Evaluation of vinification lees as a general medium for lactobacillus strains

Lactobacillus species present high nutritional requirements, so it is necessary to find new low-cost nutrient components for fermentation media. This work compares the utilization of vinification lees (an important residue of wineries) from red and white winemaking technology, distilled or not. An amount of 20 g of lees/L was used as the unique nutrient to obtain lactic acid from glucose using Lactobacillus strains with different properties: L. plantarum CECT-221, L. pentosus CECT-4023, L. casei CECT-5275, and L. coryniformis subsp. torquens CECT-25600. Only L. casei using distilled lees showed values (Pmax = 92.1 g/L and Y(P/S) = 1.05 g/g) similar to those obtained with the MRS broth. The UV spectra of white and red lees, distilled or not, allowed an interpretation of the different phenolic compounds present and their influence on the fermentation. Their detoxification by extraction with organic compounds and fermentation with L. pentosus was also considered. Time courses of glucose and lactic acid were modeled according to reported models to obtain more information about the process.     

Evaluation of an improved MPN medium for recovery of stressed and nonstressed Staphylococcus aureus

Two media used for recovery of foodborne Staphylococcus aureus were compared: trypticase soy broth with 10% salt (TSBS), used in the official AOAC method, and TSBS with 1% sodium pyruvate added (PTSB). Adding pyruvate increased recovery of 4 heat-stressed and nonstressed S. aureus foodborne strains from artificially contaminated mashed potato and ham salad substrates. The overall geometric means for the 2 media differed significantly at the alpha = 0.05 level. Recovery of S. aureus from 70 replicates of naturally contaminated Monterey Jack cheese was highest in PTSB. The overall geometric means/g were 63 in TSBS and 96 in PTSB.     

Evaluation of an automated gel permeation cleanup and evaporation systems for determining pesticide residues in fatty samples

The AutoVap 600 system, used in conjunction with an automated gel permeation chromatography (GPC) instrument, automatically collects and evaporates the effluent from the GPC column, dissolves the residue in a fixed volume of desired solvent, and quantitatively transfers it to a sealed vial. This system was evaluated and found to automate efficiently the cleanup of butterfat for pesticide residue analysis. Quantitative recoveries were obtained for each of 4 pesticides fortified in butterfat and cleaned up through the system and for 12 pesticide standards in the absence of sample matrix collected through the system. After loading, the system operates unattended and will automatically prepare up to 23 individual fat samples for determination by gas chromatography without additional cleanup.     

土壤微生物量作为土壤肥力指标的探讨

对不同利用方式19个黑土样品的微生物量和养分进行了分析,结果表明林地的微生物量明显高于玉米地和大豆地,但玉米地和大豆地之间未表现出显著差异,土壤微生物量和土壤养分含量大体上都呈现出林地>大豆地>玉米地的一致的趋势;同时土壤微生物量与土壤有机质、全氮、全磷、速效钾和碱解氮呈现出显著或极显著正相关关系,分析结果还表明土壤微生物量碳作为评价土壤肥力指标比土壤微生物量氮更为灵敏。因此,土壤微生物量可以作为评价不同利用方式的黑土肥力水平的一个生物指标。     

Evaluation of Mehlich III as an extractant for available soil sulfur

Abstract

Among the identified universal extractants, Mehlich III is one of the more reliable multielement extractant for acid soils and soilless mixes. However, the universality of the Mehlich III extractant does not include an important nutrient element, sulfur (S). This study was conducted in order to evaluate the Mehlich III extractant as an index of S availability, and comparing with four other extractants, monocalcium phosphate (MCP), MCP+HOAc, Morgan's Reagent, and calcium chloride. Soil samples representing tea growing areas of several parts of India were collected from selected tea gardens to compare S extractability. These extractants were also evaluated in a young tea plantation (3+ year old) field experiment which is situated near the foot hill soils (Typic Hapludalfs) of Indian western Himalaya. It was found that Mehlich III‐extractable S was significantly correlated with the S extracted by the other extractants from both the top and subsoils of the tea growing region. However, the largest correlation coefficient was found between the Morgan's Reagent and Mehlich III. MCP, MCP+HOAc, and Morgan reagents extracted S mainly from the adsorbed fraction, although some degree of correlation was found with water‐soluble and ester sulfate‐sulfur (SO₄‐S) fractions. In case of the Mehlich III extractant, 83 and 87% of the variability was explained by water‐soluble and adsorbed SO₄ in the respective top and subsoils. Except for the regression equation between Morgan's Reagent‐extractable S and the S content in tea shoots, all other equations were statistically significant. But, only available S extracted from the top soil by Mehlich III was found significantly correlated with S uptake, which was further confirmed by a significant coefficient of regression (r=0.552*). This suggests that the Mehlich III reagent could be a useful index for predicting the S requirement for a tea crop.     

Evaluation of common bean genotypes for phosphorus use efficiency

A greenhouse experiment was conducted to evaluate phosphorus (P)‐use efficiency of 10 promising genotypes of common bean (Phaseoius vulgaris L.) with short and normal growth duration. The genotypes were grown on an Oxisol at 25 mg P kg^‐1 (low P) and 150 mg P kg^‐1 (high P) of soil. Shoot and root dry weight, root length, P concentration in the shoot, and P uptake in the shoot were significantly (P<0.01) affected by soil P concentration and genotype. However, P level did not effect root length and genotype had no effect on root dry weight. On the basis of P‐use efficiency (mg dry weight of shoot/mg P accumulated in the shoot) genotypes were classified as efficient and responsive (ER), efficient and nonresponsive (ENR), nonefficient and responsive (NER), and nonefficient and nonresponsive (NENR). From a practical point of view, genotypes which produce a lot of dry matter in a soil with a low P level, and respond well to added P are the most desirable because they are able to express their high yield potential in a wide range of P environments. Novo Jalo and Pérola genotypes fall into this group. Genotypes Irai, Jalo Precoce and L93300166 fall into the ENR group. Genotypes Carioca, Rosinha G‐2, and Xamengo were classified NER, whereas, genotypes L93300176 and Diamante Negro were classified as NENR. There were no differences between short and normal growth duration genotypes in P‐use efficiency.     

The porosphere as an ecological medium emphasized in Professor Ghilarov's work on soil animal adaptations

Summary The author recalls that the late Professor Mercury S. Ghilarov, from the Institute of Animal Morphology and Ecology in Moscow, was a great pioneer in soil zoology and a far-sighted scientist in the evolution of terrestrial faunas. Professor Ghilarov agreed that during their evolution insects passed through the soil as a transitional medium from aquatic to terrestrial habitats. His theory, which is based on morphological and physiological observations, fits the thermodynamics of soil water the author describes when considering all porous bodies (porosphere), such as soil and other media, permitting a slow and gradual transition from an aquatic towards a xeric aerial system. In conclusion, a general concept of water accessibility for soil animals is formulated.Dedicated to the late Prof. Dr. M.S. Ghilarov     

基于生态导向的厦门生态城市综合评价与分析

基于生态学理论,通过对厦门市的环境特征分析,根据生态城市的内涵,将健康、安全和发展这3个概念引入生态城市的综合评价,建立厦门市的生态城市评价指标体系。利用主成分分析法对数据进行生态健康指数、生态安全指数和生态发展指数的计算,最终得出各城区的生态城市评价综合指数并进行了相关分析。研究结果表明:(1)基于生态导向的生态城市评价与分析是从生态健康、生态安全、生态发展3个方面将城市规划引向重建自然和保护自然的过程。(2)在厦门生态城市的评价中,岛内城区与岛外城区存在明显的差距,岛内的思明区和湖里区的评价指数明显高于岛外的集美区、海沧区、同安区和翔安区。(3)生态导向下的生态城市是集自然与人类影响于一体的和谐平衡的复合系统,在城市规划中应以生态功能为基础进行城市的布局,以生态功能区划来引导区域的建设模式,让生态理念更好地融入到城市建设中。     

土壤微生物量碳氮作为土壤肥力指标的探讨

通过对不同肥力水平黑土、棕壤、黄棕壤、红壤土壤微生物量碳氮的比较,研究和探讨土壤微生物量碳氮与土壤肥力的关系。结果表明:有机肥或无机肥施入土壤均能增加土壤微生物量C、N的含量,且有机肥与无机肥配合有显著的正交互作用。土壤微生物量C、N从北到南的地带性变化规律不强。BC/BN及TC/TN从北到南逐渐减小,BC/TC及BN/TN从北到南逐渐增加。相关分析结果表明:土壤微生物量C、N与全C、全N均呈极显著相关,可以作为指示土壤肥力的重要指标。     

基于MaxEnt模型的滑坡易发性评价--以攀枝花市为例

为了客观评价滑坡影响因子的贡献度和构建滑坡预测模型,以滑坡灾害发生较多的攀枝花市为研究区,通过筛选后选取高程、坡度、坡向、土地利用类型、归一化植被指数(NDVI)和人口密度6项因子作为滑坡易发性的评价指标;基于最大熵(maxEnt)模型和ArcGIS空间分析模块对研究区滑坡易发性进行了定量预测和分析研究。结果表明:maxEnt模型在研究区滑坡易发性研究方面的适用性等级为优秀(AUC=0.96),Kappa系数为0.86;随机选取75%的数据集用于训练模型,其余25%用于验证模型,得到的AUC值最稳定且精度最高,模型预测可信度最高;研究区高易发生和极易发生区分别占总面积的2.57%,0.80%,主要分布在人口比较密集的东部和西部地区,部分沿着金沙江、雅砻江、巴关河、安宁河和主要道路两侧发育;植被覆盖度和坡度是决定研究区滑坡易发性空间分布格局最重要的环境影响因子。     

Evaluation of a selective medium for hydrogen sulfide production by salmonella.

An evaluation was made of Padron-Dock-Stader sulfide (PDS) agar for the rapid detection of Salmonella and Arizona microorganisms in foods. Analysts from 9 Food and Drug Administration District laboratories determined the reaction of 638 Salmonella cultures, 30 Arizona cultures, and 1754 non-Salmonella and non-Arizona cultures isolated from 157 food samples in PDS agar. The degree of positive reactions of these cultures in this agar was scored on a scale of "-" to "+++". The highest percentage of Salmonella isolates (64.1%) was in the category of +++ reactions. Progressively lower percentages of Salmonella isolates occurred in the more negative reaction categories. The highest percentage of Arizona isolates (66.7%) occurred in the intermediate ++ category. The majority of non-Salmonella and non-Arizona isolates occurred in the minus (41.0%) and plus or minus (44.8%) categories. Advantages of using the PDS agar are that it is simple to use, requires no specialized training or equipment, and alerts analysts to those Salmonella cultures which produce atypical reactions in triple sugar iron agar particularly the lactosepositive Salmonella. However, in this study the occurrence of false-negative reactions ranged from 4.3 to 13.9% for Salmonella and from 0 to 6.7% for Arizona, according to the criteria used to interpret the reactions in PDS agar.     

Rice and common bean growth and nutrient concentration as influenced by aluminum on an acid lowland soil

Aluminum (Al) toxicity is a major limiting factor for crop production in many acid soils in Brazil. Two greenhouse experiments were conducted to evaluate response of rice (Oryza saliva L.) and common bean (Phaseolus vulgaris L.) to Al levels on a Low Humic Gley acid soil. The Al levels created by liming were: 0,0.03, 0.10, 0.23, 1.03, and 3.83 cmol_c kg^‐1 of soil. Rice dry matter and grain yield were significantly improved (P<0.05) with increasing Al levels in the soil solution. However, common bean dry matter as well as grain yield were significantly (P<0.01) decreased with increasing Al levels. At 3.83 cmol_c Al kg^‐1 of soil, bean did not produce any dry matter or grain yield. On an average, Al decreased nutrient concentrations in the tops of rice plant except zinc (Zn) and manganese (Mn), but in bean crop almost all the nutrients concentrations were increased with increasing Al levels. Rice showed tolerance to Al toxicity, whereas, common bean was susceptible to toxicity of this element. For successful intensive crops production lime application will be necessary in Varzea soils especially for legume production.     

Measurement of phytase activity using tethered phytic acid as an artificial substrate: Methods development

The artificial chromophoric substrate analog of phytic acid, 5-O-[6-(benzoylamino)hexyl]-d-myo-inositol-1,2,3,4,6-pentakisphosphate (T-IP₅), may prove useful in measuring soil phytase activity. This chemical probe allows for direct measurement of phytase-catalyzed dephosphorylation (i.e., hydrolysis of the phosphoester bond) using high-performance liquid chromatography with UV detection. Before T-IP₅ can be used to measure phytase activity in environmental samples (soil, stream sediment, manure) refinement of the T-IP₅ probe methodology is required. Using ³¹P nuclear magnetic resonance (NMR) spectroscopy, we identified 5-O-[6-(benzoylamino)hexyl]-d-myo-inositol-trisphosphate (T-IP₃) as the key intermediate that accumulates during phytase-catalyzed dephosphorylation of T-IP₅. An improved HPLC method for separation of reactants is also presented.     

Evaluation of calcium dihydrogen phosphate solution as an extractant for inorganic sulfate applied to soils

Abstract

To evaluate conventional calcium dihydrogen phospahte [Ca(H₂PO₄)₂] solution containing 500 mg P/L as an extractant for soluble plus adsorbed sulfate (SO₄), we added known amounts of SO₄ to 10 soil samples differed in clay mineral composition and extracted with Ca(H₂PO₄)₂ solution. The experimental results showed that the five successive extractions at a soihsolution ratio of 1:10 could quantitatively recover the added SO₄, and there was little effect of air‐drying the soils after addition of SO₄. Based upon these experimental results, we concluded that the Ca(H₂PO₄)₂ extraction is an excellent method for determining soluble plus adsorbed inorganic SO₄ in soils.     

Assessment of diet in young children with an emphasis on fruit and vegetable intake: using CADET--Child and Diet Evaluation Tool

OBJECTIVES: To develop a concise, simple tool for use by non-specialists to assess diet in children aged 3-7 years attending primary schools. DESIGN: A 24-hour food tick list covering all aspects of the diet and with a focus on fruit and vegetable consumption was developed. This was compared against a 24-hour semi-weighed food diary obtained for the same day as the tick list. SETTING: Six primary schools with a range of socio-economic and ethnic backgrounds from a large city in the north of England (Leeds). PARTICIPANTS: One hundred and eighty children returned completed packs of information; a response rate of 77% of those who were willing to take part, 48% of those approached. RESULTS: On average, 2.4 items of fruit including juice (2.1 items as 5-a-day count) were eaten and 1.6 items of vegetables (excluding potato). Twenty-seven per cent and 36% of boys and 23% and 24% of girls reported not eating any fruit or vegetables, respectively, on the recording day. Correlations comparing the diary and tick list were high for both foods (range r=0.44 to 0.89) and nutrients (range r=0.41 to 0.68). The level of misclassification was much less than would be expected by chance. Parent and teacher evaluation of the tick list was very positive. Parents felt the tick list was easy and quick to complete. CONCLUSION: The Child and Diet Evaluation Tool (CADET) tick list has been used successfully for rapid collection of food and nutrient information from children aged 3-7 years from diverse social and ethnic backgrounds. The tool has performed better than many food-frequency questionnaires in comparison to a food diary.     

Evaluation of the Mehlich 3 Reagent as an Extractant for Cations and Available Phosphorus for Soils in Mozambique

Accurate soil testing procedures contribute to agricultural development of Mozambique. The Mehlich 3 (M-3) procedure has not been evaluated for Mozambican soils despite its wide applicability. Results showed M-3 solution could extract exchangeable calcium (Ca), magnesium (Mg), and potassium (K) as well as 1 M ammonium acetate (NH₄OAc), while M-3 was not appropriate for extraction of exchangeable sodium (Na). M-3 was an alternative procedure to Bray-I for available phosphorus (P) extraction. Although M-3 extracted 1.6 times more P than Bray-I, determination coefficient between the two procedures showed significantly high value. P content in M-3 extracts can determine using inductively coupled plasma spectrophotometers (ICP) to maximize the merits of M-3. In conclusion, M-3 is applicable for determination of exchangeable Ca, Mg, K, and available P, in a single determination using ICP, and should contribute to development of effective and accurate soil diagnosis in Mozambique.     

The effects of silicon on nutrient levels and yields of tomatoes under saline stress in artificial medium culture

The purpose of this study was to determine the effects of silicon on the stem + leaf dry weight, fruit yield, quality and nutrient levels of tomatoes, cultured under saline stress on an artificial medium. Silicon doses (0, 0.5, 1.0, 2.0 mM) were combined in nutrient solution with 0, 44.4 and 70.4 mM NaCl in a factorial experiment with three replications. All silicon concentrations without NaCl increased stem + leaf dry weight and 1.0 mM Si increased fruit yield. Silicon increased fruit yield at 44.4 mM NaCl and steam + leaf dry weight at high NaCl concentrations. NaCl significantly increased the level of soluble solids in fruit and decreased the pH of fruit juice. Silicon significantly increased the pH of the tomato juice and decreased the number of fruits at high concentrations of NaCl. The effects of NaCl, Si and their interaction on nutrient contents and Si levels in leaves were statistically significant at different concentrations.     

Evaluation of the atzB gene as a functional marker for the simazine-degrading potential of an agricultural soil

The occurrence of natural simazine-degrading bacteria could be an important limiting factor to the use of the herbicide in those agricultural soils with a wide history of herbicide applications. In this work the potential of an agricultural soil to degrade simazine and the effect of the addition of urea was assayed in both fertilised and unfertilised soil microcosms. A culture-independent approach based on the fluorescence in situ hybridisation (FISH) technique, using a specific oligonucleotide probe (AtzB1), was applied to detect simazine-degrading bacteria in the soil microcosms. The presence of the atzABC genes in the agricultural soil was confirmed by PCR from soil-extracted DNA. The percentage of AtzB1 probe-target cells in the urea-untreated soil was higher than in the urea-treated one. Moreover, the greatest percentage of AtzB1 probe-target cells in the urea-untreated soil was accompanied by a greater degradation rate, compared to the urea-fertilised one. Our results indicate that the proposed approach was sensitive enough to detect changes in the natural simazine degradation capacity of the soil after fertilisation practices, which typically involve a nitrogen increase.