微生物转化六溴环十二烷的研究进展

1、应用与环境生物学报 Chin J Appl Environ Biol Doi: 10.19675/ki.1006-687x.2021.03027收稿日期 Received: 2021-03-13 接受日期 Accepted: 2021-05-03国家自然科学基金项目（31670117，31870104）资助 Supported by the National Natural Science Foundation of China (31670117, 31870104)*通讯作者 Corresponding author (E-mail: hzh)微生物转化六溴环十二烷的研究进展余 飞 胡忠*

2、广东汕头大学理学院生物系资源与环境微生物实验室 汕头 515063摘 要 六溴环十二烷（hexabromocyclododecanes，HBCDs）是一类包含多种异构体的阻燃剂，在环境中可随食物链积累，对人类和其他生物产生健康威胁。HBCDs可通过化学、物理和生物途径而被转化和降解，其中，微生物降解是清除HBCDs污染的重要途径。为提供生物修复HBCDs污染的理论依据，综述微生物转化HBCDs的研究进展。目前发现的HBCDs脱溴功能菌中，好氧菌株如Sphingobium chinhatense IP26和Pseudomonas sp. GJY可通过水解脱溴、消除溴化氢和还原脱溴途径将HBCDs

3、转化为低溴化的醇类和（或）环烯烃；厌氧微生物如Dehalococcoides mccartyi 195通过还原脱溴途径将HBCDs转化为低溴化环烯烃。HBCDs在厌氧环境中降解较快，其原因与HBCDs在化学、物理和厌氧微生物转化过程中均可作为电子受体的性质相关。另一方面，由于HBCDs包含-、-和-HBCD等多种异构体，微生物转化HBCDs的过程普遍存在着立体、对映异构体选择性，这种选择性源于脱卤酶和异构体的空间结构之间的相互选择。微生物转化HBCDs存在的问题和未来的研究方向包括：功能菌与其脱卤酶的异构体选择性存在差异的原因；微生物转化带来的具有多种异构体的低溴化产物缺乏生态毒理评价；将HB

4、CDs高效降解菌应用于环境修复的过程中，菌群结构、功能基因、脱溴产物及其归趋等需深入探索；厌氧环境下HBCDs的降解更快，可作为HBCDs污染修复的一个切入点。关键词 六溴环十二烷；微生物降解；脱溴；异构体特异性Microbial transformation of hexabromocyclododecanes, a reviewYU Fei, HU Zhong*The Lab of Resources & Environmental Microbiology, Shantou University, Shantou 515063, ChinaAbstract Hexabromocyclod

5、odecanes (HBCDs) are a type of brominated flame retardants with -, - and -HBCD as the three dominant diastereisomers. HBCDs had been listed in the Annex A of the Stockholm Convention on Persistent Organic Pollutants (POPs). They are threatening the health of human beings and other organisms due to t

6、heir toxicity and biomagnification. HBCDs generally loaded in the soil and sediment, which can be degraded via biotic and abiotic processes. Microbial degradation of HBCDs contributes to the transformation of HBCDs in the environment. By now, more than 10 bacterial strains with ability to transform

7、HBCDs have been characterized. Aerobic strains such as Sphingobium chinhatense IP26 and Pseudomonas sp. GJY transform HBCDs via hydrolytic debromination, HBr elimination and reductive debromination pathways yielding lower brominated alkanols and alkenes such as pentabromocyclododecanol, tetrabromocy

8、clododecadiol, tribromocyclododecatriol and tetrabromocyclododecene. Anaerobic strains such as Dehalococcoides mccartyi 195 transform HBCDs through reductive debromination pathways yielding lower brominated alkenes such as tetrabromocyclododecene, dibromocyclododecadiene and 1,5,9-cyclododecatriene.

9、 HBCDs can serve as electron acceptors in the reductive debromination pathway, which maybe a reason that HBCDs are degraded faster in the anaerobic environment where they can accept electron in the chemical, physical and microbial debromination. The microbial transformation of HBCDs is regio- and st

10、ereo-selective. The selection is result from the structural characters of dehalogenase and HBCDs. The selective transformation of HBCDs in the environment leads to serious concern on the toxicity of the various intermediates. Degradative strains have been applied in the bioremediation in the laborat

11、ory. However, the abundance of functional groups and genes as well as the transfer of debrominated products are not well studied during bioaugmentation. Here, for the first time, the current knowledge of microbial transformation of HBCDs are reviewed, and the anaerobic degradation of HBCDs in the bi

12、oremediation is highlighted.Keywords hexabromocyclododecanes; microbial degradation; debromination; diastereoisomer-specific六溴环十二烷（Hexabromocyclododecanes，HBCDs）是多溴联苯醚（PBDEs）之后的一类阻燃剂，已被列为有持久性有机污染物（POPs）。HBCDs被广泛应用于建材、化工和电器等领域，易在这些材料的加工和废弃过程中释放到环境。因此生产厂区和电子垃圾处理厂成为了HBCDs污染热点。除此之外，HBCDs已被发现于多种类型的土壤、水体和

13、近海沉积物，甚至南、北极地区 ADDIN EN.CITE ADDIN EN.CITE.DATA 1-4。我国表层土壤中HBCDs水平在0.88-6901 ng/g (dw)范围，高浓度的HBCDs存在于生产工厂周边土壤；相比之下，欧洲地区的HBCDs加工厂附近土壤中HBCDs水平更高，可达23200 ng/g（dw） ADDIN EN.CITE ADDIN EN.CITE.DATA 5-6。珠江口是受人类活动影响较大的地区，该区域HBCDs近年来呈现积累趋势。2003-2004年珠江口沉积物中HBCDs水平为0.414和0.579 ng/g（dw） ADDIN EN.CITE Li201314

14、1714114117Li, HonghuaShang, HongtaoWang, PuWang, YaweiZhang, HaidongZhang, QinghuaJiang, GuibinOccurrence and distribution of hexabromocyclododecane in sediments from seven major river drainage basins in ChinaJournal of Environmental SciencesJournal of Environmental Sciences69-76251HBCDsurface sedim

15、entChinese river drainage basindistribution20132013/01/01/1001-0742/science/article/pii/S1001074212600102/10.1016/S1001-0742(12)60010-27，2013年为1.52-13.3 ng/g（dw） ADDIN EN.CITE ADDIN EN.CITE.DATA 8，2015年在珠江口福田红树林沉积物达4.68-40.0 ng/g（dw） ADDIN EN.CITE ADDIN EN.CITE.DATA 9。环境中的HBCDs在食物链中积累和传递，最终对人类和其他生物的

16、健康造成严重威胁。在欧洲地区，2001年已报道在母乳中发现了HBCDs ADDIN EN.CITE Covaci2006666666617Covaci, A.Gerecke, A. C.Law, R. J.Voorspoels, S.Kohler, M.Heeb, N. V.Leslie, H.Allchin, C. R.De Boer, J.Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium. adrian.covaciua.ac.beHexabromocyclodo

17、decanes (HBCDs) in the environment and humans: a reviewEnviron Sci TechnolEnvironmental science & technologyEnviron Sci TechnolEnvironmental Science & Technology3679-8840122006/07/13AnimalsEnvironmental Monitoring/methodsEnvironmental Pollutants/*analysis/*bloodFlame Retardants/analysisFood ChainHum

18、ansHydrocarbons, Brominated/*analysis/*bloodStereoisomerism2006Jun 150013-936X (Print)0013-936x16830527NLMeng6；我国2009年报道在母乳中检测到了HBCDs ADDIN EN.CITE ADDIN EN.CITE.DATA 10。研究发现HBCDs具有潜在的神经毒性 ADDIN EN.CITE ADDIN EN.CITE.DATA 11-12，可引发慢性炎症 ADDIN EN.CITE ADDIN EN.CITE.DATA 13，影响内分泌 ADDIN EN.CITE ADDIN EN

19、.CITE.DATA 14-15，对水生生物的潜在毒性较大 ADDIN EN.CITE ADDIN EN.CITE.DATA 16。虽然HBCDs已经被禁止，中国地区也将于2021年12月25日全面停止其生产和使用，但已经被广泛使用的HBCDs还将持续释放到环境之中。因此，如何治理HBCDs带来的环境污染已成为重要的科学问题，本文就国内外微生物转化和降解HBCDs的研究进展进行综述和总结，以期增加对于HBCDs生物脱溴和污染修复的认识。HBCDs及其脱溴产物的检测技术和方法HBCDs（C12H18Br6）分子结构包含环十二烷骨架及其1, 2, 5, 6, 9, 10-位上的6个溴原子（图1、2

20、），溴原子的空间朝向差异形成了HBCDs的多种立体、对映异构体。HBCDs难溶于水，易溶于二氯甲烷和丙酮等有机试剂。研究发现HBCDs在丙酮、甲苯和甲醇等有机溶剂中会发生脱溴化氢反应(dehydrobromination)而转化 ADDIN EN.CITE Zhong20101581715815817Zhong, Y.Peng, P.Yu, Z.Deng, H.Pearl River Delta Research Center of Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese

21、 Academy of Sciences, Wushan, Guangzhou 510640, PR China.Effects of metals on the transformation of hexabromocyclododecane (HBCD) in solvents: implications for solvent-based recycling of brominated flame retardantsChemosphereChemosphereChemosphereChemosphere72-88112010/07/17Acetone/chemistryElectric

22、al Equipment and Supplies*Flame RetardantsHydrocarbons, Brominated/*chemistry*Industrial WasteKineticsMetals/*chemistryMethanol/chemistrySolvents/chemistryToluene/chemistryWaste Management/*methods2010Sep0045-65352063392310.1016/j.chemosphere.2010.06.061NLMeng17，也可以被光解，当金属和腐殖酸存在，脱溴转化更易发生 ADDIN EN.CI

23、TE ADDIN EN.CITE.DATA 17-19。另外，细菌易吸附HBCDs。以上因素均会造成非生物转化带来的误差，因此HBCDs的生物转化研究必须选择合适的方法并进行严格的对照和质控。环境介质中的HBCDs可以被乙腈、丙酮、二氯甲烷、正己烷等单一或混合有机溶剂提取 ADDIN EN.CITE ADDIN EN.CITE.DATA 20-23，经过硅胶柱层析纯化或Strata C18-E固相萃取柱富集 ADDIN EN.CITE Geng20199724979717Geng, JinyaoHan, MinYang, XinLi, YaoBartlam, MarkWang, Yingyin

24、gDifferent biotransformation of three hexabromocyclododecane diastereoisomers by Pseudomonas sp. under aerobic conditionsChemical Engineering JournalChemical Engineering Journal870-879374HBCDsBiodegradationEnantioselectivityMetabolitesDegradation pathways20192019/10/15/1385-8947/science/article/pii/

25、S1385894719312549/10.1016/j.cej.2019.05.23224，通过气相色谱-电子俘获检测器（GC-ECD） ADDIN EN.CITE ADDIN EN.CITE.DATA 25、液相色谱-质谱联用仪（LC-MS） ADDIN EN.CITE ADDIN EN.CITE.DATA 25-28、液相色谱-串联质谱（LC-MS/MS） ADDIN EN.CITE ADDIN EN.CITE.DATA 24, 28-29、高效液相色谱仪-紫外检测器（HPLC-RAM） ADDIN EN.CITE Davis20066422646417Davis, J. W.Gonsio

26、r, S. J.Markham, D. A.Friederich, U.Hunziker, R. W.Ariano, J. M.Toxicology and Environmental Research and Consulting, The Dow Chemical Company, 1803 Building, Midland, Michigan 48674, USA. jwdavisBiodegradation and product identification of 14Chexabromocyclododecane in wastewater sludge and freshwat

27、er aquatic sedimentEnviron Sci TechnolEnvironmental science & technologyEnviron Sci TechnolEnvironmental Science & Technology5395-40140172006/09/27Carbon RadioisotopesChromatography, High Pressure LiquidFresh WaterGeologic Sediments/*chemistryHydrocarbons, Brominated/*analysisMass SpectrometrySewage

28、/*chemistrySpectrophotometry, UltravioletWater Pollutants, Chemical/analysis/*metabolism2006Sep 10013-936X (Print)0013-936x16999116NLMeng22、气相色谱-质谱联用仪（GC-MS） ADDIN EN.CITE Demirtepe201948234848017Demirtepe, HaleImamoglu, IpekBiostimulation enhanced the biotic degradation of hexabromocyclododecane in

29、 sedimentsJournal of Soils and SedimentsJournal of Soils and Sediments2859-2868196285920191439-01081614-748010.1007/s11368-019-02280-z23等仪器进行鉴定和定量。细菌和脱卤酶转化HBCDs的培养物可通过乙酸乙酯进行液液萃取，或冻干培养物之后用乙酸乙酯、正己烷和乙腈等有机溶剂提取 ADDIN EN.CITE ADDIN EN.CITE.DATA 30-34，再利用以上仪器进行定量检测。鉴定HBCDs的脱溴产物的仪器包括GC-MS ADDIN EN.CITE ADDI

30、N EN.CITE.DATA 32-34、高效液相色谱-串联质谱（UPLC-MS/MS） ADDIN EN.CITE Geng20199724979717Geng, JinyaoHan, MinYang, XinLi, YaoBartlam, MarkWang, YingyingDifferent biotransformation of three hexabromocyclododecane diastereoisomers by Pseudomonas sp. under aerobic conditionsChemical Engineering JournalChemical Eng

31、ineering Journal870-879374HBCDsBiodegradationEnantioselectivityMetabolitesDegradation pathways20192019/10/15/1385-8947/science/article/pii/S1385894719312549/10.1016/j.cej.2019.05.23224、超高效液相色谱-飞行时间质谱（UPLC-TOF/MS） ADDIN EN.CITE Huang201984328484017Huang, LingWang, WeiweiShah, Syed BilalHu, HaiyangXu,

32、 PingTang, HongzhiThe HBCDs Biodegradation using a Pseudomonas Strain and Its Application in Soil PhytoremediationJournal of Hazardous MaterialsJournal of Hazardous Materials12083320190304389410.1016/j.jhazmat.2019.12083332、高效液相色谱-四极杆/飞行时间高分辨质谱（UPLC-UHR-QTOF） ADDIN EN.CITE ADDIN EN.CITE.DATA 25。中间产物

33、鉴定需根据质谱峰进行解谱，由于HBCDs特殊的分子结构，其质谱特征m/z较容易识别 ADDIN EN.CITE Geng20199724979717Geng, JinyaoHan, MinYang, XinLi, YaoBartlam, MarkWang, YingyingDifferent biotransformation of three hexabromocyclododecane diastereoisomers by Pseudomonas sp. under aerobic conditionsChemical Engineering JournalChemical Engine

34、ering Journal870-879374HBCDsBiodegradationEnantioselectivityMetabolitesDegradation pathways20192019/10/15/1385-8947/science/article/pii/S1385894719312549/10.1016/j.cej.2019.05.23224。但检测HBCDs中间产物仍存在一些限制因素，如浓度较低的脱溴产物可能会被杂质掩盖；温度条件对于中间产物的检出有不可忽视的影响：温度较低可能影响HBCDs响应，而温度过高则引起HBCDs热解 ADDIN EN.CITE ADDIN EN.

35、CITE.DATA 35。作者所在实验室发现在依托GC-MS鉴定HBCDs的脱溴产物研究中，HBCDs及其五溴和四溴产物的m/z（约为561和480）通常强度较低，难以识别；而三溴、二溴和一溴产物（m/z约为400、320和239）及其醇类产物的m/z较容易识别 ADDIN EN.CITE ADDIN EN.CITE.DATA 32-34。由于缺乏标准品，大部分中间产物不能被精确鉴定。可在检测HBCDs的条件下，同时检测微生物、非生物转化样品和HBCDs标准品，从而去除非生物转化带来的假阳性干扰，推测潜在的转化产物。图1 细菌和脱卤酶转化HBCDs的水解脱溴途径 ADDIN EN.CITE A

36、DDIN EN.CITE.DATA 24-26, 31-32, 38。粉红色箭头指示羟基化但没有脱除溴的反应 ADDIN EN.CITE Geng20199724979717Geng, JinyaoHan, MinYang, XinLi, YaoBartlam, MarkWang, YingyingDifferent biotransformation of three hexabromocyclododecane diastereoisomers by Pseudomonas sp. under aerobic conditionsChemical Engineering JournalCh

37、emical Engineering Journal870-879374HBCDsBiodegradationEnantioselectivityMetabolitesDegradation pathways20192019/10/15/1385-8947/science/article/pii/S1385894719312549/10.1016/j.cej.2019.05.23224，虚线箭头指示推测的完全羟基化产物 ADDIN EN.CITE ADDIN EN.CITE.DATA 38。Fig. 1 The hydrolytic debromination pathways of HBCD

38、s catalyzed by bacteria and dehalogenase ADDIN EN.CITE ADDIN EN.CITE.DATA 24-26, 31-32, 38. The pink arrow shows the hydroxylation without debromination ADDIN EN.CITE Geng20199724979717Geng, JinyaoHan, MinYang, XinLi, YaoBartlam, MarkWang, YingyingDifferent biotransformation of three hexabromocyclod

39、odecane diastereoisomers by Pseudomonas sp. under aerobic conditionsChemical Engineering JournalChemical Engineering Journal870-879374HBCDsBiodegradationEnantioselectivityMetabolitesDegradation pathways20192019/10/15/1385-8947/science/article/pii/S1385894719312549/10.1016/j.cej.2019.05.23224, the da

40、shed arrow shows the possible product via hydrolytic debromination ADDIN EN.CITE ADDIN EN.CITE.DATA 38.图2 细菌和脱卤酶转化HBCDs的还原脱溴和HBr消除脱溴途径。蓝色箭头指示还原脱溴途径 ADDIN EN.CITE ADDIN EN.CITE.DATA 20, 24, 32-34, 38, 42-43，紫色箭头指示HBr消除途径 ADDIN EN.CITE Geng20199724979717Geng, JinyaoHan, MinYang, XinLi, YaoBartlam, Mar

41、kWang, YingyingDifferent biotransformation of three hexabromocyclododecane diastereoisomers by Pseudomonas sp. under aerobic conditionsChemical Engineering JournalChemical Engineering Journal870-879374HBCDsBiodegradationEnantioselectivityMetabolitesDegradation pathways20192019/10/15/1385-8947/scienc

42、e/article/pii/S1385894719312549/10.1016/j.cej.2019.05.23220, 24-25, 28, 30, 39。Fig. 2 The reductive debromination pathways and HBr-elimination pathway of HBCDs catalyzed by bacteria and dehalogenases. The blue arrow shows the reductive debromination pathway ADDIN EN.CITE ADDIN EN.CITE.DATA 20, 24, 3

43、2-34, 38, 42-43, the purple arrow shows the HBr-elimination pathway ADDIN EN.CITE Geng20199724979717Geng, JinyaoHan, MinYang, XinLi, YaoBartlam, MarkWang, YingyingDifferent biotransformation of three hexabromocyclododecane diastereoisomers by Pseudomonas sp. under aerobic conditionsChemical Engineer

44、ing JournalChemical Engineering Journal870-879374HBCDsBiodegradationEnantioselectivityMetabolitesDegradation pathways20192019/10/15/1385-8947/science/article/pii/S1385894719312549/10.1016/j.cej.2019.05.23220, 24-25, 28, 30, 39.HBCDs的微生物转化相比于物理和化学方法，生物降解通常具有绿色环保的特征而备受关注。生物降解过程利用植物、藻类和微生物等富集并降解有害污染物，一

45、般不存在二次污染等问题。微生物由于具有较强的可塑性而受到研究人员青睐。但微生物转化HBCDs的研究较少，仅包括HBCDs在土壤和沉积物等基质中的生物转化和降解，以及11株功能菌和3种脱卤酶的表征。另外，少部分菌株由于转化率低而没有被详细报道。因此许多科学问题需进一步探究。2.1 HBCDs在环境中的转化环境中HBCDs主要分布于土壤、沉积物和水体，有利于微生物接触和转化，其转化与HBCDs浓度、微生物活动、环境基质类型和还原性有关。目前认为HBCDs在环境中降解转化较慢，是一个生物与非生物因素结合的复杂过程，且厌氧条件更有利于其转化。土壤中起始浓度为10.0 -80.0 ng/g的HBCDs，

46、其中75%在119 d内可被有氧转化，而92%在21 d内被厌氧转化 ADDIN EN.CITE Davis200520212020017Davis, J. W.Gonsior, S.Marty, G.Ariano, J.The Dow Chemical Company, Toxicology & Environmental Research and Consulting, 1803 Building, Midland, MI 48674, USA. jwdavisThe transformation of hexabromocyclododecane in aerobic and anaer

47、obic soils and aquatic sedimentsWater ResWater Res1075-843962005/03/16AerobiosisAnaerobiosisBiodegradation, EnvironmentalBiotransformationEnvironmental MonitoringFresh Water/*analysisGas Chromatography-Mass SpectrometryGeologic Sediments/*analysisHydrocarbons, Brominated/chemistry/*metabolismSoil Po

48、llutants/*metabolismTime FactorsWater Pollutants, Chemical/*metabolism2005Mar0043-1354 (Print)0043-1354 (Linking)15766961/pubmed/1576696110.1016/j.watres.2004.11.02421。同等浓度水平的HBCDs在河流沉积物中，21 d内 93%被有氧转化，而厌氧条件下，7 d被完全转化 ADDIN EN.CITE Davis200520212020017Davis, J. W.Gonsior, S.Marty, G.Ariano, J.The D

49、ow Chemical Company, Toxicology & Environmental Research and Consulting, 1803 Building, Midland, MI 48674, USA. jwdavisThe transformation of hexabromocyclododecane in aerobic and anaerobic soils and aquatic sedimentsWater ResWater Res1075-843962005/03/16AerobiosisAnaerobiosisBiodegradation, Environm

50、entalBiotransformationEnvironmental MonitoringFresh Water/*analysisGas Chromatography-Mass SpectrometryGeologic Sediments/*analysisHydrocarbons, Brominated/chemistry/*metabolismSoil Pollutants/*metabolismTime FactorsWater Pollutants, Chemical/*metabolism2005Mar0043-1354 (Print)0043-1354 (Linking)157

51、66961/pubmed/1576696110.1016/j.watres.2004.11.02421。浓度更高时（4.0-5.0 ng/g（dw），HBCDs在河流沉积物中的半衰期超过100 d ADDIN EN.CITE Davis20066422646417Davis, J. W.Gonsior, S. J.Markham, D. A.Friederich, U.Hunziker, R. W.Ariano, J. M.Toxicology and Environmental Research and Consulting, The Dow Chemical Company, 1803 B

52、uilding, Midland, Michigan 48674, USA. jwdavisBiodegradation and product identification of 14Chexabromocyclododecane in wastewater sludge and freshwater aquatic sedimentEnviron Sci TechnolEnvironmental science & technologyEnviron Sci TechnolEnvironmental Science & Technology5395-40140172006/09/27Car

53、bon RadioisotopesChromatography, High Pressure LiquidFresh WaterGeologic Sediments/*chemistryHydrocarbons, Brominated/*analysisMass SpectrometrySewage/*chemistrySpectrophotometry, UltravioletWater Pollutants, Chemical/analysis/*metabolism2006Sep 10013-936X (Print)0013-936x16999116NLMeng22。土壤中的非生物转化率

54、与时间相关，而河流沉积物和活性污泥中的非生物转化率贡献较大，在活性污泥中非生物转化率也可能超过生物转化率 ADDIN EN.CITE Davis20066422646417Davis, J. W.Gonsior, S. J.Markham, D. A.Friederich, U.Hunziker, R. W.Ariano, J. M.Toxicology and Environmental Research and Consulting, The Dow Chemical Company, 1803 Building, Midland, Michigan 48674, USA. jwdavis

55、Biodegradation and product identification of 14Chexabromocyclododecane in wastewater sludge and freshwater aquatic sedimentEnviron Sci TechnolEnvironmental science & technologyEnviron Sci TechnolEnvironmental Science & Technology5395-40140172006/09/27Carbon RadioisotopesChromatography, High Pressure

56、 LiquidFresh WaterGeologic Sediments/*chemistryHydrocarbons, Brominated/*analysisMass SpectrometrySewage/*chemistrySpectrophotometry, UltravioletWater Pollutants, Chemical/analysis/*metabolism2006Sep 10013-936X (Print)0013-936x16999116NLMeng22。利用同位素示踪法研究表明HBCDs在沉积物和活性污泥中的脱溴转化趋势是：通过卤化氢双消除反应依次脱除相邻的两个溴

57、离子，形成四溴环十二烯、二溴环十二碳二烯和环十二碳三烯；另外也检测到了少量同位素标记的CO2，证明HBCDs在环境中可被微生物降解（图2、4） ADDIN EN.CITE Davis20066422646417Davis, J. W.Gonsior, S. J.Markham, D. A.Friederich, U.Hunziker, R. W.Ariano, J. M.Toxicology and Environmental Research and Consulting, The Dow Chemical Company, 1803 Building, Midland, Michigan

58、48674, USA. jwdavisBiodegradation and product identification of 14Chexabromocyclododecane in wastewater sludge and freshwater aquatic sedimentEnviron Sci TechnolEnvironmental science & technologyEnviron Sci TechnolEnvironmental Science & Technology5395-40140172006/09/27Carbon RadioisotopesChromatogr

59、aphy, High Pressure LiquidFresh WaterGeologic Sediments/*chemistryHydrocarbons, Brominated/*analysisMass SpectrometrySewage/*chemistrySpectrophotometry, UltravioletWater Pollutants, Chemical/analysis/*metabolism2006Sep 10013-936X (Print)0013-936x16999116NLMeng22。2.2 转化HBCDs的功能菌株及其特性原始环境中存在着可转化天然卤化物的

60、微生物，人造有机卤化污染物排入环境促使一部分微生物经历基因突变、基因重组和代谢重组等获得降解这些污染物的能力 ADDIN EN.CITE Kaster20149436949417Kaster, A. K.Mayer-Blackwell, K.Pasarelli, B.Spormann, A. M.Department of Chemical Engineering, Stanford University, Stanford, CA, USA.Department of Civil and Environmental Engineering, Stanford University, Stan