Degradation of Sulfadiazine by Microbacterium lacus Strain SDZm4, Isolated from Lysimeters Previously Manured with Slurry from Sulfadiazine-Medicated Pigs
Degradation of Sulfadiazine by Microbacterium lacus Strain SDZm4, Isolated from Lysimeters Previously Manured with Slurry from Sulfadiazine-Medicated Pigs
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DOI：
10.1128/aem.03636-12
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发表时间：
2013-02
影响因子：
4.4
通讯作者：
W. Tappe;M. Herbst;D. Hofmann;S. Koeppchen;Sirgit Kummer;B. Thiele;J. Groeneweg
中科院分区：
文献类型：
--
作者：
W. Tappe;M. Herbst;D. Hofmann;S. Koeppchen;Sirgit Kummer;B. Thiele;J. Groeneweg
磺胺嘧啶（SDZ）降解细菌培养物富集从表层蒸渗仪，以前处理与粪便从猪与14 C标记的SDZ药物。经过3年的培养期后，约35%的应用放射性损失归因于蒸渗仪中矿化过程导致的CO2释放。来自这些蒸渗仪的潮湿土壤和土壤泥浆的微观实验证实了推测的矿化潜力，并分离出SDZ降解细菌。经鉴定为微杆菌属（Microbacterium lacus），命名为菌株SDZm 4。在M.用嘧啶环标记的SDZ对Lacus菌株SDZm 4进行处理，在10天的培养过程中，SDZ完全消失，但没有14 CO2释放。整个上样放射性（AR）保留在溶液中，可归属于2-氨基嘧啶。相比之下，对于平行孵育但使用苯环标记的SDZ，56%的AR以14 CO2形式释放，16%与生物质连接，21%保持溶解状态，尚未鉴定为14 C。因此，M.湖泊广泛矿化和部分同化的SDZ分子的苯基部分，同时形成等摩尔量的2-氨基嘧啶。这种部分降解可能是土壤微生物完全矿化SDZ的重要步骤。
ABSTRACT Sulfadiazine (SDZ)-degrading bacterial cultures were enriched from the topsoil layer of lysimeters that were formerly treated with manure from pigs medicated with 14C-labeled SDZ. The loss of about 35% of the applied radioactivity after an incubation period of 3 years was attributed to CO2 release due to mineralization processes in the lysimeters. Microcosm experiments with moist soil and soil slurries originating from these lysimeters confirmed the presumed mineralization potential, and an SDZ-degrading bacterium was isolated. It was identified as Microbacterium lacus, denoted strain SDZm4. During degradation studies with M. lacus strain SDZm4 using pyrimidine-ring labeled SDZ, SDZ disappeared completely but no 14CO2 was released during 10 days of incubation. The entire applied radioactivity (AR) remained in solution and could be assigned to 2-aminopyrimidine. In contrast, for parallel incubations but with phenyl ring-labeled SDZ, 56% of the AR was released as 14CO2, 16% was linked to biomass, and 21% remained as dissolved, not yet identified 14C. Thus, it was shown that M. lacus extensively mineralized and partly assimilated the phenyl moiety of the SDZ molecule while forming equimolar amounts of 2-aminopyrimidine. This partial degradation might be an important step in the complete mineralization of SDZ by soil microorganisms.