Identification and occurrence of the novel alkaloid pentahydroxypentyl-tetrahydro-beta-carboline-3-carboxylic acid as a tryptophan glycoconjugate in fruit juices and jams

The novel carbohydrate-derived beta-carboline, 1-pentahydroxypentyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid, was identified in fruit- and vegetable-derived products such as juices, jams, and tomato sauces. This compound occurred as two diastereoisomers, a cis isomer (the major compound) and a trans isomer, ranging from undetectable amounts to 6.5 microg/g. Grape, tomato, pineapple, and tropical juices exhibited the highest amount of this alkaloid (up to 3.8 mg/L), whereas apple, banana, and peach juices showed very low or nondetectable levels. This tetrahydro-beta-carboline was also found in jams (up to 0.45 microg/g), and a relative high amount was present in tomato concentrate (6.5 microg/g) and sauce (up to 1.8 microg/g). This beta-carboline occurred in fruit-derived products as a glycoconjugate from a chemical condensation of D-glucose and L-tryptophan that is highly favored at low pH values and high temperature. Production, processing treatments, and storage of fruit juices and jams can then release this beta-carboline. Fruit-derived products and other foods containing this compound might be an exogenous dietary source of this glucose-derived tetrahydro-beta-carboline.     

地膜作为温室固定保温幕效果研究

该研究是在有活动式内保温幕的前提下，通过增加固定式内保温幕提高保温效果。结果表明这一措施是可行的，采用地膜作为固定幕材料，在3月中旬可提高幕内气温1.0～3.1℃，各部位平均提高1.4℃；凌晨最低温度可提高1.4℃，并且在低温条件下，表现出更好的保温性。幕内热量的传递方向主要是向南侧和周边。地膜作为固定式内保温幕成本低，节能效果好，易实施，但对室内光照产生一定不利影响。     

地膜作为温室固定保温幕效果研究

该研究是在有活动式内保温幕的前提下,通过增加固定式内保温幕提高保温效果.结果表明这一措施是可行的,采用地膜作为固定幕材料,在3月中旬可提高幕内气温1.0～3.1℃,各部位平均提高1.4℃;凌晨最低温度可提高1.4℃,并且在低温条件下,表现出更好的保温性.幕内热量的传递方向主要是向南侧和周边.地膜作为固定式内保温幕成本低,节能效果好,易实施,但对室内光照产生一定不利影响.     

Identification of a new form of lipid transfer protein (LTP1) in wheat seeds

Recently, this laboratory has isolated from barley and beer extract an isoform of lipid transfer protein (LTP1), which was not fully sequenced (Jégou, S.; Douliez, J. P.; Mollé, D.; Boivin, P.; Marion, D. J. Agric. Food Chem. 2000, 48, 5023--5029). It was named LTP1b and exhibited a molecular weight 294 Da higher than that of the known LTP1. This paper reports the finding of an LTP1 isoform in wheat that also exhibits an excess of 294 Da compared to the native protein. Amino acid sequencing, reduction and alkylation, and mass spectrometry showed that this new LTP1b possesses the same N-terminal sequence as the native LTP1, suggesting that the difference resides in the binding of an adduct which has a molecular weight of 294 Da. The aim of the present paper is to highlight various biophysical techniques that afford the identification of such an isoform-like LTP1 and to correlate this finding with other isoforms of LTP1 that were isolated from other plants but not fully sequenced.     

Porphyran as a functional modifier of a soybean protein isolate through conjugation by the Maillard reaction

Porphyran (Por) prepared from dried nori was applied as a functional modifier of a soybean protein isolate (SPI) to conjugate with SPI from defatted soybean by the Maillard reaction (79% relative humidity and 60 degrees C for 7 days). Two kinds of partially denatured conjugate (Conj 45 and Conj 63) were obtained from the reaction product by sequential extraction at pH 4.5 and pH 6.3, and the respective yield and weight ratios of the SPI and Por moieties were 8.4% and 1:1 for Conj 45 and 11.7% and 1:0.16 for Conj 63. Conj 63 demonstrated improved solubility between pH 5.0 and pH 8.0, while Conj 45 exhibited substantially complete solubility over the pH range of 2.0-8.0. Conj 63 showed more tolerance against digestion with pancreatin than SPI, whereas this was lost after denaturation. Conj 63 and Conj 45 both showed a markedly higher emulsion activity index and emulsion stability than SPI, even at pH 3.0; in particular, Conj 45 exhibited outstanding emulsifying ability. Conj 63 had about a two-fold higher calcium-binding ability than SPI, and Conj 63 and Conj 45 did not aggregate with added Ca2+ and Mg2+. It is believed that Por could be a valuable functional modifier of SPI for providing soybean protein-based liquid foods such as beverages by conjugation through the Maillard reaction.     

Identification of a novel glycoside, leptosin, as a chemical marker of manuka honey

As a preliminary study, we have found that honey from manuka (Leptospermum scoparium) in New Zealand inhibits myeloperoxidase (MPO) activity. In this study, using a chromatographic technique, we isolated two active compounds for MPO-inhibition from manuka honey. One is methyl syringate (MSYR), and the other was identified as a novel glycoside of MSYR, methyl syringate 4-O-β-D-gentiobiose, which has been named "leptosin" after the genus Leptospermum . The amount of the glycoside ranged from 0.2 to 1.2 μmol/g honey. Leptosin was only found in honeys from the Oceania region, and abundantly in manuka honey including jelly bush honey from Leptospermum polygalifolium in Australia. Therefore, leptosin may be a good chemical marker for manuka honey. Interestingly, the concentration of leptosin in manuka honey was positively correlated with the unique manuka factor (UMF) value, which is expressed as phenol equivalents of its bactericidal activity.     

Competitive indices of wheat + compact-mustard intercropping in a 5:1 row proportion as influenced by fertilizer doses and seed rates of wheat varieties

A field experiment in a split-plot design with three replications was conducted on wheat + compact-mustard intercropping in a 5:1 row proportion at the research farm, Institute of Agricultural Sciences, Banaras Hindu University, India, during the winter seasons of 2005.–2006 and 2006.–2007. The main plot treatment involved a combination of three fertilizer doses [100, 120 and 140% recommended fertilizer dose (RFD) to wheat, accompanied by 100% RFD to mustard] and two wheat varieties (HD-2824 and HUW-468); the subplot treatment consisted of three seed rates of wheat (100, 115 and 130 kg ha^?1). The treatment differences were studied intensively in light of the various reciprocity indices. Wheat variety HD-2824 at 115 kg ha^?1 seed rate and 140% RFD, intercropped with compact-mustard variety Sanjukta Aschesh at 100% RFD in a 5:1 row proportion, resulted in the best land utilization, maximum productivity and monetary advantage. Among the various yield indices studied, area time equivalent ratio (ATER), competitive ratio (CR) and effective land equivalent ratio (LER) curves were found to be good for comparing the variations in fertilizer doses and seed rates used in wheat varieties. Nevertheless, to compare monetary advantage, the monetary advantage index (MAI) based on LER proved a better index than intercropping advantage (IA), which is based on actual yield loss (AYL).     

Effect of tillage below the seed on emergence of wheat seedlings in a hardsetting soil

Two field experiments investigated the effect of tilled and untilled soil below the seed and the effect of a press wheel on the emergence of wheat (Triticum aestivum L.) seedlings on a hardsetting soil at Tatura, Victoria, Australia. Soil physical properties of the seedbed including penetrometer resistance, temperature and water content were recorded. The fate of seeds and seedlings and the length of roots were determined. In the experiments, germination was high (over 90%) and was not affected by the depth of tillage, the press wheel or by temporary waterlogging, but several physical conditions of the soil restricted emergence. In the first experiment, the rate and final emergence (at Day 10) was increased by tillage below the seed (e.g. at 46–90 mm depth) in spite of the penetrometer resistance of soil at 0–20 mm depth being 50% greater than that in the treatment untilled below the seed. The roots of the seedlings in the treatments untilled below the seed were temporarily waterlogged (at Days 0–1) and grew in soil that was drier (at Days 3–9) and harder than in treatments tilled below the seed. In the second experiment, the press wheel increased the rate of emergence by decreasing the sowing depth by 10 mm. Tillage below the seed increased the rate of emergence by decreasing the penetrometer resistance of the soil to less than 2.0 MPa.     

Prediction of grain protein content in winter wheat through leaf color measurements using a chlorophyll meter

A field trial was conducted over a 3-year period at the Hokkaido Kitami Agricultural Experiment Station to examine whether the grain protein content (GPC) of a winter wheat cultivar (Triticum aestivum L. cv. Chihokukomugi) suitable for Japanese noodle-making could be predicted before harvest. The prediction of the GPC was accurate based on the color of the second leaf (just below the flag leaf) at the end of the emergence of the inflorescence, when nitrogen application was graded. In order to evaluate the reliability of this test, a survey of 95 wheat fields in the eastern part of Hokkaido was also carried out during a 3-year period. The prediction of the GPC for this cultivar based on the color of the second leaf was less accurate across many sites. The results of this survey, however, suggested that the leaf color could be used as an index for ranking the GPC as low or high in relation to processing requirements. When the leaf color value of the second leaf measured with a chlorophyll meter at the end of the emergence of the inflorescence was less than 40, it was predicted that the GPC would be lower than the processing requirement. This index could be applied to the cultivars grown in the eastern part of Hokkaido, except for those grown on peat soils.     

基于Meta分析研究气候变化对中国小麦籽粒蛋白质含量的影响

气候变化相关的环境因素可能会影响谷物营养质量。气候变化引起的CO₂浓度升高、温度升高、降水量变化对作物营养质量的影响,特别是在中国范围内对谷物蛋白质含量的影响尚未量化。为此,该研究对中国各试验站点的现有文献数据进行Meta分析,并利用中国小麦籽粒蛋白质含量数据结合气象数据评估关键气候因素对中国主要小麦种植区小麦籽粒蛋白质含量的影响。Meta分析结果表明,增温显著提升了小麦籽粒蛋白质含量(P<0.05),CO₂浓度上升显著降低了小麦籽粒蛋白质含量,降水对小麦籽粒蛋白质含量影响较为复杂。温度升高可以部分抵消由于CO₂升高和降水对小麦籽粒蛋白质产生的负面影响。2010-2018年各省份小麦生育期内平均气温呈升高趋势,在所有调查的研究区内,小麦总生育期平均温度约上升了1.27℃,不同小麦种植区内生育期平均气温变化趋势存在差异。中国不同小麦产区籽粒蛋白质含量对生育期平均温度的响应以正向为主,并且生殖生长阶段的平均温度在小麦籽粒蛋白质含量变率中起主导作用。研究结果可为气候变化对小麦籽粒蛋白质含量的影响提供科学依据,有助于区域决...     

Metabolic profiling reveals a functional succession of active fungi during the decay of Mediterranean plant litter

We evaluated the relationship between the potential activity shown by pure fungal isolates (in vitro) and their ecological role in the field. Fungal species frequency and occurrence during trophic succession on a natural resource were studied and used as a tool to gain a better understanding of the metabolic profiles obtained in vitro, thus permitting clarification of the role played by some of the key fungal species involved in the decomposition process within a Mediterranean natural ecosystem. Litter bags containing pure (homogeneous) and mixed leaves of low maquis plant species were incubated for one year in a field experiment. Functional diversity of a representative pool of fungal communities was analysed and compared using a “phenotype microarray” technique. Taking as its basis the screening of metabolic profiles using culturable isolates, this investigation showed that there was a high potentiality of functional redundancy between low, intermediate and high frequency taxa, and potential niche overlap during the different phases that occur during leaf litter decomposition. The early stages of decomposition appeared to be characterized by the presence of rare taxa (“Low” species), with a significantly higher functional potential, especially for sugar compounds. Conversely, the later phases of decomposition appeared to be characterized by species of intermediate frequency, while rare taxa at these stages seem to lose their dominant role. The importance of the different groups of substrates found across the decomposition phases also represented a key factor. For example, redundancy in the utilization of N-related compounds indicated a high potential for overlapping between species, especially in the early phases of the decomposition process, suggesting that the capacity for interspecific competition on some substrates can be considerable, particularly at the start of substrate exploitation.     

Identification of active bacteria involved in decomposition of complex maize and soybean residues in a tropical Vertisol using N-DNA stable isotope probing

As limited information is available about the relationship between microbial processes and community structure in tropical soils, we used ¹⁵N-DNA stable isotope probing (¹⁵N-DNA-SIP) to identify bacteria actively involved in decomposition of plant residues of different biochemical quality. ¹⁵N-labeled (90 atom%) and unlabeled (control) maize (C-to-N ratio: 32; cellulose content: 24.9%) and soybean (15; 15.5%) leaf residues were incubated in a tropical Vertisol for 15 days. Soil DNA was isolated, subjected to ¹⁵N-DNA-SIP and buoyant density-resolved DNA fractions were analyzed by 16S rRNA gene-based denaturing gradient gel electrophoresis (DGGE) analysis and sequencing of selected DGGE bands. Residue addition induced new bands and changed relative intensity of already existing bands in ¹⁵N-enriched SIP fractions. Phylogenetic analysis of selected, cloned DGGE bands from ‘heaviest’ ¹⁵N-enriched fractions (57.8 atom% (maize), 87.1 atom% (soybean)) revealed that soils treated with maize residues were dominated by Pseudonocardia sp., while Arthrobacter sp. and Streptomyces sp. were found in the soybean residue treated soils. Sequences related to Bacillus sp. and Saccharopolyspora sp. were found in both organic residue treatments. Our study gave clear evidence that ¹⁵N-DNA-SIP combined with 16S rRNA gene-based community fingerprinting of density-resolved fractions and an unlabeled control was suited for detecting active bacteria involved in decomposition of complex maize and soybean residues. In conclusion, we could show that residue quality, inducing contrasting N assimilation by decomposing bacteria, was a substantial determinant of certain decomposing community members assayed in this study.     

Identification of enterodiol as a masker for caffeine bitterness by using a pharmacophore model based on structural analogues of homoeriodictyol

Starting from previous structure-activity relationship studies of taste modifiers based on homoeriodictyol, dihydrochalcones, deoxybenzoins, and trans-3-hydroxyflavones as obvious analogues were investigated for their masking effect against caffeine. The most active compounds of the newly investigated taste modifiers were phloretin, the related dihydrochalcones 3-methoxy-2',4,4'-trihydroxydihydrochalcone and 2',4-dihydroxy-3-methoxydihydrochalcone, and the deoxybenzoin 2-(4-hydroxy-3-methoxyphenyl)-1-(4-hydroxyphenyl)ethanone. Starting with the whole set of compounds showing activity >22%, a (Q)SAR pharmacophore model for maskers of caffeine bitterness was calculated to explain the structural requirements. After docking of the pharmacophore into a structural model of the broadly tuned bitter receptor hTAS2R10 and docking of enterolactone and enterodiol as only very weakly related structures, it was possible to predict qualitatively their modulating activity. Enterodiol (25 mg L(-1)) reduced the bitterness of the 500 mg L(-1) caffeine solution by about 30%, whereas enterolactone showed no masking but a slight bitter-enhancing effect.     

小麦秸秆两性吸附剂的制备及其去除水中Pb2+和As5+的机制

为探究利用废弃农业生物质制备两性吸附材料处理含Pb2+和As5+废水方法,该文通过醚化反应将2种具有“钳形”结构的改性剂（阳离子改性剂IA和阴离子改性剂IM）接枝到小麦秸秆的纤维素上,制备高效两性吸附材料WS-IAIM。利用扫描电镜、红外光谱、X射线光电子能谱对其结构进行表征。通过批量处理试验,研究了该材料对水中Pb2+和As5+的去除能力和可能的吸附机理,探讨了其吸附动力学和热力学。结果表明：随着溶液pH值的增加,吸附剂对Pb2+的吸附量增大,对As5+的吸附量减少,吸附行为符合Langmuir吸附等温模型和拟二级动力学模型。根据Langmuir模型,在313 K时,对Pb2+和As5+的理论最大吸附量分别为180.12和27.48 mg/g。吸附热力学和动力学分析结果表明,该吸附是一个自发的化学吸热过程。WS-IAIM对Pb2+和As5+吸附过程的吸附机理以离子交换和络合作用为主。该吸附材料重复使用5次后,对2种重金属离子的吸附量仍然可达159.3和19.8 mg/g。研究结果可为农作物秸秆的源化利用和水体环境中复杂重金属净化提供理论依据。     

Identification of an aliphatic epoxide and the corresponding dihydrodiol as novel congeners of zearalenone in cultures of Fusarium graminearum

The mycotoxin zearalenone (ZEN) is produced by various Fusarium fungi and frequently found as a contaminant in food and feed. There are reports in the literature that several closely related analogues of ZEN are also formed in cultures of Fusarium species. We have therefore analyzed the organic extract from a 40 day culture of Fusarium graminearum by LC-DAD-MS and detected 15 compounds, which could be congeners of ZEN because of their ultraviolet, mass spectroscopy, and tandem mass spectroscopy spectra. In addition to confirming the previously reported α- and β-stereoisomers of 5-hydroxy-ZEN and 10-hydroxy-ZEN, we identified seven ZEN congeners for the first time. One of the major novel congeners was shown by nuclear magnetic resonance spectroscopy and chemical synthesis to have the structure of an aliphatic ZEN epoxide, whereas two minor products proved to be the corresponding dihydrodiols. In addition, three stereoisomers of a cyclization product of the dihydrodiols, carrying a spiro-acetal group, were identified as fungal products for the first time. The latter may be artifacts, because the ZEN epoxide and dihydrodiol are unstable under acidic conditions and rearrange easily to the spiro-acetal compounds.     

酵母蛋白替代鱼粉饲养胡子鲶试验

用不同比例的酵母蛋白替代饲料中的鱼粉 ,进行室内分阶段饲养胡子鲶试验。经对各组鱼增重率、饲料系数及综合饲养效果等指标分析 ,表明在胡子鲶饲料中 ,酵母蛋白可替代鱼粉 ,其适合用量为 1 0 %左右(即替代 50 %左右鱼粉 )     

Selenobacteria selected from the rhizosphere as a potential tool for Se biofortification of wheat crops

Cereal production in southern Chile is based on ash-derived volcanic Andisols, which present suboptimal levels of available selenium (Se). Strategies are needed to improve Se content in cereal crops and concomitantly improve the nutritional quality of grain. Here, we investigated the occurrence of Se-tolerant bacteria (STB) in Andisols and evaluated Se tolerance and accumulation in STB. The inoculation of wheat with STB and the contributions of these bacteria to Se content in plants were also evaluated under greenhouse conditions. The results showed that Se amendment of Andisols stimulated some bacterial groups (Paenibacillaceae and Brucellaceae) but inhibited others (Clostridia, Burkholderiales, Chitinophagaceae and Oxalobacteraceae), as revealed by denaturing gradient gel electrophoresis. Furthermore, we found four STB isolates that displayed 1-aminocyclopropane-1-carboxylate deaminase (ACC deaminase activity) and that carried the acdS gene as revealed by PCR. The selected STB were characterised as Stenotrophomonas, Bacillus, Enterobacter and Pseudomonas according to partial sequencing of the 16S rRNA gene. After 24 h of culture in nutrient broth, the selected STB showed the ability to grow in high Se concentrations (5 and 10 mM) and to accumulate elemental Se in micro- and nanospherical deposits, transforming 50–80 % of the Se initially added. Greenhouse experiments with wheat showed that Se associated with STB (micro- and nanospheres of elemental Se and other intracellular forms) can be translocated into leaves of wheat plantlets.     

An evaluation of the functional significance of peat microorganisms using a reciprocal transplant approach

Our current knowledge on the relevance of microbial diversity and composition for the recovery and maintenance of soil biological processes is rudimentary, partly because experimental substantiation of the importance of community composition to function is scarce. Guided by this gap, we devised a reciprocal transplant experiment to examine the functional behaviour of different microbial communities exposed to two structurally distinct peats. Sterile peat samples representing two types, one humified (sedge) and the other dominated by coarse plant material (fibric), were inoculated with a 10⁻¹, 10⁻³, 10⁻⁵, or 10⁻⁸ dilution of either the same or reciprocal peats. After 5 months of incubation, we used a nucleotide-analog technique to label the active bacterial taxa in samples receiving the 10⁻¹ and 10⁻⁸ dilutions. We assessed both the peats' functional potential (respiration and nutrient-acquiring and lignin-degrading enzyme activities) and the structures of active and total bacterial communities (PCR-DGGE). In general, we found a decline in respiration rates and increase in enzyme activities with increasing dilution level, but the effect of dilution on bacterial richness was weak. The bacterial community structure and richness depended on both the inoculum source and the peat type. The activity of enzymes involved in nutrient acquisition depended mainly on the soil type, while the lignin-degrading activity was influenced by differences in community composition between peat types. Neither active bacterial populations nor respiration were significantly influenced by peat type or inoculum source. Our results suggest that the relationship between microbial community composition and function is not only related to the taxonomic breadth of the taxa that perform a given function, but may also be shaped by interactions between microorganisms in the inoculum source and the substrate being colonized.