应用SPSS软件分析石油污染土壤微生态环境

为了对石油污染土壤进行更加有效的生物修复,应用统计分析软件SPSS分析石油污染土壤微生态环境构成要素间的典型相关性,优化提高微生物生长代谢的环境条件,并运用变性梯度凝胶电泳(DGGE)技术考察石油污染对土壤微生物群落结构及多样性的影响。结果表明,土壤中有效的氮、磷质量分数,含水率和石油污染程度是石油降解菌生长繁殖的限制因素,因此在生物修复过程中,投加适量的氮、磷营养,适当地提高土壤含水率会增加降解菌数量,可以提高石油污染土壤的修复效率;石油污染土壤中存在常见的石油烃降解菌;石油污染一定程度上使微生物种群趋于单一化和功能化,微生物种群多样性降低。通过上述研究可为调控和优化石油污染土壤的微生态环境以及识别优势群落提供客观可靠的技术依据。     

Study on Enhancing Oil Recovery by Indigenous Microorganisms in a Hypersalinity Reservoir

Abstract

The feasibility of enhancing oil recovery in Qinghai oilfield with hypersalinity was studied. The results showed that main microbial populations in the reservoir were saprophytic, hydrocarbon-oxidizing, fermentative, nitrate-reducing bacteria and methanogens. The indigenous microorganisms preferentially used nitrogen sources for emulsification, the gas–liquid ratio was 0.20, pressure reached 0.27 MPa; saturated hydrocarbon was catalyzed selectivity. The species isolated were confirmed as Oceanobacillus sp. and Staphylococcus sp.; the oil recovery was 8.42%, which shows great potential to enhance oil recovery.     

The Molecular Ecology Analysis of Microbial Communities in Waste Water–based Mud

The molecular ecology analysis of microorganisms is important for the development of biological treatment of waste water–based mud. The bacterial 16S rRNA gene clone library was constructed to detect the community diversity in waste drilling fluid in this study. The phylogenetic analysis indicated that most of clones were clustered in β, γ-proteobacteria with the phylotypes belonging to γ-proteobacteria accounting for 78.6% of the clone library. Halomonas sp. and Chromohalobacter sp. as moderately halophilic bacteria were the main bacteria in waste water–based mud, accounting for 47.8% of the total of clones. This study provides the certainty of chance of the improvement of biological treatment by the selection of dominant strain.     

Multi-process Bioremediation as an Improved Approach for Petroleum-contaminated Soil Restoration

A multiprocess bioremediation approach was applied to treat petroleum-contaminated soil from Dagang Oilfield, China. The bioremediation processes involved the use of four exogenous microbial strains and six herbage plants screened from a large number of species to remove low levels of total petroleum hydrocarbons (TPH) in contaminated soil. The experimental results indicated that the reduction of TPH increased with the improved community structure from the exogenous petroleum-degrading bacteria by over 35% as compared with that using the indigenous bacterial community. The refreshed microbial consortium was also able to accelerate the reduction of TPH via plant roots (phytoremediation) by over 47%. The TPH reduction rate diminished over time. Molecular biomarker ratios such as Ph/nC17, Pr/nC18 increased during the experiment but the ratio of Pr/Ph decreased. The results suggested that the multi-process bioremediation may significantly shorten the bioremediation duration and can be quite effective for treatment of soils contaminated by lower levels of petroleum.     

秸秆载体腐解对微生物修复石油污染的影响

以一种农作物秸秆(简称MG)为载体,采用高效石油烃降解菌群制备固定化微生物,在花盆中模拟石油污染土壤的原位修复。在污染土壤中分别加入秸秆（MG）、游离菌、秸秆（MG）+游离菌、秸秆（MG）固定化微生物,并以只含土著菌的土壤样品为对照,定期测定不同修复方式下土样中石油烃、腐殖质、胡敏酸含量和微生物数量,考察微生物对石油污染土壤的修复作用及MG腐解对修复的影响。结果表明,随着修复的进行, MG在土壤中逐渐腐解,土壤中腐殖质和胡敏酸质量分数明显增高,加入固定化微生物的土样中腐殖质和胡敏酸质量分数增长率最高,分别增加了4458%和3927%;加入固定化微生物的土样修复35 d的石油烃降解率最高,达到4178%,且微生物数量最多,其次为添加MG+游离菌的土样,石油烃降解率为 3175%,均高于只含游离菌土样的石油烃降解率2783%。载体MG腐解产生的腐殖质和胡敏酸对石油污染土壤的修复起到了明显的促进作用。     

Phragmites stimulation and natural attenuation of indigenous microbial community accelerated bioremediation of oil contaminated soil

Illumina high-throughput sequencing method was used to reflect fluctuation of indigenous microbial community during phragmites stimulation process in this study. Results showed Proteobacteria, Fimicutes, and Actinobacteria were most influential in process, Firmicutes and Deinococcus-Thermus were positively affected by nutrient amendment. Firmicutes can be seen as indicator of degradation rate. Dietzia, Salinimicrobium, and Halomonas were the most dominant genus in both Phragmites and Blank setups. These results indicated phragmites addition improved the efficiency of biodegradation and significantly regulated the microbial community structure and functions during remediation process.     

Bioremediation of Petroleum contaminated soils collected all around China: The extensive application and the microbial mechanism

A commercial microbial agent (Devoroil) was applied to study the biodegradation efficiency of four petroleum contaminated soils/sediment collected all around China. After 40 days of biodegradation, the total petroleum hydrocarbons removal rates were 41.8%, 95.7%, 84.5% and 93.5%. The soil achieved the lowest biodegradation efficiency was chosen to conduct another bioremediation experiment to study the degradation dynamics of petroleum and the microbial mechanism. The results showed that biodegradation dynamics correspond to a negative index relation. The analysis of PCR-DGGE exhibited that Thioalkalivibrio sp., Nocardia sp. and Mycobacterium sp. were probably the dominant functional microbes in the contaminated environment.     

固定化微生物对石油污染土壤生物学特性的影响

在固定化微生物对石油污染土壤修复35d的过程中,考察了土壤脱氢酶、过氧化氢酶、多酚氧化酶、脲酶活性及细菌数量几种生物学特性的变化规律,进一步分析其石油烃降解率变化与酶活性、细菌数量之间的相关性,并以添加游离菌、秸秆及土著菌的土壤对照。结果表明,固定化微生物修复石油污染土壤的各个阶段,细菌数量、酶活性均高于对照组,石油烃降解效果最好,降解率高达40.8%;土壤的脲酶活性与其石油烃降解率的相关性最显著,相关性系数为0.994,可以作为固定化微生物降解石油污染土壤效果的指标。     

A Two-stage Immobilized Cell Bioreactor With Bacillus subtilis and Rhodococcus erythropolis for the Simultaneous Production of Biosurfactant and Biodesulfurization of Model Oil

Two vertical rotating immobilized cell reactors (VRICRs), one with the bacteria Bacillus sp. BDCC-TUSA-3 and the other with R. erythropolis, were constructed, with polyurethane foams as an attachment support. They were optimized for surfactin production and biodesulfurization (BDS) of dibenzothiophene (DBT), respectively. Then, the two bioreactors were combined to form a two-stage VRICR where an appropriate fraction of Bacillus sp. reactor effluent, containing surfactin, was mixed with the influent fed into R. erythropolis bioreactor, containing DBT in hexadecane. The BDS rate and volumetric reactor productivity were greatly increased to 210.5 mM 2HBP.kg^?1.h^?1 and 16.6 mM 2HBP.L^?1.h^?1, respectively. Sulfur concentration decreased from 398 down to <5 ppm. Additionally, surfactin was produced at high concentration (4.8 g.L^?1) with a volumetric reactor productivity of 720 mg_surfactin·L^?1.h^?1, which represents an extra added-value product that could markedly decrease operating costs. This study presents a feasible technology for efficient removal of sulfur from sulfur-containing fossil fuels and the production of biosurfactant as well.     

SDBS残留对微生物修复石油污染土壤的影响

为探究表面活性剂清洗对微生物修复石油污染土壤的影响,模拟实际石油污染土壤微生物修复,考察不同十二烷基苯磺酸钠(SDBS)添加量的土壤修复过程中总石油烃降解率的变化情况,探究了SDBS对微生物修复石油污染土壤效果的影响;比较了不同微生物法修复石油污染土壤的实验方案,确定了最佳微生物修复方式。结果表明：少量的SDBS残留对后续微生物修复有促进作用,但SDBS残留质量分数大于1 mg/g时,则不宜于石油污染土壤的生物修复;土著菌+秸秆固定化微生物和土著菌+游离高效降解菌+秸秆2种修复方式,启动快,降解率的增速大,修复效率高,可以实现石油污染土壤快速和持续修复。     

Removal of petroleum hydrocarbons and heterocycles by Pseudomonas sp. LKY-5 under aerobic conditions

Environmental adaptability and biodegradability of oil pollutants on functional bacteria are two important keys to bioremediation technologies. Pseudomonas sp. LKY-5 revealed strong biological activities in high salinity (3%) and high alkalinity (pH 9.0). N-hexadecane, phenanthrene, pyrene and carbazole could be directly utilized, and inhibited by the presence of DBT. Sulfur compounds and alkanes in No. 0 diesel and FCC diesel were effectively degraded. The concentrations of short chain alkanes were increased significantly after degradation. It can be seen that strain LKY-5 is an excellent bacterial candidate for bioremediation of oil-contaminated sites and sediments.     

Aflatoxin B1 decontamination by UV-mutated live and immobilized Aspergillus niger

The decontamination of Aflatoxin B₁ (AFB₁) by immobilized cells of a new mutant strain, prepared on a base of HSCAS (hydrated sodium calcium aluminosilicate), was studied. Novel strains were induced by UV irradiation, from which 50 were screened according to their degradation efficacy on AFB_1, compared with the wild strain (FS-Z1). The FS-UV1 strain exhibited highest degradation efficacy, which was confirmed by 18SrDNA to be Aspergillus niger. The results indicate that both immobilized cells and this mutant strain which are incubated for 48 h at 30 °C, would considerably remediate AFB₁ in nutrient broth culture, by 95.32% and 82.43%, respectively. By the application of samples of contaminated cottonseed meal, with results of 93.46%∼96.82%, the degradation rate was also validated. The results of Ames test indicate the mutagenic activity of treated AFB₁ is greatly abated, with treated controls. The Application of LC-q-TOFMS (liquid-chromatography, quadrupole, time-of-flight mass spectrometry) deduces the structure and molecular formulas of the degradation products. In the vivo study, the damages of photomicrographic evidence are decreased in kidney and liver and the serum biochemical parameters is improved, in response to preventative treatment with immobilized cells. This is the application of HSCAS-prepared, immobilized A. niger cells to degrade AFB₁ of contaminated samples. The investigation in this paper offers a novel path for economical, time-saving biodegradation of AFB₁ in foods and feeds.     

秸秆与微生物协同修复石油污染土壤

选择小麦秸秆协同Alcaligenes spJ 1和 Arthrobacter spJ 2混合菌进行石油污染土壤修复,研究秸秆与微生物协同修复石油污染土壤的效果。设计腐解实验,考察秸秆腐解对微生物吸附的影响;设置秸秆固定化微生物（IMM）、秸秆 游离菌（STM）2组修复实验,以游离菌（CP）为对照,考察秸秆、微生物的2种协同修复方式IMM、STM对石油污染土壤修复效果的不同和秸秆腐解的差异。结果表明,随着秸秆腐解程度的加剧,秸秆对微生物的吸附性能变差,可能与腐解过程秸秆的结构变松散有关;IMM组石油烃降解率较高,秸秆腐解较快,比STM组石油烃降解率高10%,腐殖酸质量分数多30 g/kg;石油烃降解率与腐殖酸含量的相关关系比较显著,相关系数为0906;IMM对土壤的修复效果更好。     

A New Technique for Measurement of Oil Biodegradation

Abstract

An active strain of anaerobic thermophilic bacteria was isolated from the environment of the United Arab Emirates. The strain, identified as Bacillus species, consists of two types—round and rod-shaped bacteria. This project studied the possibility of using these two types of bacteria for biodegradation of oil under elevated temperature conditions using a new method of measurement. Chemical and physical techniques were used previously to estimate the degradation rate of oil by microbes. In this project, a technique is was used to provide more accurate and reliable measurements. Visual inspection and measurements of oil drop size as a function of time were conducted. A computer image analyzer was used in this study to track bacterial growth and capacity to survive under different environmental conditions.

The temperature of the studied systems varied between 25°C and 70°C, and salt (sodium chloride (NaCl)) concentration varied between 0 and 50,000 ppm NaCl. The temperatures were selected to include typical sea water and reservoir temperatures in the Persian Gulf region. The average bacterial concentration used in this study was 182 × 10³ cells/mL. Experimental results indicated that the bacteria have the capacity to survive in saline and high temperature environments. The maximum oil degradation was observed at 70°C for all tested salinities. The degradation rate can be maximized by lowering the salinity and increasing the temperature of the studied systems. At a high temperature of 70°C, bacterial growth tends to improve at a low salt concentration, with a maximum oil degradation rate obtained at 10,000 ppm NaCl.     

Isolation and identification of new strains of crude oil degrading bacteria from Kharg Island,Iran

Petroleum-degrading bacteria were isolated from polluted sites in Kharg Island, which is one of the most important ports for oil export in Iran. Both biochemical tests and 16S rRNA were applied to identify the strains. Experiments were performed in a mineral salt medium containing 2% of crude oil as the sole carbon. The results illustrated that the strains were: Brevibacillus sp., Microbacterium oxydans, Staphylococcus arlettae, Staphylococcus warneri, Methylobacterium persicinum, and Achromobacter xylosoxidans. Growth rates of these strains by its optical densities at the wavelength of 600 illustrated that Pseudomonas sp. (accession no. KC771232) had the highest growth rate (OD₆₀₀ 0.8).     

改性浒苔固定化微生物制剂的制备及其对柴油的降解性能研究

为了提高固定化技术在海洋溢油处理中的应用效果,采用十二烷基苯磺酸钠（SDBS）为改性剂,采用浸渍法对浒苔进行改性。SDBS改性的浒苔（SDBS-E）作为固定化的吸附载体材料。同时,以海洋降解菌Sp8（Shewanella属）为研究对象。以海藻酸钠为包埋载体,无水氯化钙为交联剂,采用包埋法制备了SDBS-E固定化微生物制剂。与游离菌的降解率（78.87%）相比,SDBS-E固定化微生物对柴油的去除率提高到90.39%。研究了SDBS-E固定化微生物去除柴油的途径,主要包括表面吸附、内吸附和生物降解。早期依靠表面吸附,后期依靠生物降解。SDBS-E固定化微生物对柴油的降解符合准一级降解动力学模型。     

Antimicrobial efficiency of film incorporated with pediocin (ALTA 2351) on preservation of sliced ham

Antimicrobial packaging, besides protecting the product from external environment, inhibits or retards microorganism growth in foods, minimizing direct addition of preservatives and satisfying the actual demand of consumers for healthier foods, containing less additives. Pediocins are antimicrobial peptides produced by Pediococcus sp. and researches have revealed their ability to inhibit the growth of some pathogenic bacteria. The objective of this work was to develop and evaluate the antimicrobial efficiency of films incorporated with pediocin on sliced ham conservation. The antimicrobial films were incorporated with pediocin (25% and 50%) in a cellulose base emulsion. The antimicrobial efficiency of the films against Listeria innocua e Salmonella sp. on sliced ham was tested by means of a challenge test, in which the slices were immersed in 0.1% peptone solution containing about 10⁶ CFU/mL of L. innocua or Salmonella sp. The experiment was set up overlapping the slices of ham with the films (control, 25% and 50% of pediocin). These systems were packaged under vacuum and stored at 12 °C. The slices of ham were analyzed for L. innocua and Salmonella sp. counts at 0, 3, 6, 9, 12 and 15 storage days. The antimicrobial films were more effective inhibiting growth of L. innocua. The 50% pediocin-film presented a reduction of 2 log cycles in relation to control treatment after 15 days of storage. The 25% and 50% pediocin-films had similar performance on Salmonella sp. inhibition, both presenting 0.5 log cycle reduction in relation to control, after 12 days of storage. Hence, the films incorporated with pediocin showed potential use as one hurdle technology added in the storage period among others good manufacturing practices for preservation of sliced ham.     

Degradation properties of petroleum degrading bacteria immobilized on modified corn straw in marine environment

Abstract

In this study, in order to more effectively improve the biodegradation of oil in oil accident, the petroleum degrading Monomonas aeruginosa sp. was immobilized on the modified corn straw to analyze degradation properties, which was carbonized at different temperatures. The results indicated that after modified, the pores on the surface of corn straw increased significantly, the biomass can reach 18.25?×?10¹⁰ CFU/g and the degradation rate of diesel could reach 59.69% after 5?days. Therefore, the modification method can further provide technical support for the immobilization technology.     

Optimization for microbial degradation of petroleum hydrocarbon (TPH) by Enterobacter sp. S-1 using response surface methodology

In this research, the response surface method designed by Box-Behnken was used to study the effect of temperature, pH value and TPH concentration on the biodegradation of Enterobacter sp. S-1contaminated soil. The value of determination coefficient (R²=0.9565) by analysis of variance (ANOVA) indicated a satisfactory agreement between the quadratic model and the experimental data. It was found that TPH degradation rate was more significantly affected (P?<?0.0006) by temperature compared with other two parameters. In the temperature of 30?°C, pH value of 7.14 and TPH concentration was 4.83?g/L, the best degradation rate was 81.63%.     

Detoxification of Zearalenone by viable and inactivated cells of Planococcus sp

The capacity of Planococcus sp. strain S118 to remove Zearalenone (ZEN) from liquid medium in varying conditions was investigated. The results indicated that Planococcus sp. S118 removed ZEN by binding process. Strain S118 significantly reduced the levels of ZEN in the liquid medium; the viable and heat-inactivated bacteria could remove 21.82% and 47.82% of ZEN, respectively. Heat, acid, and Triton-100 treatment significantly enhanced the capability of removing ZEN. The detoxifying capability depended on the incubation period, concentration of bacteria, pH, and temperature. Planococcus sp. S118 likewise possessed the capability to remove Zearalanone (ZAN), which is one of ZEN analogues. The viable and heat-inactivated bacteria could remove 16.36% and 34.26% of ZAN, respectively. The detoxifying capability of ZEN and ZAN by heat-inactivated bacteria were significantly influenced by each other.