高效纤维素分解菌复合系的构建及其环境适应性研究

以纤维素培养基和纤维素刚果红培养基为初筛和复筛培养基，从采集的样品中分离得到具有纤维素分解能力的菌株20株。选择其中具有较高纤维素酶活力的12个菌株与2株自生固氮菌和EM菌进行正交实验，得到3个组合表现出协同降解纤维素的作用，对滤纸降解效果为组合12〉组合8〉组合5。选用组合12进行了一系列的环境适应性研究，结果表明，碳源为微晶纤维素＋CMC-Na时CMC酶活最高，最适氮源为蛋白胨＋酵母膏，最适pH6．5，最适培养温度为30℃。培养第6天CMC酶活最高。     

α-苯乙胺降解菌的筛选及菌种鉴定

以α-苯乙胺为唯一碳源驯化获得降解磷霉素制药废水中α-苯乙胺的高效菌群,利用平板划线法筛选、分离、纯化得到两株降解α-苯乙胺的纯菌P1和P2,经理化性质测定并与16SrDNA测序分析结果比对,两株纯菌分别鉴定为寡养食单胞菌和罗尔斯通菌,为今后进行降解α-苯乙胺实验及实际应用提供了较好的理论价值。     

聚丙烯酰胺降解菌的分离和鉴定

三次采油产生的大量含聚丙烯酰胺(PAM)的污水急需处理,其核心问题是PAM的生物化学降解。文章叙述了从含聚合物油田污水中分离到七株PAM降解菌的过程,并对其营养物体系进行了初步研究及分子生物学鉴定。结果表明,分离到的七株菌可以以PAM为唯一氮源和碳源进行生长,但是生长速度较慢,添加液蜡或酵母膏等可导致微生物菌群的共代谢,能加快PAM的生物降解。七株菌分别归类于放线杆菌纲和α-变形菌纲及芽孢杆菌,与数据库中已知菌的同源性均超过98%。     

石油降解菌的降解特性研究

以0#柴油为唯一碳源,对石油降解菌DSP菌的生长、疏水性、产表面活性剂、脱氢酶活性及降解能力进行研究。结果表明:DSP菌在生长过程中可产生糖脂类生物表面活性剂,对石油烃的降解有很好的促进作用,其脱氢酶活性与降解率有较好的相关性。当土壤中柴油含量为10%时,利用DSP菌经过40d的处理(30℃,pH值为6),油含量下降到1.82%,降解率最高可达65.4%。     

一株降解苯酚微生物的研究

从污泥中分离出可在舍100mg/L苯酚的LIB培养基上生长的菌株，其中JF-2生长情况最好。通过逐级驯化，JF-2的降解苯酚能力明显提高，可在以苯酚为唯一碳源的培养基中降解苯酚并生长。在接种量为1％时，JF－2在24h内将300mg／L的苯酚完全降解。该菌的最适生长和降解温度为30℃，并能在pH5．5～9内降解苯酚。河水中的天然微生物降解苯酚的能力弱，需7天才可将200mg/L的苯酚完全降解。     

高效降解环己酮红球菌JDM-3-12的分离及其系统发育分析

从岳阳巴陵石化公司环己酮生产车间总出水口的污泥中筛选到一株环己酮降解菌株,菌号为JDM-3-12;该菌能以环己酮为唯一碳源且能忍受5000 mg/L的环己酮,当环己酮的质量浓度为2000 mg/L时,在温度为30℃,转速为150 r/m in,pH=7的条件下,72小时内该菌株对环己酮的降解率达到97.91%。通过形态观察、生理生化特征检测和基于16S rRNA基因序列的系统发育分析,初步鉴定其为赤红球菌(Rhodococcus ruber)中的一个菌株,该菌最适生长温度为35℃,最适生长pH 7。     

高效微生物秸秆腐熟剂技术

正由湖南泰谷生物科技股份有限公司开发的高效微生物秸秆腐熟剂技术,适用于传统种植业废弃物的处理。主要技术内容一、基本原理利用可溶性秸秆腐熟剂处理秸秆的生物处理技术,以秸秆生物发酵替代部分化肥,以拮抗菌代替部分农药,腐熟剂内含枯草芽孢杆菌、哈茨木霉、米曲霉、放线菌、生物酶、纤维分解菌、半纤维素分解菌、木质素分解菌、蛋白质分解菌、氨、硫化氢分解菌等多种活性菌,能快速分解农业秸秆中所含纤维素、半纤维素、木质素,将秸秆堆料中     

废弃钻井液微生物降解菌室内筛选研究

针对川渝地区废弃钻井液成分复杂、污染危害大的特点,提出利用微生物法处理废弃钻井液的方法。通过菌株分离、菌株筛选、菌株对废弃钻井液的降解利用实验筛选出8株降解菌株,进行了废弃钻井液的降解利用情况研究,表明筛选出的降解菌株均能够以废弃钻井液为唯一碳源,具备了快速分解废弃钻井液的能力。     

共基质条件下TNT降解菌的选育及其处理效果

选取SBR弹药销毁废水处理系统中的活性污泥作为菌源,在共基质条件下,经过驯化和筛选,分离出11株可降解TNT的单菌,从中选出生长速度较快的3株菌JT1,JT2,JT3进行了单菌及混菌降解能力测试,结果表明:混合菌JTH降解能力最强,其适宜环境条件为25℃～30℃,pH7.5～9.0,基质中添加2g/L葡萄糖可显著增强混菌JTH生长并可使24h内的TNT降解率达到96 1%;模拟废水的处理实验表明:混菌JTH对COD的去除率>80%,TNT降解率80%～90%;生物强化实验表明:以0.1的菌量污泥比在SBR系统中投加混合菌可使系统的出水COD稳定在100mg/L左右,出水TNT浓度<5mg/L。     

石油降解菌的分离筛选及混合菌群的构建与优化

以河南濮阳油田超重质原油为研究对象,从污染井场土壤中分离并筛选出几株高效降解细菌、酵母菌和霉菌。由于不同类型微生物对碳源的利用目标和方式有所不同,而将3类不同类型菌种进行排列组合进行降解实验,最终优选出一组石油降解优势菌群。该文还利用正交优化法对降解菌的最佳添加量进行计算,结果显示,最佳接种量为X25：1．5％,Z3：1％,X18：1％,Z28：2％。利用该优化结果进行降解实验,石油的降解率在一定程度上提高了。在对濮阳、南阳和延长油田不同原油进行为期8d的降解实验中,显示了较高的降解效率,降解率分别为56．93％、65．66％、82．69％。实验证明,该降解菌群能不仅能有效够降解超重油,而且对重质原油和轻质原油表现出更好的降解能力。因此,该研究为石油污染物的降解提供了有效的菌种资源。     

Rock phosphate solubilizing and cellulolytic actinomycete isolates of earthworm casts

Four microbial isolates, OP2, OP3, OP6, and OP7, of earthworm casts ofPontoscolex corethrurus were found to be acid tolerant actinomycetes and efficient rock phosphate (RP) solubilizers that could grow fast on NH₄Cl-enriched or N-free carboxymethyl cellulose or glucose as sole carbon source. CMC (carboxymethyl cellulose) induced production of extracellular cellulase enzyme and the production of reducing sugar in all the isolates. RP solubilizing power was observed to be inversely related to glucose consumption. The most efficient RP solubilizer was found to consume the least glucose. Growth was faster on cellulose than on glucose media. N-free CMC induced greater glucose production than NH₄Cl-enriched CMC medium. Both CMC and glucose media were acidified by all the isolates, however, RP solubilizing power decreased with acidification. Solubilization power was greatest with isolate OP7, which also produced the greatest amount of reducing sugar per gram CMC. Both RP solubilizing power and the cellulolytic efficiency varied among isolates. A minimum of 631 μg P/0.1 g RP and a maximum of 951.4 μg P/0.1 g RP was recorded.     

Recirculating sand filters for treatment of synthetic dairy parlor washings

Land-spreading and spray irrigation are the most widely used practices for the disposal of dairy wastewaters in Ireland but in some cases there can be problems due to contamination of surface and ground water. The use of intermittent sand filtration has been suggested as an alternative treatment process. However, a single pass through a sand filter limits denitrification because of the absence of reducing conditions following nitrification and the lack of an available carbon source. This leads to poor total nitrogen (TN) reduction and an effluent that is high in nitrate nitrogen (NO3-N). This paper follows a previous paper in which two instrumented stratified sand filter columns (0.9 and 0.425 m deep, and both 0.3 m in diameter) were intermittently loaded with synthetic dairy parlor washings at a number of hydraulic loading rates, leading to a TN reduction of 27 to 41%. In the present study, under a chemical oxygen demand (COD) of 23.4 g m(-2) d(-1), the TN was reduced by 83.2% when three-quarters of the sand filter effluent was recirculated through an anoxic zone. This produced an effluent NO3-N concentration of 60 mg L(-1). With recirculation, the improvement in the removal of organic matter and ammonia N (NH4-N) is minimal. Recirculating sand filters appear to offer a mechanically simple and effective method for the removal of nitrogen from dairy parlor effluents and are a significant improvement over a single-pass sand filter.     

Enrichment and isolation of endosulfan-degrading microorganisms

Endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,3,4-benzo-dioxathiepin-3-oxide) is a cyclodiene organochlorine currently used as an insecticide all over the world and its residues are posing a serious environmental threat. This study reports the isolation and identification of enriched microorganisms, capable of degrading endosulfan. Enrichment was achieved by using the insecticide as either the sole source of carbon or sulfur in parallel studies. Two strains each of fungi (F1 and F4) and bacteria (BF2 and B4) were selected using endosulfan as a sole carbon source. A Pandoraea species (Lin-3) previously isolated in our laboratory using lindane (gamma-HCH) as a carbon source was also screened for endosulfan degradation. F1 and F4 (Fusarium ventricosum) degraded alpha-endosulfan by as much as 82.2 and 91.1% and beta-endosulfan by 78.5 and 89.9%, respectively, within 15 d of incubation. Bacterial strains B4 and Lin-3 degraded alpha-endosulfan up to 79.6 and 81.8% and beta-endosulfan up to 83.9 and 86.8%, respectively, in 15 d. Among the bacterial strains isolated by providing endosulfan as a sulfur source, B4s and F4t degraded alpha-endosulfan by as much as 70.4 and 68.5% and beta-endosulfan by 70.4 and 70.8%, respectively, after 15 d. Degradation of the insecticide occurred concomitant with bacterial growth reaching an optical density (OD600) of 0.366 and 0.322 for B4 and Lin-3, respectively. High OD600 was also noted with the other bacterial strains utilizing endosulfan as a sulfur source. Fungal and bacterial strains significantly decreased the pH of the nutrient culture media while growing on endosulfan. The results of this study suggest that these novel strains are a valuable source of potent endosulfan-degrading enzymes for use in enzymatic bioremediation.     

9,10-Phenanthrenequinone photoautocatalyzes its formation from phenanthrene, and inhibits biodegradation of naphthalene

Polycyclic aromatic hydrocarbons (PAHs) have earned considerable attention due to their widespread environmental distribution and toxicity. In the environment, PAHs decompose by a variety of biotic and abiotic pathways. In both polar and nonpolar environments, phenanthrene (Phe, a common, three-ring PAH) is converted by sunlight to more polar products such as 9,10-phenanthrenequinone (PheQ) and subsequent oxidation products such as the corresponding open-ring dicarboxylic acid product. Biodegradation of phenanthrene also usually leads to oxidative metabolites, and eventually ends in mineralization. Our experimental objective was to investigate the photodegradation of phenanthrene and determine the effect of reaction products such as PheQ on microbial biodegradation of two- and three-ring PAHs. Abiotic experiments were performed to examine the photolytic breakdown of Phe; Phe was converted to PheQ, which catalyzed its own formation. In biodegradation experiments PheQ (0.04-4 mg/L) caused marked inhibition of naphthalene (Nap) biodegradation by a Burkholderia species; Phe did not. Only 20% of the naphthalene was degraded in the presence of PheQ compared with 75% in the control culture with no PheQ added. No PAH-degrading cultures were able to use PheQ as sole carbon source; however, the Phe-degrading enrichment culture dominated by a Sphingomonas species was able to degrade PheQ cometabolically in the presence of Phe. These results may explain why photooxidized phenanthrene-containing mixtures can resist biodegradation.     

Traffic-related air quality assessment for open road tolling highway facility

Open road tolling (ORT) design has been considered as an effective means of smoothing highway traffic and reducing travel delay on toll highways. In this paper it is demonstrated that ORT can also achieve significant air quality benefits over the conventional toll plaza design. The near roadside carbon monoxide (CO) concentration levels can be reduced by up to 37%, and diesel particulate matter (DPM) emissions can decrease by as much as 58%. These large expected air quality benefits have great implications to the regional efforts of reducing mobile source air pollution toward achieving attainment status and healthier living environment.     

Direct utilization of kitchen waste for bioethanol production by separate hydrolysis and fermentation (SHF) using locally isolated yeast

Kitchen wastes containing high amounts of carbohydrates have potential as low-cost substrates for fermentable sugar production. In this study, enzymatic saccharification of kitchen waste was carried out. Response surface methodology (RSM) was applied to optimize the enzymatic saccharification conditions of kitchen waste. This paper presents analysis of RSM in a predictive model of the combined effects of independent variables (pH, temperature, glucoamylase activity, kitchen waste loading, and hydrolysis time) as the most significant parameters for fermentable sugar production and degree of saccharification. A 100 mL of kitchen waste was hydrolyzed in 250 mL of shake flasks. Quadratic RSM predicted maximum fermentable sugar production of 62.79 g/L and degree of saccharification (59.90%) at the following optimal conditions: pH 5, temperature 60°C, glucoamylase activity of 85 U/mL, and utilized 60 g/L of kitchen waste as a substrate at 10 h hydrolysis time. The verification experiments successfully produced 62.71 ± 0.7 g/L of fermentable sugar with 54.93 ± 0.4% degree of saccharification within 10 h of incubation, indicating that the developed model was successfully used to predict fermentable sugar production at more than 90% accuracy. The sugars produced after hydrolysis of kitchen waste were mainly attributed to monosaccharide: glucose (80%) and fructose (20%). The fermentable sugars obtained were subsequently used as carbon source for bioethanol production by locally isolated yeasts: Saccharomyces cerevisiae, Candida parasilosis, and Lanchancea fermentati. The yeasts were successfully consumed as sugars hydrolysate, and produced the highest ethanol yield ranging from 0.45 to 0.5 g/g and productivity between 0.44 g L^–1 h^–1 and 0.47 g L^–1 h^–1 after 24-h incubation, which was equivalent to 82.06–98.19% of conversion based on theoretical yield.     

脉冲袋式除尘器的阻力分析

分析了脉冲袋式除尘器阻力的构成及分布,提出了降低袋式除尘器阻力的途径和要点,并阐述了袋式除尘器节能的根本措施。     

Growth factors, kinetics and biodegradation mechanism associated with Pseudomonas nitroreducens TX1 grown on octylphenol polyethoxylates

The growth properties and biodegradation mechanism of a Gram-negative bacterium, Pseudomonas nitroreducens TX1 that was able to grow on branched octylphenol polyethoxylates (OPEO(n), average n=9.5) as the sole carbon source over a wide concentration range (1-100,000 mgl(-1)) were studied. Analysis of growth factors indicated the highest specific growth rate (micro) of 0.53 h(-1) was obtained at an initial concentration of 5,000 mgl(-1) OPEO(n). An optimal C/N ratio of 12 was obtained for (NH(4))(2)SO(4) as the nitrogen source in a cultivated medium at pH 7. The kinetic analysis demonstrated that bacterial growth and OPEO(n) degradation followed the Monod equation and were based on a substrate concentration inhibition model and pseudo-first-order reaction, respectively. The substrate inhibition coefficient was over 18,000 mgl(-1) and this indicates that the strain has an ability to sustain growth at high concentrations of OPEO(n) and use it as the sole carbon source under such a stress condition. Furthermore, LC-MS analysis showed that the biodegradation mechanism of dodecyl octaethoxylate (AEO8) by P. nitroreducens TX1 was the sequential cleavage of the ethoxylate chain.