (ODNs), such as CpG ODNs, are potent stimulators of innate immunity. Here, we identified a strong immunostimulatory CpG ODN, which we named MsST, from the lac Z gene of Streptococcus (S.) thermophilus ATCC19258, and we evaluated its immune functions. In in vitro studies, MsST had a similar ability as the murine prototype CpG ODN 1555 to induce inflammatory cytokine production and cell proliferation. In mouse splenocytes, MsST increased the number of CD80+CD11c+and CD86+CD11c+ dendritic cells and CD4+CD25+ regulatory T cells. We also analyzed the effects of MsST on the expression of regulatory cytokines by real-time quantitative PCR. MsST was more potent at inducing interleukin-10 expression than the ODN control 1612, indicating that MsST can augment the regulatory T cell response via Toll-like receptor 9, which plays an important role in suppressing T helper type 2 responses. These results suggest that S. thermophilus , whose genes include a strong Immunostimulatory sequence-ODN, is a good candidate for a starter culture to develop new physiologically functional foods and feeds.  相似文献   
95.
To investigate the effects of bovine growth hormone (bGH) gene polymorphism on carcass traits and fatty acid compositions in Japanese Black cattle caused by nucleotide substitution of CTG (allele A)/GTG (allele B) at codon 127 and of ACG (allele A and B)/ATG (allele C) at codon 172 of bGH, GH genotypes of 135 cattle were determined using allele specific-multiplex polymerase chain reaction (PCR). Allele A gave greater rib thickness and lower melting point of fat (MP) while allele B gave higher C18:1% ( P  < 0.05). Allele C gave higher C18:1, monounsaturated fatty acid (MUFA), unsaturated fatty acid (USFA) percentages ( P  < 0.05). It also gave lower saturated fatty acid (SFA) percentages, higher MUFA/SFA and USFA/SFA ratios, and lower MP ( P  < 0.05). Interactions of sex and GH alleles were analyzed. In heifers, allele A gave higher carcass weight, daily carcass gain, rib eye area, rib thickness, subcutaneous fat thickness, and BMS while allele B gave greater rib eye area and rib thickness ( P  < 0.05). Allele C gave higher C18:1 ( P  < 0.01), MUFA ( P  < 0.01), USFA percentages ( P  < 0.05) and MUFA/SFA and USFA/SFA ratios ( P  < 0.01), and lower C16:0 and SFA percentages ( P  < 0.05) and MP ( P  < 0.01). GH gene polymorphism affected carcass traits and fatty acid compositions although the effects were more pronounced in heifers.  相似文献   
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鲭鱼鱼肉中组胺菌的分离及其理化性质分析   总被引:1,自引:0,他引:1  
利用组氨酸肉汤培养液,对鲭鱼鱼肉中的组胺生成菌进行筛选,然后通过生物化学和形态学实验,进而对组胺生成菌进行分析。结果表明:分离得到2株组胺菌,菌种I在5~25℃的培养温度范围内,随温度升高,组胺生成量逐渐增加,在25℃组胺生成量最高,约2700mg/kg。菌种Ⅱ在20℃组胺生成量最高,约为2000mg/kg。依据2种组胺菌的特征和生理生化特征,分离菌可能分别属于摩尔摩根氏菌、嗜水性气单胞菌属。  相似文献   
98.
市售鱼类及其加工品中组胺含量的调查   总被引:1,自引:0,他引:1  
陶志华  佐藤实 《现代农业科技》2009,(19):334-334,336
2006年3月对市售鲭鱼20尾、秋刀鱼30尾、金枪鱼6块等进行组胺含量分析,结果表明,20尾鲭鱼中有1尾组胺含量为20mg/kg;30尾秋刀鱼肉中有1尾组胺含量为16mg/kg,另一尾为10mg/kg;6块金枪鱼样品及其他鱼类样品未能检测到组胺。鲭鱼20尾中1尾检出酪胺23mg/kg,尸胺为36mg/kg,腐胺及亚精胺未检出;秋刀鱼30尾中2尾检出10mg/kg和15mg/kg的酪胺,1尾栓出52mg/kg腐胺,2尾检出35mg/kg和55mg/kg尸胺。  相似文献   
99.
BACKGROUND: Botanical insecticides do not play a major role as crop protectants, but they are beneficial in some applications. The authors investigated the actions of naturally occurring alkaloids on insect nicotinic acetylcholine (ACh) receptors (nAChRs) by evaluating their abilities to inhibit specific binding of [3H]imidacloprid (IMI) to nerve‐cord membranes from Periplaneta americana L. Two alkaloids were also tested for their actions on nAChRs expressed by cockroach neurons using patch‐clamp electrophysiology. RESULTS: Four natural quinolizidine alkaloids (matrine, sophocarpine, cytisine and aloperine) exhibited more than 50% inhibition of [3H]IMI binding at 10 µM , although other compounds were found to have no or low inhibitory activity. The rank order of potency based on concentration–inhibition curves was cytisine > sophocarpine ≥ aloperine ≥ matrine. Patch‐clamp analysis indicated that sophocarpine and aloperine were not agonists of nAChRs expressed in P. americana neurons, yet, at 10 µM , aloperine, but not sophocarpine, suppressed ACh‐induced inward currents significantly. CONCLUSION: Three of the four natural alkaloids tested possess structural moieties that are necessary for interaction with P. americana nAChRs. Aloperine, which possesses a unique structure and showed a distinctive dose–response curve, was found to act as an antagonist. Appropriate modifications of these alkaloids might result in novel insecticidal nAChR ligands. Copyright © 2008 Society of Chemical Industry  相似文献   
100.
The aim of this study was to determine whether autonomic nervous activity of a rider with no disability was altered by one practical and applicable horse trekking (HT) exercise. Changes in autonomic nervous activity were analyzed by heart rate variability (HRV). Twenty‐three participants with no disability rode horses along a predetermined HT course at trotting and walking for 60 min. HRV was sampled at 60 min before and immediately, following 60 min, and 120 min after HT. As a control, the same measurements were performed for 22 age‐matched participants during their rest. Only in the HT group, the value of normalized unit in high frequency component (HF nu), an index of parasympathetic nervous activity, was higher at 120 min after treatment than before HT (P < 0.05). The low / high frequency ratio (LF / HF), believed to reflect sympathetic nervous activity, was lower in the HT group than those in the control group at 60 min (P < 0.05) and 120 min after treatment (P < 0.01). These findings suggest that a single HT shifted the autonomic nervous balance of a rider toward parasympathetic dominance. The results obtained by the present study could accelerate the use of horses for human health.  相似文献   
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