Introduction to the International Symposium on Lipid Science and Health and research progress in lipid science and health

The International Symposium on Lipid Science and Health (ISLSH), which was organized annually by Oil Crops Research Institute of Chinese Academy of Agricultural Sciences (OCRI-CAAS) since 2016, has gained a strong reputation and attracted hundreds of delegates from around the world for discussion of lipid research trends and advances every year, to promote research and academic exchanges in the fields of lipid science and health. The 5th International Symposium on lipid Science and Health was successfully held in Wuhan, China, from October 23rd to 25th, 2020, to celebrate the 60th anniversary of OCRI-CAAS. The two-day symposium gathered well-known experts specialized in lipid science to share the current state of lipid research with emphasis on aspects covering: (1) lipid profiling and characterization, (2) lipid preparation and modification, (3) lipid improvement and regulation, and (4) lipid nutrition and health. The symposium was conducted by a combination of on-site and network meeting. More than 250 distinguished delegates from academia and industry participated in the on-site multidisciplinary meeting, and thousands of scholars attended the virtual event. This paper is as a record of the symposium proceedings and a brief summary of the advances and trends in 4 aspects of lipid science and health.     

3种■体内微量元素测定与比较

测定了3种■(白缘■Liobagrus marginatus、拟缘■Liobagrus marginatoides、黑尾■Liobagrus nigricauda)肝、肾、肌肉和尾鳍4种组织中铬、锰、铁、铜和锌的含量,并将其与鲫(Carassius auratus)、黄颡鱼(Pelteobagrus fulvidraco)进行了比较分析。结果显示:鱼体5种微量元素总量由高到低依次为:白缘■、黑尾■、拟缘■、鲫、黄颡鱼;肌肉中5种元素含量由高到低依次为拟缘、黄颡鱼、鲫、黑尾■、白缘■;白缘■对铬和锌的富集作用比较突出,在上述几种组织中肝脏的富集作用最强。     

Development of diets for the intensive culture of Pacific lamprey

The Pacific lamprey Entosphenus tridentatus is an ancestral species of critical importance to the ecosystem and indigenous cultures in the Pacific Northwest. Conservation aquaculture has been proposed as a potential technique to restore Pacific lamprey populations. Intensive culture methods and diets for this species have not been developed. A sixteen week feeding trial tested the effects of seven diet treatments on the survival, growth, fatty acid profile and whole body lipid content of Pacific lamprey ammocoetes. Dietary treatments were: active dry yeast, yeast plus fish oil emulsion, micro‐algae, micro‐algae plus fish oil emulsion, yeast with micro‐algae, yeast with micro‐algae plus fish oil emulsion and yeast with larval fish diet. Each diet was offered to five replicate tanks stocked with 20 ammocoetes that were 51 days post hatch. Survival during the trial was not affected by diet. The greatest length and weight increases were in fish fed diets containing yeast. Growth decreased as the amount of algae in the diet was increased. Lipid retention was significantly higher in fish fed yeast with larval fish diet relative to the other treatments. Feed conversion ratio was lowest in fish fed diets containing yeast. Whole body fatty acid profiles tended to reflect the fatty acid profile of the diet. Percentages of 20:5n‐3 and 22:6n‐3 were significantly higher in fish fed diets containing fish oil emulsion. Overall, yeast with larval fish diet provided the best growth performance in larval Pacific lamprey.     

不同卵密度与培养条件对夜蛾斯氏线虫侵染期幼虫形成的影响

利用24孔培养板研究不同营养水平、pH值、温度和卵密度对夜蛾斯氏线虫侵染期幼虫形成的影响。结果表明:在Ringer溶液中,无论卵密度高低,卵或初孵幼虫均很快死亡;在10%基本培养液营养水平条件下线虫的发育停滞在二龄阶段;20%~100%的基本培养液营养水平下,侵染期幼虫的形成比率同营养水平呈负相关,与线虫卵密度呈正相关;适宜线虫向发育期三龄幼虫发育的pH值为7~8,温度为20~25℃,高于或低于此pH值或温度范围均可促使侵染期幼虫的形成;夜蛾斯氏线虫在pH值小于5或温度高于30℃条件下会很快死亡。     

基于营养竞争原理的大豆根腐病生防芽孢杆菌的筛选及其特性研究

利用营养竞争平板筛选法获得了可在大豆麦麸(SWB)培养基上快速生长并拮抗大豆根腐病菌Fusarium oxysporum和F.solani的芽孢杆菌菌株B006和B010。通过16S rDNA序列分析、形态观察和生理生化性状测定,将其鉴定为枯草芽孢杆菌(Bacillus subtilis)。田间小区试验结果表明,以种子处理(108cfu/mL,药种比为1∶60)和以麦麸为载体的固体菌剂土壤沟施(106cfu/g,用量195 kg/ha)B006和B010菌剂对真叶期大豆根腐病的防治效果分别为74.6%和63.5%,高于商品化学农药35%多福合剂种子处理的防效(P=0.05),大豆产量分别增加13.8%和24.0%。利用特异引物对生防功能基因的扩增结果表明,bmyB、fenD、bioA和srfAA基因以及srfAB基因簇的片段在2个菌株中均存在,而ituC基因仅存在于B010菌株中。对菌株生防功能基因的分析有助于今后高效菌株的快速筛选和对生防菌作用机制的研究。     

The effects of maternal nutrition during the first 50 d of gestation on the location and abundance of hexose and cationic amino acid transporters in beef heifer uteroplacental tissues

We hypothesized that maternal nutrition during the first 50 d of gestation would influence the abundance of hexose transporters, SLC2A1, SLC2A3, and SLC2A5, and cationic amino acid transporters, SLC7A1 and SLC7A2, in heifer uteroplacental tissues. Angus-cross heifers (n = 43) were estrus synchronized, bred via artificial insemination, and assigned at breeding to 1 of 2 dietary intake groups (CON = 100% of requirements to achieve 0.45 kg/d of BW gain or RES = 60% of CON intake) and ovariohysterectomized on day 16, 34, or 50 of gestation (n = 6 to 9/d) in a completely randomized design with a 2 × 3 factorial arrangement of treatments. Uterine cross-sections were collected from the horn ipsilateral to the corpus luteum, fixed in 10% neutral buffered formalin, sectioned at 5 µm, and stained via immunofluorescence for transporters. For each image, areas of fetal membrane (FM; chorioallantois), luminal epithelium (ENDO), superficial glands (SG), deep glands (DG), and myometrium (MYO) were analyzed separately for relative intensity of fluorescence as an indicator of transporter abundance. Analysis of FM was only conducted for days 34 and 50. No transporters in target areas were influenced by a day × treatment interaction (P ≥ 0.06). In ENDO, all transporters were differentially abundant from days 16 to 50 of gestation (P ≤ 0.04), and SLC7A2 was greater (P = 0.05) for RES vs. CON. In SG, SLC7A1 and SLC7A2 were greater (P ≤ 0.04) at day 34 vs. day 16. In DG, SLC2A3 and SLC7A1 were greater (P ≤ 0.05) for CON vs. RES heifers; furthermore, SLC7A1 was greater (P < 0.01) at day 50 vs. days 16 and 34 of gestation. In MYO, SLC7A1 was greater (P < 0.01) for CON vs. RES and was greater (P = 0.02) at days 34 and 50 vs. day 16. There were no differences in FM (P ≥ 0.06). Analysis of all uterine tissues at day 16 determined that SLC2A1, SLC2A3, and SLC7A2 were all differentially abundant across uterine tissue type (P < 0.01), and SLC7A1 was greater (P = 0.02) for CON vs. RES. Analysis of all uteroplacental tissues at days 34 and 50 demonstrated that all transporters differed (P < 0.01) across uteroplacental tissues, and SLC7A1 was greater (P < 0.01) for CON vs. RES. These data are interpreted to imply that transporters are differentially affected by day of gestation, and that hexose and cationic amino acid transporters are differentially abundant across utero-placental tissue types, and that SLC7A1 is responsive to maternal nutritional treatment.     

Effects of different arginine/lysine level on growth performance,body composition and digestive enzyme activity of Macrobrachium rosenbergii

Given the universal presence of antagonism between arginine and lysine, determining the optimal dietary arginine/lysine level is of great importance. In this study, eight diets were formulated to contain different arginine/lysine level, followed by a 9‐week feeding trial with shrimps of 2.10 ± 0.01 cm in length and 0.38 ± 0.02 g in weight to determine the effect of dietary arginine/lysine level on growth performance, body composition and enzyme activity. The results showed that the Diet 6 (arginine/lysine level of 29.4/21.0 g/kg) group had significantly higher weight gain rate, and specific growth rate than the control group and most of the other groups (p < .05) did. Similarly, the retention efficiency of arginine and lysine in the Diet 6 group was significantly higher than the control group and most of the other groups (p < .05). Moreover, most digestive enzymes had higher activity levels in the Diet 6 group, and evident antagonism between dietary arginine and lysine was detected. In summary, dietary arginine/lysine level of 29.4/21.0 g/kg produced the best growth performance, suggesting that a better growth performance in Macrobrachium rosenbergii culture can be obtained by adjusting the dietary arginine/lysine level.