A method for isolating fungi from soil microhabitats

Summary A technique is described for the separation and washing of soil micro-habitats (the separation being on a size basis). Tests of the efficiency of the washing technique show that, for the soil under experiment, 25 to 30 washings are required to remove most of the fungal spores; the number of washings required will vary from soil to soil. Data is given on the use of this method for fungal isolations from a cultivated soil.     

污染土壤淋洗修复技术研究进展

土壤淋洗修复技术是一种行之有效的污染土壤治理技术,适合于快速修复受高浓度重金属和有机物污染土壤与沉积物。本文综述了土壤淋洗修复技术的特点、技术流程、土壤淋洗剂的研究与应用进展,指出异位土壤淋洗修复技术因修复效果稳定,易于实现系统控制和废弃物减量化等优点而具有更广阔的应用前景,天然螯合剂和生物表面活性剂等环境友好型淋洗剂正逐渐取代人工螯合剂和化学表面活性剂成为土壤淋洗剂研究的主流方向,而现代超分子化学的引入和发展有可能对复合污染土壤的高效淋洗修复研究产生新的影响。     

DNA microarrays on nanoscale-controlled surface

We have developed new surface to ensure a proper spacing between immobilized biomolecules. While DNA microarray on this surface provided each probe DNA with ample space for hybridization with incoming target DNAs, the microarray showed enhanced discrimination efficiency for various types of single nucleotide polymorphism. The high discrimination efficiency holds for all tested cases (100:<1 for internal mismatched cases; 100:<28 for terminal mismatched ones). In addition, by investigating influence of hybridization temperature and washing condition on the fluorescence intensity and the discrimination efficiency with and without controlled mesospacing, it was observed that the nanoscale-controlled surface showed good discrimination efficiency in a wide range of temperature (37–50°C), and hybridization behavior on the surface was in agreement with the solution one. Intriguingly, it was found that washing process after the hybridization was critical for the high discrimination efficiency. For the particular case, washing process was so efficient that only 30 s washing was sufficient to reach the optimal discrimination ratio.     

Improving the quality of washed and buffy coat-free erythrocyte concentrates]

Washing buffy-coat free erythrocyte concentrates three times in bottles used for blood storage will diminish their leukocyte content to 0.22 +/- 0.11 x 10(9) per TE (= 9% of the initial value in whole blood, and the thrombocyte content to 0.3 +/- 0.5 x 10(9) per day (= 2% of the initial value in whole blood). Even 50% of leukocytes (mainly lymphocytes) and 80% of thrombocytes are eliminated simply by buffy coat separation. 30% of erythrocytes are lost by the washing process. Due to increasing haemolysis (0.22%) a subsequent storage of 24 hours should not be exceeded for washed erythrocyte concentrates. Further quality parameters, such as morphological index, pH, ATP, 2,3-P2G and K+ and Na+, were investigated. As far as selected quality parameters are concerned, washing erythrocyte concentrates three times in bottles for blood storage may be compared with washing them once in blood bags. The present findings confirm the conclusion that the washing of erythrocyte concentrates with a solution of sodium chloride in order to eliminate leukocytes may for the most part exclude non-haemolytic febrile transfusion reactions, but not immunization. More effective procedures of eliminating leukocytes, such as filtration, TTK or even glycerin, treatment of erythrocyte concentrates without cryoconservation, are indispensable.     

Optimization of Influencing Parameters on Phenanthrene Removal Efficiency in Soil Washing Process by Using Response Surface Methodology

Response surface methodology (RSM) under Box–Behnken design (BBD) was applied to evaluate the effect of the influencing parameters including surfactant concentration, liquid/soil ratio, Humic Acid concentration, and washing time on phenanthrene removal efficiency in soil washing process by using the nonionic surfactant Tween 80 and find an optimal operational conditions to achieve the highest removal efficiency. A polynomial quadratic model was used to correlate phenanthrene removal efficiency and four independent variables (R² = 0.9719). Based on the obtained results the most influential parameter on phenanthrene removal efficiency was surfactant concentration with an impact value of 69.519%. Liquid/soil ratio was also another factor that significantly influenced on removal efficiency with an impact value of 25.014%. The interaction between surfactant concentration and liquid/soil ratio was also shown to have a positive significant effect on removal efficiency (p_value = 0.0027). However, the other independent variables Humic Acid concentration and time were not significant in the ranges selected in this study. Based on the optimization results maximum removal efficiency of 70.692 ± 3.647% was achieved under the conditions of surfactant concentration 5000 mg L^?1, liquid/soil ratio 30 v/w, HA concentration 9.88 mg L^?1, and washing time 2 h, which was in good agreement with predicted value (66.643%).     

Wireworm populations in relation to crop production: I. A large-scale flotation method for extracting wireworms from soil samples and results from a survey of 600 fields

The wireworm survey in the Eastern Counties revealed many cases where the observed wireworm damage failed to correspond with the estimated field population. A possible explanation for this was the inaccuracy of counts made by picking wireworms out of the soil samples by hand. Tests showed that such methods recovered an extremely variable proportion of the wireworms in the- samples and, on the average, only two-fifths of the larvae were obtained. A modified form of the washing and flotation technique used by Salt & Hollick (1944) was introduced for large-scale work and is described. By this method, ten samples of soil (4 in. diam. and 6 in. deep) bulked together are examined at a time and can be dealt with at the rate of 13 samples per man per hour with an efficiency of 95-100% in the extraction of wireworms. The populations estimated on 600 fields sampled between December 1942 and May 1943 have thrown more light on the size and composition of the wireworm population in grass and arable fields. Inspection of the crop results on fields tested by the washing process showed a much closer relationship between wireworm population and wireworm damage than had been obtained by the hand-sorting method in the previous year.     

Cadmium removal from contaminated soil by thermally responsive elastin (ELPEC20) biopolymers

Cadmium contamination of soil is a major concern in the biosphere. Beyond the suite of available physico-chemical treatment methods, green and more efficient technologies are desired to reduce cadmium and other heavy metal contaminants to acceptable levels. Elastin-like polypeptides (ELP) composed of a polyhistidine domain (ELPH12) can be used as an environmentally benign chelating agent for ex situ soil washing. However, ELPH12 is relatively non-selective. A biopolymer with metal-binding domains that have stronger affinity, capacity, and selectivity would have distinct advantages. The aim of this work is to investigate the use of a new generation of ELP biopolymer, ELPEC20, containing synthetic phytochelatin (EC) as the metal-binding domain for ex situ soil washing. ELPEC20 was shown to bind cadmium more effectively and selectively than ELPH12. The binding constant of ELPEC20 is an order of magnitude higher and the binding capacity is fivefold higher than ELPH12. In contrast to ELPH12, no decrease in cadmium binding was observed in the presence of other competing metal ions. The improved selectivity and binding capacity provided by ELPEC20 were directly reflected in the enhanced cadmium extraction efficiency from contaminated soil. In batch washing studies up to 62% of the bound cadmium was removed by ELPEC20 while less than 12% was removed by ELPH12. Cadmium was removed not only from the exchangeable fraction but also the oxidizable fraction. The high-affinity binding sites of ELPEC20 also results in very rapid extraction with complete removal achieved within 1 h, suggesting that ELPEC20 could be used as part of a rapid (short retention time) technology with minimum possibility for the biodegradation of biopolymers.     

Current views on EDDS use for ex situ washing of potentially toxic metal contaminated soils

The paper presents a mini-review on EDDS use for ex situ chemical washing of potentially toxic metal contaminated soil. The attention is focused, initially, on studies aimed at verifying the biodegradability and the toxicity of free EDDS and metal-EDDS complexes. Free EDDS is found to be highly biodegradable. Metal-EDDS complexes, instead, are indicated as having variable biodegradability, but their toxicity is found to be always very low. The results obtained during soil washing treatments are successively reviewed. Removal percentages as high as 80–90 % are indicated as maximum obtained values. The extraction process is initially very fast, and then tends to slow down reaching the final equilibrium in about 1 week or even more. Generally acidic conditions are favourable to enhance the process. The influence of organic matter on process efficiency and the interactions between EDDS and soil minerals are also considered, revealing variable effects of the organic matter presence depending on its characteristics, and highlighting the possibility of iron and aluminium washing off during the remediation treatment.     

Alginate microparticles as novel carrier for oral insulin delivery

Alginate microparticles produced by emulsification/internal gelation were investigated as a promising carrier for insulin delivery. The procedure involves the dispersion of alginate solution containing insulin protein, into a water immiscible phase. Gelation is triggered in situ by instantaneous release of ionic calcium from carbonate complex via gentle pH adjustment. Particle size is controlled through the emulsification parameters, yielding insulin-loaded microparticles. Particle recovery was compared using several washing protocols. Recovery strategies are proposed and the influence on particle mean size, morphology, recovery yield (RY), encapsulation efficiency, insulin release profile, and structural integrity of released insulin were evaluated. Spherical micron-sized particles loaded with insulin were produced. The recovery process was optimized, improving yield, and ensuring removal of residual oil from the particle surface. The optimum recovery strategy consisted in successive washing with a mixture of acetone/hexane/isopropanol coupled with centrifugation. This strategy led to small spherical particles with an encapsulation efficiency of 80% and a RY around 70%. In vitro release studies showed that alginate itself was not able to suppress insulin release in acidic media; however, this strategy preserves the secondary structure of insulin. Particles had a mean size lower than the critical diameter necessary to be orally absorbed through the intestinal mucosa followed by their passage to systemic circulation and thus can be considered as a promising technology for insulin delivery.     

Bacteria-mediated PAH degradation in soil and sediment

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the natural environment and easily accumulate in soil and sediment due to their low solubility and high hydrophobicity, rendering them less available for biological degradation. However, microbial degradation is a promising mechanism which is responsible for the ecological recovery of PAH-contaminated soil and sediment for removing these recalcitrant compounds compared with chemical degradation of PAHs. The goal of this review is to provide an outline of the current knowledge of biodegradation of PAHs in related aspects. Over 102 publications related to PAH biodegradation in soil and sediment are compiled, discussed, and analyzed. This review aims to discuss PAH degradation under various redox potential conditions, the factors affecting the biodegradation rates, degrading bacteria, the relevant genes in molecular monitoring methods, and some recent-year bioremediation field studies. The comprehensive understanding of the bioremediation kinetics and molecular means will be helpful for optimizing and monitoring the process, and overcoming its limitations in practical projects.     

DNA sequencing by hybridization with an oligonucleotide matrix (SHOM). The theory of DNA elution after hybridization]

The theoretical treatment of the process of washing out of a single stranded DNA fragment after hybridization with short oligonucleotides immobilized within the polyacrylamide gel layer is presented. The theory describes satisfactorily the main body of experimental findings, obtained earlier in connection with the elaboration of a new DNA sequencing method based on hybridization with the matrix of immobilized oligonucleotides [K.R. Khrapko et al.@J. DNA Sequencing Mapp. 1991. V. 1. P. 373-388]. In particular the theory explains and describes well quantitatively the observed dependence of the "washing off temperature" Tw on the concentration of the immobilized oligonucleotides. The Tw dependence on inherent physico-chemical parameters such as the enthalpy and the entropy of duplex formation and on those selected by the experimenter (washing time duration, the gel thickness etc.) is also considered. A simple approximate expression for the calculation of "washing off temperature" is given. Some inconsistencies between calculated and observed washing curves are discussed.     

A real-scale soil phytoremediation

In the present investigation, a phytoremediation process with a combination of different plant species (Populus nigra (var.italica), Paulownia tomentosa and Cytisus scoparius), and natural growing vegetation has been proposed at real-scale (10.000 m²) to bioremediate and functionally recover a soil historically contaminated by heavy metals and hydrocarbons. In the attempts to assess both effectiveness and evolution of the remediation system towards a natural soil ecosystem, besides the pollution parameters, also parameters describing the efficiency of the microbiological components (enzyme activities), were investigated. In 3 years, the total content of hydrocarbons and heavy metals in soil decreased with time (40 % and 20–40 %, respectively), reaching concentrations under the limit of National legislation and making the site suitable for environmental reusing. The reduction in pollutants was probably the reason of the increase in dehydrogenase (indicator of overall microbial activity), β-glucosidase and phosphatase activities, enzymes related to C and P cycles, respectively. However, this trend was obviously due also to the increase of chemical nutrients, acting as substrate of these enzymes. Moreover, a phytotest carried out with Raphanus sativus, showed, after 3 years, a significant increase in percentage of plant growth, confirming a reduction in soil toxicity and an improvement in soil nutritional state. Therefore, this phytoremediation system seems very promising to perform both decontamination and functional recovery of a polluted soil at real-scale level.     

重金属污染土壤修复技术中有关淋洗剂的研究进展

淋洗法是修复污染土壤的一种很有效的方法 ,是对污染土壤生物修复的一种补充 ,使污染土壤修复的系统化成为可能。淋洗法就是使用淋洗剂来清洗土壤 ,使土壤中污染物随淋洗液流出 ,然后对淋洗液及土壤进行后续处理 ,从而达到修复污染土壤的目的。而淋洗剂的选择是影响这一技术效率高低的主要因素之一。本文对目前淋洗剂的应用情况 ,作用机制进行了总结和评价。探讨了天然有机酸、生物表面活性剂等对环境影响小的淋洗液的应用前景。并根据“以废治污”的指导思想提出并分析了以柠檬酸废水和味精废水作为淋洗剂修复重金属污染土壤的可行性。     

分子模拟指导核酸适配体文库设计

核酸适配体是利用配体指数富集的系统进化技术（SELEX）从随机文库中筛选获得一段有功能的单链寡核苷酸。但因筛选过程中的文库选择、洗涤次数、分离效率、缓冲液离子含量和pH值等多种因素的影响,迄今所报道的亲和力与特异性都很高的核酸适配体为数不多。初始文库是核酸适配体筛选的源头,作为SELEX技术的根本,其设计是否合理直接影响到筛选的成败和效率。分子模拟能以核酸适配体文库为主体,计算机为主要工具,发展多种结构模拟与分析工具,辅助核酸适配体文库的合理设计。本文综述了现阶段利用分子模拟进行核酸适配体初始文库设计的相关方法,希望能为从源头上提高核酸适配体筛选的成功率提供线索。     

Study of a new device for washing and concentrating cryopreserved hematopoietic stem cells and mononuclear cells: a single center experience

Background aimsCryopreserved cellular products, as parts of hematopoietic progenitor cell (HPC) transplants, mononuclear cell reinjections for donor lymphocyte infusion or extracorporeal photopheresis, can be washed before being reinjected into the patient or infused directly, depending on local practices. The aim of washing is to reduce the incidence and severity of adverse reactions (ARs) due to the dimethyl sulfoxide (DMSO) used as a cryoprotective agent and other factors, such as dead cell debris. At the authors’ cell therapy laboratory (CTL) in Poitiers, France, as in 76% of Etablissement Français du Sang (EFS) CTLs, all cryopreserved products undergo thawing in a water bath followed by washing with the COBE 2991. As this device will soon cease to be available, an alternative process needs to be assessed.MethodsThe authors compared two closed systems: the authors’ semi-automatic system using the traditional centrifugation method (COBE 2991) and an automated device using spinning membrane filtration (Lovo). A total of 72 HPC bags available for research were used. The authors first performed a paired comparison, processing one or two HPC bags washed by each device. A second study was carried out to compare two different washing solutions generally used by EFS CTLs along with variable storage conditions. Finally, the authors studied the efficiency of the Lovo with three or four thawed bags. The main parameters studied were viable CD34+ cell recovery and viability, CD3+ cell recovery, stability up to 6 h after washing, DMSO elimination and center feasibility.ResultsThe Lovo device showed better CD34+ cell recovery compared with the COBE 2991 while maintaining CD34+ viability and stability over 6 h. Moreover, Lovo efficiency seemed to be independent of the number of thawed bags processed and washing solution used in the authors’ study. CD3+ cell recovery met the authors’ internal specifications (cell recovery >50%), with similar results seen when processing with either the COBE 2991 or Lovo. Additionally, on average, 97% of DMSO was removed after washing with Lovo, minimizing the risk of ARs. The storage conditions post-processing indicated preferred storage conditions of 7 ± 3°C. Finally, if processing time seemed shorter using COBE 2991 for one bag washed, the Lovo device required only one staff member regardless of the number of HPC bags processed.ConclusionsThe Lovo device seems to provide an opportunity to standardize HPC processing, ensuring patient safety, with, on average, 97% of DMSO removed, while improving recovery of cells of interest and maintaining viability over time in case of delayed transplant. The Lovo device consequently seems to be a serious alternative to the COBE 2991.     

Sequential Push-Pull Pumping Mechanism for Washing and Evacuation of an Immunoassay Reaction Chamber on a Microfluidic CD Platform

A centrifugal compact disc (CD) microfluidic platform with reservoirs, micro-channels, and valves can be employed for implementing a complete immunoassay. Detection or biosensor chambers are either coated for immuno-interaction or a biosensor chip is inserted in them. On microfluidic CDs featuring such multi-step chemical/biological processes, the biosensor chamber must be repeatedly filled with fluids such as enzymes solutions, buffers, and washing solutions. After each filling step, the biosensor chamber needs to be evacuated by a passive siphoning process to prepare it for the next step in the assay. However, rotational speed dependency and limited space on a CD are two big obstacles to performing such repetitive filling and siphoning steps. In this work, a unique thermo-pneumatic (TP) Push-Pull pumping method is employed to provide a superior alternative biosensor chamber filling and evacuation technique. The proposed technique is demonstrated on two CD designs. The first design features a simple two-step microfluidic process to demonstrate the evacuation technique, while the second design shows the filling and evacuation technique with an example sequence for an actual immunoassay. In addition, the performance of the filling and evacuation technique as a washing step is also evaluated quantitatively and compared to the conventional manual bench top washing method. The two designs and the performance evaluation demonstrate that the technique is simple to implement, reliable, easy to control, and allows for repeated push-pulls and thus filling and emptying of the biosensor chamber. Furthermore, by addressing the issue of rotational speed dependency and limited space concerns in implementing repetitive filling and evacuation steps, this newly introduced technique increases the flexibility of the microfluidic CD platform to perform multi-step biological and chemical processes.     

Evaluation of the efficiency of extraction for the quantitative estimation of hydrogen bacteria in soil

The efficiency of extraction of hydrogen bacteria from soil for plate counting was evaluated by using pure cultures adsorbed to sterilized soil. The utilization of model materials which interact with bacteria by adhesive, capillary or electrostatic forces and the use of extraction fluids with buffering, detergent or chelating activity demonstrated the major importance of capillary forces for the retention of hydrogen bacteria.Utilization of Tris buffer (pH 7.5) as extraction fluid and separation of extracted bacteria from soil particles by sedimentation for 15 min resulted in the highest recovery. A second extraction step including sonication did not increase the efficiency. The extraction efficiency of 8 different strains of hydrogen bacteria adsorbed to 3 different soils demonstrated a high degree of variation with respect to bacterial strains, but not to soil types. The recovery was inversely related to cell parameters such as size, motility and slime formation.     

Losses of14C from roots of pulse-labelled wheat and barley during washing from soil

In crop carbon budget studies losses of root material during storage and washing of samples may cause considerable errors. To correct data from field experiments where rhizosphere C fluxes in wheat and barley were determined by¹⁴C pulse-labelling at different development stages, experiments were performed to quantify losses of¹⁴C from roots during washing. Losses of¹⁴C from wheat roots grown on nutrient solution and stored in different ways, decreased from on average 45% of total¹⁴C content 8 days after labelling to 27% after 21 days. This decrease was probably related to the incorporation of¹⁴C into structural compounds. During washing of oven-dried soil cores of held-grown wheat and barley 3 weeks after labelling, different size classes of losses of¹⁴C from the roots increased substantially with the development stage of the crop at labelling. The 0.3–0.6 mm size class increased from 5% of the¹⁴C in roots > 0.3 mm in young plants to 25% at ripening, and the < 0.3 mm size class increased from 8 to 41% of total¹⁴C content. The latter size class was, however, determined by washing handpicked roots and may therefore partly consist of adhering exudates, mucilages and microorganisms. The effect of development stage on root washing losses was attributed to root senescence which increases the fragility of roots. Thus, especially at the rate development stages root washing losses caused a severe underestimation of the root¹⁴C content. However, with these results the¹⁴C distribution patterns of the field experiments could be adequately corrected.Communication No. 77 of the Dutch Programme on Soil Ecology of Arable Farming Systems.     

Desorption of Nitroaromatic Compounds From Explosive-contaminated Soil by Washing

The soil contaminated by explosive production wastewater was treated by washing using water as solvent. The effect of contact time and temperature, water/soil ratio and washing steps on desorption efficiency was investigated. Six kinetic models—parabolic diffusion model, zero-order equation, pseudo-first-order equation, pseudo-second-order equation, power function equation and Elovich equation—were used to study the desorption kinetics of nitroaromatic compounds from contaminated soil to water. The eluent of contaminated soil before and after washing was characterized by UV–vis analysis. The results showed that the removal rate was fast at the initial stage and then slowed down after 60 min. The desorption of contaminants from soil to water is endothermic. Washing with small quantities of water in high frequency is preferred when water volume is limited. The pseudo-second-order model can be used to describe the desorption process. Soil washing can remove most of the contaminants from the contaminated soil.     

Quantifying drivers of variability in life cycle greenhouse gas emissions of consumer products—a case study on laundry washing in Europe

Purpose

Variability in consumer behaviour can significantly influence the environmental performance of products and their associated impacts and this is typically not quantified in life cycle assessments. The goal of this paper is to demonstrate how consumer behaviour data can be used to understand and quantify the variability in the greenhouse gas emissions from domestic laundry washing across Europe.

Methods

Data from a pan-European consumer survey of product usage and washing habits was combined with internal company data on product format greenhouse gas (GHG) footprints and in-home measurement of energy consumption of laundry washing as well as literature data to determine the GHG footprint of laundry washing. The variability associated with four laundry detergent product formats and four wash temperature settings in washing machines were quantified on a per wash cycle basis across 23 European countries. The variability in GHG emissions associated with country electricity grid mixes was also taken into account. Monte Carlo methods were used to convert the variability in the input parameters into variability of the life cycle GHG emissions. Rank correlation analysis was used to quantify the importance of the different sources of variability.

Results and discussion

Both inter-country differences in background electricity mix as well as intra-country variation in consumer behaviour are important for determining the variability in life cycle GHG emissions of laundry detergents. The average GHG emissions related to the laundry washing process in the 23 European countries in 2014 was estimated to be 5?×?10² g CO_2?eq/wash cycle, but varied by a factor of 6.5 between countries. Intra-country variability is between a factor of 3.5 and 5.0 (90% interval). For countries with a mainly fossil-based electricity system, the dominant source of variability in GHG emissions results from consumer choices in the use of washing machines. For countries with a relatively low-carbon electricity mix, variability in life cycle GHG emissions is mainly determined by laundry product-related parameters.

Conclusions

The combination of rich data sources enabled the quantification of the variability in the life cycle GHG emissions of laundry washing which is driven by a variety of consumer choices, manufacturer choices and infrastructural differences of countries. The improved understanding of the variability needs to be balanced against the cost and challenges of assessing of consumer habits.