In-Situ Bioremediation of DDTs and PAH Contaminated Aging Farmland Soil Using Blood Meal

The use of blood meal was studied for in-site bioremediation of contaminated farmland soil. The combination of blood meal and indigenous microorganisms helped to in-site remediate the combined contaminated aging farmland soil of DDTs and PAH in Shenyang, China. The concentration of DDTs and PAHs was 47.94 ± 0.63 μg/kg and 690.10 ± 5.16 μg/kg, respectively. Biostimulation using blood meal or glucose promoted the bioremediation rate of DDTs and PAHs. Compared to glucose, blood meal was a longer term repair additive of DDTs and PAHs, and the remediation result was more efficient and durable. In the blood meal treatment, plowing the soil once every 7 days could increase the soil enzyme activities and bacterial populations, and it could significantly promote the remediation rates of DDTs (P < 0.05) and more evidently promote the remediation rates of PAHs. The DDTs and PAHs remediation rates increased from 32.18% and 20.17% to 43.41% and 26.09%, respectively, in soil treated with blood meal and plowed weekly after the five month remediation. This study provides an highly efficient in-site farmland soil bioremediation technology that could have practical utility.     

南方鲇的营养学研究:饲料中大豆蛋白水平对生长的影响

以初始体重为 2 3 .78± 0 .0 9g的南方鲇幼鱼为实验对象 ,在室内循环水养殖系统中进行为期 6周的生长实验。以大豆蛋白分别替代 0 %、1 3 %、2 6 %、3 9%、5 2 %和 6 5 %的鱼粉蛋白 ,配制成 6种等氮 (粗蛋白为 48%)、等能 (总能 2 0 KJ/ g)的饲料 ,用于探讨饲料中鱼粉蛋白与大豆蛋白的不同比例对南方鲇生长及饲料转化率的影响。实验在 2 7.5± 0 .2℃水温条件下进行 ,溶氧维持在 5 mg/ L以上 ,光照周期为 1 4L:1 0 D。实验结果表明 ,当大豆蛋白分别替代1 3 %、2 6 %和 3 9%的鱼粉蛋白时 ,3组之间的特定生长率 (SGR)的差异不显著 (P>0 .0 5 ) ,但均显著高于 5 2 %和 6 5 %替代水平 (P<0 .0 5 )。其中 1 3 %和 2 6 %的替代水平的特定生长率(SGR)显著高于对照组 (P<0 .0 5 ) ;3 9%替代水平的特定生长率 (SGR)与对照组之间差异不显著 (P>0 .0 5 ) ;而 5 2 %和 6 5 %替代水平的特定生长率 (SGR)则显著低于对照组 (P<0 .0 5 )。饲料转化率 (FCE)、蛋白质效率 (PER)和蛋白质累积率 (PPV)分别在各处理组之间的差异关系与特定生长率 (SGR)在各组之间的变化相类似。因此 ,本文提出南方鲇饲料中大豆蛋白替代 3 9%的鱼粉蛋白是适宜的 ,过量的添加将影响南方鲇的生长及饲料转化率。通过分析认为大豆蛋白影响南方鲇生     

Effect of lactic acid fermentation of wheat and barley whole meal flour on carbohydrate composition and digestibility in mink (Mustela vison)

Wheat and barley whole meal flours (WMFs) were subjected to treatment by fermentation, autoclaving, and fermentation followed by autoclaving. The WMFs were analysed for chemical composition, formulated into wet diets (282 g kg⁻¹) and fed to adult mink (Mustela vison) for determination of total tract digestibility of total starch, total carbohydrate, crude protein and fat. Fermentation of WMF/water mixtures inoculated with a Lactobacillus sp. (strain AD₂) was performed at 30°C for 16 h. Autoclaving was carried out for 60 min at 120°C. Fermentation increased colony-forming units (CFUs) to about 10⁸ g⁻¹ and lowered pH to 3.7–3.8 in both WMFs. All carbohydrate parameters were affected by type of cereal, and were, except for total starch, affected by treatment. Levels of total dietary fibre and β-glucans decreased by fermentation in both WMFs. The decrease in total β-glucans from 33.5 to 18.4 g kg⁻¹ in barley WMF, was mainly restricted to the soluble fraction. Glucose levels in barley WMF increased simultaneously from 0.6 to 12.3 g kg⁻¹. The main effects of autoclaving were increased levels of total dietary fibre, maltose, and increased hydration capacity. With fermentation prior to autoclaving, increases in levels of the fibre fractions and maltose were prevented while hydration capacity prevailed as an effect of autoclaving. Compared with fermentation alone, the combined treatment increased damaged starch levels and hydration capacity. Digestibilities of total carbohydrate, crude protein and fat were significantly higher for wheat than for barley. Fermentation had no effect on digestibility of total starch or total carbohydrate of wheat, but increased digestibility of total starch of barley significantly from 0.742 to 0.880, and of total carbohydrate from 0.457 to 0.616. Autoclaving had no significant effect on digestibility of total starch and total carbohydrate of wheat. Digestibility of total starch and total carbohydrate in barley increased significantly after autoclaving. Total starch and total carbohydrate digestibility of both wheat and barley were significantly enhanced by combined fermentation and autoclaving compared with fermentation alone. Compared with autoclaving alone, combined fermentation and autoclaving promoted no significant improvement of total starch and total carbohydrate digestibility in wheat, whereas total carbohydrate digestibility in barley increased from 0.605 to 0.672. Fat digestibility was slightly improved by both fermentation and autoclaving. Autoclaving of cereals reduced significantly the faecal dry matter contents of mink. This effect could be counteracted by preceding fermentation. In conclusion, lactic acid fermentation of wheat and especially barley provided chemical changes of benefit for carbohydrate digestion in the mink.     

有机肥对桃园土壤硝态氮分布的影响

于2004—2005年在北京市平谷区有机桃园设置不同有机肥处理：2年连续施有机肥,年均67 500 kg·hm^-2（T₁）;第一年不施肥,第二年施有机肥135 000 kg·hm^-2（T₂）;第一年不施肥,第二年施有机肥67 500 kg·hm^-2（T₃）;不施肥对照（CK）,并于2006年对0～120 cm土层土壤进行取样分析,研究施用有机肥对土壤硝态氮分布和淋失的影响.结果表明：对照土壤中硝态氮分布较均匀,T₁和T₃在0～120 cm土层硝态氮浓度变化呈单峰曲线,其中60 cm以上较高,在60～120 cm逐渐降低;而T₂土壤硝态氮浓度由浅到深逐渐增加,峰值出现在100～120 cm土层,其在60 cm以下土层的硝态氮浓度在所有处理中最高,说明过量施用有机肥易导致硝态氮的淋失.相关分析表明,土壤硝态氮的浓度和分布与多年施氮总量、最近一年施氮量和检测点与树的距离呈显著相关关系,并据此建立了有机肥施用与土壤剖面硝态氮浓度之间的相关模型.     

Effect of heat treatments on stability of altemariol, alternariol monomethyl ether and tenuazonic acid in sunflower flour

A study was carried out to evaluate the effect of heat treatment on the stability of alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TeA) in sunflower flour and the effectiveness of this treatment by a biological assay in rats. The concentrations of AOH and AME remained constant during heating at 100°C for up to 90 minutes while TeA concentration decreased with time to 50% after 90 minutes. The most effective treatment in reducing AOH and AME levels was heating at 121°C for 60 minutes. Histopathological evaluation in the biological assay in rats fed withAlternaria toxins showed marked atrophy and fusion of villi in the intestines and liver cell damage; these lesions were less severe in rats fed heat-treated sunflower flour in line with the reduced toxin content. However, a lower weight gain and a noticeable renal damage in rats were produced when they fed decontaminated flour.     

添加茶籽粕和EDTA对土壤中镍和锌形态变化及植物有效性的影响

采用盆栽试验,研究了茶籽粕和EDTA对土壤中重金属镍和锌形态变化和植物有效性的影响.结果表明:随着茶籽粕施用量的增加,甘蔗根、茎、叶的生物量逐渐增加,而EDTA处理甘蔗茎、叶的生物量与对照无显著差异.茶籽粕和EDTA的添加提高了土壤中酸溶态镍和锌含量,促进甘蔗对镍和锌的吸收及向地上部位转运,并且随着茶籽粕施用量的增加,其促进效果逐渐增强.与EDTA相比,茶籽粕对提高甘蔗体内镍和锌积累量效果明显,使甘蔗从土壤中迁移出更多的镍和锌.甘蔗茎、叶中镍和锌含量与茶籽粕的用量呈极显著正相关,而根中镍和锌含量与茶籽粕用量呈极显著负相关.     

捕食量和温度对麦长管蚜在多异瓢虫体内可测定时间的影响

为了方便准确评价麦田捕食性天敌对麦长管蚜 Sitobion avenae (Fabricius) 的控制作用,应用单克隆抗体及间接 ELISA 方法研究了捕食量和温度对麦长管蚜在多异瓢虫 Adonia variegata（Goeze）体内可测定时间的影响。结果表明：在不同的温度和捕食量下,麦长管蚜在多异瓢虫体内的降解中间产物曲线均为单峰型。温度对猎物的可测定时间有显著的影响,随着温度的上升,猎物的可测定时间不断缩短。特别是当温度达到 30℃时,猎物的降解速率迅速上升,其可测定时间只有 1.18 天。捕食量对猎物的可测定时间也有显著影响,随着捕食量的增加,猎物的可测定时间延长。在 25℃的条件下,当捕食量从 1 头蚜虫增加到 3 头蚜虫,可测定时间从 2.81 天延长到 4.25 天。     

蓝藻堆积和螺类牧食对苦草生长的影响

设计了双因素四组处理(对照组,加螺组,加藻组,螺藻组)的室外受控实验,模拟湖泊沿岸带水华蓝藻的堆积以及底栖螺类的牧食活动对沉水植物苦草生长的影响。结果表明:蓝藻堆积(水体叶绿素a浓度为220μg/L)对苦草的生长具有明显的抑制作用,和对照组以及加螺组相比,加藻组和螺藻组中苦草的相对生长率分别下降了40.9%和36.4%,分株数也分别下降了56.4%和64.1%,分析认为蓝藻在水体表层堆积所产生的遮光可能是抑制底层苦草生长的主要原因。然而,环棱螺能在一定程度上促进苦草的生长,加螺组和螺藻组中苦草的相对生长率和分株数分别要明显高于对照组和加藻组,这可能要归因于螺类的牧食去除了沉水植物表面附着生物。实验中蓝藻堆积和螺类牧食对苦草的各项生长指标均无显著的交互作用,但蓝藻对苦草生长的抑制作用要远大于螺类对植物生长的促进作用。研究证实了在富营养浅水湖泊中,水华蓝藻在湖泊沿岸带的堆积会严重胁迫沉水植物的生长,而底栖螺类的牧食活动则能在一定程度上提高植物在不良环境下的生存能力。