Galacto-oligosaccharide synthesis from lactose solution or skim milk using the β-galactosidase from Bacillus circulans

The synthesis of galacto-oligosaccharides (GOS) catalyzed by a novel commercial preparation of β-galactosidase from Bacillus circulans (Biolactase) was studied, and the products were characterized by MS and NMR. Using 400 g/L lactose and 1.5 enzyme units per milliliter, the maximum GOS yield, measured by HPAEC-PAD analysis, was 165 g/L (41% w/w of total carbohydrates in the mixture). The major transgalactosylation products were the trisaccharide Gal-β(1→4)-Gal-β(1→4)-Glc and the tetrasaccharide Gal-β(1→4)-Gal-β(1→4)-Gal-β(1→4)-Glc. The GOS yield increased to 198 g/L (49.4% w/w of total carbohydrates) using a higher enzyme concentration (15 U/mL), which minimized the enzyme inactivation under reaction conditions. Using skim milk (with a lactose concentration of 46 g/L), the enzyme also displayed transgalactosylation activity: maximum GOS yield accounted for 15.4% (7.1 g/L), which was obtained at 50% lactose conversion.     

Anthocyanins from Chinese bayberry extract protect β cells from oxidative stress-mediated injury via HO-1 upregulation

Oxidative stress plays a pivotal role during the islet transplantation procedure, and antioxidant supplementation may protect grafts against oxidative injury. Chinese bayberry is one of six Myrica species native to China, and we demonstrated here that anthocyanins from Chinese bayberry extract (CBE) protect pancreatic β cells (INS-1) against hydrogen peroxide (H(2)O(2))-induced necrosis and apoptosis. Anthocyanins time- and dose-dependently upregulated heme oxygenase-1 (HO-1) gene expression in β cells and primary islets. HO-1 knockdown increased H(2)O(2)-induced cell death and attenuated the cytoprotective effect of anthocyanins. Anthocyanin treatment activated ERK1/2 and PI3K/Akt signaling, and ERK1/2 and PI3K inhibitors partially attenuated anthocyanin-mediated induction of HO-1. Additionally, β cells pretreated with anthocyanins displayed a decreased extent of apoptosis after transplantation. In summary, these results suggest that anthocyanins in CBE protect β cells from H(2)O(2)-induced cell injury via ERK1/2- and PI3K/Akt-mediated HO-1 upregulation.     

Extraction of humic-β-glucosidase fractions from soil

Humic compounds with -glucosidase activity were extracted from soil using tetrasodium pyrophosphate as extracting solution. Mixture of soil samples with 0.01 M pyrophosphate in a ratio of 1:5 (w/v), adjustment to pH 7.0–7.3, extraction for 18 h with reciprocating agitation, and bacteriological filtration after centrifugation were the optimum conditions for extraction of the -glucosidase complexes. Otherwise, experimental conditions for extraction indicated that the concentration and pH of pyrophosphate were the factors with the most influence on enzymatic extraction yields. The results indicated that the -glucosidase was extracellular and associated with soil humates.     

Do fences protect birds from human disturbance?

Outdoor recreation and ecotourism are becoming increasingly popular, but such human activities are not entirely benign to birds. One way to manage wildlife habitats is to restrict public access with a fence or some similar barrier, under the assumption that this provides wildlife with a refuge from human activities. We tested this assumption by measuring the responses of 10 species of birds at a site containing a fence with a relatively large number of visitors on only one side. We compared these responses to those at a less-visited, control site. Responses were measured by quantifying flight initiation distance (FID), the distance birds would allow a human to approach before fleeing. Overall, we found birds on the protected side of the fence responded similarly to birds at the low visitation control site, and significantly differently from birds at the high visitation site. Our results suggest that by reducing the number of humans and providing areas of refuge within highly visited habitats, protective barriers allow birds to behave as they would in an undisturbed environment.     

Potassium release from selected slow‐release fertilizers

Abstract

Potassium (K) release rate from Osmocote 14–6.3–11.6 (N‐P‐k), MagAmp 7–18–5, Choice 10–4.3–8.3, Scotts 21–3–5.8 and Unimix 10–8.7–4.2 was determined. During the 63‐day experiment Osmocote and Scotts had relatively linear release rates while the release rate from the other fertilizers was initially rapid and decreased over time.     

Mineralogical Characteristics of Yellow- Red Soils Derived from Granite

Mineral constituents and their weathering in yellow-red soils derived from granite in middle and lower reaches of the Yangtze R iver were studied. Light minerals in fractions greater than silt contained over 80% quartz and feldspar, and heavy ones contained more than 60% various iron minerals and about 30% mica and hornblende. Kaolinite was the main clay mineral, the content of which was about 300 -400 g/kg. Quartz was weathered very weakly, Ca-feldspar was weathered over 65%, and about 25% of Na-feldspar was weathered. The vermiculitisation of mica was relativly obvious, > 50% of mica being weathered to vermiculite. Weatherable minerals were also obviously weathered, the weathering being about 60%. Soil vermiculite was evolved through the process of mica→hydromica→vermiculite-chlorite→vermiculite, which was closely related to leaching situation and oxidic condition.     

Proton Dissociation from Surfaces of Variable Charge Soil andMnierals

Experiments on proton dissociation from the surfaces of goethite, amorphous Al oxide, kaolinite and latosol were carried out, showing amphoteric behavior with reactions of proton dissociation-association on the surfaces and buffering capacity in such a sequence as amorphous Al oxide>latosol>kaolinite>goethite. Dissociation constants of surface proton, pKsa, are significantly correlated with surface charge density, which has been proved with an electrochemical model. The intrinsic constants of proton dissociation, Ksa(int), gained by extrapolation to zero charge conditions of plots of pKsa against ao, could be used to estimate the acidity strength of variable charge surfaces. The value of pKse(int) is 8.08 for goethite, 1.2 for morphous Al oxide, 6.62 for kaolinite and 5.32 for latosol.     

Preventing Hg Transference from Soil to Terrestrial Food Chain

Hg in acid soil could be activited by liming and become available to plant,if excessive or insufficient amount of line was applied.The changes of Hg activity in acid soil with different rates of CaCO3 amendment were studied by a pot experiment.To predict the adequate amount of lime application,a simple method using the pH(EDTA) as an indicator was suggested.The suitable range of lime application was the amount of lime addition when the pH of soil-EDTA system was raised to 4.0-4.3.     

Fate of N from Green Manures and Ammonium Sulfate

By means of ^15N tracer technique the fate of N in ammonium sulfate,milk vetch,sesbania and azolla,and the availability of their residual N were studied in a microplot experiment.Results showed that a) at the end of the first crop of early rice,both plant recovery and loss of N from ammonium sulfate were the highest whereas those from azolla were the lowest with those from milk vetch and sesbania in between;the sequence was reversed in terms of recovery of N in soil;the net residual N from ammonium sulfate was very low,about 1/7-1/4 of that from green manures,indicating that chemical N fertilizer contributes little to the soil N reserve;b) plant recovery of the residual N was low and it did not always decrease with time;the total plant recovery (from the second to the fifth crops) of the residual N from various test fertilizers was only 8-11% of the total N originally applied;c) the plant recovery of the residual N from ammonium sulfate was the highest,followed by those from milk vetch and sesbania,and that from azolla was the lowest,no matter in which cropping season (from the second to the fifth);N availability ratio showed the same trend,indicating that chemical N fertilizer helps renovate soil organic N,maintain and increase availability of soil N.     

Has agriculture dispersed worldwide from a single origin?

Some eleven thousand years ago hunter–gatherers in the Near East initiated their transition to farming using an assemblage of eight founder crops: three cereals, four legumes and flax. The evidence show that each of these plant species was brought into domestication once or mostly twice, with no further redomestication. It seems that these species were carefully chosen by humans from the many hundreds of plants used. Apparently, these eight crops were those that best responded to the sowing–reaping agrotechnique, reflecting the biological factors that were later manifested in the success of these founder crops. While changing their own life style, the novel, successful farmers have gained extra food, prestige, property, power, and as a result more spouses and children, eventually leading to their higher biological fitness. This in turn led to the expansion of agriculture either by idea diffusion or by the dispersal of the farmers themselves with their original founder crops. Farming has dispersed to Europe, Asia and North Africa during the following millennia. Concurrently, other remote hunter–gatherer populations in additional worldwide centers, notably East Asia and the Americas have also moved to farming life, conceiving local plant species and the relevant agrotechniques. Regarding the life history of the various cultivated plant species and the capabilities of our ancestors it is suggested that the simplest explanation for the beginning of agriculture in the new worldwide centers is the idea diffusion to these remote areas.     

Nitrogen mineralization from ‘AU Golden' sunn hemp residue

The tropical legume sunn hemp (Crotalaria juncea L.) cultivar ‘AU Golden’ has the potential to provide substantial nitrogen (N) to subsequent crops to reduce recommended application rates of synthetic N fertilizers. A mineralization field trial was conducted to measure mass decomposition and N and carbon (C) amounts remaining from sunn hemp residue following three planting dates (May, June, and July) during the 2013 growing season at the Tennessee Valley (TVS) and Coastal Plain (WGS) locations of AL. Residue from June and July plantings contained 50.0% and 61.1% N at WGS and 41.5% and 66.5% N at TVS by the end of their respective incubation periods compared to residue from the May planting, which contained 21.1% N at WGS and 47.8% at TVS. In order to create a more synchronous relationship between ‘AU Golden’ residue N mineralization and crop demand, termination must be delayed until approximate planting of the following crop.     

Liquefaction Susceptibility of Soils With Clay Particles from Earthquake-induced Landslides

The main reason for earthquake-induced landslides is liquefaction of soil, a process considered to occur mostly in sandy soils. Liquefaction can occur in clayey soils has also been reported and proven in the recent literature, but liquefaction in clayey soils still remains unclear and there are many questions that need to be addressed. In order to address these questions, an depth study on the liquefaction potential of clayey soils was conducted on the basis of field investigation and a series of laboratory tests on the samples collected from the sliding surface of the landslides. The liquefaction potential of the soils was studied by means of undrained cyclic ring-shear tests. Research results show that the liquefaction potential of sandy soils is higher than that of clayey soils given the same void ratio; the soil resistance to liquefaction rises with an increase in plasticity for clayey soils; relation between plasticity index and the liquefaction potential of soil can be used in practical application to estimate the liquefaction potential of soil.     

Vapour intrusion from the vadose zone—seven algorithms compared

Background, aim and scope  

Vapours of volatile organic compounds (VOCs) emanating from contaminated soils may move through the unsaturated zone to the subsurface. VOC in the subsurface can be transported to the indoor air by convective air movement through openings in the foundation and basement. Once they have entered the building, they may cause adverse human health effects. Screening-level algorithms have been developed, which predict indoor air concentrations as a result of soil (vadose zone) contamination. The present study evaluates seven currently used screening-level algorithms, predicting vapour intrusion into buildings as a result of vadose zone contamination, regarding the accuracy of their predictions and their usefulness for screening purpose. Screening aims at identifying contaminated soils that should be further investigated as to the need of remediation and/or the presence of an intolerable human health risk. To be useful in this respect, screening-level algorithms should be sufficiently conservative so that they produce very few false-negative predictions but they should not be overly conservative because they might have insufficient discriminatory power.     

Isolation and characterization of fungal inhibitors from Epichloë festucae

A series of studies was conducted to test the antifungal activity of clavicipitaceous endophytes and to identify potential fungal inhibitors in this symbiotic infection. A diverse group of endophytes was screened for antifungal activity using organic extracts from liquid fermentation cultures. Fungal inhibitors were purified from fermentation cultures of Epichlo? festucae using a bioassay-directed extraction with Cryphonectria parasitica as the test organism. Compounds shown to have antifungal activity were subsequently identified using NMR and GC-MS. Extracts from a wide range of fungal isolates had various degrees of antifungal activity, but the greatest antifungal activity was observed in E. festucae and Neotyphodium tembladerae. Three types of inhibitors were isolated from a batch culture of E. festucae, including several indole derivatives, a sesquiterpene, and a diacetamide. Among the indole derivatives, indole-3-acetic acid and indole-3-ethanol were identified as the major indoles. These compounds were previously reported in endophytic fungi, and this study suggests a role in host disease resistance against other pathogens. The diversity in fungal inhibitors produced by this endophyte also suggests that fungal inhibitors may act additively or synergistically to reduce colonization of endophyte-infected hosts by potential fungal competitors.     

Mineral Composition and Weathering of Soils Derived from Xiashu Loess

Mineralogical, physical and chemical analyses of the soils derived from Xiashu loess were carried out. The primary minerals of these soils were found to be mainly composed of light minerals, such as quartz, feldspar and mica, with traces of heavy minerals. Clay minerals, more complicate in composition, were dominated by hydromica, accompanied by smectite, vermiculite, chlorite, kaolinite, 2:1/1:1 randomly interstratified minerals and small amounts of quartz, goethite, lepidocrocite and hematite, Clay minerals were characterized by low crystallinity and fine particle size. In light of the quartz/feldspars ratio of the 0.01-0.05mm silt fraction, and the clay mineral composition, the freeness of iron oxide, and the silica/sesquioxide and silica/alumina ratios in < 0.002mm clay fraction, it is concluded that the weathering intensity of these soils was lower than those of red soil and yellow earth, but higher than that of brown earth, and that the soil allitization, depotassication and hydroxylation of cl     

Leaching of nitrogen forms from controlled‐release nitrogen fertilizers

Abstract

Application of soluble forms of nitrogen (N) fertilizers to sandy soils may cause leaching of nitrate N (NO₃‐N) resulting in contamination of groundwater. The leaching loss of N may be reduced to a certain extent by the use of controlled‐release N formulations. A leaching column study was conducted to evaluate the leaching of urea, ammonium N (NH₄‐N), and NO₃‐N forms from selected urea‐based controlled‐release formulations (Meister, Osmocote, and Poly‐S) and uncoated urea under eight cycles of intermittent leaching and dry conditions. Following leaching of 1,760 mL of water (equivalent to 40 cm rainfall) through the soil columns, the recovery of total N (sum of all forms) in the leachate accounted for 28, 12, 6, or 5% of the total N applied as urea, Poly‐S, Meister, and Osmocote, respectively. Loss of urea‐N from all fertilizer sources was pronounced during the initial leaching events (with the exception of Meister). Cumulative leaching of urea‐N was 10% for uncoated urea while <1.7% for the controlled‐release formulations. Cumulative leaching of NH₄‐N was 6.2% for uncoated urea while <0.5% for the controlled‐release formulations. Cumulative leaching loss of NO₃‐N was 3.78% for Osmocote, 4.6% for Meister, 10.4% for urea, and 10.5% for Poly‐S. This study demonstrates a significant reduction in leaching of N forms from controlled‐release formulations as compared to that from the soluble form.