传染性脾肾坏死病毒_ConA和L_省略_对体外鳜的头肾淋巴细胞转化的影响

采用MTT颜色反应法研究传染性脾肾坏死病毒（ISKNV）、伴刀豆球蛋白A（concanavallin A,ConA)和脂多糖(lipopolysaccharide,LPS）在离体状态下对健康和ISKNV感染后存活30d或60d的鳜的头肾淋巴细胞转化的影响。结果表明，ConA和LPS能促进健康鳜头肾淋巴细胞的转化，而对感染后存活30d或60d的鳜头肾淋巴细胞没有作用；纯化的ISKNV对健康鳜头肾淋巴细胞没有促进淋巴细胞转化的作用，但对ConA的作用有抑制，对感染后存活的30d或60d的鳜头肾淋巴细胞，纯化的ISKNV有一定的促进转化的作用，感染存活的鳜头肾中有对ISKNV的免疫记忆性T细胞。另外，用建立的ISKNV PCR检测方法对健康和ISKNV感染后存活的鲜组织进行了检测，结果显示，健康鳜为阴性，而ISKNV感染后存活的鱼，头肾、后肾、脾脏和部分鱼的心脏为阳性。ISKNV在鳜体内形成潜伏感染。     

The persistence of infectivity of Tetracapsulabryosalmonae-infected water for rainbow trout, Oncorhynchus mykiss (Walbaum)

Proliferative kidney disease (PKD) is caused by the infection of susceptible salmonid fish with spores of the myxozoan Tetracapsula bryosalmonae , a parasite harboured and released by several species of bryozoans. Under natural conditions, PKD is a water-borne infection of fish, whose outcome and spatio-temporal dissemination depend on the viability of spores present in the water. In order to evaluate the duration of parasite infectivity, juvenile rainbow trout, Oncorhynchus mykiss , were exposed for 20 h to T. bryosalmonae -infected water at various times post-water collection or after different filtration procedures. When infected water was held in a temperature range of 14.5–17 °C for up to 14 days, PKD was transmitted to the fish only between 0 and 12 h post-water collection and its infectivity vanished between 12 and 24 h. Similarly, the infectivity of water passed through 25 μm but not through 1 μm mesh filters, and was lost in the material eluted from the 1 μm filtration membrane although the parasite's DNA was amplified from this material. The parasitic infectivity in water appears to be fragile and this may offer opportunities to decrease the impact of PKD in trout farms by the implementation of management procedures aimed at reducing the number of the bryozoan-holding surfaces located in the river, immediately upstream from these farms.     

Risk factors associated with mortalities attributed to infectious salmon anaemia virus in New Brunswick, Canada

Outbreaks of unexplained mortalities attributed to infectious salmon anaemia (ISA) were examined in the 1996 year class of Atlantic salmon in three regions of New Brunswick, Canada. A total of 218 net pens at 14 sites deemed to have been exposed to ISA virus (ISAV) were surveyed for mortality records and management, environmental and host characteristics. Based on definitions of mortality patterns, clinical ISA disease outbreaks occurred in 106 net pens. There were eight sites in which >50% of net pens experienced ISA outbreaks during the study period. Factors related to their potential role in transmission of virus to new sites or new net pens at the same site were identified as sea lice vectors, divers visiting multiple sites, sites belonging to companies with more than one site, exposure to other year classes at the site, and proximity to other infected net pens. Host resistance factors associated with greater risk of outbreaks were identified as larger groupings, general health following smolt transfer, stressful husbandry procedures during growout, and health or productivity during colder water periods. Despite very close proximity between sites, modification of these management factors would probably influence the severity of mortalities caused by ISAV.     

蚕豆发芽过程中蛋白质和抗氧化能力的变化

为更好地开发利用蚕豆资源,研究蚕豆发芽过程中蛋白质及蛋白抗氧化能力的变化规律,采用凯氏定氮法测定发芽蚕豆的蛋白质含量,采用氨基酸分析仪测定氨基酸组分含量,运用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)技术观察发芽蚕豆蛋白组成的变化,通过测定发芽蚕豆蛋白的1,1-二苯基-2-三硝基苯肼(DPPH)自由基和2,2'-联氮双-(3-乙基苯并噻唑啉-6-磺酸)二铵盐(ABTS)自由基的清除能力分析其抗氧化能力。结果表明,蚕豆发芽过程中蛋白和氨基酸含量升高,促进部分蚕豆蛋白由大分子量转化分解成小分子量,提高了蚕豆蛋白的抗氧化能力,在蚕豆发芽第9天时蛋白质含量达到34.1 g·100g^-1、氨基酸含量为29.16 g·100g^-1,均达到最大值,蚕豆蛋白的自由基清除能力达到最强。综上,蚕豆的发芽过程可以增加蚕豆的营养物质成分含量,增强蚕豆的抗氧化能力。本研究结果为蚕豆蛋白、蚕豆芽等功能食品的开发利用提供了参考依据。     

9个鲜食蚕豆品种低温保鲜比较试验

以苏蚕2号、海门大青皮、上虞田鸡青、美国蚕豆、陵西一寸、通鲜6号、日本大白皮、慈溪大白蚕以及自主研制新品系（长荚型蚕豆）共9个鲜食蚕豆品种为试材,进行低温保鲜比较试验。结果表明：以豆荚形式贮藏,以上虞田鸡青的保鲜效果最好,慈溪大白蚕、日本大白皮和长荚型蚕豆等3个品种次之,以2℃贮藏28d为宜。以豆粒形式贮藏,日本大白皮和慈溪大白蚕等2个品种保鲜效果最好,以2℃贮藏21d为宜。     

毛霉型豆豉中总DNA提取的比较研究

[目的]对毛霉型豆豉中总DNA的提取方法进行比较。[方法]选用常用的3种DNA提取方法(溶菌酶法、蛋白酶K-CTAB(十六烷基三甲基溴化铵)法和改良溶菌酶法)提取发酵豆豉中的总DNA,并测定总DNA的纯度,比较3种方法的优劣。[结果]通过琼脂糖凝胶电泳对提取效果进行观察比较发现,蛋白酶K-CTAB法提取豆豉中微生物的宏基因组DNA的纯度最好,质量最高。[结论]蛋白酶K-CTAB法更适合豆豉这类发酵食品宏基因组DNA粗提取,可以作为豆豉宏基因组学研究的基础。     

NaHCO3碱度对5种幼鱼的生存及鳃、肾组织的影响

为摸清大鳞鲃在碱性水域推广的可行性,对大鳞鲃（ Barbus capito）、草鱼（ Ctenopharyngodon idllus）、镜鲤（ Songpu mirror carp）、鲫鱼（ Carassius auratus）和白鲢（ Hypophthalmichthys molitrix）幼鱼进行96 h急性NaHCO3碱度毒性试验,测定了水体中NaHCO3碱度对5种鱼的致死浓度,以及对鳃、肾组织的影响。结果显示,大鳞鲃、草鱼、镜鲤、鲫鱼和白鲢5种幼鱼NaHCO3碱度96 h半致死浓度LC50分别为123．325 mmol/L,91．825 mmol/L,114．262 mmol/L,134．045 mmol/L,86．246 mmol/L,其耐受能力大小顺序依次为：鲫鱼,大鳞鲃,镜鲤,草鱼,白鲢。观察了NaHCO3碱度对鳃和肾脏的病理组织切片,在高碱胁迫下,鳃小片缩短,细胞间隙增大,鳃小片上皮细胞出现不同程度的水肿,甚至脱落;肾组织中肾小管出现不同程度的萎缩,肾小管管腔变大。     

微波消解-原子荧光光谱法测定豆粉中总汞的不确定度评定

为了得到准确而完善的检测结果,对微波消解-原子荧光光谱法测定豆粉中总汞结果的不确定度进行了评定,结合各不确定度分量对测定方法中不确定度的主要来源进行了分析。结果表明:样品的前处理方法以及试样的重复性对获得准确测定结果尤为重要,标准曲线的配制也是重要的不确定度来源,同时需要确保仪器的稳定性,而试样定容和样品称样引入的不确定度极低,可以忽略。通过不确定度的评定,明确了测定过程中主要误差的来源,为降低检测过程中的误差提供了依据。     

菜豆叶片原生质体的分离条件

以菜豆幼嫩叶片为材料,研究了预处理、酶液组合、酶解时间、酶解方式、甘露醇浓度及纯化时的离心转速对菜豆叶片原生质体分离的影响。结果表明:菜豆叶片质壁分离1 h后,在2%纤维素酶+1%离析酶+10%甘露醇+0.1%BSA+5 mmol/L MES+10 mmol/L CaCl2·2H2O,pH为5.8的混合液中,(25±1)℃黑暗条件下振荡酶解12 h可获得大量有活力的绿色原生质体。纯化时400 r/min离心3 min效果较好。     

苗期短日照处理小豆的开花和结荚变化

为了对小豆的高产栽培提供理论依据,以中晚熟小豆品种冀红4号为材料,在出苗到开花阶段进行 SD-14（光/暗,14 h/10h）、SD-12（光/暗,12 h/12h）和 SD-10（光/暗,10 h/14h）3个短日照试验,观察了小豆开花和结荚情况。结果表明：短日照处理加速了植株的生育进程,花期缩短了9～10 d,荚期缩短了3～7 d,总花荚期缩短了5～6 d,差异达显著水平;植株的开花期提早,开花高峰期提前18～20 d,日开花量呈先增后降的趋势;植株的初花节位降低1～2节,单株总荚数达最大值时间提早12 d,结荚数集中于1～10节位,占88．49％以上;各短日处理单荚粒数差异不显著,百粒重均高于对照,单株荚数则低于对照,产量均低于对照,差异不显著。综合比较,短日照处理以 SD-12较好。