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极低蛋白日粮补充不同形式氮营养素对生长猪回肠食糜菌群、代谢产物和屏障功能的影响 被引量:10
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作者 刘壮 慕春龙 +3 位作者 彭宇 彭燮 车炼强 朱伟云 《南京农业大学学报》 CAS CSCD 北大核心 2019年第3期526-534,共9页
[目的]本试验旨在研究极低蛋白(ELP)日粮下,补充不同形式氮营养素(氨基酸或酪蛋白)对生长猪回肠微生物、代谢产物和屏障功能的影响。[方法]试验选用80头PIC阉公猪(体质量约15.57 kg,48日龄),随机分为4组:中等蛋白组(MP)、低蛋白组(LP)... [目的]本试验旨在研究极低蛋白(ELP)日粮下,补充不同形式氮营养素(氨基酸或酪蛋白)对生长猪回肠微生物、代谢产物和屏障功能的影响。[方法]试验选用80头PIC阉公猪(体质量约15.57 kg,48日龄),随机分为4组:中等蛋白组(MP)、低蛋白组(LP)、极低蛋白+氨基酸组(ELP-AA)和极低蛋白+酪蛋白组(ELP-CAS),日粮粗蛋白(CP)水平分别为17%、15%、13%和13%。每个处理5个重复,每个重复4头仔猪。试验期28 d。MP和LP两组添加必需氨基酸(AA),ELP-AA组添加非必需AA以达到LP组日粮水平,ELP-CAS组使用3%酪蛋白部分替代ELP-AA组的单体AA,使其满足营养需要。于第29天每个重复挑选1头接近栏平均体质量的猪屠宰,采集回肠食糜和肠道组织样品,用于各项指标测定。[结果]与MP组相比,ELP-AA组回肠食糜中双歧杆菌属(Bifidobacterium)、乳酸杆菌属(Lactobacillus)和消化链球菌属(Peptostreptococcus)的数量显著降低(P<0.05),短链脂肪酸、氨态氮和生物胺的含量均显著下降(P<0.05),而补充酪蛋白后,乙酸、丁酸、氨态氮、腐胺和精胺的含量得到显著恢复(P<0.05)。基因表达方面,与LP组相比,ELP-AA组部分肠道屏障功能相关基因(MUC-1、MUC-2和Occludin)的表达量均显著下调(P<0.05),而MUC-1和Occludin的表达量在ELP-CAS组和MP或LP组之间无显著差异(P>0.05)。相关性分析结果表明,Lactobacillus数量与丁酸和生物胺含量、MUC-1、MUC-2和Occludin基因表达量显著正相关。[结论]饲喂极低蛋白日粮补充单体氨基酸对回肠微生物数量、代谢以及肠道组织屏障均产生不利影响,而补充酪蛋白能部分改善回肠有益微生物的生长并恢复部分肠道屏障相关基因的表达,提示在极低蛋白质水平下,补充酪蛋白对维持机体正常氮利用、肠道微生物生长代谢和肠道屏障功能具有重要作用。 展开更多
关键词 蛋白水平 氮营养素 肠道微生物 屏障功能
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胃酸分泌的化学感应及其对氮营养素应答的研究进展
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作者 申俊华 赵小刚 +1 位作者 郭吉余 苏勇 《中国畜牧杂志》 CAS 北大核心 2022年第12期36-40,共5页
胃的一项重要功能是分泌胃酸,胃酸对养分消化吸收和肠道健康具有重要意义。饲粮中蛋白质的初步消化、胃消化酶的活化以及食物源微生物的杀灭都离不开胃酸的作用,而胃酸的分泌也受到营养物质的调控。本文从胃酸分泌的胞外刺激信号、胞内... 胃的一项重要功能是分泌胃酸,胃酸对养分消化吸收和肠道健康具有重要意义。饲粮中蛋白质的初步消化、胃消化酶的活化以及食物源微生物的杀灭都离不开胃酸的作用,而胃酸的分泌也受到营养物质的调控。本文从胃酸分泌的胞外刺激信号、胞内应答路径以及质子泵H+,K+-ATPase的活化过程等方面阐述胃酸分泌的机制,并从氮营养素角度分析其对胃酸分泌的调节作用,为进一步研究营养物质消化吸收与胃酸分泌之间双向交流提供参考。 展开更多
关键词 胃酸分泌 氮营养素 调控机制
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大肠菌群与氮营养素互作及其对机体健康的影响 被引量:2
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作者 刘壮 申军士 朱伟云 《微生物学报》 CAS CSCD 北大核心 2017年第1期8-14,共7页
蛋白质不仅是构建机体组织的主要原料,而且对动物新陈代谢活动至关重要。数目庞大的肠道细菌在机体营养素,尤其是氮营养素的代谢过程中发挥重要作用。小肠细菌能代谢部分氨基酸,进而影响宿主整体氨基酸的代谢。与小肠相比,大肠拥有更为... 蛋白质不仅是构建机体组织的主要原料,而且对动物新陈代谢活动至关重要。数目庞大的肠道细菌在机体营养素,尤其是氮营养素的代谢过程中发挥重要作用。小肠细菌能代谢部分氨基酸,进而影响宿主整体氨基酸的代谢。与小肠相比,大肠拥有更为丰富的菌群和更长的蠕动时间。一方面,进入大肠的氮营养素会影响大肠菌群的代谢和群落结构;另一方面,大肠菌群也能广泛参与氮营养素的代谢与利用,生成许多代谢产物,进而影响机体健康。本文主要综述了日粮蛋白质对大肠菌群的影响、大肠菌群代谢氨基酸的产物及其对肠道生理和机体健康的影响。 展开更多
关键词 大肠 肠道菌群 氮营养素 代谢产物 机体健康
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一株氮磷营养素降解菌的筛选和鉴定
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作者 李玉晖 朱清华 杨丽 《安徽农业科学》 CAS 北大核心 2009年第16期7538-7539,7626,共3页
[目的]筛选能够高效降解氮和磷营养素的菌株。[方法]以尿素为唯一氮源,以STTP为唯一的磷源,配制氮磷选择性培养基,对生活污水和一些工业废水中的微生物进行分离培养和筛选,采用显微镜观察技术和分子生物学技术相结合对筛选出的菌株进行... [目的]筛选能够高效降解氮和磷营养素的菌株。[方法]以尿素为唯一氮源,以STTP为唯一的磷源,配制氮磷选择性培养基,对生活污水和一些工业废水中的微生物进行分离培养和筛选,采用显微镜观察技术和分子生物学技术相结合对筛选出的菌株进行了鉴定。[结果]通过分离和筛选,从生活污水和工业废水中得到了一株能够利用STTP和尿素作为能源的菌株lyh6A。该菌株在较高浓度尿素(4.00 mg/ml)和STTP(0.50 mg/ml)选择性培养基上生长良好。根据菌落的形态、菌株显微形态及18S rDNA序列同源比较结果,确定所筛选出的菌株lyh6A与曲霉属杂色曲霉等亲缘关系较近,18S rDNA序列相似性达到99%以上。[结论]该研究将为利用微生物进行氮、磷富营养化污染水体的治理提供基础。 展开更多
关键词 营养素 微生物降解 菌株鉴定 18SrDNA
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强化后期氮素营养对提高水稻结实率及改善米质的作用 被引量:11
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作者 周阮宝 谷丽萍 周嘉槐 《植物生理学通讯》 CSCD 1992年第3期171-176,共6页
加强后期氮素营养能提高杂交水稻碳氨同化能力和结实率,稻米的蛋白质和八种必需氨基酸含量、谷类蛋白的赖氨酸和苏氨酸也有提高。
关键词 米质 水稻 结实率 营养
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基于图像处理的茶树含氮量诊断方法初步研究 被引量:5
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作者 刘连忠 李孟杰 +2 位作者 林源丰 张正竹 张嫚嫚 《北华大学学报(自然科学版)》 CAS 2019年第1期114-120,共7页
为快速获取茶树的氮营养素水平,基于图像处理技术研究茶树氮营养素诊断方法.采摘不同施氮地块同一生长部位的茶树叶片,在白色背景、自然光下用数码相机对叶片拍照,用化学法测得叶片含氮量.利用Open CV计算机视觉库编写图像处理程序,从... 为快速获取茶树的氮营养素水平,基于图像处理技术研究茶树氮营养素诊断方法.采摘不同施氮地块同一生长部位的茶树叶片,在白色背景、自然光下用数码相机对叶片拍照,用化学法测得叶片含氮量.利用Open CV计算机视觉库编写图像处理程序,从原始图像中分割出叶片图像,提取叶片的R,G,B均值,并计算归一化的NRI,NGI,NBI及H,S,I均值,另选取R/G,B/G,B/R,R/(R+G-B),G/(R+G-B),B/(R+G-B)构成15个颜色特征参数,使用SPSS软件对颜色特征参数和含氮量进行回归分析,在误差分析基础上建立茶树氮营养素估算模型.将该模型运用于验证样本,得到含氮量估算值与实测值的平均相对误差为9. 28%,RMSE为0. 265.结果表明,该模型可用于茶树氮营养素水平的快速诊断. 展开更多
关键词 茶树 生长监测 图像处理 氮营养素诊断 精准施肥
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Influences of Nitrogen Level on Carbon Metabolism of Spring Maize 被引量:5
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作者 其其格 李可 +2 位作者 李刚 李春艳 曹国军 《Agricultural Science & Technology》 CAS 2010年第4期34-36,共3页
[Objective]To study the effect of supplies of nitrogen level on spring maize leaf blade carbon metabolism.[Method]In this experiment,field trail and biochemistry analysis were used to study the effect of the diference... [Objective]To study the effect of supplies of nitrogen level on spring maize leaf blade carbon metabolism.[Method]In this experiment,field trail and biochemistry analysis were used to study the effect of the diference-nitrogen level on the content of chlorophyl and carboxylase activity of RuBP and PEP in the leaf of spring maize during main growing period.[Result]Applying proper amount of N could keep relative higher content of chlorophyl and higher activity of carboxylase of RuBP and PEP in the leaf of spring maize,insufficient or excessive(N 400 kg/hm^2) of nitrogenous fertilizer has the adverse effect.[Conclusion]In this experiment,applying 300 kg/hm^2 amount of N could keep relative higher content of chlorophyl and higher activity of carboxylase of RuBP and PEP in the leaf of spring maize during main growing period.It was important to strengthens the leaf blade photosynthesis ability,promote the yield formation and postpone the decline of leaf blade. 展开更多
关键词 Nitrogen nutrition Spring maize Carbon metabolism
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Effect of Paclobutrazol plus Ethephon Treatment on Endogenous Hormones and Carbon and Nitrogen Nutrients in Litchi Variety ‘Feizixiao' 被引量:5
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作者 陈炫 陶忠良 +4 位作者 吴志祥 王令霞 符惠珍 周兆德 范武波 《Agricultural Science & Technology》 CAS 2013年第8期1125-1131,共7页
[Objective] This study aimed to investigate the effect of spraying the mixture of paclobutrazol and ethephon on the endogenous hormones and carbon and nitrogen nutrients in litchi variety 'Feizixiao'.[Method] [Resul... [Objective] This study aimed to investigate the effect of spraying the mixture of paclobutrazol and ethephon on the endogenous hormones and carbon and nitrogen nutrients in litchi variety 'Feizixiao'.[Method] [Result] The results showed that foliar spraying of the mixture of paclobutrazol and ethephon could effectively inhibit litchi variety 'Feizixiao' to produce winter shoots,promote the flower bud differentiation and improve flower formation rate; meanwhile,this treatment could also increase the contents of ABA and ZR,and the ratios of ABA/IAA,ABA/GA3,ZR/IAA,ZR/GA3,and decrease the contents of IAA and GA3; additionally,it could increase the contents of soluble sugar,starch and total nitrogen,and raise C/N ratio,thus improving the flower formation rate.[Conclusion] Foliar spraying of the mixture of paclobutrazol and ethephon is an effective pathway for solving warmth damage to litchi. 展开更多
关键词 Litchi variety 'Feizixiao' Paclobutrazol and ethephon Endogenous hormones Carbon and nitrogen nutrients
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Effects of Spraying Nitrogen and Zinc Fertilizers after Flowering on Grain Weight and Nutritional Quality of Winter Wheat 被引量:2
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作者 左毅 马冬云 +2 位作者 马英 张斌 郭天财 《Agricultural Science & Technology》 CAS 2013年第4期630-634,650,共6页
In order to explore the effect of spraying fertilizers after flowering on grain weight and nutritional quality of different winter wheat cultivars, twenty wheat culti- vars in wheat zones along Yellow River and Huai R... In order to explore the effect of spraying fertilizers after flowering on grain weight and nutritional quality of different winter wheat cultivars, twenty wheat culti- vars in wheat zones along Yellow River and Huai River, were used to investigate the change of thousand kernel weight (TKW), phytic acid content (PAC), contents of Fe, Zn and Mg and bioavailability by spraying zinc and nitrogen fertilizers after flowering. The results showed that both of TKW and protein content in grains in- creased by spraying Zn and N fertilizers, and the effect of N fertilizer proved more significant. The PAC decreased significantly after Zn treatment, for example, PAC of "955159", a wheat cultivar, decreased by 27.95%. However, PAC was in- significantly influenced by N fertilizer. On the other hand, Zn content in wheat grains were improved after spraying Zn fertilizer and the increase aveaged 54.38%. Furthermore, Fe and Zn contents grew significantly after spraying N fertilizer, and the increase averaged 36.88% and 11.25% respectively. However, Mg content in grains declined by N fertilizer. Still, the bioavailability of zinc in grains was enhanced after spraying Zn fertilizer, and of Fe was also increased greatly after spraying N fertilizer. In conclusion, grain weight, and content and effectiveness of mineral ele-ments can be improved simultaneously by rational spraying of N and Zn fertilizers to improve quality of grains. 展开更多
关键词 Winter wheat Spraying fertilizer after flowering Nitrogen and zinc fertil- izers Grain weight Nutrient elements
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Variation Dynamics of Total Nitrogen and Nicotine of Burley Tobacco at Various Growing Stages under Different Nitrogen Nutrition Levels 被引量:2
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作者 柴家荣 《Agricultural Science & Technology》 CAS 2012年第11期2327-2331,共5页
[Objective] This study aimed to investigate the variation dynamics of total nitrogen and nicotine of burtey tobacco at various growing stages under different ni- trogen nutrition levels to provide reference for optimi... [Objective] This study aimed to investigate the variation dynamics of total nitrogen and nicotine of burtey tobacco at various growing stages under different ni- trogen nutrition levels to provide reference for optimizing fertilization technologies for burley tobacco. [Method] Fresh burley tobacco leaves were collected at various growing stages and dried to measure the content of total nitrogen, protein and nico- tine by using INTEGRAL automated chemical analyzer and analyze the correlation with nitrogen application level. [Result] Regardless of the nitrogen application level, the content of total nitrogen and protein showed a downward trend since root ex- tending stage and reached the minimum at mature stage; the content of nicotine showed an upward trend since early vigorous growing stage and increased to the maximum at mature stage; the content of total nitrogen, protein and nicotine all in- creased after air curing; the content of total nitrogen, protein and nicotine showed positive correlation with nitrogen application level, while total nitrogen/nicotine was negatively correlated. The results indicate that nitrogen level is closely related to the total nitrogen and nicotine of burley tobacco at growing period and post-air curing, rational application of nitrogen is an important measure to regulate the content of total nitrogen and nicotine of tobacco. [Conclusion] This study provides scientific ba- sis for rational fertilization of burley tobacco. 展开更多
关键词 Burley tobacco Nitrogen nutrition Growth period Total nitrogen NICOTINE
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COMPARATIVE STUDIES ON NITROGEN BUDGETS OF CLOSED SHRIMP POLYCULTURE SYSTEMS 被引量:3
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作者 齐振雄 李德尚 +1 位作者 张曼平 董双林 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2001年第3期233-242,共10页
April to October, 1997 comparative studies on the nitrogen budgets of closed shrimp polyculture systems showed that, in all the studied polyculture systems, nitrogen from feeds and fertilizers were the main input item... April to October, 1997 comparative studies on the nitrogen budgets of closed shrimp polyculture systems showed that, in all the studied polyculture systems, nitrogen from feeds and fertilizers were the main input items, which comprised 70.7%-83.9% of the total input nitrogen, 3.2%-7.4% of which was provided by nitrogen fixation. It was in monoculture enclosures (Y 4, Y 11 and Y 12) that the percentage reached the maximum value. The output nitrogen in harvested products comprised 10.8%-24.6% of total input nitrogen, and the highest percentage, 24.6%, was found in shrimp fish tagelus polyculture systems. In shrimp monoculture and shrimp fish polyculture systems, they were 19.1% and 21.9%, respectively. The nitrogen utilization efficiency was different and varied from 12.2% to 20.1%. The highest, 20.1%, was found in shrimp fish tagelus polyculture systems, and the average of 20.0% was found in shrimp tagelus polyculture systems. The lowest, 12.2%, was found in shrimp monoculture systems. All the nitrogen utilization efficiencies in shrimp fish systems or shrimp scallop systems seemed to be higher than that of the monoculture system, but they showed little statistical difference. The main outputs of nitrogen were found in sediment mud, and comprised 48.2%-60.8% of the total input, the lowest percentage was found in shrimp fish tagelus polyculture systems, and the highest percentage in shrimp scallop systems. During the experiment, nitrogen lost through denitrification and ammonia volatilization comprised 1.9%-6.2%, averaged 2.8%, of the total input, and the loss through seepage comprised 5.9%-8.9% of the total. The estimated nitrogen attached to the enclosure wall comprised 3.7%-13.3% of the total, and was highest in shrimp monoculture systems. Compared with the classic shrimp farming industry, the closed shrimp polyculture systems may improve the nitrogen utilization efficiency, and hence reduce the environmental impacts on coastal waters. The nitrogen discharging rates for all the studied polyculture systems ranged from 3.0% to 6.0% of total input nitrogen. 展开更多
关键词 nitrogen budget shrimp culture polyculture system
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Trophic ecology of small yellow croaker (Larimichthys polyactis Bleeker): stable carbon and nitrogen isotope evidence 被引量:7
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作者 纪炜炜 陈雪忠 +1 位作者 姜亚洲 李圣法 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第5期1033-1040,共8页
The trophic ecology of the small yellow croaker (Larimichthys polyactis) was studied using stable isotope analyses. Samples were collected from July to September 2009 and 34 individuals from eight sites were examine... The trophic ecology of the small yellow croaker (Larimichthys polyactis) was studied using stable isotope analyses. Samples were collected from July to September 2009 and 34 individuals from eight sites were examined for stable carbon and nitrogen isotopes. Stable carbon isotope ratios (~3C) ranged from -20.67 to -15.43, while stable nitrogen isotope ratios (~SN) ranged 9.18-12.23. The relationship between fi^3C and ~SN suggested high resource partitioning in the sampling area. Significant differences in stable isotope values among the eight sampling sites may be linked to environmental diversities involving various physical processes (such as ocean current, wind and tide) and different carbon sources. Furthermore, the stable isotope ratios may also explain the ontogenetic variability in diet and feeding, because δ13C and δ15N varied significantly with increasing body size. The findings are consistent with other studies on diet analyses in small yellow croaker. It was also demonstrated that stable isotope analysis could be used to estimate the trophic characters of small yellow croaker in feeding patterns and migrating habits. 展开更多
关键词 small yellow croaker stable isotope analysis trophic strategy East China Sea
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Influence of climate and litter quality on litter decomposition and nutrient release in sub-tropical forest of Northeast India 被引量:5
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作者 N.Bijayalaxmi Devi P.S.Yadava 《Journal of Forestry Research》 SCIE CAS CSCD 2010年第2期143-150,I0004,共9页
Leaf litterfall,litter decomposition and nutrient return through litterfall of three dominant species,i.e.Quercus serrata,Schima wallichi and Lithocarpus dealbata were studied in different months throughout the year t... Leaf litterfall,litter decomposition and nutrient return through litterfall of three dominant species,i.e.Quercus serrata,Schima wallichi and Lithocarpus dealbata were studied in different months throughout the year to assess the input and release of nutrient in the forest soil of a sub-tropical mixed oak forest of Manipur,northeastern India.Oaks in northeastern region of India are economically important species for the production of Tasar silk.The monthly litterfall ranged from 25.6 g·m^-2(July) to 198.0 g·m^-2(February) and annual litterfall was 1093.8g·m^-2 in the forest site.At initial month(on November 3),the concentrations of N and C were the highest in L.dealbata,followed by Q.serrata and lowest in S.wallichi,whereas lignin and cellulose concentrations at initial month were the highest in S.wallichi,followed by Q.serrata and L.dealbata.L.dealbata(k=0.54) exhibited a high rate of litter decomposition,coinciding with high concentrations of N and C and low cellulose in the litter at initial month.However,low rate of litter decomposition in S.wallichi(k=0.33) coincided with low value of N and C and highest value of lignin and cellulose at initial month.The remaining biomass in different months was positively correlated with the lignin,C,C/N ratio and cellulose,but it negatively correlated with nitrogen concentrations at initial month.The rate of litter decomposition was the highest in rainy summer months,owing to congenial environmental conditions and lowest rate of litter decomposition in cool and dry winter months. 展开更多
关键词 nutrient use efficiency Quercus serrata NITROGEN lignin and litter quality
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Effect of Silicon and Nitrogen Nutrition on Pest and Disease Intensity in Rice 被引量:1
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作者 Kasthuri Rajamani Bhupal Raj Gunti +1 位作者 Shashi Vemuri Ramesh Bellamkonda 《Journal of Agricultural Science and Technology(A)》 2013年第7期568-574,共7页
Nutrition management is the most important for high yield production but it may affect the response of rice plants to pest and diseases due to the change of microclimate under rice plant canopy. The knowledge of nutri... Nutrition management is the most important for high yield production but it may affect the response of rice plants to pest and diseases due to the change of microclimate under rice plant canopy. The knowledge of nutrition management and its relation with pest and diseases are basis for setting up a high yield production system. Most of the pest and disease control procedures used by farmers can be considered as soil fertility management and these nutrition practices can have impact on the physiological susceptibility of crop plants to pest and diseases by affecting the plant resistance. Silicon content of plants is particularly effective against pest and diseases in rice and certain rice genotypes are more efficient accumulators of silicon, thus making them more resistant. In the absence of natural heritable resistance in rice varieties, resistance could be induced by altemate strategies to suppress certain pest and pathogens. Hence experiments were carried out in two stages during kharif 2010 and 2011 to assess the concentration of silicon in the index leaves of rice plant utilizing 133 varieties in four locations. The silica content of promising varieties ranged from 1.50% to 3.20%, 1.60% to 3.15%, 1.49% to 3.20% and 1.55% to 3.06% with a mean values of 2.50%, 2.48%, 2.51% and 2.43% at Jagtial, Warangal, Rajendranagar and Rudrur centres of Telangana region and not much variation in mean silica content in index leaves at different places. The overall yield from four locations ranged from 2,653 kg/ha to 6,860 kg/ha with a mean of 5,624 kg/ha. The yields recorded at Jagtial, Warangal, Rajendranagar and Rudrur centres ranged from 2,886 to 7,198, 2,653 to 6,831, 2,653 to 6,860 and 4,399 to 5,950 kg/ha, respectively. The lowest mean yield 5,069 kg/ha was noticed at Rudrur and the highest yield 5,940 kg/ha was found at Warangal. The variations in yields might be due to genotypic variations and also due to variations in climatic conditions of different locations. 展开更多
关键词 Nutrition management conventional rice silicon rice genotypes pest and diseases.
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Role of Nitrogen and Nutrients in Crop Nutrition 被引量:4
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作者 Vicente Torres-Olivar Oscar Gabriel Villegas-Torres +5 位作者 Martha Lilia Dominguez-Patifio Hoctor Sotelo-Nava Antonio Rodrlguez-Martme Rosa Maria Melgoza-Aleman Luis Alonso Valdez-Aguilar Irfin Alia-Tejacal 《Journal of Agricultural Science and Technology(B)》 2014年第1期29-37,共9页
Nutrition is an important factor for the growth and development of plants. Among the main nutritional elements, there are nitrogen (N) and calcium (Ca). The N comes from two forms of inorganic ions, ammonium (NH... Nutrition is an important factor for the growth and development of plants. Among the main nutritional elements, there are nitrogen (N) and calcium (Ca). The N comes from two forms of inorganic ions, ammonium (NH4+) and nitrate (NO3) whose functions in the plant are the increase in leaf area and improving the succulence of many crops, among other essential physiological processes. Both the deficit and excess NO3- have a negative impact on plants increasing susceptibility to insect pests and pathogens, while Ca as divalent ion absorbed Ca2+ plays an important role in control of physiological disorders and the resistance of plants to diseases to increase the mechanical strength. The N and Ca have a close relationship in the nutritional role of the plant, because the Ca absorption acting nitrates, so that a proper balance affects plants better growth and higher strength. 展开更多
关键词 IONS ABSORPTION NITRATE AMMONIUM concentration.
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Characterization of the start-up period of single-step autotrophic nitrogen removal in a sequencing batch reactor
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作者 郭劲松 《Journal of Chongqing University》 CAS 2008年第1期17-22,共6页
The characteristics of the start-up period of single-step autotrophic nitrogen removal process were investigated. The autotrophic nitrogen removal process used a sequencing batch reactor to treat wastewater of medium ... The characteristics of the start-up period of single-step autotrophic nitrogen removal process were investigated. The autotrophic nitrogen removal process used a sequencing batch reactor to treat wastewater of medium to low ammonia-nitrogen concentration, with dissolved oxygen (DO), hydraulic retention time (HRT) and temperature controlled. The experimental conditions were temperature at (30±2) ℃, ammonia concentration of (60 to 120) mg/L, DO of (0.8 to 1.0) mg/L, pH from 7.8 to 8.5 and HRT of 24 h. The rates of nitrification and nitrogen removal turn out to be 77% and 40%, respectively, after a start up period going through three stages divided according to nitrite accumulation: sludge domestication, nitrifying bacteria selection and sludge adaptation, It is demonstrated that dissolved oxygen is critical to nitrite accumulation and elastic YJZH soft compound packing is superior to polyhedral hollow balls in helping the bacteria adhere to the membrane. 展开更多
关键词 wastewater treatment single-step autotrophic nitrogen removal sequencing batch reactor NITRIFICATION
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Effects of Exogenous Nutrient Additions on Azodye Wastewater Treatment
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作者 Zhiqiang YU Xingjuan CHEN Yuming ZHONG 《Agricultural Science & Technology》 CAS 2016年第9期2157-2160,2166,共5页
Since the azo dyes widely used in textile-dyeing industry are toxic, highly persistent, and ubiquitously distributed in the environment, their treatment efficiencies and fade in ecosystems have received worldwide atte... Since the azo dyes widely used in textile-dyeing industry are toxic, highly persistent, and ubiquitously distributed in the environment, their treatment efficiencies and fade in ecosystems have received worldwide attention. Due to the microbes play important roles in azo-dye degradation, exogenous nutrient addition is used as a promising biostimulation strategy to improve the treatment efficiencies of azo-dye wastewater. However, little is known about the effects of different kinds of exogenous nutrients on the azo-dye wastewater treatment directly. Here, three kinds of common nutrients, glucose, starch and yeast extract, were added to the sequencing batch reactors (SBR) for the treatment of wastewater containing acid red 73 to compare the biostimulation efficiencies by investigating the dye's removal efficiencies and the changes of related water qualities. Our results showed that the reactors added yeast extract had highest removal efficiencies and chemical oxygen demand (COD) as well, followed by glucose and starch. The removal rates of acid red 73 and COD were 90.63% and 8713% in the reactors added yeast extract, respectively, while 86.49% and 78.4% in those with glucose and 85.38% and 75.2% in those with starch. This study provided some useful information for the biostimulation strategy of azo-dye wastewater treatment and preliminarily suggested that yeast extract would be the optimal choice. 展开更多
关键词 Exogenous nutrient additions Azo-dye wastewater Sequencing batch reactor Acid red 73
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Validation of a Critical Nitrogen Curve for Summer Maize in the North China Plain 被引量:14
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作者 YUE Shan-Chao SUN Fu-Lai +5 位作者 MENG Qing-Feng ZHAO Rong-Fang LI Fei CHEN Xin-Ping ZHANG Fu-Suo CUI Zhen-Ling 《Pedosphere》 SCIE CAS CSCD 2014年第1期76-83,共8页
The concept of critical N concentration(N_c)has been widely used in agronomy as the basis for diagnosis of crop N status,and allows discrimination between field situations of sub-optimal and supra-optimal N supply.A c... The concept of critical N concentration(N_c)has been widely used in agronomy as the basis for diagnosis of crop N status,and allows discrimination between field situations of sub-optimal and supra-optimal N supply.A critical N dilution curve of N_c=34.0W^(-0.37),where W is the aboveground biomass(Mg DM ha^(-1))and N_c the critical N concentration in aboveground dry matter(g kg^(-1)DM),was developed for spring maize in Europe.Our objectives were to validate whether this European critical N dilution curve was appropriate for summer maize production in the North China Plain(NCP)and to develop a critical N dilution curve especially for summer maize production in this region.In total 231 data points from 16 experiments were used to test the European critical N dilution curve.These observations showed that the European critical N dilution curve was unsuitable for summer maize in the NCP,especially at the early growth stage.From the data obtained,a critical N dilution curve for summer maize in the NCP was described by the equation of N_c=27.2W^(-0,27),when aboveground biomass was between 0.64 and 11.17 Mg DM ha^(-1).Based on this curve,more than 90%of the data for the N deficiency supply treatments had an N nutrition index(NNI)<1 and 92%of the data for the N excess supply treatments had an NNI>1. 展开更多
关键词 critical N dilution curve N nutrition index optimal N management plant-based N diagnostic indicator
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Expression Patterns of Nine Ammonium Transporters in Rice in Response to N Status 被引量:11
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作者 LI Su-Mei LI Bao-Zhen SHI Wei-Ming 《Pedosphere》 SCIE CAS CSCD 2012年第6期860-869,共10页
Nitrogen use efficiency (NUE) was very low in China and a loss of as much as 7070 of the applied nitrogen fertilizers was reported in high-yielding rice fields. In order to investigate the molecular basis of high-af... Nitrogen use efficiency (NUE) was very low in China and a loss of as much as 7070 of the applied nitrogen fertilizers was reported in high-yielding rice fields. In order to investigate the molecular basis of high-affinity ammonium transport or uptake into rice (Oryza sativa L.), we analyzed the expression profiles of nine ammonium transporters (AMT), three each of OsAMT1, OsAMT2 and OsAMT3, at two different N requirement stages (young seedling stage and tillering stage) of rice growth as well as the changes in these expression patterns according to external N status using real-time reverse transcription polymerase chain reaction (RT-PCR). The results suggested that the nine OsAMT genes were expressed in different organs of rice plants, including mature roots, new roots, stems, old leaves and new leaves and that the expression patterns were organ specific and independent of the positions of the corresponding proteins in the phylogenetic tree. OsAMT1;1, 3;2 and 3;3 were expressed in the roots and shoots, primarily old leaves, OsAMT1;2 and 1;3 mainly in the roots, and OsAMT2;1, 2;2, 2;3 and 3;1 mainly in the shoots, primarily in new leaves, and relatively more in the stems than other genes. The expression patterns at the two different N requirement stages were the same; however, at the tillering stage with greater N requirements, the OsAMTs transcript levels were greater than those at the young seedling stage with low N requirements. N starvation for 48 h up-regulated OsAMT1;1, 1;2, 3;1, 3;2, 3;3 and down-regulated OsAMT1;3 mRNA abundance. Following N starvation, NH4+ and NH4NO3 re-supply down-regulated OsAMT1;2 and 3;3 and up-regulated OsAMT1;3, whereas NO3 re-supply down-regulated OsAMT1;1 and 1;2. These suggested that the organ-specific expression pattern of OsAMT could be regulated by N requirement and external N status. 展开更多
关键词 external N level gene expression growth stage N requirement plant organ
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Multifractal methods for rapeseed nitrogen nutrition qualitative diagnosis modeling
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作者 Jian-Hui Li Fang Wang +2 位作者 Jin-Wei Li Rui-Biao Zou Gui-Ping Liao 《International Journal of Biomathematics》 2016年第4期285-297,共13页
Nutrition diagnosis plays a key role in the crop's growth, which has mainly been car- ried out in the field by agricultural workers. Currently, automatic nutrition recognition technologies have been widely used in th... Nutrition diagnosis plays a key role in the crop's growth, which has mainly been car- ried out in the field by agricultural workers. Currently, automatic nutrition recognition technologies have been widely used in this field. A procedure is proposed in this paper to diagnose nitrogen nutrition non-destructively for rapeseed qualitatively based on the multifractal theory. Twelve texture parameters are given by the method of multifractal detrended fluctuation (MF-DFA), which contains six generalized Hurst exponents and six relative multifractal parameters that are used as features of the rapeseed leaf images for identifying the two nitrogen levels, namely, the N-mezzo and the N-wane. For the base leaves, central leaves and top leaves of the rapeseed plant and the three-section mixed samples, three parameters combinations are selected to conduct the work. Five classifiers of Fisher's linear discriminant algorithm (LDA), extreme learning machine (ELM), support vector machine and kernel method (SVMKM), random decision forests (RF) and K-nearest neighbor algorithm (KNN) are employed to calculate the diagno- sis accuracy. An interesting finding is that the best diagnose accuracy is from the base leaves of the rapeseed plant. It is explained that the base leaf is the most sensitive to the nitrogen deficiency. The diagnose effect by the base leaves samples is outshining the existing result significantly for the same leaves samples. For the mixed samples, the aver- aged discriminant accuracy reaches 97.12% and 97.56% by SVMKM and RF methods with the 10-fold cross-validation respectively. The resulting high accuracy on N-levels identification shows the feasibility and efficiency of our method. 展开更多
关键词 Rapeseed leaf image nitrogen diagnosis multifractal detrended fluctuationanalysis classifiers.
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