CAJ | 학술논문

在不同C：N(5、10、15、20)条件下研究了一株溶藻弧菌(Vibrio alginolyticus)Z5对单一氮源(有机氮源、NH4-N、NO2-N)及混合氮源(有机氮源与NH4-N、有机氮源与NO2-N、NH4-N与NO2-N)的吸收利用特性及蛋白酶、谷氨酰胺合成酶(GS)和亚硝酸还原酶(NiR)等3种氮代谢相关酶的活力响应。研究结果表明，溶藻弧菌 Z5对有机氮与无机氮的吸收均受到环境中碳含量的影响，在C：N=20时，对NH4-N和NO2-N的吸收率分别是C：N=5时吸收率的3.39倍和2.25倍。在C：N=15和C：N=20的水平下，溶藻弧菌Z5对NH4-N和NO2-N的吸收均没有显著性差异(P>0.05)。溶藻弧菌(Z5)吸收利用NH4-N和NO2-N的途径分别为NH4-N→细菌菌体蛋白和NO2-N→NH4-N→细菌菌体蛋白。在高 C：N 条件下，溶藻弧菌 Z5对无机氮源(NH4-N 和 NO2-N)的吸收增强，细菌菌体蛋白中来自 NH4-N 和 NO2-N的量分别由C：N=5时的25.0%和19.4%上升到C：N=20时的41.3%和43.0%。GS酶活力受NH4-N调控明显，相比之下，蛋白酶和NiR酶受氮源种类调控不明显。
재불동C：N(5、10、15、20)조건하연구료일주용조호균(Vibrio alginolyticus)Z5대단일담원(유궤담원、NH4-N、NO2-N)급혼합담원(유궤담원여NH4-N、유궤담원여NO2-N、NH4-N여NO2-N)적흡수이용특성급단백매、곡안선알합성매(GS)화아초산환원매(NiR)등3충담대사상관매적활력향응。연구결과표명，용조호균 Z5대유궤담여무궤담적흡수균수도배경중탄함량적영향，재C：N=20시，대NH4-N화NO2-N적흡수솔분별시C：N=5시흡수솔적3.39배화2.25배。재C：N=15화C：N=20적수평하，용조호균Z5대NH4-N화NO2-N적흡수균몰유현저성차이(P>0.05)。용조호균(Z5)흡수이용NH4-N화NO2-N적도경분별위NH4-N→세균균체단백화NO2-N→NH4-N→세균균체단백。재고 C：N 조건하，용조호균 Z5대무궤담원(NH4-N 화 NO2-N)적흡수증강，세균균체단백중래자 NH4-N 화 NO2-N적량분별유C：N=5시적25.0%화19.4%상승도C：N=20시적41.3%화43.0%。GS매활력수NH4-N조공명현，상비지하，단백매화NiR매수담원충류조공불명현。
Nitrogen assimilation characteristics of a Vibrio alginolyticus strain (Z5) were investigated under both single (organic nitrogen, NH4-N, or NO2-N) and mixed nitrogen sources (organic nitrogen and NH4-N, organic nitrogen and NH4-N, or NH4-N, and NO2-N) at C/N ratios of 5, 10, 15, and 20 respectively. Activity of protease, glutamine synthetase, and nitrite reductase, which are all involved in nitrogen metabolism, was also determined. The results showed that both organic and inorganic nitrogen assimilation rates of V. alginolyticus were affected by C/N ratio. NH4-N and NO2-N assimilation rates under a C/N ratio of 20 were 3.39 and 2.25 times higher, respec-tively, than those under a C/N ratio of 5. There were no significant differences in the assimilation of NH4-N and NO2-N between C/N ratios of 15 and 20 (P>0.05). The NH4-N and NO2-N assimilation processes may be NH4-N→bacterial protein and NO2-N→NH4-N→bacterial protein, respectively. Inorganic nitrogen (NH4-N and NO2-N) assimilation rates increased with higher C/N; the protein nitrogen content of the bacteria enriched from NH4-N and NO2-N increased from 25.0% and 19.4% under a C/N of 5 to 41.3% and 43.0% under a C/N of 20, respectively. In addition, glutamine synthetase activity was significantly regulated by NH4-N while protease and NiR activity were not regulated significantly by the nitrogen species.