Effects of bacterial counts and temperature on the biodegradation of bisphenol A in river water

Total 15 surface river waters were collected from thirteen different rivers to investigate a relationship of bacterial counts and temperature to the degradation of bisphenol A (BPA). Autoclaved and non-autoclaved river water samples were spiked with 0.2 mg/l BPA. The spiked samples were placed at temperatures of 4, 20, and 30 degrees C and analyzed by high performance liquid chromatography. BPA was degraded at all temperatures in the non-autoclaved samples. However, BPA in the autoclaved samples was not changed at all temperatures for 20 d. These results show that the primary factor of BPA degradation in river water is bacteria. Moreover, three groups [group A (> 10000 CFU/ml), group B (2000-10000 CFU/ml), and group C (< 2000 CFU/ml)], were made on the basis of bacterial counts of the samples. Half-lives for BPA degradation in groups A, B, and C were 2, 3, and 6 d at 30 degrees C and were 4, 5, and 7 d at 20 degrees C, respectively. But at 4 degrees C, the loss of BPA was about 40%, 20%, and 10% in groups A, B, and C for 20 d, respectively. Bacterial counts exerted an influence on BPA degradation in river water with temperature. Our results also show that BPA-degrading bacteria are widely distributed in river waters.     

油污土中降解柴油细菌的分离鉴定及降解能力研究

从所采集柴油污染土壤样品中富集、分离得到柴油降解优势菌株,命名为B-3和B-4.根据其生理生化性质及16S rDNA序列比对分析,确定2株菌分别属于Tetrathiobacter kashmirensis、假单胞菌属(Pseudomonas sp.).由于实验中,B-3的生长曲线较特殊,故以B-3和典型石油烃降解菌假单...     

对氨基苯磺酸降解菌的分离及其特性研究

从温州地区受污染的河水中分离到一株能降解对氨基苯磺酸的菌株WZR-3,该菌株能以对氨基苯磺酸为惟一碳源、能源生长。经对其形态特征、生理生化以及16S rDNA序列分析,该菌株初步鉴定为人苍白杆菌(Ochrobactrum anthropi)。该菌株利用对氨基苯磺酸生长时最适生长温度和pH值分别为30℃和7。该菌在10 g/L对氨基苯磺酸时仍能生长,最适生长浓度为300 mg/L对氨基苯磺酸。降解底物广谱性测试表明,该菌株还能降解多种芳香类化合物。     

一株耐盐柴油降解菌的分离鉴定及其降解性能

从某油田附近受石油污染土壤中分离出一株以柴油为惟一碳源的耐盐菌株LS1。通过对菌株的生理生化特性、菌体的形态观察及16S rDNA基因序列分析鉴定菌株LS1为假单胞菌属(pseudomonas)。该菌株可耐受的最高盐度(NaCl)和柴油浓度分别为6%~8%和12 000 mg/L。菌株生长的适宜pH和温度条件分别为6.0~8.0和28~36℃。在盐度为6%、pH为7.0、温度为32℃、菌种投加量为10%的条件下,初始浓度为3 000 mg/L的柴油经6 d降解后,去除率可达78.3%,加入适量外加碳源葡萄糖和蔗糖,可使降解率分别提高至92%和90%左右。菌株LS1的耐盐机理可能是通过在细胞内积累甜菜碱以调节菌株细胞内外渗透压平衡。投加甜菜碱可提高耐盐菌LS1在高盐环境下对柴油的降解效率。     

一株多重耐受性高效反硝化细菌的分离鉴定及特性

从活性污泥中筛选获得一株多重耐受性的高效反硝化细菌,命名为W32,通过个体形态特征的观察、生理生化实验和16S rDNA同源性比对分析,确定该菌株为施氏假单胞菌（Pseudomonas stutzeri）。分别从温度、pH和盐浓度研究该菌株对环境的耐受性,在10℃时、pH为11.0及盐浓度为5%的条件下对TN仍具有较好的去除率,分别可以达到88.12%、72.22%和55.48%;在10℃、静置缺氧、初始NO3--N质量浓度为296.42 mg·L-1、以10%的接种量的条件下,在72 h内NO3--N和TN去除率分别为100%和90.54%,且无氨氮与亚硝态氮的积累;研究该菌株在垃圾渗滤液中对TN的去除,在10 d内将TN去除了55.68%。研究表明,该菌株对低温、强碱、高浓度盐均具有良好的耐受性,是一株兼性好氧的高效反硝化细菌,在废水处理中具有广阔的应用前景。     

Biodegradation of nicotine by a novel Strain Shinella sp. HZN1 isolated from activated sludge

The nicotine-degrading bacterium HZN1 was isolated from activated sludge and identified as Shinella sp. based on its physiological characteristics and analysis of 16S rDNA gene. Strain HZN1 is capable of using nicotine as the sole carbon source in the mineral salts medium. The optimum temperature and pH for strain HZN1 growth and nicotine degradation were 30°C and 7.0, respectively. It could degrade approximately 100 % of 0.5 g L(-1) of nicotine within 9 h. Three intermediate metabolites were produced by the strain HZN1 and identified as cotinine, myosmine and nicotyrine using gas chromatography-mass spectrometry. This is the first report of nicotine-degrading strain from the genus of Shinella. The results showed that strain HZN1 could be potentially employed in bioremediation of nicotine. Our findings would provide a new insight into the biodegradation of nicotine.     

一株五溴联苯醚(BDE-99)降解菌的分离、鉴定及降解特性

采用梯度压力驯化法从高海拔地区土壤样品中分离到1株能以BDE-99作为碳源生长的细菌菌株,命名为BHS-4,通过生理生化及对16S rDNA扩增,T/A克隆后测序鉴定,并进一步分析初始pH、温度、碳源、细胞表胞疏水性（MATH法）及共存重金属离子对菌株降解效果的影响。结果表明：菌株BHS-4与产碱杆菌属Alcaligenes cupidus同源性为99%。菌株降解BDE-99最适pH和温度分别为8.0、20 ℃,经11 d培养后,对浓度0.4 mg·L-1的BDE-99,降解率达86.1%,在15~20 ℃范围具有较高降解率。降解特性研究结果显示,乳糖、麦芽糖和葡萄糖的添加促进了BHS-4对BDE-99的降解,而淀粉和乙酸钠添加对降解率产生了显著抑制作用（P4NO3的添加,使细胞表面疏水率（CSH）增加了49.5%,CSH与降解率呈极显著正相关（r=0.99, P2+、Zn2+在0.1~0.3 mg·L-1浓度下促进BDE-99降解;Cr6+在0.1~0.6 mg·L-1范围内对降解作用影响表现为先抑制、再促进、最后抑制。菌株BHS-4能在较低温度下对BDE-99进行高效降解且对Cu2+、Zn2+、Cr6+具有一定的耐性,可应用于低温地区BDE-99的生物处理,同时可为进一步研究低温条件下BDE-99生物降解的代谢途径和机理提供一定的基础资料。     

热活化过硫酸盐对双酚A的降解及其机理

研究了热活化过硫酸盐对双酚A的氧化降解效能及机理,探讨了温度,反应物初始浓度,pH值,阴离子和腐殖酸对双酚A降解的影响。结果表明:在实验范围内,双酚A的降解率随温度和过硫酸钠初始浓度的升高而增加;双酚A在酸性条件下的降解率比在中性和碱性条件下要高;阴离子的存在会抑制溶液中双酚A的降解,抑制作用依次为SO42- >Cl- >NO3-;加入腐殖酸后,双酚A的降解受到抑制。双酚A的降解中间产物主要为对苯二酚、对异-丙烯基苯酚、2-甲基-2,3-二氢苯并呋喃和3-甲基-2,3-二氢苯并呋喃。     

一株高效MC—RR降解菌的分离鉴定及其降解特性

为了得到一株具有降解微囊藻毒素一RR（MC—RR）特性的产芽孢菌株,采用加热富集芽孢菌的方法,从太湖分离到一株MC．RR降解菌CMl,该菌对MC—RR具有强烈的降解特性。通过形态学特征、生理生化特征及16SrDNA序列分析鉴定该菌株属于耐硼赖氨酸芽孢杆菌（Lysinibacillusb oronitolerans）。通过研究温度和pH值对菌株CMl降解MC—RR能力的影响,发现菌株CMl在60h将MC—RR由12．77μg／mL降解到1．67μg／mL,降解率达86．90％,最适降解温度为37℃,最适pH值为7．0。CMl菌株的胞外物质和胞内物质均能降解MC—RR,但胞内物质具有更强烈的降解特性,12h可以将7．27μg／mL的MC-RR完全降解。为丰富MC-RR降解菌纯菌种研究以及在去除水体中MC—RR应用研究方面提供了理论基础。     

UV-TiO_2光催化氧化降解双酚A的动力学研究

采用自制光催化氧化反应器,研究了双酚A(BPA)在纳米TiO_2悬浆体系中的光催化氧化特性.结果表明:(1)UV-TiO_2对水中BPA有较强光催化氧化降解作用.在10 W低压汞灯照射下,当纳米TiO_2用量为1.0 g/L、pH为5.5、BPA初始质量浓度为10 mg/L、曝气量为4.0 mL/min、温度为室温、反应时间为120 min时,BPA去除率可达97.1%.当pH≥9.5时,120 min后BPA已经基本光催化氧化降解完全.(2)BPA的光催化氧化降解曲线均很好地符合一级反应动力学方程.其速率常数与纳米TiO_2用量、pH、BPA初始浓度、曝气量有关;促进·OH和电子-空穴对的生成是提高光催化氧化反应速率的重要途径.     

Studies on biodegradation of nicotine by Arthrobacter sp. strain HF-2

A nicotine-degrading bacterium, strain HF-2, was isolated from tobacco waste-contaminated soil and identified as a member of Arthrobacter sp. based on morphology, physiological tests, 16S rDNA sequence and phylogenetic characteristics. At thermal denaturation test indicated that the G + C mol% of strain HF-1 was 63.5. The relationship between the growth of the isolate and the nicotine degradation suggested that strain HF-2 could utilize nicotine as sole sources of carbon, nitrogen and energy. Blue pigment was observed during the nicotine degradation by strain HF-2. The isolate grew well at 20 to 33 degrees C, initial pH 6.5 to 8.0 and 0.5 to 2.0 g L-1 of nicotine concentration in the nicotine inorganic salt media. The maximum growth and nicotine degradation occurred at 30 degrees C, initial pH 7.0 and 0.7 g.L-1 of nicotine concentration in media under natural incubation condition. Strain HF-2 could degrade 100% of nicotine under the optimized incubation conditions for 43 h. The concentrations of nicotine were monitored by high performance liquid chromatography. This study demonstrates Arthrobacter sp. strain HF-2 had a great ability to degrade nicotine, and it may be available for the application to the bioremediation of environments contaminated by tobacco waste.     

Characteristics of styrene degradation by Rhodococcus pyridinovorans isolated from a biofilter

A novel strain (PYJ-1) of Rhodococcus pyridinovorans that was isolated from a biofilter was able to degrade styrene at a maximum rate of 0.16 mg (mg protein)(-1) h(-1) in batch culture at 97 mg l(-1) of initial styrene gas concentration. The optimum pH and temperature for styrene degradation were 7 and 32 degrees C, respectively. The degradation kinetic constants were obtained using substrate inhibition kinetics. In a perlite-packed biofilter the maximum styrene removal rate by the strain was 279 gm(-3)h(-1). Styrene removal in the biofilter was more sensitive to the temperature than in the batch culture.     

负载型Co3O4活化过二硫酸盐非自由基降解有机污染物

通过在三维矿物载体表面包覆金属-多酚配合物并煅烧实现了Co₃O₄纳米颗粒的原位负载,制得了易分离回收的负载型Co₃O₄催化剂,利用SEM、XRD以及XPS表征分析其形貌和微观结构,采用活化过二硫酸盐(PDS)降解药、护品类有机污染物以评价其催化性能。以双酚A为目标污染物,考察了初始pH、PDS浓度、催化剂投加量、共存阴离子(CO₃²⁻、SO₄²⁻、NO₃⁻、Cl⁻)以及腐殖酸(HA)对BPA降解效率的影响。结果表明,负载型Co₃O₄能有效活化PDS降解有机物,在Co₃O₄投加量0.075 g·L⁻¹,BPA初始浓度0.04 mmol·L⁻¹,PDS初始浓度0.4 mmol·L⁻¹以及初始pH=7的最优条件下,120 min内BPA可被完全去除。淬灭实验与EPR实验结果表明,负载型Co₃O₄活化PDS通过单线态氧(¹O₂)主导的非自由基途径氧化分解有机物。     

Biodegradation of nicotine by a novel Strain Shinella sp. HZN1 isolated from activated sludge

The nicotine-degrading bacterium HZN1 was isolated from activated sludge and identified as Shinella sp. based on its physiological characteristics and analysis of 16S rDNA gene. Strain HZN1 is capable of using nicotine as the sole carbon source in the mineral salts medium. The optimum temperature and pH for strain HZN1 growth and nicotine degradation were 30°C and 7.0, respectively. It could degrade approximately 100 % of 0.5 g L^?1 of nicotine within 9 h. Three intermediate metabolites were produced by the strain HZN1 and identified as cotinine, myosmine and nicotyrine using gas chromatography-mass spectrometry. This is the first report of nicotine-degrading strain from the genus of Shinella. The results showed that strain HZN1 could be potentially employed in bioremediation of nicotine. Our findings would provide a new insight into the biodegradation of nicotine.     

一株反硝化细菌的分离鉴定及其反硝化特性

从处理城镇污水的移动床生物膜反应器中分离获得一株反硝化细菌D3,并进一步研究该菌株的系统发育地位及反硝化特性。采用16S rDNA序列分析对菌株进行初步鉴定,探讨了基质浓度、起始pH和温度对菌株反硝化活性的影响。根据形态学特征、生理生化特性及16S rDNA序列测定分析,初步鉴定菌株属于寡养单胞菌属。该菌能利用硝酸钠或亚硝酸钠进行反硝化作用,最佳电子受体是硝酸盐氮,反硝化速率最大为19.86 mg/（L·h）,最适生长pH为7.36,最适生长温度为33.5℃。菌株D3在初始硝态氮浓度为140 mg/L,以乙酸钠为惟一碳源,pH为7.36,温度33.5℃的最优生长条件下,培养10 h进入对数生长期,倍增时间为9.9 h,48 h内硝酸盐还原率达95%。     

Bioremediation of environmental endocrine disruptor di-n-butyl phthalate ester by Rhodococcus ruber

In this study DBP-degradation strain CQ0301 was isolated from rubbish landfill soil. According to the biophysical, biochemical characteristics and analysis of 16S rRNA, the strain was identified as Rhodococcus ruber. Three new protein bands could be fractioned after DBP-inducing, which were suspected to participate the process of DBP-degrading. Catechol was suspected to be an intermediate product of DBP and cleaving the benzene ring was catalyzed by catechol 1,2-dioxygenase, because a highly activity of catechol 1,2-dioxygenase could be detected after DBP-inducing. The results of this study also showed the optimal pH value, optimal temperature which influenced the degradation rate in soil: pH 7.0-8.0, 30-35 degrees C. Kinetics of degradation reaction had been performed at different initial concentration and different time. Analyzed with SPSS10.0 software, the DBP degradation can be described as the same exponential model when the initial DBP concentration was lower than 50 mg/kg. The kinetics equation was lnC=-0.1332t + A, with the degradation half-life of DBP in soil (5.20 d). Inoculating CQ0301 could relieve DBP content in plant. We also found that adding nutrient materials into soil was useful for decreasing the DBP content in plant. In summary, we isolated a bacterium capable of degrading DBP and decreasing DBP content in plant. We also explored the mechanism of biodegradation and characterized the environmental factors influencing the degradation process in contaminated soil. Based on this work, we hope that these findings can provide some information for applying of bioremediation of DBP contaminated soil.     

Leaching of bisphenol A (BPA) from polycarbonate plastic to water containing amino acids and its degradation by radical oxygen species

In this study, (1) the change in the concentration of bisphenol A (BPA) leached from polycarbonate plastic (PCP) tube to water samples containing phosphate, sodium barbital, glycine, methionine or albumin at 37 degrees C as a function of time, and (2) the degradation rate of BPA leached from PCP tube to amino acid solutions in the presence of radical oxygen species (ROS) were investigated. The BPA leaching velocity (BPA-LV) from PCP tube to 50 mM glycine at pH 6 or 7 was twice that to control water, and the leaching was enhanced above pH 8. At pH 11, BPA-LV was significantly higher in 50 mM glycine and methionine solutions than in 50 mM NaOH. These results indicate that basic pH and amino acids contained in water could accelerate BPA leaching. The BPA-LV in phosphate buffer was different from the BPA-LVs in other buffers (barbital and glycine) at the same pH. BPA leached to the glycine or methionine solutions at pH 11 was degraded time dependently in a similar manner as the control water in the presence of ROS. The degradation of leached BPA was inhibited in the glycine solution, but was accelerated in the methionine solution. However, degradation of BPA added to freshly prepared methionine was inhibited in a similar manner to BPA in glycine. BPA degradation could be influenced by some kinds of amino acids, but glycine and methionine might be involved in BPA degradation in different ways.     

Studies on Biodegradation of Nicotine by Arthrobacter sp. Strain HF-2

A nicotine-degrading bacterium, strain HF-2, was isolated from tobacco waste-contaminated soil and identified as a member of Arthrobacter sp. based on morphology, physiological tests, 16S rDNA sequence and phylogenetic characteristics. At thermal denaturation test indicated that the G + C mol% of strain HF-1 was 63.5. The relationship between the growth of the isolate and the nicotine degradation suggested that strain HF-2 could utilize nicotine as sole sources of carbon, nitrogen and energy. Blue pigment was observed during the nicotine degradation by strain HF-2. The isolate grew well at 20 to 33°C, initial pH 6.5 to 8.0 and 0.5 to 2.0 g L^?1 of nicotine concentration in the nicotine inorganic salt media. The maximum growth and nicotine degradation occurred at 30°C, initial pH 7.0 and 0.7 g·L^?1 of nicotine concentration in media under natural incubation condition. Strain HF-2 could degrade 100% of nicotine under the optimized incubation conditions for 43 h. The concentrations of nicotine were monitored by high performance liquid chromatography. This study demonstrates Arthrobacter sp. strain HF-2 had a great ability to degrade nicotine, and it may be available for the application to the bioremediation of environments contaminated by tobacco waste.     

Leaching of bisphenol A (BPA) to seawater from polycarbonate plastic and its degradation by reactive oxygen species

In this study, (1) change in the concentration of bisphenol A (BPA) leached from polycarbonate (PC) tube to control water (BPA free), seawater and river water at 20 and 37 degrees C as a function of time, (2) the fate of BPA caused by addition of H(2)O(2) and Fe(3+) to seawater containing BPA leached from PC tube were assessed. BPA leached from PC tube to all water samples increased with the ascendant of temperature and with the passage of time. The BPA leaching velocity in seawater was the fastest in three samples (11 ng/day for seawater, 4.8 ng/day for river water 0.8 ng/day for control water at 37 degrees C).BPA leaching velocity from PC tube was significantly high at pH 8 (50 mM Na(2)HPO(4)) and increased dose-dependently. There was no difference in the velocity of BPA among the 50 mM phosphate-buffers at pH 6.5, 7.0 and 7.5. BPA was leached three times higher by addition of Na(+) than K(+). However, the higher the K(+) concentration, the larger the BPA leached from PC tube. Na(+) mixed with PO(4)(-) was effective on BPA leaching from PC tube, but not with SO(4)(-) or Cl(-). The results suggested that BPA leaching from PC tube would be attributed to the concentration of bibasic phosphate such as Na(2)HPO(4) and K(2)HPO(4) in water samples. BPA was degraded in both control water and seawater in the presence of radical oxygen species, but the degradation rate was lower in seawater than in control water, suggesting that anti-oxidative system exists in seawater. Neo-synthesized substance in both control water and seawater in the presence of reactive oxygen species was identified as BPA-quinone by LC-MS.     

微波-Fenton高级氧化工艺降解水中BPA

以提高目标物的降解效果和投加药剂利用率、缩短反应时间及节约处理成本为目的,探讨4种不同光助-Fenton氧化工艺对环境内分泌干扰物双酚A（BPA）的降解效果。以BPA的去除率和反应速率作为评价指标,采用紫外分光光度计、TOC测定仪及分子荧光光度计分别对BPA的去除率、反应体系的矿化度和·OH的生成量进行研究。确定了微波-Fenton氧化工艺降解水中BPA的效果最佳,并深入研究pH值、H2O2投加量、n（H2O2）/n（Fe2+）、微波反应功率及时间对微波-Fenton氧化工艺的影响。结果表明：pH=3,n（H2O2）/n（Fe2+）为20,H2O2浓度为2 mmol·L-1,反应时间为5 min,反应功率为300 W的条件下,BPA初始浓度为100 mg·L-1时其去除率最高达99.67%,矿化度达53%;pH值在2~6范围内对BPA均有降解效果,铁泥量也有一定的减少。为微波-Fenton氧化工艺的实际应用奠定了理论基础,并且提供了技术支持。