沼泽红假单胞菌发酵培养的研究

沼泽红假单胞菌是目前光合细菌中应用和研究得较为广泛的光合细菌之一。通过对沼泽红假单胞菌的生长条件进行研究,发现pH值、温度、接种量等影响沼泽红假单胞菌的生长,并且它们之间又相互影响。经过单因素试验得出:在酵母膏浓度为0.25%、光照强度为5625Lx、pH值为6、接种量为10%、培养温度为25～30℃的条件下,沼泽红假单胞菌的生长态势最好。     

沼泽红假单胞发酵培养的研究

沼泽红假单胞菌是目前光合细菌中应用和研究得较为广泛的光合细菌之一.通过对沼泽红假单胞菌的生长条件进行研究,发现pH值、温度、接种量等影响沼泽红假单胞菌的生长,并且它们之间又相互影响.经过单因素试验得出在酵母膏浓度为0.25%、光照强度为5 625 Lx、pH值为6、接种量为10%、培养温度为25～30℃的条件下,沼泽红假单胞菌的生长态势最好.     

沼泽红假单胞菌与鸡肠源沙门氏菌颉颃作用的研究

为了探索和研究沼泽红假单胞菌及代谢物对鸡肠源沙门氏菌生长繁殖的抑制或颉颃作用,试验采用不同培养方式分别观察沼泽红假单胞菌全菌液、菌体及代谢混合物与鸡肠源沙门氏菌和甲型副伤寒沙门氏菌标准菌株的颉颃或抑菌现象,检测其最小抑菌浓度,并测定其繁殖生长曲线以定量评价其抗菌活性。结果表明:沼泽红假单胞菌全菌液、菌体及代谢混合物对鸡肠源沙门氏菌分离株和甲型副伤寒沙门氏菌都具有抑制或颉颃作用。相比较而言,萃取得到的沼泽红假单胞菌菌体及代谢混合物的抑菌作用更明显。说明沼泽红假单胞菌是一个不错的治疗和控制鸡肠源沙门氏菌感染的益生菌。     

枯草芽孢杆菌和沼泽红假单胞菌对鲫鱼免疫机能的影响及其代谢产物的抑菌活性研究

为了检测枯草芽孢杆菌和沼泽红假单胞菌对鲫鱼免疫机能的影响及其代谢产物对小肠耶尔森氏菌、金黄色葡萄球菌和大肠杆菌的抑菌活性,试验将鲫鱼分成3组,分别为沼泽红假单胞菌组、等比例沼泽红假单胞菌和枯草芽孢杆菌的复合菌组和未加菌处理的对照组,在养殖水体中分别加入不同的微生物,在第30天静脉采血,测定血浆中碱性磷酸酶(ALP)、总超氧化物歧化酶(SOD)、溶菌酶(LZM)的活性以及丙二醛(MDA)的浓度;利用超声波破碎细胞,旋蒸浓缩得到枯草芽孢杆菌和沼泽红假单胞菌胞内外代谢产物,采用牛津杯法以小肠耶尔森氏菌、金黄色葡萄球菌和大肠杆菌为指示菌株,测定代谢产物的抑菌圈直径。结果表明:沼泽红假单胞菌组与复合菌组的鲫鱼血浆中ALP的活性显著高于对照组(P0.05),LZM活性高于对照组,MDA的浓度低于对照组,SOD的活性与对照组的差异不显著(P0.05);两种菌的胞外代谢产物对金黄色葡萄球菌的抑菌活性较强,沼泽红假单胞菌胞内代谢产物对金黄色葡萄球菌的抑菌活性较强,枯草芽孢杆菌胞内代谢产物对小肠耶尔森氏菌抑菌活性较强。说明沼泽红假单胞菌和复合菌对鲫鱼的免疫机能有一定的增强作用,两种益生菌胞内外代谢产物对小肠耶尔森氏菌、金黄色葡萄球菌、大肠杆菌均有抑制作用。     

不同微生态制剂对海月水母生存与生长的影响

采用对比试验法,研究不同微生态制剂对海月水母生存与生长的影响。生存试验分为5组:Ⅰ组为对照组,饲喂基础水母配合饲料;Ⅱ组、Ⅲ组、Ⅳ组和Ⅴ组依次添加屎肠球菌、胶红酵母、沼泽红假单胞菌和EM10,结果显示:屎肠球菌和胶红酵母能在24 h内使海月水母严重受损,其余3组至72 h完好无损。生长试验分为4组,A组为对照组,B组~D组分别添加沼泽红假单胞菌、EM10和沼泽红假单胞菌与EM10的混合微生态制剂。每周测量水母伞径、收缩频率和pH值,NH_3-N、NO_2-N水平等指标。试验结果表明,沼泽红假单胞菌能促进海月水母的生长(P0.05);EM10会抑制海月水母的生长(P0.05);其与沼泽红假单胞菌的混合组水母生长性能介于两者之间(P0.05),光合细菌是水母适宜的微生态制剂。     

沼泽红假单胞菌16S rDNA PCR快速检测方法研究

目的:依据反映光合菌物种属性和高度保守性的16S rDNA序列,设计其特异性引物,优化并确定PCR反应条件,探索沼泽红假单胞菌快速鉴别的方法。方法:提取沼泽红假单胞菌菌体染色体DNA,分离和纯化;从Gen Bank分别获取假单胞菌属、大肠杆菌和诺卡氏菌属的16S rDNA基因序列,分析比较并确定其可变区的基因序列片段,设计种属特异引物;对影响PCR扩增的因素进行分析和预试,确定PCR扩增的最佳条件;随后进行PCR扩增试验,对其产物克隆测序,同时进行沼泽红假单胞菌形态特征和生化特性的检测。结论:以16S rDNA的种属特征序列设计引物,PCR扩增检测沼泽红假单胞菌样本的方法 ,特异强、灵敏度高、重复性好、操作性强、价格低廉;从分离提取样本DNA到完成PCR扩增,可在3h左右对沼泽红假单胞菌作出鉴定。     

沼泽红假单胞菌与地衣芽胞杆菌对奶牛生产性能的影响

沼泽红假单胞菌和地衣芽胞杆菌可调节动物消化系统的微生态环境,为宿主提供优质的营养物质及多种利于消化功能的生物活性酶。以泌乳末期荷斯坦奶牛为实验动物,探究沼泽红假单胞菌和地衣芽胞杆菌对奶牛采食量、产奶量和发病情况等生产性能指标的影响。结果表明:在奶牛全混合日粮(TMR)中添加沼泽红假单胞菌和地衣芽胞杆菌可以显著提升奶牛生产性能,日采食量下降8.05%,日产奶量显著提高5.42%(P<0.05),饲料转化率提高14.70%,同时,奶牛消化水平和健康状况也得到明显改善。     

日粮中添加沼泽红假单胞菌对生长牛生长性能和血液生理生化指标的影响

本试验旨在研究沼泽红假单胞菌对生长牛的生长性能和血液生理生化指标的影响。选择8月龄健康的西门塔尔与本地黄牛杂交生长牛40头,平均体重(151.87±6.25)kg,随机分成4组,每组10头,其中公牛4头,母牛6头。对照组喂基础饲粮,处理组在基础饲粮基础上分别每头添加100、200、300 mL/d沼泽红假单胞菌液,预试期7 d,正试期80 d。结果表明:与对照组相比,100、200、300 mL/d沼泽红假单胞菌液组牛的平均日增重分别提高4.17%(P0.05)、12.26%(P0.05)和11.35%(P0.05),各试验组的干物质采食量和耗料增重比与对照组差异均不显著;与对照组相比,200、300 mL/d沼泽红假单胞菌液组牛的血液淋巴细胞计数显著提高,提高了血液白细胞计数和淋巴细胞百分比(P0.05),降低了血液中间细胞计数和中性粒细胞计数及其百分比(P0.05),100 mL/d沼泽红假单胞菌液组牛的血液生理生化指标与对照组无显著差异;与对照组相比,200、300 mL/d沼泽红假单胞菌液组显著提高血钙含量和钙/磷比,显著降低血液谷丙转氨酶含量,提高了血液碱性磷酸酶、血糖和球蛋白含量(P0.05),降低了血液尿素氮、肌酐和磷含量(P0.05)。总之,生长牛日粮中添加沼泽红假单胞菌可显著提高日增重、血液淋巴细胞计数、血钙含量和钙/磷,显著降低谷丙转氨酶含量,本试验条件下,最佳添加水平为每头200 mL/d沼泽红假单胞菌液。     

红假单胞菌的分离鉴定及有机肥盐度对其生长的影响

本试验采用平板涂布法从混合光合细菌中分离筛选出红假单胞菌,然后将分离出的红假单胞菌接种在有机肥中进行光照厌氧培养,使用NaCl母液将有机肥体系的盐度w(NaCl)分别调整为0、0.2%、0.4%、0.6%、0.8%和1.0%,通过平板计数方法观察细菌的生长状况。结果表明,红假单胞菌在盐度为0~0.8%范围内生长良好,且在盐度为0.4%时生长最好,随着盐度的升高,红假单胞菌的生长情况直线下降。     

多种益生菌固态湿发酵豆粕营养品质变化研究

为探究不同益生菌固态湿发酵对豆粕营养品质的影响，选择地衣芽孢杆菌（Bac-l）、凝结芽孢杆菌（Bac-c）、罗伊氏乳杆菌(Lac)、米曲霉(Asp)、酿酒酵母(Sac)、沼泽红假单胞菌(Pho) 6种益生菌，固态发酵48 h，以粗蛋白、酸溶蛋白、蛋白酶、抗营养因子等为指标，从发酵豆粕营养指标、酶活性、抗营养因子含量等方面进行评定。结果表明：沼泽红假单胞菌发酵豆粕粗蛋白含量增加至31.55%(P<0.05)；酿酒酵母和沼泽红假单胞菌发酵豆粕后酸溶蛋白含量提升至12.98%(P<0.05)；罗伊氏乳杆菌能够有效降低pH(P<0.05)，提高干物质回收率达到94%(P<0.05)；发酵豆粕时，沼泽红假单胞菌的酸性蛋白酶活性最高，酿酒酵母的中性蛋白酶活性最高，地衣芽孢杆菌的碱性蛋白酶活性最高（P<0.05），酿酒酵母的植酸酶和纤维素酶活性最优；米曲霉分解大分子蛋白质的能力最强，对3种抗营养因子（大豆球蛋白、β-伴大豆球蛋白、胰蛋白酶抑制因子）的降解率也最高，分别达到64.71%、78.94%和98.07%(P<0.05)。说明益生菌发酵可以改善豆粕营养品质，...     

沼泽红假单胞菌发酵工艺研究

从鱼塘底泥中分离得到一株经鉴定为沼泽红假单胞菌菌株,对其发酵培养基参数碳源、氮源、营养因子等进行了研究,结果表明,乙酸钠为碳源、氯化铵为氮源较佳,酵母膏、微量元素对菌数增长有明显的促进作用。     

禾顶囊壳小麦变种对草坪禾草的致病性研究

应用人工接种法测定了禾顶囊壳小麦变种中国菌系对草地早熟禾、多年生黑麦草、匍茎剪股颖、高羊茅、硬羊茅和狗牙根等6种草坪禾草24个品种的致病性。结果表明,该菌对供试各草种都能正常致病,引起典型全蚀病症状。大多数供试品种的病根率和病根严重度都很高,属于感病类型,仅匍茎剪股颖的绿宝石品种具有中度抗侵入性和高度抗侵染性,高羊茅Shorter品种和硬羊茅参试品种具有中度抗侵染性。由于该菌引起的小麦全蚀病在我国分布广泛,可以提供大量菌源侵染草坪禾草,从而对草坪构成严重威胁。     

The susceptibility of Lymnaeid snails to Paramphistomum cervi infections in Mexico

The occurrence of Paramphistomum cervi has been reported in Mexico, but its intermediate hosts have not been identified. Five species of snails of the genus Lymnaea, L. bulimoides, L. columella, L. cubensis, L. humilis and L. palustris, were collected in Mexico. Only three of the exposed species, L. palustris, L. cubensis and L. humilis, became infected with P. cervi. The first of these snail species was highly susceptible to infection and a higher number of the exposed snails shed cercariae. It is suggested that L, palustris may act as an important vector of P. cervi in Mexico.     

遮阴对10种野生观赏植物生长及生理特性的影响

为了探讨野生观赏植物在遮阴条件下的生态适应性及寻求适度的遮阴比例,选取兰州地区10种野生观赏植物为试验材料,比较测定不同光强生境(全光照、25%、50%、70%遮光率)对10种野生观赏植物生长和生理生化的影响。结果表明,角茴香(Hypecoum erectum)和驴蹄草(Caltha palustris)含水率随着遮阴度的增加而增加,小花草玉梅(Anemone rivularis)在75%遮阴度时干重最大,显著高于其余遮阴处理及全光照(CK)(P0.05);藤本铁线莲(Clematis florida)可溶性糖含量随着遮阴度的增加而减少,鹅绒委陵菜(Potentilla anserina)、角茴香、水杨梅(Geum aleppicum)和驴蹄草的叶绿素含量随着遮阴度的增加而增加;东方草莓(Fragaria orientalis)、角茴香和驴蹄草在全光照下丙二醛的含量显著高于其它处理(P0.05),香青(Anaphalis sinica)和水杨梅在75%遮阴度下丙二醛含量较高。综上所述,香青、莓叶委陵菜(Potentilla chinensis)、藤本铁线莲和野棉花(A.vitifolia)比较适合全光照生长;鹅绒委陵菜、小花草玉梅、东方草莓、角茴香和水杨梅可以忍耐适当的遮阴环境;驴蹄草适合在遮阴条件下生长。     

Association between heterophil/lymphocyte ratio, a marker of 'resistance' to stress, and some production and fitness traits in chickens

1. A stock of cross-bred CD hens was divided into 'resistant' (R) and 'sensitive' (S) to stress on the basis of the heterophil/lymphocyte (H/L) ratio using the lower 99% confidence limit method for selection. A first generation was produced from these R and S females mated with similarly selected R and S local Barred males. The association between 'resistance' and some production traits was investigated. 2. The proportions of R:S among CD females and Barred males was 51.2:48.8 and 52:48, respectively. Mean H/L ratios for Barred males and females, respectively, were 0.87 +/- 0.03 and 0.83 +/- 0.03 (P > 0.05). 3. Compared with the S group in CD females, the R group had greater egg production (59% vs 51%), egg weight (65.5 g vs 62.6 g) and body weight at 39 weeks (115 g heavier). 4. The superiority of R in terms of proportion of fertile eggs, hatchability and the proportion hatched from those set amounted to 4.8, 6.1 and 5.4%, respectively. 5. The proportion of dead embryos in the R group (5.4%) was lower than in the S group (9.3%). 6. With the F1 generation the R chicks were heavier at hatching. 7. Percentage mortality of male F1 chicks, from hatching to 4 weeks and from 4 to 8 weeks, was lower in the R group. A similar, but non-significant, trend was noted for R females. 8. The progeny of the R group was heavier than the S progeny at 4 and 8 weeks and also the percentage dressed weight of males was greater at 8 weeks. The R group was heavier than the S group at 4, 8 and 12 weeks. 9. These results suggest that selection for general 'resistance', on the basis of the H/L ratio using the 99% lower confidence limit method of selection, is positively correlated with several important production and reproduction traits. Establishing resistant lines with high production rates seems feasible.     

Estimation of sow milk nutrient output

Ten replicates of two littermate gilts were used during a 21-d lactation in order to calculate relationships between milk nutrient intake and piglet growth rate and composition of gain. Gilts were fed 14.2 or 10.4 Mcal ME/d and litter size was standardized to 9 or 10 piglets. Piglets had no access to creep feed. Milk production was measured on 10 sucklings over 12 h on d 1, 5, 9, 13, 17 and 21 by the weigh-suckle-weigh method. Heat production of the piglets was measured (RQ method) on the same days in a confinement chamber. Milk composition was determined on the days following milk production measurements. Four to ten piglets/litter were slaughtered at weaning and their body composition was determined. Milk nutrient production during part of lactation was related closely to piglet weight gain and body weight (R2 = .80 to .96). Milk DM, energy and N output over the entire lactation were predicted from piglet ADG (R2 = .87 to .90) when, for each litter, the difference between energy in piglet daily weight gain measured by the slaughter technique and energy in piglet daily weight gain estimated by the RQ method was included in the model. This variable corrects for milk production measurement errors. The relationships were slightly improved, especially for energy output, when the composition of piglet weight gain was taken into account (R2 = .93 to .97).     

一种水产养殖用微生物制剂的研究

利用枯草芽孢杆菌、干酪乳杆菌、沼泽红假单胞菌和啤酒酵母4种菌株配制了一种复合微生物制剂,试验结果表明,该制剂除含有丰富的营养成分外,在水产养殖中还能起到净水剂的作用,它能增加水中的溶解氧,显著降低氨氮、亚硝态氮、硫化物等不利于水产养殖的污染成分。此微生物制剂在水产养殖中将能发挥营养、保健及净化水质的功效。     

Selected parameters in urine as indicators of milk production in lactating sows: a pilot study

Although insufficient milk production in lactating sows may cause tremendous economic losses, reliable methods for estimating milk production in sows under field conditions are not available. This study aimed to investigate whether urine parameters could be used to predict milk production in sows. The milk production of 18 sows was determined during early and mid-lactation. Morning (a.m.) and afternoon (p.m.) urinary levels of potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), lactose and creatinine were analysed. The absolute concentrations, the ratios relative to creatinine, and the fractional excretions of all elements in urine were not significantly associated with milk production. The p.m./a.m. ratios of K, Na and Ca concentrations in urine (K(R), Na(R), and Ca(R)) were significant predictors for milk production, but only during mid-lactation. The total variation in milk production (r(2) value) explained by K(R), Na(R), Ca(R) amounted to 72%, 55%, 42%, respectively. Analysis of minerals and especially K in the a.m. and p.m. urine of sows during mid-lactation provided an acceptable indication of milk production. Further research is necessary to investigate whether the present results can be used to estimate milk production in hypogalactic sows under field conditions.     

Survival of snails and characteristic lesions of Fasciola hepatica infection in four European species of Lymnaea.

The survival of snails and characteristic organ lesions were investigated in four different age categories (new-born, 1 and 2 mm shell height, adults) and in four species of Lymnaea (L. glabra, L. palustris, L. peregra ovata, L. truncatula) infected by Fasciola hepatica. Mortalities were higher in infected groups on Days 30 and 45 post-infection (+42% and +45%, respectively) than in controls. Lesions depended on the species and age of the Lymnaea. Epithelial necrosis of the kidney was recorded in L. glabra, L. palustris and L. p. ovata, whereas intralamellar deposits were found in the same organ of L. truncatula. All categories of L. truncatula had evolutive infections (snails with living parthenitae); the young snails of other species became infected, but the adults did not, as estimated at Day 45 post-infection. The lesions were related to the intensity of evolutive infections: necrosis of the digestive gland was found in moderate to low infections and, conversely, gonadal atrophy with epithelial necrosis was found in highly infected snails.     

Relation of growth hormone response to growth hormone-releasing hormone to estimation of milk production via deuterium oxide dilution in beef cattle

Current methods of estimating milk production in beef cows can be time-consuming, labor-intensive, and subject to high variability. The weigh-suckle-weigh (WSW) method requires repeated separation of offspring from their dams. Machine milking requires that animals be acclimated to the equipment prior to the estimation. The objective of Exp. 1 was to validate a deuterium oxide (D2O) dilution method of estimating milk production in cattle. In Exp. 1, Holstein calves (n = 5) averaging 29+/-2 d of age and 52.6+/-2.5 kg (+/- SE) were used as the model. Blood was collected for baseline D2O measurements followed by an injection of 300 mg D2O/kg BW. Syringes were weighed before and after the injection to gravimetrically determine the dose. Another blood sample was collected after D2O was allowed to equilibrate with body water for 2 h, and on each of the next five consecutive days, prior to feeding. Actual milk intake was measured by disappearance (i.e., amount of milk replacer offered to the calf minus the amount refused). Deuterium oxide in plasma was measured by mass spectrometry and milk intake was computed from the disappearance curve of D2O in blood plasma for each calf. Accumulated milk intake estimated by D2O dilution was highly correlated (y = 0.9x + 0.6; R2 = 0.99; P < 0.001) with actual milk intake. The objectives of Exp. 2 were to determine whether 1) D2O dilution was comparable to a standard measure of milk production in beef heifers and 2) growth hormone (GH) response to GH-releasing hormone (GHRH) in heifers at weaning is predictive of subsequent milk production. Deuterium oxide dilution and WSW were compared using 14 first-calf Angus heifers and their calves. Deuterium oxide dilution was used to estimate milk production of 40 first-calf Angus heifers that had been challenged with GHRH at weaning. Results indicate that the D2O dilution method is correlated (R2 = 0.89; P = 0.04) to the WSW estimation of milk production. Growth hormone response to GHRH in weanling heifers is positively related (R2 = 0.22; P = 0.03) to their subsequent milk production. Deuterium oxide dilution in calves offers an additional approach to the estimation of milk production of the dam in typical beef cattle production settings.