该研究运用生命周期评价方法对规模化生猪农场系统的生猪养殖、粪污处理和水稻种植等过程的碳氮足迹进行特征分析(基准情景S0),并对比了低蛋白日粮(S1)、粪尿酸化(S2)、沼气利用(S3)、水稻侧深施肥(S4)、有机无机配施(S5)以及综合技术(...该研究运用生命周期评价方法对规模化生猪农场系统的生猪养殖、粪污处理和水稻种植等过程的碳氮足迹进行特征分析(基准情景S0),并对比了低蛋白日粮(S1)、粪尿酸化(S2)、沼气利用(S3)、水稻侧深施肥(S4)、有机无机配施(S5)以及综合技术(S6)等减排措施对农场系统环境排放的影响。结果表明:规模化生猪农场系统碳足迹为332.9 kg CO_(2)-eq·FU^(-1),氮足迹为4.55 kg Nr·FU^(-1)。其中,粪便储存环节碳氮足迹的贡献最高,分别占29%和50%。各环节单项技术(S1~S5)应用能够减少碳排放6.44%~11.25%,氮排放6.51%~30.37%;低蛋白日粮技术(S1)和粪尿酸化技术(S2)对农场系统碳、氮足迹的减排效果最佳,分别为11.25%和30.37%;综合技术(S6)能够实现系统碳氮足迹减排35.39%和51.66%。因此,生猪养殖场应重点关注饲料营养和粪尿管理过程,以减少农场系统碳氮排放,实现绿色发展。展开更多
NifA in Azospirillum brasilense plays a key role in regulating the synthesis and activity of nitrogenase in re- sponse to ammonia and oxygen available. In this work we used the yeast two-hybrid system to identify the ...NifA in Azospirillum brasilense plays a key role in regulating the synthesis and activity of nitrogenase in re- sponse to ammonia and oxygen available. In this work we used the yeast two-hybrid system to identify the proteins that interact with NifA. The nifA gene was fused to the yeast two-hybrid vector pGBD-C2, and three A. brasilense Sp7 genomic libraries for use in yeast two-hybrid studies were constructed. Screening of the libraries identified four clones encoding proteins that interact with NifA. The confirmation of the interactions of each gene product of the four clones and NifA were carried out by exchanging the vectors for nifA and the four clones and by mutageneses of the four clones with shift reading frame experiments in yeast two-hybrid studies. DNA sequence analyses showed that two clones en- code proteins containing PAS domains that play an impor- tant role in signal transduction. One clone has high similarity with the fhuE gene of Escherichia coli, whose gene product is involved in iron uptake and transportation, and the other clone encodes an unknown protein.展开更多
文摘该研究运用生命周期评价方法对规模化生猪农场系统的生猪养殖、粪污处理和水稻种植等过程的碳氮足迹进行特征分析(基准情景S0),并对比了低蛋白日粮(S1)、粪尿酸化(S2)、沼气利用(S3)、水稻侧深施肥(S4)、有机无机配施(S5)以及综合技术(S6)等减排措施对农场系统环境排放的影响。结果表明:规模化生猪农场系统碳足迹为332.9 kg CO_(2)-eq·FU^(-1),氮足迹为4.55 kg Nr·FU^(-1)。其中,粪便储存环节碳氮足迹的贡献最高,分别占29%和50%。各环节单项技术(S1~S5)应用能够减少碳排放6.44%~11.25%,氮排放6.51%~30.37%;低蛋白日粮技术(S1)和粪尿酸化技术(S2)对农场系统碳、氮足迹的减排效果最佳,分别为11.25%和30.37%;综合技术(S6)能够实现系统碳氮足迹减排35.39%和51.66%。因此,生猪养殖场应重点关注饲料营养和粪尿管理过程,以减少农场系统碳氮排放,实现绿色发展。
基金supported by the National Natural Science Foundation of China(Grant No.30170020)by the Doctoral Fellowship of the Education Ministry of China(Grant No.20010019002).
文摘NifA in Azospirillum brasilense plays a key role in regulating the synthesis and activity of nitrogenase in re- sponse to ammonia and oxygen available. In this work we used the yeast two-hybrid system to identify the proteins that interact with NifA. The nifA gene was fused to the yeast two-hybrid vector pGBD-C2, and three A. brasilense Sp7 genomic libraries for use in yeast two-hybrid studies were constructed. Screening of the libraries identified four clones encoding proteins that interact with NifA. The confirmation of the interactions of each gene product of the four clones and NifA were carried out by exchanging the vectors for nifA and the four clones and by mutageneses of the four clones with shift reading frame experiments in yeast two-hybrid studies. DNA sequence analyses showed that two clones en- code proteins containing PAS domains that play an impor- tant role in signal transduction. One clone has high similarity with the fhuE gene of Escherichia coli, whose gene product is involved in iron uptake and transportation, and the other clone encodes an unknown protein.
