二次中和法制取菜籽复合氨基酸新工艺研究

为得到高质量的菜籽复合氨基酸,以脱皮菜籽粕为原料,研究了硫酸水解制备复合氨基酸的新工艺一二次中和法,解决了氨基酸脱色和副产品植酸的利用问题。水解的最佳工艺参数是3mol·L-1的H2SO4水解18h;ca(OH)2作中和剂,第一次中和和脱色的最佳pH为2-4,第二次中和的最佳pH为6.5-7.0,中和后的溶液经减压浓缩,喷雾干燥,制得菜籽复合氨基酸。复合氨基酸得率≥40％,纯度≥40％;副产品植酸钙得率10％左右,纯度40％-50％。     

“Show me which parasites you carry and I will tell you what you eat”, or how to infer the trophic behavior of hematophagous arthropods feeding on wildlife

Most emerging infectious diseases are zoonoses originating from wildlife among which vector‐borne diseases constitute a major risk for global human health. Understanding the transmission routes of mosquito‐borne pathogens in wildlife crucially depends on recording mosquito blood‐feeding patterns. During an extensive longitudinal survey to study sylvatic anophelines in two wildlife reserves in Gabon, we collected 2,415 mosquitoes of which only 0.3% were blood‐fed. The molecular analysis of the blood meals contained in guts indicated that all the engorged mosquitoes fed on wild ungulates. This direct approach gave only limited insights into the trophic behavior of the captured mosquitoes. Therefore, we developed a complementary indirect approach that exploits the occurrence of natural infections by host‐specific haemosporidian parasites to infer Anopheles trophic behavior. This method showed that 74 infected individuals carried parasites of great apes (58%), ungulates (30%), rodents (11%) and bats (1%). Accordingly, on the basis of haemosporidian host specificity, we could infer different feeding patterns. Some mosquito species had a restricted host range (An. nili only fed on rodents, whereas An. carnevalei, An. coustani, An. obscurus, and An. paludis only fed on wild ungulates). Other species had a wider host range (An. gabonensis could feed on rodents and wild ungulates, whereas An. moucheti and An. vinckei bit rodents, wild ungulates and great apes). An. marshallii was the species with the largest host range (rodents, wild ungulates, great apes, and bats). The indirect method substantially increased the information that could be extracted from the sample by providing details about host‐feeding patterns of all the mosquito species collected (both fed and unfed). Molecular sequences of hematophagous arthropods and their parasites will be increasingly available in the future; exploitation of such data with the approach we propose here should provide key insights into the feeding patterns of vectors and the ecology of vector‐borne diseases.     

Sleep duration,nightshift work,and the timing of meals and urinary levels of 8-isoprostane and 6-sulfatoxymelatonin in Japanese women

It has been hypothesized that disruption of circadian rhythms affects human health. Shift work and sleep deprivation are thought to disrupt the normal light–dark cycle, although the disruption due to shiftwork may be dependent on sleep deprivation. Both conditions have been suggested to be associated with an increased risk of cardiometabolic disorders. Non-photic environmental factors, such as the timing of eating, are also thought to regulate circadian rhythm and thus, may have effects on health, but the evidence from human studies is scarce. Oxidative stress is a risk factor of cardiometabolic disorders. Some laboratory studies suggest an involvement of circadian clock genes in the regulation of the redox system. The present study aimed to examine the association of sleeping habits, nightshift work, and the timing of meals with urinary levels of 8-isoprostane, a marker of oxidative stress, and 6-sulfatoxymelatonin, the principal metabolite of melatonin. Study subjects were 542 women who had previously attended a breast cancer mass screening in a community in Japan. Information on bedtimes and wake-up times, history of nightshift work, and the timing of meals was obtained by a self-administered questionnaire. The 8-isoprostane and 6-sulfatoxymelatonin were measured using the first morning void of urine and expressed per mg of creatinine. The geometric mean of 8-isoprostane levels was 12.1% higher in women with ≤6 hours of sleep than that in those with >8 hours of sleep on weekdays, and longer sleep duration on weekdays was significantly associated with lower urinary levels of 8-isoprostane after controlling for covariates (p for trend = 0.04). Women who were currently working the nightshift had a 33.3% higher geometric mean of 8-isoprostane levels than those who were not working nightshift (p = 0.03). Urinary 6-sulfatoxymelatonin levels were unrelated to sleep habits or nightshift work. Women who ate breakfast at irregular times had a 19.8% higher geometric mean of 8-isoprostane levels than those who ate breakfast at a regular time or who did not eat (p = 0.02). Women who ate nighttime snacks at irregular times had a 16.2% higher geometric mean of 8-isoprostane levels than those who did not eat nighttime snacks or who ate nighttime snacks at a regular time (p = 0.003). Among women who ate dinner at a regular time, earlier times for dinner were associated with higher 8-isoprostane and 6-sulfatoxymelatonin levels (p values for trends were 0.01 and 0.02, respectively). However, the times of dinner and nighttime snack are overlapping, and the time of last meal of the day was not associated with 8-isoprostane and 6-sulfatoxymelatonin levels. The time of breakfast or lunch was not associated with these biomarkers among women who ate the meal at regular times. Disturbing the rhythmicity of daily life may be associated with oxidative stress.     

液态发酵豆粕制备纳豆激酶方法的优化

纳豆激酶是一种丝氨酸蛋白酶,具有很强的纤溶活性,由于具有安全性好、作用迅速持久、成本低等优点,适合用于开发新一代的溶栓剂或保健食品,具有广阔的市场前景。本研究探讨了以豆粕为原料液态发酵豆粕生产纳豆激酶的发酵方法。首先通过单因素实验发现影响产酶的主要因素有接菌量、发酵时间、培养基pH及豆粕含量,再由正交实验得到最优组合为接菌量1%,豆粕含量2%,pH为7.0,发酵时间48h,该条件下发酵酶活力最高达到4 429.6U/mL。本研究确定了以豆粕为原料制备纳豆激酶的最佳条件,为豆粕的合理使用和纳豆激酶的工业化生产提供了实验依据。     

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.