Bacteria belonging to the genus Cycloclasticus play a primary role in the degradation of aromatic hydrocarbons released in a marine environment
Bacteria belonging to the genus Cycloclasticus play a primary role in the degradation of aromatic hydrocarbons released in a marine environment
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DOI：
10.1128/aem.68.11.5625-5633.2002
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发表时间：
2002-11-01
影响因子：
4.4
通讯作者：
Harayama, S
中科院分区：
文献类型：
--
作者：
Kasai, Y;Kishira, H;Harayama, S
为了确定在海洋环境中对石油多核芳烃（PAHs）的好氧降解中起主要作用的细菌，以2-甲基萘、菲或蒽为碳源和能量源，从海水中富集细菌。我们发现，在富集培养中，Cycloclasticus属的成员成为优势。本研究分离的Cycloclasticus菌株可以在原油和原油中降解的多环芳烃成分上生长，包括未取代和取代的萘、二苯并噻吩、菲和芴。为了推断环裂菌菌株在沿海地区溢油中的作用，在1英寸宽、1.5米长、1米高的模拟海滩水箱中，研究了该细菌群在浸在海水中的被油包裹的砾石颗粒上的繁殖情况。储水池中有三分之二的砾石，不断向储水池中注入海水；水位在砾石层表面以上30 cm和以下30 cm之间变化，以模拟12 h的潮汐循环。在加入原油之前，与颗粒相关的环裂菌细胞数约为10(3)个细胞/g颗粒，加入原油后，环裂菌细胞数增加到3 × 10(6)个细胞/g颗粒。添加氮肥和磷肥时，14 d后细胞数进一步增加，达到10 × 10(6)个细胞/g粒，而不添加氮肥时，细胞数仍为3 × 10(6)个细胞/g粒。多环芳烃的降解过程与受石油污染的砾石颗粒表面环裂细胞的生长过程平行。这些观察结果表明，环裂菌属细菌在海洋环境中石油多环芳烃的降解中起着重要作用。
To identify the bacteria that play a major role in the aerobic degradation of petroleum polynuclear aromatic hydrocarbons (PAHs) in a marine environment, bacteria were enriched from seawater by using 2-methylnaphthalene, phenanthrene, or anthracene as a carbon and energy source. We found that members of the genus Cycloclasticus became predominant in the enrichment cultures. The Cycloclasticus strains isolated in this study could grow on crude oil and degraded PAH components of crude oil, including unsubstituted and substituted naphthalenes, dibenzothiophenes, phenanthrenes, and fluorenes. To deduce the role of Cycloclasticus strains in a coastal zone oil spill, propagation of this bacterial group on oil-coated grains of gravel immersed in seawater was investigated in beach-simulating tanks that were I In wide by 1.5 m long by 1 m high. The tanks were two-thirds filled with gravel, and seawater was continuously introduced into the tanks; the water level was varied between 30 cm above and 30 cm below the surface of the gravel layer to simulate a 12-h tidal cycle. The number of Cycloclasticus cells associated with the grains was on the order of 10(3) cells/g of grains before crude oil was added to the tanks and increased to 3 x 10(6) cells/g of grains after crude oil was added. The number increased further after 14 days to 10(8) cells/g of grains when nitrogen and phosphorus fertilizers were added, while the number remained 3 x 10(6) cells/g of grains when no fertilizers were added. PAH degradation proceeded parallel with the growth of Cycloclasticus cells on the surfaces of the oil-polluted grains of gravel. These observations suggest that bacteria belonging to the genus Cycloclasticus play an important role in the degradation of petroleum PAHs in a marine environment.