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41.
对减压内部沸腾法提取壶瓶枣多糖及其脱色工艺进行了研究。以蛋白质和多糖得率为指标,通过正交试验优化得到的最佳工艺条件为:体系内温度60℃,液料比为20∶1(m L∶g),时间为30 min,此时真空度为80 k Pa,外界温度为70℃,蛋白质和多糖得率分别为0.13%和2.60%。与传统热浸提相比,其得率分别提高了18.18%和23.22%。对10种脱色材料的筛选结果表明D900型大孔吸附树脂是理想脱色材料,通过正交试验优化得到的D900型大孔吸附树脂脱色优化工艺参数为D900添加量3.5%,时间20 h,p H值11.7,温度40℃,此时脱色率、脱蛋白率和多糖保留率分别为81.94%、38.19%和87.42%。 相似文献
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Sylvie Nèble Virgile Calvert Jean Le Petit Stéven Criquet 《Soil biology & biochemistry》2007,39(11):2735-2742
As part of a study of the processes involved in litter biodegradation following sewage sludge (SS) addition, the variations over 14 months of phosphatase activities in a cork oak litter (Quercus suber L.) were investigated. A field experimental design was carried out using the litter-bag method on both a fertilized plot receiving SS applications (twice ) and a control plot. Acid (APH) and alkaline (BPH) phosphatases were measured, along with several biotic and abiotic variables potentially involved in the regulation of these enzymes. These included moisture, temperature, pH, water-extractable inorganic P (PW), culturable heterotrophic bacteria and fungi. Sludge addition had significant effects on all the variables measured. Indeed, sludge increased significantly BPH activities, available PW, microbial densities (i.e. bacteria and fungi) and pH in the fertilized plot. In contrast, APH activities decreased significantly following sludge addition. As a consequence, the BPH/APH ratio increased markedly and immediately in the fertilized plot, but only after the 1st amendment. Following the 1st preconditioning SS amendment, the 2nd fertilization had fewer effects on biological variables, because of summer dryness. The different properties examined varied significantly with incubation time, and most were significantly related to the seasonal patterns of litter moisture in this Mediterranean forest ecosystem. Hence, sewage sludge application modified the intensity of microbial responses to environmental factors, but biological patterns regulating P turn-over were maintained. 相似文献
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J.I. LEENHOUWERS D. ADJEI-BOATENG J.A.J. VERRETH & J.W. SCHRAMA 《Aquaculture Nutrition》2006,12(2):111-116
The objective of the present study was to investigate if dietary soluble non‐starch polysaccharides (NSP) increase digesta viscosity, reduce nutrient digestibility and increase organ weights in African catfish. The fish (mean weight 80 g) were fed diets supplemented with the soluble NSP guar gum at three levels, 0 g kg?1 (GG0), 40 g kg?1 (GG4) and 80 g kg?1 (GG8). Guar gum inclusion significantly increased digesta viscosity in the proximal (GG0: 1.7 centipoise or cP; GG4: 84.9 cP; GG8: 98.3 cP) and distal (GG0: 1.9 cP; GG4: 109.8 cP; GG8: 66.4 cP) intestine. Apparent digestibility coefficients (ADC) were significantly lower for the GG8 diet than the GG0 diet (dry matter: 52% versus 69%; protein: 77% versus 90%; ash: 41% versus 54%; energy: 60% versus 77%). The ADC of dry matter and energy were significantly lower for the GG4 diet than the GG0 diet. The relative growth rate of metabolic weight (14.5–15.4 g kg?0.8 day?1) and feed conversion ratio (0.8) did not differ between diets. Fish fed the GG8 diet had a significantly higher somatic stomach index than GG0 fish (0.71% versus 0.65% body weight). The intestinal somatic index tended to increase with increasing guar gum supplementation (GG0: 1.08%; GG4: 1.23%; GG8: 1.59%). In conclusion, high digesta viscosities in the guar gum fed fish may explain the observed reduced nutrient digestibilities and increases in digestive organ weights. 相似文献
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D. Epel 《Aquaculture International》2005,13(1-2):19-28
Research on how the young embryo protects itself from normal environmental stresses reveals that the earliest phases of development have unique, innate mechanisms to protect the embryo during this most sensitive phase of embryogenesis. This paper shows ways in which knowledge of these protection mechanisms might be used to advantage in the aquaculture situation. These include novel mechanisms to deter bacteria and fungi such as secretion of anti-bacterial/anti-fungal substances from the egg at fertilization, as well as the utilization of anti-fungal metabolites provided by symbiotic bacteria associated with egg cases. UV damage is avoided by provision of unique sunscreens to the embryos so that UV penetration into the cytoplasm is avoided. Finally, embryos have exaggerated mechanisms to avoid the effect of toxicants on development but these are inadequate to remove pollutants present in feed used in aquaculture. Approaches are suggested on how this knowledge about adaptations might be used in the aquaculture setting to avoid pathogens, increase UV resistance and reduce levels of pollutants. 相似文献
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《The Journal of Applied Poultry Research》2014,23(4):715-723
The experimental design consisted of 5 dietary treatments including a positive control (PC), a negative control (NC; with a reduction of 88 kcal/kg of AME through the starter and grower 1 phase and a reduction of 132 kcal/kg of AME in the grower 2, finisher, and withdrawal phases compared with the PC), and the NC supplemented with either β-mannanase, nonstarch polysaccharide-degrading enzymes (NSPase; cocktail carbohydrase), or β-mannanase and NSPase intermittently fed. The intermittent treatment included β-mannanase from d 1 to 21 (starter and grower 1 phases) and NSPase from d 22 to 47. Each treatment included 9 replicate pens with 35 male broilers placed per replicate (1,575 total chicks placed). The dietary program consisted of 5 dietary phases, including the starter through d 10, grower 1 through d 21, grower 2 through d 32, finisher through d 40, and withdrawal through d 47. Broilers were weighed and feed consumption determined on days of dietary changes. On d 48, following an 8-h feed withdrawal, 6 broilers from each replicate pen were removed and processed for whole bird and fat pad measurements. The reduction in energy in the NC diet reduced BW and increased mortality rate, and the inclusion of β-mannanase and NSPase separately and intermittently in the NC diet improved growth performance and reduced mortality to levels that were comparable to the PC. The NC yielded the highest cumulative mortality-corrected FCR and all enzyme inclusion treatments reduced FCR to levels comparable to the PC for the duration of the trial. The NC diet yielded the lowest processing yields and the inclusion of β-mannanase and NSPase separately and intermittently increased multiple processing parameters to a level similar to the PC. These data confirm the ability of β-mannanase and NSPase inclusion separately and intermittently to improve performance parameters in reduced-energy broiler diets. 相似文献
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在2010年10月至2013年5月间,通过对采自海南省儋州、文昌、澄迈、五指山、白沙、三亚、东方、临高、定安、琼中、陵水等11个市、县的中、老龄橡胶树林段及其防护林的病、死树及树桩上的灵芝属真菌标本180余份进行鉴定,初步鉴定出灵芝属真菌17种,分别为白边树舌(Ganoderma albornartginatm)、层叠灵芝(G.lobatum)、长管灵芝(G.annulare)、黄边灵芝(G.luteomarginatum)、灵芝(G.lucidum)、南方树舌灵芝(G.australe)、热带灵芝(G.tropicum)、唐氏灵芝(G.donkii)、橡胶灵芝(G.pseudoferreum)、有柄树舌灵芝(G.gibbosm)、树舌灵芝(G.applanatum)、菲律宾灵芝(G.philippii)、褐灵芝(G.brownii)、薄盖灵芝(G.capense)、马蹄状灵芝(G.ungulatum)、吊罗山灵芝(G.diaoluoshanense)和无柄灵芝(G.resinaceum)。其中橡胶灵芝和菲律宾灵芝为引起橡胶树红根病的重要病原菌,热带灵芝(G.tropicum)、薄盖灵芝(G.capense)为引起台湾相思、木麻黄、桉树等防护林树木枯死的重要病原菌。 相似文献