高效复合菌对多菌灵的生物降解

将多菌灵降解菌Alcaligenes sp.和Rhodococcua sp.(编号为A和R)按不同比例进行复配,并采用三波长校正法和HPLC法测定不同复配降解体系中多菌灵的残留量,比较了纯培养和复合菌群对多菌灵的降解效果,最后对高效复合菌的降解条件进行了优化.试验结果表明,得到的高效降解复合菌群AR5(A∶R复配比例1...     

Characterization of the effective cellulose degrading strain CTL-6

An efficient cellulose degrading bacteria exists in the thermophilic wheat straw-degrading community, WDC2. However, this strain cannot be isolated and cultured using conventional separation techniques under strict anaerobic conditions. We successfully isolated a strain of effective cellulose degrading bacteria CTL-6 using a wash, heat shock, and solid-liquid alternating process. Analysis of its properties revealed that, although the community containing the strain CTL-6 grew under aerobic conditions, the purified strain CTL-6 only grew under anaerobic culture conditions. The strain CTL-6 had a striking capability of degrading cellulose (80.9% weight loss after 9 days of culture). The highest efficiency value of the endocellulase (CMCase activity) was 0.404 μtmol/(min-mL), cellulose degradation efficiency by CTL-6 was remarkably high at 50-65°C with the highest degradation efficiency observed at 60°C. The 16S rRNA gene sequence analysis indicated that the closest relative to strain CTL-6 belonged to the genus Clostridium thermocellum. Strain CTL-6 was capable of utilizing cellulose, celiobiose, and glucose. Strain CTL-6 also grew with Sorbitol as the sole carbon source, whereas C.therrnocellum is unable to do so.     

甲胺磷降解菌的分离与降解特性研究

从长期受甲胺磷农药污染的土壤中采集土样,经过富集培养,稀释倒平板后划线分离得到3个菌株,分别编号为J-1,J-2,J-3菌株。将分离到的3个菌株接种到富集培养基中培养后,利用钼锑抗分光光度法测定磷含量变化,明显可以看出J-3菌株具有较高的降解能力,因此选择J-3菌株作为下一步研究的对象。经形态学和生理生化指标初步鉴定J-3菌株为假单胞菌。J-3菌株能在没有外加碳氮源的情况下以甲胺磷作为唯一的碳源和氮源生长。另外,确定J-3菌株降解甲胺磷的最适温度为37℃,最适pH为7.0,外加碳氮源分别为葡萄糖和蛋白胨,最适装液量和接种量分别为100,250mL和8%等降解特性。     

脱氮副球菌W12在游离生长与附着生长条件下对吡啶去除作用的研究

分离到1株吡啶降解菌——脱氮副球菌(Paracoccus denitrificans W12),将其附着生长于颗粒活性竹炭(ABC)制备成生物活性竹炭(BABC),分别以游离菌和固着菌开展对水中吡啶的去除实验.结果表明,0.31g·L-1游离态W12菌可在26.5～48.9h内将48.70～1399mg·L-1的吡啶完全降解;附着于ABC的W12菌不仅保持其降解能力,而且BABC通过吸附与降解的协同作用更高效地去除吡啶,当温度为35℃,BABC投加量为10.0g·L-1时,692.2mg·L-1的吡啶在前3.6h主要通过吸附作用降低52%,其后主要通过生物降解作用至23.7h被基本去除,随着BABC投加量和处理批次的增加,吡啶去除效率显著提高.研究进一步从微观结构上对BABC去除水中吡啶的协同作用机制进行了探讨.     

多功能细菌复合系NSC-7的菌种组成多样性

NSC-7是一组具有降解纤维素和林丹双重功能的细菌复合系.为系统了解复合系的菌种组成,在有氧条件下,利用传统的平板画线法分离到11株单菌,将11株单菌按体积比1∶1重新组合并不具备分解纤维素的能力,利用单层和双层平板滤纸法检测NSC-7的分解能力,发现只有双层平板上的滤纸变黄且降解,说明复合系内纤维素降解的关键菌是厌氧或微好氧菌.利用现代分子生物学技术对NSC-7构建克隆文库,获得了195个16S rDNA片断,经DGGE筛选获得25个代表克隆,其序列数据库比对结果中有60％的近缘种为已知菌,分别归属于Clostridium、Petrobacter、Bacteria、Paenibacillus、Proteobacterium 5个属,其余40％的近缘种为难培养菌株.     

微生物降解苯酚的研究进展

苯酚是一种生物毒性物质,即使在低浓度下对人体及微生物也有毒害作用。从微生物对苯酚降解的生化机制和关键酶、高效降酚微生物菌种的分离筛选,降解特性以及利用高效基因工程菌处理酚类化合物的研究进展等方面,对微生物降解苯酚进行了综述。     

Biodegradation of malathion by Acinetobacter johnsonii MA19 and optimization of cometabolism substrates

To enhance the removal efficiency of malathion in the wastewater from organophosphate pesticide mill, a bacterium, Acinetobacter johnsonii MA19, that could degrade malathion with cometabolism was isolated from malathion-polluted soil samples using enrichment culture techniques. Four kinds of additional compounds, sodium succinate, sodium acetate, glucose, and fructose were tested to choose a favorite carbon source for the cometabolism of strain MA19. The results showed that sodium succinate and sodium acetate could promote malathion biodegradation and cell growth. The investigation results of effects of sodium succinate concentrations on the malathion biodegradation indicated that the more sodium succinate supplied resulted in quick degradation ofmalathion and fast cells multiplied. Zero-order kinetic model was appropriate to describe the malathion biodegradation when the concentration of sodium succinate was more than 0.5144 g/L. The degradation rate constant (K) reached the maximum value of 3.5837 mg/(L·h) when the mass ratio of sodium succinate to malathion was 128.6 mg/mg. The aquatic toxicity of the malathion was evaluated using the test organism, Limnodrilus hoffmeisteri. The data obtained suggested that the toxicity of malathion could be ignored after 84 h biodegradation. Our result demonstrates the potential for using bacterium A. Johnsonii MA19 for malathion biodegradation and environmental bioremediation when some suitable conventional carbon sources are supplied.     

利用复合微生物菌剂控制水华的治理工程试验

为了探索利用微生物控制正在爆发水华的富营养化城市内湖的效果,试验利用光合细菌(Rhodop seudomonas palustris)、芽孢杆菌(Bacillus subtilis)2种微生物菌剂,采用直接投放的方式,治理武汉市重度富营养化湖泊四美塘湖(西),治理时间从2008年8月1日持续到2008年9月27日,治理结束后,湖水水质从劣Ⅴ类提高到Ⅴ类,高锰酸钾盐指数除去率达52.78%,TN除去率达49.26%,TP除去率达73.02%,氨氮除去率达16.18%,Chl-a含量降低了46.70%。治理进行1个月后,湖水的感官效果大幅提高,藻类水华完全消失,透明度提高,不良气味消失。在投菌结束后的3个月内,湖水水质仍然保持良好,没有出现反弹。利用复合微生物菌剂治理富营养化湖泊,控制水华的爆发,是一种经济、快速、无二次污染的富营养化水体治理方法,如将其与其他的治理技术相结合将会使其在富营养化水体治理领域中发挥重要的作用。     

优势复合菌剂处理黑臭河水的实验研究

初试条件下系统的考察了优势复合菌剂对西洋河黑臭河水水体的处理效果,实验结果表明:(1)优势复合菌剂能有效降低黑臭河水的COD、氨氮和总磷,去除率达到80%以上;(2)好氧条件下的处理效果要优于自然条件下的处理效果;(3)不同的接种量(V菌/V水)、温度、pH值及摇床转速对处理效果均有不同的影响,由正交试验得到的最佳降解条件为接种量10/10000、温度35℃、pH值9、转速100r/min。在优化条件下对COD、氨氮和总磷的去除率分别达到67.83%、70.29%、70.59%。     

菲在土壤中的微生物降解研究

研究了不同条件土壤中多环芳烃菲的降解动态。结果表明：温度和底物浓度对土壤中菲的降解有较大影响,未灭菌土壤中菲的降解半衰期为5.1d;从污染土壤中分离到一株高效降解菲的菌株,经16S rDNA鉴定为产碱杆菌属（Alcaligenes bacterium LBM.）,同源性高达99%;随着优势菌接种量增加,基础培养基中菲降解速率逐渐加快;Fe3＋、Co2＋和Cu2＋对优势菌降解菲能力均有不同程度影响,其中以Fe3＋影响最明显。