Metaproteome analysis to determine the metabolically active part of a thermophilic microbial community producing biogas from agricultural biomass

Complex consortia of microorganisms are responsible for biogas production. A lot of information about the taxonomic structure and enzymatic potential of such communities has been collected by a variety of gene-based approaches, yet little is known about which of all the assumable metabolic pathways are active throughout the process of biogas formation. To tackle this problem, we established a protocol for the metaproteomic analysis of samples taken from biogas reactors fed with agricultural biomass. In contrast to previous studies where an anaerobic digester was fed with synthetic wastewater, the complex matrix in this study required the extraction of proteins with liquid phenol and the application of paper bridge loading for 2-dimensional gel electrophoresis. Proteins were subjected to nanoHPLC (high-performance liquid chromatography) coupled to tandem mass spectrometry for characterization. Several housekeeping proteins as well as methanogenesis-related enzymes were identified by a MASCOT search and de novo sequencing, which proved the feasibility of our approach. The establishment of such an approach is the basis for further metaproteomic studies of biogas-producing communities. In particular, the apparent status of metabolic activities within the communities can be monitored. The knowledge collected from such experiments could lead to further improvements of biogas production.     

Measuring personal exposure to airborne mutagens and nicotine in environmental tobacco smoke

The exposure of individuals to environmental tobacco smoke (ETS) is of increasing public health concern because epidemiological studies have associated passive smoking with increased risk of a variety of adverse health effects among non-smokers including lung cancer. As a way to measure individual exposure to the mutagenic compounds in the complex mixture of ETS, we used a sensitive Salmonella/microsome micro pre-incubation (microsuspension) assay to detect mutagenicity of particulate matter collected on filters from low volume (1.7 1/min flow rate) personal sampling pumps. Airborne nicotine was collected concurrently as a marker for ETS exposure. In pilot-field studies, individual exposure to ETS was measured in two separate indoor environments in which smokers were present: a gambling casino and a bingo parlor. Total suspended particulate matter (TSP) was collected on filters worn near the breathing zone of non-smoking individuals. Sampling times ranged from 40 min to 6 h. All extracts of filters had detectable levels of mutagenic activity (TA98, +S9) resulting in airborne mutagenic activity concentrations of 500-5000 rev/m3. The mutagenic activity of the filters from the casino and bingo parlors was significantly correlated with total particulate matter per filters (n = 12; Rho = 0.85, p less than 0.01) and with airborne nicotine per filter (n = 12; Rho = 0.95, p less than 0.01). The microsuspension assay was sufficiently sensitive to detect the mutagens associated with extracts of particulate matter from low volume samples (0.2-0.6 m3) in these indoor environments over a relatively short sampling time, and could be useful in studies of personal exposure to the mutagens in environmental tobacco smoke. Further, airborne nicotine concentrations were highly correlated with airborne mutagenicity and the mutagenic activity associated with ETS could therefore be estimated by the concentrations of nicotine.     

Air-sampled Filter Analysis for Endotoxins and DNA Content

Outdoor aerosol research commonly uses particulate matter sampled on filters. This procedure enables various characterizations of the collected particles to be performed in parallel. The purpose of the method presented here is to obtain a highly accurate and reliable analysis of the endotoxin and DNA content of bio-aerosols extracted from filters. The extraction of high molecular weight organic molecules, such as lipopolysaccharides, from sampled filters involves shaking the sample in a pyrogen-free water-based medium. The subsequent analysis is based on an enzymatic reaction that can be detected using a turbidimetric measurement. As a result of the high organic content on the sampled filters, the extraction of DNA from the samples is performed using a commercial DNA extraction kit that was originally designed for soils and modified to improve the DNA yield. The detection and quantification of specific microbial species using quantitative polymerase chain reaction (q-PCR) analysis are described and compared with other available methods.     

Life Cycle Assessment of Biosolids Land Application and Evaluation of the Factors Impacting Human Toxicity through Plant Uptake

Due to increasing environmental concerns in the wastewater treatment sector, the environmental impacts of organic waste disposal procedures require careful evaluation. However, the impacts related to the return of organic matter to agricultural soils are difficult to assess. The goals of this study are to assess the environmental impacts of land application of two types of biosolids (dried and composted, respectively) from the same wastewater treatment plant in France, and to improve the quantification of human toxicity. A life cycle assessment (LCA) was carried out on a case study based on validated data from an actual wastewater treatment plant. Numerous impacts were included in this analysis, but a particular emphasis was laid on human toxicity via plant ingestion. For six out of the eight impact categories included in the analysis, the dried biosolids system was more harmful to the environment than the composting route, especially regarding the consumption of primary energy. Only human toxicity via water, soil, and air compartments and ozone depletion impacts were higher with the composted biosolids.     

Collection and characterization of a bulk PM2.5 air particulate matter material for use in reference materials

A contemporary PM_2.5 (particulate matter smaller than 2.5 Μm aerodynamic diameter) aerosol material from an urban site has been collected for the production of a new standard reference material that will be made available for the development of new PM_2.5 air quality standards. Air particulate matter corresponding to the PM_2.5 fraction was collected at an established Environmental Protection Agency monitoring site in Baltimore, Maryland. The air-sampling system that has been constructed for this collection separates fine particles with a cyclone separator and deposits them onto an array of Teflon membrane filters. The fine air particulate material is removed by ultrasonication or by mechanical means and collected for further preparation of standards. The composition of the collected PM_2.5 aerosol, as well as the composition of the deposited PM_2.5 aerosol, are determined by instrumental nuclear activation analysis and other techniques.     

The assessment of airborne bacterial contamination in three composting plants revealed site-related biological hazard and seasonal variations

AIMS: The purpose of this study was to evaluate the degree of bacterial contamination generated by three Italian composting plants (1, 2 and 3) in two different seasons and to assess the health risk for the employees. METHODS AND RESULTS: Aerosols samples were collected with an agar impact sampler. Several plant sites and external upwind and downwind controls were examined. Total colony-forming counts of mesophilic and thermophilic bacteria, actinomycetes and streptomycetes, Gram-negatives, coliforms and sulfite-reducers were determined. Selective media were used in order to isolate pathogenic bacteria. The levels of total mesophilic and thermophilic micro-organisms ranged between 33 and >40,000 CFU m(-3) in plant 1, 39 and 18,700 CFU m(-3) in plant 2 and 261 and 6278 CFU m(-3) in plant 3. Strains of Escherichia coli, Staphylococcus aureus and Clostridium perfringens were also found. CONCLUSIONS: The plants monitored in this study have proved to be sources of aerosolized bacteria. The activities involving mechanical movement of the composting mass and the indoor activities were of greatest potential risk. In all the studied plants, a statistically significant dependence was found between the bacterial contamination and the season for some or almost all the analysed parameters, but a clear seasonal trend could not be observed. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides broad evidence of bacterial aerosol dispersion and site-related biological hazards that may be useful to the regional government to implement regulations on worker safety in composting plants.     

The response of a co-culture lung model to fine and ultrafine particles of incinerator fly ash at the air-liquid interface

Elevated concentrations of particulate matter in the environmental atmosphere constitute a potential risk to human health. In vitro cell-based assays are therefore necessary to evaluate the toxicological potential of inhaled particulate emissions. In this study, the exposure of a co-culture cell model at the air-liquid interface was used to evaluate the dose-dependent biological effects of a test aerosol. The CULTEX system was used to expose human cells to an environmentally-relevant aerosol, generated from fly ash collected in a commercial municipal waste incinerator and resuspended in filtered air. Human bronchial epithelial cells, BEAS-2B, co-cultured with differentiated THP-1 macrophages growing on Transwell inserts, were employed in the bioassay. Analyses of cell viability, interleukin-8 (IL-8) release, intracellular glutathione, and haeme oxygenase-1 enzyme expression were performed. Transportation of the cells and exposure to humidified filtered air or the test aerosol, at 100 ml/min for 1 to 6 hours, were well tolerated by the cells and had no effect on their viability. Levels of IL-8 release and haeme oxygenase-1 expression were elevated by exposure to fly ash aerosol as a function of time, but not by exposure to clean air. For IL-8 release, a dose-dependent effect was demonstrated with the assumption that the deposited mass of the particles correlated with exposure time. Exposure to the test aerosol did not affect the intracellular glutathione concentration. This in vitro approach simulates particle deposition in the human lung more realistically than does submerged exposure, and it preserves the inherent properties of the particles. It shows promise for use to detect particulate emissions which are potentially detrimental to human health.     

Seasonal variability of bacteria in fine and coarse urban air particulate matter

The current knowledge about the microbial communities associated with airborne particulate matter, particularly in urban areas, is limited. This study aims to fill this gap by describing the microbial community associated with coarse (PM10) and fine (PM2.5) particulate matter using pyrosequencing. Particulate matter was sampled on Teflon filters over 3 months in summer and 3 months in winter in Milan (Italy), and the hypervariable V3 region of the gene 16S rRNA amplified from the DNA extracted from the filters. The results showed large seasonal variations in the microbial communities, with plant-associated bacteria dominating in summer and spore-forming bacteria in winter. Bacterial communities from PM10 and PM2.5 were also found to differ from each other by season. In all samples, a high species richness, comparable with that of soils, but a low evenness was found. The results suggest that not only can the sources of the particulate influence the presence of specific bacterial groups but also that environmental factors and stresses can shape the bacterial community.     

气溶胶中抗生素抗性基因研究进展

抗生素的不合理使用导致细菌耐药问题日趋严峻,给人类健康造成巨大威胁。学者们对抗生素抗性菌和抗生素抗性基因(antibiotic resistance genes, ARGs)在多种环境介质中的环境行为开展了大量研究。气溶胶作为ARGs的潜在储存库,是抗生素抗性基因在环境中的重要传播途径之一。目前缺乏对其来源、传播、人类接触和健康风险系统性的梳理。本文针对人类生活功能场所、养殖场、城市污水处理厂和医院等4类气溶胶研究的典型场所,重点综述了上述4类典型场所中气溶胶ARGs的来源、传播途径及对人体的暴露和对健康的危害,为气溶胶中ARGs的预防和控制提供参考。     

Chlorine resistance patterns of bacteria from two drinking water distribution systems.

The relative chlorine sensitivities of bacteria isolated from chlorinated and unchlorinated drinking water distribution systems were compared by two independent methods. One method measured the toxic effect of free chlorine on bacteria, whereas the other measured the effect of combined chlorine. Bacteria from the chlorinated system were more resistant to both the combined and free forms of chlorine than those from the unchlorinated system, suggesting that there may be selection for more chlorine-tolerant microorganisms in chlorinated waters. Bacteria retained on the surfaces of 2.0-microns Nuclepore membrane filters were significantly more resistant to free chlorine compared to the total microbial population recovered on 0.2-micron membrane filters, presumably because aggregated cells or bacteria attached to suspended particulate matter exhibit more resistance than unassociated microorganisms. In accordance with this hypothesis, scanning electron microscopy of suspended particulate matter from the water samples revealed the presence of attached bacteria. The most resistant microorganisms were able to survive a 2-min exposure to 10 mg of free chlorine per liter. These included gram-positive spore-forming bacilli, actinomycetes, and some micrococci. The most sensitive bacteria were readily killed by chlorine concentrations of 1.0 mg liter-1 or less, and included most gram-positive micrococci, Corynebacterium/Arthrobacter, Klebsiella, Pseudomonas/Alcaligenes, Flavobacterium/Moraxella, and Acinetobacter.     

Agrochemical characterisation of "alperujo", a solid by-product of the two-phase centrifugation method for olive oil extraction

Introduction of the two-phase centrifugation system for olive oil extraction during the early nineties in Spain has led to the generation of approximately four million tons per year of a solid olive-mill by-product called "alperujo" (AL). Agrochemical characterisation showed that AL has a high moisture content, slightly acidic pH values and a very high content of organic matter, mainly composed by lignin, hemicellulose and cellulose. It also has a considerable proportion of fats, proteins, water-soluble carbohydrates and a small but active fraction of hydrosoluble phenolic substances. Amongst plant nutrients, AL is rich in potassium, less so in (mainly organic) nitrogen and poor in phosphorus and micronutrients. Some of those properties are not compatible with agricultural requirements, for which reason composting may be considered a suitable alternative for its disposal. AL needs to be characterised before composting, and so an attempt was made to correlate the easily determined ash content with other parameters; the regression models thus obtained are discussed.     

The study of the aerobic bacterial microbiota and the biotoxicity in various samples of olive mill wastewaters (alpechin) during their composting process

Five different piles were prepared by mixing olive mill wastewater (alpechin) and alpechin sludge with two bulking agents (cotton waste and maize straw) and two organic wastes with high content of nitrogen (sewage sludge and poultry manure), which were composted by the Rutgers static pile composting system in a pilot plant. The aim of this work was to study the evolution of total nitrogen and different forms of organic matter and evaluate the variation in the aerobic bacterial microbiota present and biotoxicity during the composting process.In piles prepared with alpechin, the use of the maize straw as a bulking agent reduced the nitrogen losses whereas the use of sewage sludge, instead of poultry manure, with cotton waste originated the highest degradation of organic matter. In piles prepared with alpechin sludge a similar evolution of the composting process was observed. There were not great variations during composting in the aerobic bacterial microbiota present in the mixtures. However, the pile prepared with alpechin sludge and maize straw was only one to present bacteria capable of growing in alpechin, and the toxicity study showed that this was only present in the starting mixtures.     

Scale‐down models to optimize a filter train for the downstream purification of recombinant pharmaceutical proteins produced in tobacco leaves

The extraction of biopharmaceutical proteins from intact leaves involves the release of abundant particulate contaminants that must be removed economically from the process stream before chromatography, for example, using disposable filters that comply with good manufacturing practice. We therefore scaled down an existing 200‐kg process for the purification of two target proteins from tobacco leaves (the monoclonal antibody 2G12 and the fluorescent protein DsRed, as monitored by surface plasmon resonance spectroscopy and fluorescence imaging, respectively) and screened different materials on the 2‐kg scale to reduce the number of depth filtration steps from three to one. We assessed filter cost and capacity, filtrate turbidity, and protein recovery when the filter materials were challenged with extracts from different tobacco varieties and related species grown in soil or rockwool. PDF4 was consistently the most suitable depth filter because it was the least expensive, it did not interact significantly with the target proteins, and it had the greatest overall capacity. The filter capacity was generally reduced when plants were grown in rockwool, but this substrate has a low bioburden, thus improving process safety. Our data concerning the clarification of plant extracts will help in the design of more cost‐effective downstream processes and accelerate their development.     

The microbial signature of aerosols produced during the thermophilic phase of composting

Aims:  The microbial diversity of bioaerosols released during operational activities at composting plants is poorly understood. Identification of bacteria and fungi present in such aerosols is the prerequisite for the definition of microbial indicators that could be used in dispersal and exposure studies.
Methods and Results:  A culture-independent analysis of composting bioaerosols collected at five different industrial open sites during the turning of composting piles in fermentation was performed by building 16S rDNA and 18S rDNA libraries. More than 800 sequences were analysed. Although differences in the phylotypes distribution were observed from one composting site to another, similarities in the structure of microbial diversity were remarkable. The same phyla dominated in the five bioaerosols: Ascomycota among fungi, Firmicutes and Actinobacteria among bacteria. For each phylum, some dominant phylotypes were common to at least four bioaerosols. These common phylotypes belonged to Thermomyces , Aspergillus , Penicillium , Geobacillus, Planifilum , Thermoactinomyces , Saccharopolyspora , Thermobifida and Saccharomonospora .
Conclusions:  The microbial signature of aerosols produced during the thermophilic phase of composting was determined. The similarities observed may be explained by the selection of thermophilic and sporulating species.
Significance and Impact of the Study:  Several bacteria and fungi identified in this study may represent potential indicators of composting bioaerosols in air.     

Significance of exploiting non-living biomaterials for the biosorption of wastewater pollutants

Industrial effluents from various sectors have become a matter of major environmental concern. The treatment of wastewater in recent year plays a significant role in order to remove the pollutants and to safeguard the water resource. The conventional wastewater treatment is considered costlier and associated with problem of sludge generation. Biosorption methods are considered as the potential solution due to their economical efficiency, good adsorption capacity and eco-friendliness. In this review, an extensive list of biosorbents from algae, bacteria, fungi and agricultural byproducts have been compiled. The suitability of biosorbents towards the eradication of heavy metals, textile dyes and phenolic compounds were highlighted. It is evident from the literature survey of recently published research articles that the biosorbents have demonstrated outstanding removal potential towards the wastewater pollutants. Therefore, biosorbents from the source of dead microbial and agricultural byproduct can be viable alternatives to activated carbon for the wastewater treatment.     

Olive mill waste composting: A review

Olive mill wastes exacerbate environmental problems in Mediterranean countries. These wastes are highly phytotoxic and contain phenolic compounds, lipids and organic acids. They also contain high percentages of organic matter and a vast range of plant nutrients that could be reused as fertilizers for sustainable agricultural practices. In this paper, recent research on composting wastes of 2-phase and 3-phase olive mills is reviewed, concentrating on factors affecting composting such as bulking agents, aeration strategy, physicochemical characteristics (duration of the thermophilic phase, moisture content, organic matter, volatile solids, total organic carbon, water soluble carbon, total nitrogen, total phosphorus, potassium, C/N ratio, phenols and the humification process), and phytotoxicity. The review highlights the effects of composting operational factors (bulking agent, additives, and aeration strategy) on the physicochemical characteristics of the final compost, and the production of a good quality soil amender or fertilizer.     

结合激光雷达分析上海地区一次连续浮尘天气过程

通过分析2010年3月至20日至3月22日上海地区一次典型的连续浮尘天气过程,利用激光雷达数据资料反演得到的气溶胶消光系数图和垂直廓线图,结合地面气象数据和气溶胶观测资料以及卫星遥感资料,初步得出了此次连续浮尘天气形成的原因。外源性输入和垂直风场分布是导致此次浮尘天气发生的重要原因,大气层结变化决定着浮尘天气发生的强度,当存在接地逆温时,浮尘天气维持,而太阳辐射强度变化决定着边界层高度的变化。第一次浮尘过程以大颗粒污染为主,且在消光作用中散射性气溶胶的贡献大于吸收性气溶胶,而第二次回流浮尘过程则PM2.5比重上升,吸收性气溶胶对消光系数的贡献与散射性气溶胶大体相当。     

Transformation of buffalo manure by composting or vermicomposting to rehabilitate degraded tropical soils

The addition of composted buffalo manure may lead to qualitative and quantitative improvement of the organic matter content of degraded tropical agricultural soils in Northern Vietnam. The objectives of this study were to follow the biochemical changes occurring during composting of buffalo manure with and without earthworms during 3 months and to study the effect of the end products (compost and vermicompost) on soil biochemical parameters and plant growth after two months of incubation under controlled conditions in an open pot experiment. Our conceptual approach included characterisation of organic matter of the two composts before and after addition to soil by elemental, isotopic analysis and analytical pyrolysis and comparison with conventional fertilisation. We also analysed for lignin content and composition.Our results showed that composting in the presence of earthworms led to stronger transformation of buffalo manure than regular composting. Vermicompost was enriched in N-containing compounds and depleted in polysaccharides. It further contained stronger modified lignin compared to regular compost. In the bulk soil, the amendment of compost and vermicompost led to significant modification of the soil organic matter after 2 months of exposure to natural weather conditions. The lignin component of SOM was unaffected whatever the origin of the organic amendment. Compost and vermicompost amendments both enhanced aggregation and increased the amount of organic matter in water stable aggregates. However, vermicompost is preferable to compost due to its beneficial effect on plant growth, while having similar positive effects on quantity and quality of SOM.     

Mutagenicity studies on complex environmental mixtures: selection of solvent system for extraction.

The mutagenic activities in the Salmonella/microsome assay of dichloromethane (DCM) and acetone extracts of complex environmental mixtures were compared. The particulate samples used in the IPCS collaborative study were Soxhlet-extracted twice with DCM followed by a third extraction with acetone. Compared with the mutagenic activity of the first extract, the third (acetone) extract of the urban particulate matter showed a relatively high mutagenic activity. In contrast to this the third extract of the diesel particulate matter contributed very little additional mutagenic activity. Furthermore, 10 filter samples of air particulates from a suburban airport area were collected for comparison of the extraction efficiency of DCM and acetone. Each sample was divided into two samples of identical size followed by extraction with acetone and DCM, respectively. No clear difference in the mutagenic activity of these extracts was observed in strains TA98 and TA98NR. It is concluded that for ambient air particulates (but not emission samples) acetone may extract some mutagenic compounds which are not extracted by DCM. The amount of these additional extractable compounds seems to depend on the composition of the sample. As DCM extracts are better suited for further fractionation and chemical analysis DCM is considered to be the best choice for a general solvent system for extraction of complex environmental mixtures.     

Analysis of contaminants in factor VIII preparations administered to patients with hemophilia.

Cryoprecipitate and the more purified factor VIII concentrates are all heterogeneous preparations that contain not only a high concentration of factor VIII but also various other materials, some of which might be injurious, causing liver damage after long-term exposure. The efficiency of three standard cryoprecipitate filters, two microaggregate filters and the appropriate factor VIII concentrate filters in reducing the amount of particulate matter delivered to the patient was assessed. Filtration of cryoprecipitate through the standard filters removed less than 20% of the contaminating microaggregates and very few of the large number of intact platelets, although the total dose of factor VIII was delivered. Microaggregate filters were no better in reducing the platelet contamination, although the total number of particles delivered was halved. However, 25% of the factor VIII was retained in the bed volume of the filter. The concentrate preparations also contained significant amounts of particulate matter that was unrelated to factor VIII and was not removed following filtration through the designated filter. These findings indicate that a new filter should be developed for administration of factor VIII concentrate that would remove the particulate matter while delivering all of the factor VIII to the patient.