硫丹降解菌C7在土壤中的降解性能及其酶促降解试验

Ochrobactrum sp. C7是一株高效硫丹降解菌。本试验对C7在土壤中降解硫丹的效果以及C7产生的硫丹水解酶(粗酶液)的性质进行了研究。结果表明,该菌在30天内能很好地降解土壤中的硫丹;降解酶在30~45℃、pH5.5~7.5的条件下活性较高;在pH7和40℃时显示最大的硫丹水解酶活性。初步判断水解酶的表达可能是组成型的,此粗酶液可用于果蔬表面农药残留的快速解毒和清除,从而为高效降解菌株的应用与环境中的生物修复提供了理论依据。     

Enzymatic degradation of FODMAPS via application of β-fructofuranosidases and α-galactosidases- A fundamental study

Cereals and pulses often contribute to the intake of Fermentable Oligo-, Di-, Monosaccharides, and Polyols (FODMAPs) due to high amounts of fructans or galactooligosaccharides (GOS). FODMAPs can trigger symptoms of Irritable Bowel Syndrome (IBS) and therefore, the development of foods and beverages with a lower FODMAP-content are favourable for IBS patients. Enzyme technology is a promising tool to reduce the FODMAP-content in foods and to maintain product quality. This fundamental study investigates the efficiency of invertase, inulinase, and α-galactosidase as potential food additives to reduce the total FODMAP content of food ingredients. Extracts of high FODMAP ingredients, such as wheat and lentil, and standard solutions of various fructans and GOS were incubated with invertase, inulinase and α-galactosidase for 1 h and 2 h. Contents of oligosaccharides before and after treatment and related IBS-triggering reaction products were quantified using ion chromatography. Inulinase showed a high degradation yield (over 90% of degradation) for both GOS and fructans. For invertase only low degradation yields were measured. α-Galactosidase showed the highest efficiency in decomposing GOS (100% of degradation) and led to non-IBS triggering degradation products. This indicates a high potential for a combined inulinase/α-galactosidase treatment for products containing both fructans and GOS.     

酵素菌剂对设施盐碱地土壤理化性状的影响

摘要：设施盐碱地改良是当前农业发展的一项紧迫任务。本研究采用酵素菌微生物法对不同地区不同程度的设施盐碱地进行改良，经过两年的跟踪检测得出，采用酵素菌剂改良后设施盐碱土壤均有不同程度的改善，pH值上口镇由7.90下降至7.50，稻田镇由8.21降至7.48，营里镇由8.65降至7.98，电导率（EC值）上口镇由890μs/cm降至776μs/cm，稻田镇由1011μs/cm降至880μs/cm，营里镇由1270μs/cm降至1003μs/cm，活菌数量、有机质、全氮、有效磷、速效钾不同程度增加，且中轻微程度设施盐碱改善效果明显。     

5α-Reductase inhibitory compounds produced by polymerization of resveratrol with horseradish peroxidase

To produce 5-reductase inhibitory compounds, resveratrol was enzymatically oxidized in a horseradish peroxidase (HRP)/H₂O₂ system. Ethyl acetate extract of the oxidation products showed strong 5-reductase inhibitory activity with 10%–15% organic solvents in the system, whereas without organic solvent little inhibitory activity was exhibited. The optimum pH of enzymatic oxidation for acquisition of the inhibitory activity was 4.5. The inhibitory compounds were isolated and identified as resveratroltrans-dehydrodimer and resveratrolcis-dehydrodimer by comparing with published nuclear magnetic resonance data. The two resveratrol dehydrodimers have stronger inhibitory activity than natural resveratrol dimers and trimers found inShorea species.     

Purification and characterization of polyphenol oxidase from Henry chestnuts (<Emphasis Type="Italic">Castanea henryi</Emphasis>)

Polyphenol oxidase from Castanea henryi nuts was partially purified. Some characteristics of the enzyme were then determined to help devise measures for the prevention of undesirable enzymatic browning during storage and processing of the nuts. Preparation of acetone powder extracts of the nuts, ammonium sulfate precipitation, dialysis, and gel filtration resulted in 37-fold purification of the enzyme with a yield of 13%. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the excitation spectrum confirmed the enzyme preparation to be homogeneous. The approximate molecular weight of the enzyme was determined by gel filtration to be 69kD. The enzyme catalyzed the oxidation of catechol and pyrogallic acid as substrates but did not affect cresol or tyrosine. Using catechol as substrate, p-nitrophenol, thiourea, orcinol, and naphthol showed strong inhibition. The optimal pH and temperature for the enzyme were pH 5.0 and 40°C, respectively. The enzyme proved heat labile. When the enzyme was incubated at 70°C for 30min, the remaining activity of the enzyme was only 8%. Possible approaches to applying the results of this study to the prevention of enzymatic browning in the production of C. henryi nuts is also discussed.     

酶解血粉饲料的发酵工艺及饲喂畜禽效果

应用生物自显影术复壮和优选酶解血粉饲料生产用菌种,改良发酵载体配方和发酵工序,经化验分析和饲喂畜禽试验证实,产品质量提高,经济效益良好.     

植物油浸出技术研究进展

分别介绍了植物油浸出技术中的有机溶剂浸出工艺、水浸出制油技术、酶法浸出工艺和超临界二氧化碳浸出工艺的最新研究进展及各自的优缺点,旨在为今后油脂工业的发展提供参考。     

The functional structure of ectomycorrhizal communities in an oak forest in central France witnesses ancient Gallo-Roman farming practices

The activities of nutrient-mobilising enzymes secreted by ectomycorrhizas of sessile oak (Quercus petraea) have been measured in 24 plots in a forested area in central France where many rural Gallo-Roman settlements (first to fifth centuries AD) have been discovered. Data have been related with tree growth and soil chemical properties. Although soil near the past settlements is still enriched in N and P, this does not always correspond to the higher productivity of oak trees. However, when this is the case, the ectomycorrhizal community displays higher chitinase, protease and phosphatase activities (involved in N and P mobilisation from soil organic matter). A few specialised ectomycorrhizal fungal species are responsible for this adaptation to the long-lasting modification of soil conditions.     

Azinphos-methyl and carbaryl resistance in adults of the codling moth (Cydia pomonella (L.), Lepidoptera: Tortricidae) from Northeastern Spain

The resistance of Cydia pomonella (L.) to organophosphates is widespread throughout the pome fruit growing areas. The lethal effects of two insecticides inhibitors of the acetylcholine esterase, azinphos-methyl and carbaryl, were evaluated in adults of five and four field populations of the codling moth, respectively. The lethal concentrations (LC₅₀ and LC₉₀) of these insecticides were determined in a susceptible strain from Spain (S_Spain). Topical bioassays using the approximate LC₉₀ values (3000 mg (a.i.)/L of carbaryl and 2000 mg (a.i.)/L of azinphos-methyl) that were obtained in S_Spain were tested as diagnostic concentrations. The enzymatic activities of mixed-function oxidases (MFO), glutathione S-transferases (GST) and esterases (EST) were measured to investigate their potential role in the detoxification of these insecticides.Carbaryl and azinphos-methyl caused ?53% and ?39% corrected mortality, respectively, in field populations, although the diagnostic concentrations applied were twofold and fourfold higher than the maximum concentration registered in Spain, respectively. The activities of MFO and GST were 7.3- to 16.1-fold higher and 2.5- to 3.7-fold higher in all the field populations compared to those in S_Spain, respectively.     

Soil amendment with seed meals: Short term effects on soil respiration and biochemical properties

In the last decades, worldwide biofuel production increased up to 105 billion liters in 2010; in this year, the world's first biodiesel producer was the European Union. Biodiesel is produced from a variety of oils, mainly soybean, Brassicaceae and sunflower. One of the most important biodiesel production byproducts are seed meals. The most common use of seed meals is for animal nutrition, but another potential use is agricultural soil organic amendments. Soil biological and biochemical properties have been widely used as soil quality indicators, due to their quick response to changes in soil management. Although there are many studies on the effects of regular amendments on respiration and enzymatic activities of the soil, very few papers refer to the effect of seed meals. Therefore, the aim of this study was to investigate the short-term effect of seed meal amendment on soil respiration and enzymatic activities (alkaline phosphatase, dehydrogenase, fluorescein diacetate hydrolase, arylsulphatase and β-glucosidase). The two seed meals used were obtained from Brassica carinata (A.) Braun (Ethiopian mustard) and sunflower (Helianthus annuus L.). The study was carried out, from June 2007 to October 2007, at an experimental farm of CRA-ORT, Battipaglia, in the Sele River (Plain Salerno, Campania Region, Italy). The results of this study support an alternative use of seed meals as organic amendments. Generally, a significant positive response of enzymatic activities, evaluated in this study, to the addition of seed meals, indicates a beneficial effect on soil quality as regards microbial activity.