Anderson Robin C, Krueger Nathan A, Stanton Thaddeus B, Callaway Todd R, Edrington Thomas S, Harvey Roger B, Jung Yong Soo, Nisbet David J
United States Department of Agriculture, Agricultural Research Service, College Station, TX 77845, USA.
Bioresour Technol. 2008 Dec;99(18):8655-61. doi: 10.1016/j.biortech.2008.04.064. Epub 2008 Jun 5.
Ruminal methane (CH(4)) production results in the loss of up to 12% of gross energy intake and contributes nearly 20% of the United States' annual emission of this greenhouse gas. We report the effects of select nitrocompounds on ruminal fermentation after 22 h in vitro incubation (39 degrees C) with or without additions of hydrogen (H(2)), formate or both. In incubations containing no added reductant, CH(4) production was inhibited 41% by 2-nitro-1-propanol (2NPOH) and >97% by 3-nitro-1-propionic acid (3NPA), nitroethane (NE) and 2-nitroethanol (2NEOH) compared to non-treated controls and H(2) did not accumulate. With formate as the sole added reductant, nitro-treatment reduced CH(4) production by >99% and caused 42% to complete inhibition of formate catabolism compared to controls, and the accumulation of H(2) increased slightly. Nitro-treatment decreased CH(4) production 57-98% from that of controls when supplied H(2) or formate plus H(2). Formate catabolism was decreased 42-84% from that in controls by all nitro-treatments except 3NPA with both formate and H(2). Greater than 97% of the added H(2) was catabolized within controls; >84% was catabolized in nitro-treated incubations. Acetate, propionate and butyrate accumulations were unaffected by nitro-treatment irregardless of reductant; however, effects on ammonia and branched chain fatty acid accumulations varied. These results suggest that nitro-treatment inhibited formate dehydrogenase/formate hydrogen lyase and hydrogenase activity.
瘤胃甲烷（CH₄）的产生导致高达12%的总能摄入量损失，并且占美国该温室气体年排放量的近20%。我们报告了在39℃体外培养22小时后，添加或不添加氢气（H₂）、甲酸盐或两者时，特定硝基化合物对瘤胃发酵的影响。在未添加还原剂的培养中，与未处理的对照相比，2-硝基-1-丙醇（2NPOH）使CH₄产量降低41%，3-硝基-1-丙酸（3NPA）、硝基乙烷（NE）和2-硝基乙醇（2NEOH）使CH₄产量降低>97%，且H₂没有积累。以甲酸盐作为唯一添加的还原剂时，与对照相比，硝基处理使CH₄产量降低>99%，并导致甲酸盐分解代谢完全抑制42%，且H₂的积累略有增加。当供应H₂或甲酸盐加H₂时，硝基处理使CH₄产量比对照降低57 - 98%。除了同时添加甲酸盐和H₂的3NPA外，所有硝基处理均使甲酸盐分解代谢比对照降低42 - 84%。在对照中，超过97%添加的H₂被分解代谢；在硝基处理的培养中，>84%被分解代谢。无论还原剂如何，乙酸盐、丙酸盐和丁酸盐的积累不受硝基处理的影响；然而，对氨和支链脂肪酸积累的影响各不相同。这些结果表明，硝基处理抑制了甲酸盐脱氢酶/甲酸盐氢裂解酶和氢化酶的活性。
