滇池与洱海鱼腥藻的分离纯化及其生长特性的初步研究

本研究分别于2004年、2005年和2006年分离纯化滇池和洱海主要鱼腥藻种类,选取其中7株藻株,通过研究生长状况、色素组成及光合效率,分析比较了它们在相同实验室培养条件下的生长差异。研究结果表明,培养期间各藻株生长状态良好,但各藻株在实验室培养条件下的生长优势状况与在自然水体中明显不同;光合色素含量与生长状况明显相关;培养期间,各分离藻株均保持了较高的Yield、rETRmax和Alpha值,说明各藻株生长状态良好;在光合色素含量相对较低时,为保证藻株正常生长,光系统Ⅱ（PSⅡ）的光量子产量（Yield）、最大相对电子传递速率（rETRmax）和P-I曲线初始斜率（Alpha）相对增大,补偿光合作用。本研究结果为滇池和洱海两湖泊鱼腥藻生态生理学的后续研究提供了基础资料。     

胎儿肝干细胞的分离培养与鉴定

从人胎儿肝脏中分离、纯化肝干细胞并进行鉴定。采用改进Seglen胶原酶原位灌注消化,结合Percoll密度梯度离心分离纯化胎儿肝干细胞,计数并测定细胞活性,光镜、电镜对其形态进行观察,用免疫细胞化学法(ICC)检测细胞表面标志表达情况。结果表明,所分离细胞活性率为90.80%±2.04%,细胞平均为(2.74±0.77)×107个/肝(n=10),光镜、电镜下观察其具有肝干细胞形态及超微结构特点,ICC染色,AFP、CK19、CK8及CD34等呈阳性,原代培养可形成肝干细胞集落。研究结果为人胎儿肝干细胞的存在提供了直接依据。     

动物饲料中植物源性外源转基因成分的检测

针对宠物饲料、奶牛饲料和浓缩饲料等不同类型饲料的特点,采取相应的不同DNA提取方法,通过对组成饲料的所有作物成分相应内源基因的检测,确定待测饲料样品的作物组成成分,并建立了各类饲料中转基因成分的检测技术。有针对性地论述了饲料检测中可能出现的问题、技术难点和关键技术,为实际检验工作提供可借鉴的建议。     

红麻下胚轴原生质体的分离与培养

采用暗培养3日龄的红麻无菌苗下胚轴,在0.45 mol·L-1甘露醇的渗透压条件下,以5.0mg·L-1纤维素酶(Cellulose R-10)和5.0mg·L-1果胶酶(Pectinase)酶解12 h,原生质体的产率最高,活力较强.以5.0×104个·mL-1的密度,在改良的KM8P培养基中,附加0.5 mg·L-1 2,4-D和0.5 mg·L-1 6-BA,用微滴法培养,对原生质体的分裂和愈伤组织的形成极为有利.     

基础隔震结构水平剪切刚度的敏感性分析

采用退化迟滞模型,代表叠层橡胶隔震支座的非线形滞回恢复力特性,对基底隔震结构的动力反应进行了研究。通过算例,对叠层橡胶支座水平剪切刚度对基底隔震结构隔震效果的影响进行了定性的分析。结果表明:在峰值位移反应处于允许范围内时,适当的降低隔震系统的刚度值,可以达到较为理想的隔震效果。     

牛源抗氧化芽孢杆菌的分离鉴定及生物特性研究

【目的】从奶牛瘤胃中分离具有抗氧化能力且耐受性好的芽孢杆菌,为牛源益生菌作为抗氧化添加剂使用提供理论依据及参考。【方法】采集3头成年荷斯坦奶牛瘤胃内容物,通过细菌分离纯化、形态观察、生化检测及16S rDNA分子检测进行鉴定,同时检测筛选菌株的超氧自由基和羟自由基清除率、耐酸、耐胆盐能力及对抗生素的耐药性。【结果】从奶牛瘤胃液中共获得了12株菌,通过特异性培养基与革兰氏染色共筛选出5株芽孢杆菌(X-1～X-5)。对5株芽孢杆菌进行分子鉴定,确定X-1为热噬淀粉芽孢杆菌,X-2为短小芽孢杆菌,X-3为解蛋白芽孢杆菌,X-4为枯草芽孢杆菌,X-5为沙福芽孢杆菌。抗氧化能力检测结果显示,5株菌均具有一定的抗氧化能力,X-5菌株抗氧化能力最高,超氧自由基和羟自由基清除率分别达到73.81%和73.54%。当pH为2.5时,5株芽孢杆菌存活率均在25%以上;胆盐浓度为0.6%时,5株芽孢杆菌存活率均在60%以上,说明菌株具有良好的耐受性。药敏试验结果显示,试验分离出来的大多数菌株对氧氟沙星、呋喃妥因、红霉素等高度敏感;对头孢呋辛、头孢噻肟、链霉素等耐受;对卡那霉素、环丙沙星、氨苄西林等中度敏感。...     

山东地区乳房炎和非乳房炎牛奶中金黄色葡萄球菌的分离鉴定与耐药分析

为了解山东地区不同类型牛奶中金黄色葡萄球菌流行情况和耐药特征,对37个牧场的乳房炎和非乳房炎奶样进行细菌分离鉴定及MIC测定试验。采用常规方法与PCR技术进行金黄色葡萄球菌的分离鉴定,微量肉汤稀释法进行MIC测定,卡方检验进行数据差异显著性分析。①共分离到150株金黄色葡萄球菌,检出率为11.26%(150/1332),且乳房炎奶样显著高于非乳房炎(P=0.009);②12种药物的MIC与EUCAST分布趋势大致相同;③分离菌株对青霉素(91.38%)耐药最严重,且乳房炎/非乳房炎奶样差异显著(P=0.047);④116株分离菌株中多重耐药(≥3)菌株为34(29.31%)株,乳房炎/非乳房炎奶样差异不显著(P=0.611);⑤威海对6种药物的耐药率在60%以上,其他地区仅对1~2种药物的耐药率在50%以上。乳房炎奶样的金黄色葡萄球菌检出率显著高于非乳房炎;分离菌株对青霉素严重耐药且乳房炎奶样多重耐药问题突出;不同地区均呈现不同程度的耐药。     

Evaluation of hemato-immunological parameters during the reproductive cycle of the scallop Nodipecten nodosus in association with a carotenoid-enriched diet

The cultivation of scallops Nodipecten nodosus is a promising activity emerging in Brazil. The purpose of this study was to characterize the immune system of N. nodosus and evaluate the modulation of some hemato-immunological parameters during the reproductive cycle, in association with an astaxanthin-enriched diet. It was hypothesized that a supplementation on astaxanthin could enhance scallop immune system and minimize stress of reproduction. Scallops were separated in different groups: juveniles (J), adults (A), sexually mature (M), and recently spawned (S) animals. The last two groups were fed standard (M and S) or astaxanthin-enriched (Ma and Sa) diets. Scallop hemolymph contained two hemocyte populations: hyaline (HH) and granular hemocytes (GH). Antimicrobial peptides, similar to mussel defensins and mytilins, were found by immunodetection within the GH granules, even though the scallop hemolymph did not exhibit significant antimicrobial activity against different bacteria, including marine vibrios. Scallop hemocytes were able to phagocytose zymosan and produce reactive oxygen intermediates (ROI–NBT reduction). The number of circulating hemocytes (Neubauer chamber) varied from 12 to 26.10⁶ cells mL^− 1, and the GH was always the predominant cell type (67–99%). The plasma of N. nodosus contained lectins, specific to galactose and sialoconjugates, and their agglutinating activity was partially calcium-dependent. A phenoloxidase (PO) activity (146–446 U min^− 1 mg^− 1) was observed in the scallop hemolymph. However, this activity was not induced by trypsin or components of microorganism surface, and was strongly enhanced by alkaline pH (≥ 8.5). The total protein concentration of the plasma varied from 240 to 660 μg mL^− 1. In general terms, all examined hemato-immunological parameters (hemograms, superoxide anion production, PO activity, lectin titers and total protein concentration) had a similar profile during all the scallop reproductive cycle. Their levels increased significantly from juveniles to adults (except PO activity), and declined markedly (immune depletion) in the sexually mature scallops. After spawning, the animals had a tendency to recover the standard levels of their immune parameters. Apparently, the astaxanthin-enriched diet had no effect on the tested immune parameters except for a slight influence on the scallop immune-oxidative reactions (ROI production). The results obtained in this study suggested the occurrence of a general immune depletion in the sexually mature scallops, confirming that the reproductive stage is a critical period in scallop life.     

Spatial patterns in reproductive traits of the temperate parrotfish Sparisoma cretense

Reproductive biology and social behaviour of the parrotfish Sparisoma cretense was studied in the Azores Islands, northeast Atlantic, to characterize its spawning season and general reproductive biology in the region, to clarify the species mating system and associated spawning behaviours, and to evaluate the relationship between its reproductive traits and habitat features. S. cretense exhibits a dual mating system where males hold female harems within year-round territories or live in multi-male groups. Group behaviour predominates in smaller size classes, and territoriality in larger size classes. Males mature and become territorial earlier in life than females, and the best territories are held by larger males. The two behavioural modes are usually spatially segregated, with larger territorial fish preferring exposed and deeper reef ledges, and group fish occupying shallower, protected habitats. However, they frequently interact and overlap in space, especially during reproduction in the summer. Our findings indicate a highly competitive system and suggest that high quality spawning sites are important for the reproductive success of both types of fish. Patchiness of habitat along shorelines determines the relative distribution and equilibrium of territorial versus group fish. The complexity of this relationship between social structure and habitat might impact the populations’ productivity, and could influence the success of marine protected areas for this species.     

雏鹅大肠杆菌的分离鉴定及药敏试验

该试验对荣昌县某养鹅专业户发病种雏鹅分离的细菌经培养特性及生化试验,鉴定为大肠杆菌。经动物试验表明该菌株有较强的致病性。用临床上常用的22种抗菌素纸片对分细菌进行药敏试验,结果所分离的大肠杆菌对菌必治、先锋噻肟、氨曲南、丁胺卡那霉素和复达欣5种药物高度敏感,对呋喃妥因和庆大霉素中度敏感,而对头孢呋新、左氟沙星、克拉霉素等药物表现为耐药性。