Development of a biofertilizer based on filamentous nitrogen-fixing cyanobacteria for rice crops in Chile

The purpose of this study was to develop a biofertilizer based on filamentous nitrogen-fixing cyanobacteria selected from rice fields and to generate a technological package compatible with its use for the rice crop in Chile. Thirty-four Chilean rice fields, located between Maule and BioBío regions, were sampled during the 1998/1999 and 1999/2000 growing seasons. A total of 9 species and 3 varieties of cyanobacteria were found, and the nitrogen fixation rate under laboratory conditions was determined for 6 of them. Only 4 were used for the small-scale production of a biofertilizer, which was assayed in field trials. To check the efficiency of the biofertilizer during the rice crop, the nitrogen fixation rates in soil samples were estimated. Additionally, the biofertilizer application efficiency was tested in combination with nitrogen synthetic fertilizer, in rates that were previously established in field trials. Biofertilization allowed a decrease of up to 50% in the use of nitrogen synthetic fertilizer (50 kg N ha⁻¹), resulting in the same grain yield (7.4 t ha⁻¹) and quality in relation to the fertilized control. The use of biofertilizers based on local strains of cyanobacteria shows promise to increase nitrogen use efficiency in rice.     

Acid-mechanical,alkaline and enzymatic treatment of agricultural wastes to obtain substrate for microbiological conversion

The present paper deals with almost wasteless technologies of pretreatment and obtaining of sugars and biomass from straw and potato tops. Several variants ensure a 1 t of straw per hour productivity using original auger reactors 290 and 150 mm in diameter. The authors have studied the submerged and solid state cultivation of various microorganisms applying the obtained substrates.     

城市生活垃圾蚯蚓处理的因素优化及其重金属富集研究

采用模拟试验、小区试验与生产试验等研究了垃圾成分、软化方式、培养方式、环境温度和蚯蚓杂交等因素对蚯蚓处理城市生活垃圾的影响及其重金属富集效应。结果表明,改变垃圾成分、提高垃圾碳氮比,在20℃温度左右时,采用蚯蚓粪软化和室内层床培养方式,可使蚯蚓增殖率和垃圾腐解率都有所提高,同时利用驯化的重庆赤子爱胜蚓与背暗异唇蚓进行杂交,也可以提高蚯蚓处理垃圾的效果,蚯蚓处理过程中重金属富集系数与软化方式之间没有显著相关性,而与重金属种类、培养方式之间具有较强的依存性,砷、镉在腐解物中最易富集,而汞不易富集,垄埂式培养比层床式容易富集重金属,露天培养比室内培养更易富集重金属。     

Design and application of a pre-composting test step to determine the effect of high fat food wastes on an industrial scale in-vessel composting system

The high fat content in food wastes was suspected to inhibit an industrial in-vessel composting process from reaching the European Union Animal By-Product Regulation (composting temperature >70 °C for 1 h). The aim of this study was to design a test step to guide the mixing ratio of food waste to green waste to meet the regulation. A 15-compartment composting unit was designed to contain the compost mixes. Sausage and cheese wastes were mixed with green waste at 1:1; 1:2; 1:3 and 1:4 ratios by wet weight volume. Only the sausage waste mix ratio of 1:4 gave an average temperature of 70 °C for at least 1 h after 2 days of composting (fat content - 17%; C: N ratio - 8.6). All the cheese waste mixes did not reach 70 °C after 15 days of composting. This study demonstrated that using a simple pre-composting test step could reduce the chances of process failure during industrial composting. Although both sausage and cheese wastes are high in fat, they performed very differently in the composting process. Two linear equations were fitted to model the impact of these wastes on the maximum composting temperature.     

Weakly nonlinear analysis of a hyperbolic model for animal group formation

We consider an one-dimensional nonlocal hyperbolic model for group formation with application to self-organizing collectives of animals in homogeneous environments. Previous studies have shown that this model displays at least four complex spatial and spatiotemporal group patterns. Here, we use weakly nonlinear analysis to better understand the mechanisms involved in the formation of two of these patterns, namely stationary pulses and traveling trains. We show that both patterns arise through subcritical bifurcations from spatially homogeneous steady states. We then use these results to investigate the effect of two social interactions (attraction and alignment) on the structure of stationary and moving animal groups. While attraction makes the groups more compact, alignment has a dual effect, depending on whether the groups are stationary or moving. More precisely, increasing alignment makes the stationary groups compact, and the moving groups more elongated. Also, the results show the existence of a threshold for the total group density, above which, coordinated behaviors described by stationary and moving groups persist for a long time.      

比较医学动物实验计算机辅助设计系统的研发

目的开发一款辅助研究者设计比较医学动物实验方案和学习实验设计的应用软件。方法根据实验动物应用的"科学、伦理、经济"原则筛选比较医学动物实验技术资料,运用关系数据库架构原理分析和组织入选数据,通过解析比较医学动物实验规律和特点设计程序框架和模块,采用C++语言、MFC库进行面向用户的程序设计。结果建立了程序相关资源库和模型选择、实验动物、环境条件、实验步骤、方案输出5个功能模块,并完成整个软件测试。结论研发成功比较医学动物实验计算机辅助设计系统,该系统能够基于微型计算机为用户提供有效、易用的动物实验辅助设计和自助学习功能。     

Thermophilic co-digestion of organic fraction of municipal solid wastes with FOG wastes from a sewage treatment plant: reactor performance and microbial community monitoring

Working at thermophilic conditions instead of mesophilic, and also the addition of a co-substrate, are both the ways to intend to improve the anaerobic digestion of the source-collected organic fraction of municipal solid wastes (SC-OFMSW). Addition of sewage treatment plant fat, oil and grease wastes (STP-FOGW), that are nowadays sent to landfill, would represent an opportunity to recover a wasted methane potential and, moreover, improve the whole process. In this study, after a first period feeding only SC-OFMSW, a co-digestion step was performed maintaining thermophilic conditions. During the co-digestion period enhancements in biogas production (52%) and methane yield (36%) were achieved. In addition, monitoring of microbial structure by using PCR-DGGE and cloning techniques showed that bacterial community profiles clustered in two distinct groups, before and after the extended contact with STP-FOGW, being more affected by the STP-FOGW addition than the archaeal one.     

Efficacy of organic wastes amendment on the establishment and biomass yield of grass species on a degraded Alfisol

Abstract

Deficiencies of organic matter and essential nutrients are important features of derelict/degraded lands; these characteristics have profound effects on the establishment of functional soil-plant systems on such lands. This work reports on the impact of organic wastes amendments on the establishment, growth and biomass yield of grass mixtures grown on a degraded soil. The experimental site was a heavily compacted and eroded land due to excavation (scrapping) of topsoil layer for urban construction activities. Zero, 10 and 20cm layers each of substrates collected from an old (abandoned) municipal refuse and from site affected by long-term surface disposal of livestock litter and topsoil collected under fallow vegetation were applied on soil surface, before the establishment of a mixture of grass species. Substrates collected from old municipal refuse contained high amount of essential nutrients and metals and, on application, produced upward shift in soil pH and electrical conductivity. Nevertheless, these properties neither significantly retarded plant growth nor impaired biomass yield. Plant establishment and biomass yield were comparable under topsoil application and organic waste amended soil and produced significantly higher biomass yield when spread at 20cm layers were made of them. This experimental group also produced superior biomass yield over the unamended control. The agronomic benefits of organic waste incorporation stemmed from improved soil properties in surface horizon and contents of essential nutrients supportive of the establishment and development of plant cover. Nutrient supply is related to soil organic matter status, organic wastes are therefore important to the reconstruction of effective nutrient cycling and the eventual functional soil-plant system on this degraded ecosystem. The goal of these revegetation efforts is to improve soil and plant productivity, plant diversity, conservation of native grasslands and aesthetic.     

Development of a procedure for discriminating among Escherichia coli isolates from animal and human sources

Counts of Escherichia coli cells in water indicate the potential presence of pathogenic microbes of intestinal origin but give no indication of the sources of the microbial pollution. The objective of this research was to evaluate methods for differentiating E. coli isolates of livestock, wildlife, or human origin that might be used to predict the sources of fecal pollution of water. A collection of 319 E. coli isolates from the feces of cattle, poultry, swine, deer, goose, and moose, as well as from human sewage, and clinical samples was used to evaluate three methods. One method was the multiple-antibiotic-resistance (MAR) profile using 14 antibiotics. Discriminant analysis revealed that 46% of the livestock isolates, 95% of the wildlife isolates, and 55% of the human isolates were assigned to the correct source groups by the MAR method. Amplified fragment length polymorphism (AFLP) analysis, the second test, was applied to 105 of the E. coli isolates. The AFLP results showed that 94% of the livestock isolates, 97% of the wildlife isolates, and 97% of the human isolates were correctly classified. The third method was analysis of the sequences of the 16S rRNA genes of the E. coli isolates. Discriminant analysis of 105 E. coli isolates indicated that 78% of the livestock isolates, 74% of the wildlife isolates, and 80% of the human isolates could be correctly classified into their host groups by this method. The results indicate that AFLP analysis was the most effective of the three methods that were evaluated.     

The ARRIVE guidelines,a welcome improvement to standards for reporting animal research

Here we introduce the ARRIVE (Animal Research: Reporting In Vivo Experiments) guidelines, produced by the National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), which are published in this issue of the journal with our endorsement, and will be incorporated into our Instructions to Authors. Copyright © 2010 John Wiley & Sons, Ltd.     

典型固体废物中冶金微生物及其浸出机理研究进展

典型固体废物(废电器、废电池、污泥、焚烧飞灰、废催化剂等)含有大量金属资源，回收再利用的价值极高。微生物浸出典型固体废物受多因素影响。对不同微生物浸出金属的菌种筛选、浸出规律和机理的掌握，有助于典型固体废物中金属资源的绿色高效回收，可为我国“双碳”目标作出贡献。本文综述了从典型固体废物中浸出金属的各类微生物，分析了冶金微生物的作用机制，并展望了微生物冶金的应用前景，以期为微生物冶金技术在典型固体废物中的高效应用提供理论参考。     

Dynamics of bacterial community in up-flow anaerobic packed bed system for acid mine drainage treatment using wine wastes as carbon source

The dynamics of the bacterial populations in an up-flow anaerobic packed bed system (UAPB), applied in acid mine drainage treatment using wine wastes as carbon and nutrients source was elucidated by temperature gradient gel electrophoresis (TGGE) analysis. Moreover, TGGE fingerprints of the bacterial communities developed in a UAPB fed with wine wastes and a UAPB fed with pure ethanol were compared. TGGE fingerprinting and phylogenetic analysis showed that the composition of the community in the UAPB fed with wine wastes remained stable during whole time of operation and its bacterial diversity was higher. The bacterial community of the UAPB fed with wine wastes was composed by bacteria affiliated with Desulfovibrio, Clostridium, Citrobacter and Cronobacter genera and with Bacteroidales order, sp. The dominant community developed in the UAPB fed with ethanol was composed by bacteria affiliated with Desulfovibrio sp. The presence of several bacterial groups in the bioreactor fed with wine wastes suggests a synergistic interaction between the different populations. Syntrophic interaction may be the key factor for the utilization of wine wastes, a complex organic substrate, as carbon and electron source for sulphate reduction.     

Using porphyritic andesite as a new additive for improving hydrolysis and acidogenesis of solid organic wastes

The effects of porphyritic andesite on the hydrolysis and acidogenesis of solid organic wastes were investigated by batch and continuous experiments using a rotational drum fermentation system. The results of the batch experiment show that if porphyritic andesite (1%, 3%, and 5% reactants) is added initially, the pH level increases and hydrolysis and acidogenesis are accelerated. The highest surface based hydrolysis constant (26.4 × 10⁻³ kg m⁻² d⁻¹) and volatile solid degradation ratio (43.3%) were obtained at a 1% porphyritic andesite addition. In the continuous experiment, porphyritic andesite elevated the first order hydrolysis constant from 13.10 × 10⁻³ d⁻¹ to 18.82 × 10⁻³ d⁻¹. A particle mean diameter reduction rate of 33.05 μm/d and a volatile solid degradation rate of 3.53 g/L d⁻¹ were obtained under the hydraulic retention time of 4, 8, 12 and 16 d.     

Development of a highly selective fluorescence probe for alkaline phosphatase

We have developed the first highly selective fluorescence probe for alkaline phosphatase (ALP), TG-mPhos. This probe shows selectivity for ALP over protein tyrosine phosphatase and protein serine/threonine phosphatase. Our previously developed TG-Phos, which has a phenolic phosphate linkage in place of the alcoholic phosphate linkage of TG-mPhos, lacks this selectivity. TG-mPhos should enable precise fluorescence imaging of ALP activity in biological applications.     

Development of a new grading system to assess the foster performance of lactating sows

Increasing litter size has created the need for more sophisticated, accurate, and welfare-oriented systems for assessing the foster performance of lactating sows. The estimation of milk yield alone is not sufficient for meeting these requirements. Therefore, the aim of the current study was to develop a grading system for assessing the foster performance of lactating sows that can be easily applied in commercial farm practice. Data were collected in two German conventional farrow-to-feeder farms with a total sample size of 639 sows (4.05 ± 2.86 parities) and 1 728 litters. Besides general performance data, the piglets were weighed individually within the first 24 hours after birth and at the peak of lactation (day 18.22 ± 2.48). Based on these data, we proposed a new score referring to the milk score (MS). This score was compared with the commonly used formula for estimating milk yield (est. MY), which solely involves litter weight gain and litter size. The improvement of the developed MS allowed us to distinguish between the birth and foster performances of the lactating sows through considering cross-fostering, litter size, individual piglet weights, and piglet mortality during lactation. Both scores showed a similar progression across parities. It was found that litter size had a significant impact on the performance of lactating sows. A high est. MY was found to be associated with a significantly higher number of piglets per litter (15.79 ± 2.20), lower weight gain per piglet, and increased piglet mortality during lactation compared with sows with high MS, which showed a smaller litter size (13.51 ± 2.18) (P < 0.05). The focus on smaller litter size indicates a performance limitation, which seems to be related to the average teat number of 13–15 teats per sow. We recommend the consideration of the number of functional teats, because a litter size above it will not result in a sow having higher foster performance. In conclusion, as an extension of the common est. MY calculation, the MS considers cross-fostering as current farm-management practice when dealing with larger litters. Our recommendations emphasise the importance of an MS which indicates smaller litter size, higher piglet weight gain, and lower piglet mortality during lactation; these factors are related to an improvement in animal welfare for sows and piglets. Moreover, the presented MS could be used to develop a management tool for farmers to assess the foster performance of lactating sows, considering individual farm-management practices.     

Alkaline protease from a non-toxigenic mangrove isolate of Vibrio sp. V26 with potential application in animal cell culture

Vibrio sp. V26 isolated from mangrove sediment showed 98 % similarity to 16S rRNA gene of Vibrio cholerae, V. mimicus, V. albensis and uncultured clones of Vibrio. Phenotypically also it resembled both V. cholerae and V. mimicus. Serogrouping, virulence associated gene profiling, hydrophobicity, and adherence pattern clearly pointed towards the non—toxigenic nature of Vibrio sp. V26. Purification and characterization of the enzyme revealed that it was moderately thermoactive, nonhemagglutinating alkaline metalloprotease with a molecular mass of 32 kDa. The application of alkaline protease from Vibrio sp. V26 (APV26) in sub culturing cell lines (HEp-2, HeLa and RTG-2) and dissociation of animal tissue (chick embryo) for primary cell culture were investigated. The time required for dissociation of cells as well as the viable cell yield obtained by while administering APV26 and trypsin were compared. Investigations revealed that the alkaline protease of Vibrio sp. V26 has the potential to be used in animal cell culture for subculturing cell lines and dissociation of animal tissue for the development of primary cell cultures, which has not been reported earlier among metalloproteases of Vibrios.     

Haptenylation of antibodies during affinity purification: a novel and convenient procedure to obtain labeled antibodies for quantification and double labeling

 Haptenylation of primary antibodies is a useful technique for multiple purposes. It is a technically straightforward procedure, as many haptens are available as N-hydroxysuccinimide esters or isothiocyanates. Unfortunately, the hapten group may become covalently attached to or close to the combining site of antibodies, lectins, or other ligand-binding proteins during the process of haptenylation. Thus, the interaction of the corresponding protein with its ligand may become severely hampered. To overcome this restriction, we developed a novel procedure for the haptenylation of polyclonal antibodies that combines purification and haptenylation. Haptenylation during adsorption to the affinity matrix combines two advantages: the antigen binding site is protected and the labeling procedure becomes most convenient, as overlabeled proteins and unreacted haptens are easily removed by simple washing. Haptenylation during adsorption to the affinity matrix is a two-phase reaction, which requires different conditions to the conventional procedure. To obtain such optimal conditions, stabilities and reactivities of N-hydroxysuccinimide esters and isothiocyanate groups were investigated with a newly developed assay. Based on this information, antibodies against two recently described calcium-binding proteins, NCS-1 and NVP-3, were biotinylated or digoxigenylated. The haptenylated antibodies were successfully applied for biochemical determination and simultaneous immunoenzymatic double labeling of the two proteins. Accepted: 9 March 1998     

Potential of biotechnological conversion of lignocellulose hydrolyzates by Pseudomonas putida KT2440 as a model organism for a bio‐based economy

Lignocellulose‐derived hydrolyzates typically display a high degree of variation depending on applied biomass source material as well as process conditions. Consequently, this typically results in variable composition such as different sugar concentrations as well as degree and the presence of inhibitors formed during hydrolysis. These key obstacles commonly limit its efficient use as a carbon source for biotechnological conversion. The gram‐negative soil bacterium Pseudomonas putida KT2440 is a promising candidate for a future lignocellulose‐based biotechnology process due to its robustness and versatile metabolism. Recently, P. putida KT2440_xylAB which was able to metabolize the hemicellulose (HC) sugars, xylose and arabinose, was developed and characterized. Building on this, the intent of the study was to evaluate different lignocellulose hydrolyzates as platform substrates for P. putida KT2440 as a model organism for a bio‐based economy. Firstly, hydrolyzates of different origins were evaluated as potential carbon sources by cultivation experiments and determination of cell growth and sugar consumption. Secondly, the content of major toxic substances in cellulose and HC hydrolyzates was determined and their inhibitory effect on bacterial growth was characterized. Thirdly, fed‐batch bioreactor cultivations with hydrolyzate as the carbon source were characterized and a diauxic‐like growth behavior with regard to different sugars was revealed. In this context, a feeding strategy to overcome the diauxic‐like growth behavior preventing accumulation of sugars is proposed and presented. Results obtained in this study represent a first step and proof‐of‐concept toward establishing lignocellulose hydrolyzates as platform substrates for a bio‐based economy.