多个环境因素对嗜水气单胞菌感染团头鲂致病力的影响

目的研究pH对拟态弧菌(Vibrio mimicus)感染相关表型及胞外产物特性的影响。方法测定不同pH (6.0、7.0、8.0、8.5和9.0)下拟态弧菌的增殖、泳动、自聚集和生物膜形成以及胞外产物(extracellular products,ECPs)的蛋白质量浓度、酶活性、溶血性、细胞毒性和毒力等特性。结果pH 6.0~9.0范围内,随着pH值升高,拟态弧菌的增殖先增强后减弱,pH 8.5时增殖最强;自聚集、生物膜形成和ECPs毒力先减弱后增强,pH 8.5时显著减弱(P<0.05);泳动以及ECPs蛋白质量浓度和细胞毒性减弱,pH 6.0时显著强于其他pH (P<0.05);ECPs酶活性和溶血性呈波动性,酶活性在pH 6.0时最强、pH 8.0时最弱,溶血性在pH 8.0时最强、pH 8.5时最弱。转录组分析显示：拟态弧菌pH 8.5较pH 7.0时,与ATP合成相关的糖酵解、TCA循环和氧化磷酸化等过程的基因表达上调,而与ADP合成相关的嘌呤合成基因、与蛋白质合成相关的核糖体亚基合成基因以及与蛋白分泌和膜运输相关的基因表达下调。结论pH对拟态弧菌感染相关表型及ECPs特性具有明显影响,且pH可能是通过调节拟态弧菌能量代谢与膜运输等过程影响其相关生物学特性。     

艾格里生物肥-丰农调节莴笋生长的效果研究

用艾格里生物肥一丰农进行了调节莴笋生长的田间效果试验。结果表明，艾格里生物肥一丰农150倍液、300倍液对促进莴笋生长效果明显，鲜质量增产分别为30．61％、27．30％，且该产品对环境无污染，是一种较好的可部分替代化学肥料或激素的纯生物制剂。     

Regulation by growth hormone of number of chondrocytes containing IGF-I in rat growth plate

Whether growth hormone stimulates longitudinal bone growth by a direct effect at the site of the growth plate or indirectly by increasing the concentration of circulating somatomedins (insulin-like growth factors) has been the subject of controversy. Immunohistochemical methods were used to explore the localization and distribution of insulin-like growth factor I (IGF-I) immunoreactivity in the epiphyseal growth plate of the proximal tibia of male rats. Cells in the proliferative zone of the growth plate of normal rats exhibited a bright immunofluorescence, whereas cells in the germinal and hypertrophic zones stained only weakly. In rats subjected to hypophysectomy, the number of fluorescent cells was markedly reduced. When the hypophysectomized rats were treated with growth hormone, either systemically or at the site of the growth plate, the number of IGF-I-immunoreactive cells in the proliferative zone was increased. The results show that IGF-I is produced in proliferative chondrocytes in the growth plate and that the number of IGF-I-containing cells is directly regulated by growth hormone. These findings suggest that IGF-I has a specific role in the clonal expansion of differentiated chondrocytes and exerts its function locally through autocrine or paracrine mechanisms.     

Inhibitor of bacterial growth released by human cells in culture

Used medium from cultured human cells contains a factor that inhibits growth of the "less virulent" strains of pathogenic bacteria, but only retards growth of the "more virulent" strains. The factor is heat-stable, dialyzable, and unaffected by change in pH; it chromatographs as material of molecular weight between 700 and 1500. There is evidence that this factor is an alpha-ketoaldehyde attached to a carrier.     

盐度对罗非鱼病原菌增殖的影响

NaCl浓度对淡水养殖罗非鱼常见病原菌增殖的试验结果显示:当NaCl浓度在0.05%～1.55%范围内时,提高盐度可以一定程度上抑制多数测试菌株的生长.结果表明,咸水养殖可以抑制常见病原菌的增殖,降低罗非鱼养殖中细菌性病害造成的风险.     

3株溶藻菌对水华鱼腥藻生长的效应

以分光光度法测定3株溶藻菌(AL-1、AL-6和AL-8)对水华鱼腥藻(Anabaena flos-aquae)生长效应和光合色素的影响.结果表明:3株溶藻菌均能显著抑制水华鱼腥藻的生长,对其生长速率、干重的抑制效应明显,并表现出一定的浓度相关性;且3株溶藻菌均能影响水华鱼腥藻的色素吸收光谱.3株溶藻菌溶藻方式略有不同,AL-1和AL-6可以通过分泌热稳定的物质和热不稳定的物质间接起到溶藻效果,而AL-8可同时通过直接和间接方式溶藻.     

菌肥对长山核桃容器苗生长的影响

通过对长山核桃容器苗进行不同微生物菌肥穴施试验,探讨菌肥对长山核桃容器苗生长及生理状况的影响。结果表明,对长山核桃一年生容器苗施用溶磷菌、解钾菌和溶磷菌解钾菌混合菌肥均可促进苗木高生长和地径生长,增加苗木的生物量,且提高叶片叶绿素、可溶性蛋白及可溶性糖的含量。其中溶磷菌对长山核桃容器苗的施肥效果优于解钾菌,混合菌肥的效果不如单施肥的效果。     

内生枯草芽孢杆菌BS-2对水稻苗生长的效应

结果表明:内生枯草芽孢杆菌BS2(Bacillussubtilis)菌株含量为103cfu·mL-1时即可进入水稻体内定殖;该菌的菌体、不同菌液含量及外分泌物对水稻苗生长均表现出不同程度的促进作用,如增加植株的鲜重与干重.从其促生机理来看,该菌能提高水稻叶绿素的含量,提高其保护酶活性,并通过提高水稻对外界环境的适应性,提高其抗逆性,促进其生长.     

不同浓度光合菌肥对小麦生长和产量的影响

以百农矮抗58小麦品种为试验材料,用3种不同浓度的光合菌肥(分别稀释25倍、50倍、100倍)在小麦拔节期进行叶面喷施,以喷等量清水作对照.喷后分别在拔节期、孕穗期、抽穗期测量新生叶面积、新生叶重量、株高、叶绿素含量.在灌浆期测定叶片光合速率.在成熟期调查每667 m2穗数、穗粒数.收获后进行室内考种,测量单株鲜重、单株干重、基部小穗退化数、千粒重.结果表明,不同浓度光合菌肥都能明显提高小麦新生叶面积,以稀释100倍、50倍的效果较优,孕穗期新叶面积分别比对照增加17.46％、8.58％;光合菌肥可以增加拔节后叶片叶绿素含量,提高光合速率,从而提高生物产量,喷施100倍、50倍、25倍光合菌肥,分别比对照增产24.19％,13.93％、6.20％.     

月光花素调控下甘薯的生长发育

用天然生长调节物质月光花素处理徐薯１８的研究结果表明，经０．１活性单位月光花素处理，甘薯插枝发根量增加１培多，根系活力明显增强；植株生长快，叶面积增加２０％—６０％，高叶面积时期从１个月延长到２个月，因而有效光合叶面积和光合时间明显增加．合理施用月光花素，可使幼薯分化提早１０天，薯数增加１８％，薯块肥大加速，约可提前２０天成熟，甘薯产量平均可提高１４％，相当于每公顷净增鲜薯４５００ｋｇ，作者在文中还比较了在甘薯生长的不同发育时期，用不同方法施用不同浓度的月光花素，对甘薯生长发育的影响。     

生物菌肥对桂花移栽苗生长的影响

研究了施用生物菌肥对桂花移栽幼苗的影响,试验表明,施用生物菌肥后,桂花移栽苗的成活率提高了24．44％;苗高生长量提高了7．00％;AMF感染率提高了22．87％;N、P、K、Na、Ca和Mg元素的含量分别提高了12．77％、18．04％、10．07％、1．28％、12．72％和9．64％;可溶性糖、叶绿素和脯氨酸的含量分别提高了13．98％、9．85％和8．77％。在干旱胁迫试验中,施用生物菌肥后,桂花幼苗的成活率和苗高生长量分别提高了38．10％和11．34％;脯氨酸和可溶性糖含量分别提高了44．71％和22．82％。说明生物菌肥可以促进桂花移栽苗体内重要元素和化合物的积累,提高桂花移栽苗的抗旱性、成活率和苗高生长,为桂花幼苗移栽种植提供了新的技术支撑。     

Host proteasomal degradation generates amino acids essential for intracellular bacterial growth

Legionella pneumophila proliferates in environmental amoeba and human cells within the Legionella-containing vacuole (LCV). The exported AnkB F-box effector of L. pneumophila is anchored into the LCV membrane by host-mediated farnesylation. Here, we report that host proteasomal degradation of Lys(48)-linked polyubiquitinated proteins, assembled on the LCV by AnkB, generates amino acids required for intracellular bacterial proliferation. The severe defect of the ankB null mutant in proliferation within amoeba and human cells is rescued by supplementation of a mixture of amino acids or cysteine, serine, pyruvate, or citrate, similar to rescue by genetic complementation. Defect of the ankB mutant in intrapulmonary proliferation in mice is rescued upon injection of a mixture of amino acids or cysteine. Therefore, Legionella promotes eukaryotic proteasomal degradation to generate amino acids needed as carbon and energy sources for bacterial proliferation within evolutionarily distant hosts.     

发酵床养殖对仔猪胃肠道大肠杆菌和乳酸菌增殖的影响

为阐明发酵床养殖对断奶仔猪消化道菌群的影响,对发酵床和水泥地养殖仔猪消化道大肠杆菌和乳酸菌的动态变化进行比较分析。试验期为42d。15头30日龄断奶仔猪分别在试验开始第1天(断奶当天)、第21天和第42天进行扑杀,每次每组扑杀3头,取胃、回肠、盲肠、结肠粘膜层及各段内容物进行2类细菌的分离计数,同时检测相同时间点发酵床表层与深层垫料中的细菌数量。结果发现:随着养殖时间的延长(1～42d),消化道大肠杆菌呈下降趋势,如发酵床仔猪结肠段大肠杆菌由开始的6.4×107降低到2.2×105,而乳酸菌先下降后上升,如发酵床仔猪回肠段内容物乳酸菌数量由4.6×109降到2.6×108后再增加到1.4×1010。发酵床养殖未改变仔猪胃肠道细菌变化规律,同时发酵床垫料中的乳酸菌数量不影响断奶仔猪消化道内的乳酸菌数量;此外,随着发酵床使用时间延长,发酵床垫料中致病菌的数量和种类增加,发酵床垫料底层大肠杆菌在试验开始未检测到,在试验42d时增加到6.1×107。     

Regulation of maternal behavior and offspring growth by paternally expressed Peg3

Imprinted genes display parent-of-origin-dependent monoallelic expression that apparently regulates complex mammalian traits, including growth and behavior. The Peg3 gene is expressed in embryos and the adult brain from the paternal allele only. A mutation in the Peg3 gene resulted in growth retardation, as well as a striking impairment of maternal behavior that frequently resulted in death of the offspring. This result may be partly due to defective neuronal connectivity, as well as reduced oxytocin neurons in the hypothalamus, because mutant mothers were deficient in milk ejection. This study provides further insights on the evolution of epigenetic regulation of imprinted gene dosage in modulating mammalian growth and behavior.     

土壤有机磷降解菌的筛选、鉴定及其生长特性研究

【目的】从土壤中筛选有机磷降解菌,并对其进行鉴定和生长特性研究,为研制具有降解土壤有机磷功效的生物有机肥提供高效稳定的菌种。【方法】用解磷圈法和液体摇瓶培养法,分别以植酸钙和卵磷脂为惟一磷源,从采自陕西杨凌的农药厂排污渠、棉花地、果园、菜地等不同生态类型土壤中分离筛选有机磷降解菌,对其进行生理生化特征分析和分子生物学鉴定,并确定其最适生长温度和初始pH值。【结果】从采集的不同利用类型的土壤中共初筛分离出了25株有机磷降解菌,复筛选出解磷率较高的Z2-3、Z3-5、Z3-8、Z4-1 4株植酸钙降解菌和L5-2、L7-1 2株卵磷脂降解菌。其中Z2-3、Z3-5、Z3-8和Z4-1在植酸钙液体培养基中的解磷率分别达到64.2%,71.5%,67.2%和58.1%,L5-2和L7-1在卵磷脂液体培养基中的解磷率分别为76.7%和84.1%。生理生化特征测定结果和分子生物学分析结果表明,Z2-3、Z3-5、Z3-8、Z4-1、L5-2、L7-1株菌依次为变形假单胞菌(Pseudomonas plecoglossicida)、恶臭假单胞菌(Pseudomonas putida)、荧光假单胞菌(Pseudomonas fluorescens)、荧光假单胞菌(Pseudomonas fluorescens)、成团泛菌(Pantoea agglomerans)和土壤短芽孢杆菌(Brevibacillus agri)。植酸钙降解菌和卵磷脂降解菌的最适生长温度分别为28~35和28℃,最适初始pH值分别为8.0~8.5和7.5。【结论】分离、筛选、鉴定出了解磷率较高的6株有机磷降解菌,获得了其最适生长温度和最适初始pH值。     

3种生长调节剂对金鱼草穴盘苗生长调控作用

【目的】探明能有效控制金鱼草穴盘苗出圃不及时造成徒长的生长调节剂种类和质量浓度。【方法】以金鱼草穴盘苗为材料,设置不同质量浓度梯度的矮壮素、B9和多效唑,测定株高、最大节间长、叶片数和冠幅。【结果】结果表明3种调节剂均能够有效抑制金鱼草的株高和节间,但对叶片数和冠幅无明显作用。矮壮素适宜质量浓度为750mg/L、B9为3 000mg/L、多效唑为2mg/L。【结论】使用矮壮素、B9和多效唑3种生长调节剂均可有效控制金鱼草穴盘苗徒长,提高穴盘苗质量。     

988生物菌肥对夏玉米生长、产量及品质的影响

田间小区试验结果表明,施用988生物菌肥拌种,不仅促进夏玉米的营养生长,增强其抗性,而且对其产量性状影响较大,一般比对照增产5%～10%,籽粒品质亦有不同程度的提高。