阴沟肠杆菌对石油烃污染物的降解特性

考察了阴沟肠杆菌E．cloacae对石油烃代表物十六烷及菲的降解特性,分析了菌在各碳源中的生长动力学曲线及各碳源的降解动力学曲线。结果表明E.cloacae在十六烷、菲、十六烷和菲的混合物这三种碳源中都能较好地生长,生长速率较高,生长过程中都有二次生长现象;E．cloacae对葡萄糖、十六烷、菲、以及十六烷和菲混合物中所含菲在1天内平均降解速率大小关系为十六烷〉葡萄糖〉菲（十六烷与菲混合）〉菲,E．cloacae对十六烷具有很强的降解能力,1天内其对十六烷的平均降解速率是其对葡萄糖的2．4倍,是对单独菲及混合菲的6200倍。最终结果表明E．cloacae是一种高效的石油烃降解菌。     

混合培养微生物降解氯氰菊酯的特性研究

通过富集培养,获得了降解氯氰菊酯的混合微生物。结果表明,该混合微生物发挥最优降解力的温度是35℃,pH为7.5,培养时间为72h。氯氰菊酯降解速度和混合培养微生物生长对外加碳源有较强的依赖性。培养液中添加5g.L-1葡萄糖和3g.L-1酵母粉,72h氯氰菊酯去除率可达80%以上,氯氰菊酯降解速率可达0.56mg.L-1.h-1;当氯氰菊酯作为培养菌生长的唯一碳源、氮源和能源时,72h内氯氰菊酯去除率为65%,降解速率为0.45mg.L-1.h-1。     

有机碳源对发状念珠藻单体细胞生长和光合作用的影响

采用液体悬浮培养方法研究了有机碳源对发状念珠藻(Nostoc flagelliforme)单体细胞生长及光合作用的影响.结果表明发状念珠藻单体细胞具有利用有机碳源进行混合营养生长的能力,葡萄糖和蔗糖对其生长具有明显的促进作用,乳糖、木糖、乙酸钠和甘油也能促进其生长.在BG-11培养基中添加浓度为3.98 g·L-1葡萄糖,培养7 d,细胞生物量(干重)达到1.77 g·L-1,是同等培养条件下光合自养所得干重的4.81倍.通过测定添加有机碳源初时和生长2 d后发状念珠藻单体细胞的光合放氧速率的变化情况,发现在培养初时,低光照强度(低于50 μmol·m-2s-1)有机碳源不能促进藻细胞的光合作用;在光饱和点(100 μmol·m-2s-1)混合营养藻细胞的净光合放氧速率达到192.31 μmolO2·(mgChl)-1·h-1,是光合自养细胞的1.57倍.进入对数期后,混合营养藻细胞的净光合作用降低,但是呼吸速率达到703.43 μmolO2·(mgChl)-1·h-1,是光合自养细胞的14.27倍;真正光合作用(净光合作用和呼吸作用之和)提高.     

细菌Enterobacter dissolvens的直流电解刺激过程

以葡萄糖为唯一碳源,研究了细菌Enterobacter dissolvens在直流电条件下的生长和代谢过程. 实验结果表明,当使用盐桥屏蔽电极反应时,细胞生长曲线和葡萄糖代谢速率基本不受电流强度的影响,而当采用铂丝电极时,反应体系中发生水解反应,采用10 mA电流通电12 h后,菌液中细胞的脱氢酶比活力和葡萄糖降解率分别为对照的1.98倍和1.48倍,细胞生长亦有所加快,但在其活力下降时出现大量死亡. 扫描电镜照片显示细胞结构受到明显破坏,并发生细胞膜穿孔现象,这表明可能受到了过氧化氢等阳极水解中间产物的刺激作用.     

正十六烷降解菌的分离、鉴定及降解特性

以正十六烷为唯一碳源进行选择性富集培养,从石油污染土壤中筛选出1株正十六烷降解菌;根据形态观察和自动化鉴定分析,初步确定其为铜绿假单胞菌(Pseudomonas aeruginosa);采用气相色谱法测定了其对正十六烷的降解作用。结果表明,该菌株降解正十六烷的作用明显,在pH值为7.0时降解效果最好。     

生物活性炭法吸附降解正十六烷的研究

以正十六烷为目标物，研究了生物活性炭（BAC）系统对正十六烷的吸附特征、生物吸附动力学以及活性炭的生物再生能力。研究结果表明：使用颗粒活性炭吸附正十六烷可行且具有较强的抗冲击负荷能力，等温吸附方程为a=74．088c^0.49；生物活性炭法比活性污泥法对正十六烷的降解速率快，且适合长期高浓度运行使用：经过14d培养后，     

3种单一及其混合碳源的生物反硝化脱氮效能

分别以乙酸钠、乙醇、葡萄糖及其两两混合物作为外碳源,对生活废水进行生物反硝化研究。结果表明,不同碳源系统均出现了NO2^--N的短时间积累,与单一碳源系统相比,对应混合碳源系统NO2^--N最大积累量较低。从培养初始至120 min时,随培养时间增加,单一和混合碳源系统中NO3^--N含量均大幅降低,乙酸钠、乙醇、葡萄糖、乙酸钠+乙醇、乙醇+葡萄糖、乙酸钠+葡萄糖系统的平均反硝化速率分别为6.9、5.1、4.3、7.2、5.7、6.0 mg/(g·h),至120 min时,各系统NO3^--N去除率分别为100%、77.8%、64.8%、100%、78.4%、85.1%。乙酸钠、乙酸钠+乙醇、乙酸钠+葡萄糖系统NO3^--N去除率分别在120、120、210 min时达到100%。从脱氮效果、碳源成本、环境风险角度,乙酸钠+.葡萄糖更适合作为工程应用上的外碳源。     

不同碳源对小球藻(Chlorella vulgaris)生长及含油量的影响

为了研究不同碳源对小球藻(Chlorella vulgaris)生长及油脂积累的影响,选取了葡萄糖、麦芽糖、淀粉等共11种碳源分别作为唯一碳源对小球藻进行培养.研究小球藻的生长及油脂积累情况.结果表明,葡萄糖和麦芽糖都可作为唯一碳源,小球藻的最大细胞浓度分别为4.495×108 cell/L和2.725×108 cell/L,含油率分别为53.27％和38.54％.     

一株芽孢杆菌对多环芳烃的降解性能

从长期被焦化废水污染的污泥中分离出一株芽孢杆菌，它对蒽、菲、芘在单基质及混合基质条件下均有良好降解转化性能，在单基质条件下，起初的82h内，该菌株对蒽的降解转化效果最好，菲最差，反应进行到106h，各PAHs的浓度均接近于O；在混合基质条件下，菲的竞争代谢能力最强，芘最小；淘米水能明显促进单基质条件下芘的降解转化；在单基质蒽、菲、芘反应体系中，该芽孢杆菌能生长繁殖，菲存在下，细菌总数量大能增长到原加入量的16500倍，蒽存在下，相应的增加倍数为4120，含芘的体系中，则能增长到原加入量的920倍。     

五种常见氨基酸的热分解动力学及热稳定性的研究

研究了几种常见氨基酸的热稳定性及热降解,建立动力学方程.用TG DTG热重仪测定氨基酸的热解曲线.用多升温速率法、Coats-Redfern积分法和Achar微分法确定热分解函数,根据TG-DTG热解曲线和红外图谱推断出的热分解过程并求出其热分解动力学方程.分解活化能的大小顺序为组氨酸＞色氨酸≥DL半胱氨酸＞L-苯丙氨酸＞L-脯氨酸.开始分解的温度大小顺序为色氨酸＞L-苯丙氨酸≥L-脯氨酸＞DL半胱氨酸＞组氨酸.     

phenanthrene biodegradation in soil slurry systems: Influence of salicylate and triton X-100

The effects of a nonionic surfactant (Triton X-100) and a metabolic inducer (salicylate) were investigated in order to enhance the biodegradation rate of phenanthrene in soil slurry systems. The addition of salicylate reduced the time for the complete degradation of phenanthrene up to about 3 times (12.9 mg/L-d) even at highly concentrated soils of 650 mg/kg. The inducer was beneficial not only by increasing metabolic activity of existing cells, but also by increasing cell mass since it was utilized as an additional carbon source. The fraction of fast growing bacteria in total with salicylate addition was much higher compared to that without salicylate. The addition of Triton X-100 ranging from 0 to 10 g/L increased the apparent solubility of phenanthrene in soil slurry, but significantly inhibited the phenanthrene degradation in both slurry and pure liquid systems without any inhibition to cell growth. The phenanthrene degradation was inhibited much more with increasing the surfactant concentration. The inhibition by surfactant addition might be due to the prevention of bacterial adhesion to phenanthrene sorbed to soil and/or decrease of micellar-phase bioavailability     

高效石油降解菌的筛选及初步鉴定

经过以石油烃为唯一碳源的选择性培养基平板初筛和三角瓶发酵复筛,采用紫外分光光度法测定石油降解率,从江汉油田和冀东油田石油污染的土壤和水体中,筛选出有降解石油能力的微生物9株.其中3株细菌(X-1,X-2,X-3)降解石油能力较高,X-1菌株的石油降解率最高达64.28%.根据形态学观察和部分生理生化特征初步鉴定,该菌为节杆菌属(Arthrobacter sp.).     

Branched Metabolic Pathway for Phenanthrene Degradation in a Pyrene-Degrading Bacterium

Mycobacterium sp. strain KR2 utilizes phenanthrene and pyrene as the sole sources of carbon and energy. Its pathway for phenanthrene degradation is branched. Besides complete degradation following the Aeromonas-pathway phenanthrene is metabolized via cis-9,10-phenanthrene dihydrodiol to diphenic acid which accumulates during incubation. Both substances are not described as bacterial metabolites of phenanthrene as of yet.     

Phenanthrene Metabolites from a New Polycyclic Aromatic Hydrocarbon-Degrading Bacterium Aeromonas salmonicida subsp. Achromogenes Strain NY4

A new polycyclic aromatic hydrocarbon (PAH)-degrading Gram-negative bacterium Aeromonas salmonicida subsp. achromogenes strain NY4 was isolated from coking wastewater sludge. Strain NY4 could not grow on1-hydroxy-2-naphthoic acid, hexadecane or hexanol as sole carbon source but phenanthrene. This strain was able to utilize several known microbial metabolites of PAHs, including catechol, protocatechuic acid, salicylic acid, and phenol as sole carbon source. The mixture of the acidic and neutral fraction, acidic fraction alone and neutral fraction alone of phenanthrene metabolites were prepared and analyzed by GC-MS. A total of at least 27 metabolites were identified as the degradation products of phenanthrene by strain NY4. Among them, 1-hydroxy-α-oxo-2-naphthaleneacetic acid, 2-hydroxy-α-oxo-1-naphthaleneacetic acid, 2-hydroxy-1-(1-hydroxy-2-naphthalenyl)-ethanone, 1,2-dihydro naphtha [2,1-b] furan-2-ol and 2,3-dihydro naphtha [1,2-b] furan-2-ol have not been reported as the metabolites of phenanthrenes so far. The accumulation patterns of phenanthrene metabolite accumulation by strain NY4 depended on the incubation time, inoculum size and concentration of phenanthrene. Based on the degradation metabolites of phenanthrene by strain NY4, degradation pathways are proposed. This is the first report of PAH degradation in Aeromonas salmonicida, which lay the foundation for recognition and further characterization of PAH degradation metabolites and pathways in Aeromonas salmonicida strains.     

On the biodegradation of beta-peptides

A consortium of microorganisms was established that was able to grow with the beta-tripeptide H-beta-HVal-beta-HAla-beta-HLeu-OH, with the beta-dipeptide H-beta-HAla-beta-HLeu-OH, and with the beta-amino acids H-beta-HAla-OH, H-beta-HVal-OH, and H-beta-HLeu-OH as the sole carbon and energy sources. This growth was achieved after several incubation-transfer cycles with the beta-tripeptide as the substrate. During degradation of the beta-tripeptide H-beta-HVal-beta-HAla-beta-HLeu-OH, the temporary formation of a metabolite was observed. The metabolite was identified as the beta-dipeptide H-beta-HAla-beta-HLeu-OH by nuclear magnetic resonance spectroscopy and mass spectrometry. This result indicates that in the course of the degradation of the beta-tripeptide, the N-terminal beta-HVal residue was cleaved off by a not yet known mechanism. During the subsequent degradation of the beta-dipeptide, formation of additional metabolites could not be detected. The growth-yield coefficients Y(x/s) for growth on the beta-di- and beta-tripeptide both had a value of 0.45. When a 1:1 mixture of the beta-tripeptide and the corresponding alpha-tripeptide H-Val-Ala-Leu-OH was added to the enrichment culture, the alpha-peptide was completely utilized in six days and thereafter growth of the culture stopped. This result indicates that even in beta-peptide enrichment cultures, alpha-peptides are the preferred substrates. Our experiments clearly show for the first time that beta-peptides and beta-amino acids are amenable to biodegradation and that a microbial consortium was able to utilize these compounds as sole carbon and energy sources. Furthermore, the preparation of beta-amino acids, of derivatives thereof, and of beta-di- and beta-tripeptides is described.     

Isolation and Identification of Phenanthrene Degrading Bacteria from the Soil around Oil Company of Andimeshk and Investigation of Their Growth Kinetics

Polycyclic aromatic hydrocarbons are particularly important due to large distribution in the environment, high toxicity and their carcinogen and mutagen properties. The purpose of this study was isolation and identification of phenanthrene degrading bacteria from the soil around Oil Company of Andimeshk (Iran) and investigation of their growth kinetics. Sampling from three stations was done at two seasons, spring and summer. Phenanthrene degrading bacteria were isolated from soil using enrichment method. Bacterial identification was performed by biochemical tests and 16S rRNA gene sequencing. Minimum inhibitory concentrations (MIC) were determined at various concentrations of phenanthrene. Bacterial biodegradation rate was determined using HPLC analysis. Finally, the growth kinetics of resistant bacteria was determined with culturing at concentrations of 0.5–0.8 g/l of phenanthrene. According to biochemical and molecular tests Pseudomonas aeruginosa strain SBL, Bacillus cereus strain Z4B-11, Staphylococcus epidermidis, and Micrococcus luteus were identified as phenanthrene degrading bacteria. The results showed that P. aeruginosa SBL and B. cereus Z4B-11 with the greatest amount of MIC are the most phenanthrene resistant bacteria, respectively. These two strains degraded 70% and 50% of phenanthrene after one week of incubation, respectively. The most growth in different concentrations of phenanthrene belonged to P. aeruginosa SBL and B. cereus Z4B-11 while the least growth belonged to S. epidermidis and M. luteus, respectively. It could be concluded that two new strains SBL and Z4B-11 which were isolated in the soil around Oil Company of Andimeshk have relatively high potential to be used for bioremediation of phenanthrene.     

外加碳源类型对A2/O-BCO系统脱氮除磷性能的影响

反硝化除磷系统可实现氮、磷的同步去除,但在处理实际低C/N污水时,常需补充碳源以解决碳源不足的问题。采用A²/O-BCO（anaerobic anoxic oxic-biological contact oxidation）反硝化除磷系统,通过投加两种常用的外碳源控制进水C/N在4.3左右,考察碳源类型（丙酸钠、乙酸钠）对A²/O-BCO系统长期运行效果的影响,并采用批次试验进一步探究不同外加碳源条件下活性污泥的内碳源贮存和利用特性。结果表明：碳源种类的变化会改变微生物的底物贮存和利用特性,进而影响系统的脱氮除磷效果。当采用丙酸钠为外加碳源时,PO₄^3--P去除效果稳定在94%左右,实现了磷的高效去除,但TIN的去除率仅为70.82%;而以乙酸钠为外加碳源时,系统TIN的平均去除率可以达到74%,但磷的出水浓度出现波动现象,平均去除率仅为89.90%。碳源转化分析表明,厌氧条件下,进水丙酸钠含量增多,PHV的合成比例增加,相反,乙酸钠含量增多,PHB合成比例增多;缺氧条件下,DPAOs对PHB和PHV的降解效果与其含量相关,丙酸钠作为外碳源时,PHV的降解速率高且微生物产能效率高,因此PO₄^3--P吸收速率较快。此外,本文提出了不同外加碳源条件下系统的优化运行策略。     

Statistical Impact of the Extent of Desorption,Compound Aging,and Bacteria Inoculation on Polycyclic Aromatic Hydrocarbon Biodegradation

The objective of this study was to investigate the effects of compound aging in soil, bacterial type inoculated, and the number of desorption steps on the biodegradation of phenanthrene and pyrene. A batch biodegradation study was conducted in a 3 2 3 Latin Square design to achieve this objective. The results indicated that only the number of desorption steps used yielded a statistical difference ( p < .05). To compare the significance of the desorption effects in conjunction with compound aging and bacteria type, the Tukey's honestly significant difference test ( f = 0.05) was performed. As expected, the zero-time desorption step yielded a more significant increase in biodegradation than two- and six-time desorption steps which had similar results. Furthermore, the presence of a recalcitrant cosolute (pyrene) had a detrimental effect on phenanthrene degradation with bacteria that had been acclimated with phenanthrene as the sole carbon source. Increases in the number of desorption steps decreased the toxicity of pyrene to the phenanthrene-degraders. As anticipated, the lack of substrate availability yielded limited microbial growth and subsequent contaminant biodegradation.     

Statistical Impact of the Extent of Desorption,Compound Aging,and Bacteria Inoculation on Polycyclic Aromatic Hydrocarbon Biodegradation

The objective of this study was to investigate the effects of compound aging in soil, bacterial type inoculated, and the number of desorption steps on the biodegradation of phenanthrene and pyrene. A batch biodegradation study was conducted in a 3 2 3 Latin Square design to achieve this objective. The results indicated that only the number of desorption steps used yielded a statistical difference ( p < .05). To compare the significance of the desorption effects in conjunction with compound aging and bacteria type, the Tukey's honestly significant difference test ( f = 0.05) was performed. As expected, the zero-time desorption step yielded a more significant increase in biodegradation than two- and six-time desorption steps which had similar results. Furthermore, the presence of a recalcitrant cosolute (pyrene) had a detrimental effect on phenanthrene degradation with bacteria that had been acclimated with phenanthrene as the sole carbon source. Increases in the number of desorption steps decreased the toxicity of pyrene to the phenanthrene-degraders. As anticipated, the lack of substrate availability yielded limited microbial growth and subsequent contaminant biodegradation.