变性淀粉在我国的应用及发展趋势

本文介绍了我国食品、纺织、造纸等工业上应用的主要变性淀粉,其中重点介绍了羧甲基淀粉、交联淀粉、酸改性淀粉、阳离子淀粉的生产工艺、性质及其应用,同时对接枝共聚淀粉、复合淀粉等新型变性淀粉也作了简要介绍。     

改良MRS对消除培养基自身抑制幽门螺杆菌生长的研究

在进行乳杆菌抑制幽门螺杆菌生长的体外实验中发现,乳杆菌选择性培养基MRS自身对幽门螺杆菌生长有较强的抑制作用。改良后的MRS在保证乳杆菌良好生长的前提下,消除了这种抑制作用。在筛选体外对幽门螺杆菌具有拮抗作用的乳杆菌时,采用这种改良MRS作为筛选介质所获得的结果更为可靠。此方法对于同类实验均具有借鉴意义。     

植物安全性表达载体的构建策略:以表达水稻反义蜡质基因的载体构建为例

基于转基因作物的安全性考虑,在用于转化的表达载体上除了含有目的基因以及控制该目的基因表达的启动子和终止子外,最好不存在其它有可能存在安全性争议的DNA序列,由此培育的转基因植物可能将更易于被消费者所接受。本研究以pCAMBIA1300载体为基础,基因操作去除pCAMBIA1300质粒上的潮霉素抗性基因和花椰菜花叶病毒的35S启动子序列,构建了两种只含有水稻蜡质基因启动子引导蜡质基因反义片段的表达载体,p13AWY-1和p13AWY-2。其中p13AWY-1表达载体含有一个由水稻蜡质基因启动子、第一内含子、反义蜡质基因（W axy pro＋intron1＋anti-W axy）的融合基因单元;而p13AWY-2表达载体含有两个正向排列的W axy pro＋intron1＋anti-W axy融合基因单元。我们通过构建水稻反义蜡质基因安全性表达载体,试图为植物安全性表达载体的构建提供一种思路,为今后大规模商业化采用转基因技术改良农作物遗传特性提供安全的转基因方法。     

Processed soybean meal as an alternative protein source for yellow perch (Perca flavescens) feed

The goal of this study was to compare conventional soybean meal (SBM) with modified SBM (MSBM) after chemical and enzyme pretreatment to potentially reduce the antinutritional factors (ANF), as a fishmeal (FM) replacer at 50% or 100% in the diets of yellow perch (Perca flavescens). Half of the SBM and MSBM diets contained an enzyme cocktail (of phytase and carbohydrate‐degrading enzyme), and the other half received no enzyme supplementations. Fingerlings (297; initial weight, 11.01 ± 0.19 g) were randomly distributed over nine treatments, in triplicate, and fed these isonitrogenous diets (crude protein 410 g/kg) that included replacing FM with SBM at 50% or 100% without or with enzyme supplementations (S50, S100, S50+E or S100+E, respectively), MSMB at 50% or 100% without or with enzyme supplementations (MS50, MS100, MS50+E or MS100+E, respectively) or a control FM‐based diet. After 10 weeks, the growth performance, feeding efficiencies, proximate composition, intestinal/pyloric caeca digestive enzymes and liver metabolic/antioxidant enzymes in P. flavescens were measured. The highest (p < 0.05) growth performance and nutrient utilization parameters (protein efficiency ratio and protein productive value, PPV) were observed for the MS_50+E group, which was not statistically different to parameters for the control and MS₅₀ groups, and significantly (p < 0.05) higher than all other groups. The lowest and highest growth performance and feed conversion ratios, respectively, were observed in the S100, S100+E and MS100 groups. The highest protease activity (in both intestine and pyloric caeca) was observed for the control group, but was significantly similar to MS₅₀, MS_50+E and S_50+E groups. The lowest value was observed for 100% replacement of FM protein by SBM and MSBM fed groups. However, inclusion of exogenous enzymes in feed showed positive effects in MS_50+E (compared to MS₅₀) for PPV, lipid productive value and amylase activity in the intestine. Activity of protein metabolism enzymes (i.e., alanine transaminase and aspartate aminotransferase) in the liver was the highest in the control group, which was similar (p < 0.05) to the MS_50+E and MS₅₀ groups. Antioxidant enzymes (catalase, superoxide dismutase and glutathione peroxidase) in the liver were the lowest in the control group, which was significantly similar (p < 0.05) to the group given the feed with 50% replacement of FM protein. Complete (100%) replacement of FM protein exhibited the highest antioxidant enzyme activity. Conclusively, performance of the MS₅₀ and MS_50+E groups was similar to the FM group and better than SBM group; therefore, MSBM with high protein and low ANFs has considerable potential as an alternative to FM in aquafeed.     

Assessment of the use of precipitating agents and ceramic membranes for treatment of effluents with high concentrations of nitrogen and phosphorus from recirculating aquaculture systems

Following the culturing of post‐juvenile African catfish, wastewaters were purified using single and integrated processes. Iron coagulant (IC), aluminium coagulant (AC), lanthanum modified bentonite (LMB) and ceramic membranes (NF – nanofiltration) were each tested in single processes, while the combination of IC + NF and AC + NF were used in the integrated process tests. Among the single processes, membrane filtration was the most effective in purifying the aquaculture effluent. The total suspended solids (TSS) were removed entirely and there was a near‐complete removal of turbidity (99.2%), as well as effective removal of Al and Fe (80.8% and 67.4% respectively). Precipitating agents overall removed TSS most faithfully, from 37.5% removal with AC, through 50.2% with IC, to 62.3% with LMB. Using integrated processes, the highest removal efficacy was recorded for TSS (100%) and turbidity (99.7% – IC + NF; 99.9% – AC + NF). Additionally, integrated processes attained a 96.8%–98.4% removal of NO₂^‐‐N. This study confirms the possibility of using IC, AC and LMB in chemical purification of effluents from recirculating aquaculture systems (RAS). However, due to their low removal efficacy for nitrogen and phosphorus, it is preferable to use NF or integrated processes – membrane filtration combined with chemical precipitation, methods which proved to be most effective for water purification in RAS.     

不同浓度1-甲基环丙烯处理对蓝莓贮藏品质的影响

为探究不同浓度1-甲基环丙烯（1-MCP）结合自发气调包装（MAP）对蓝莓冷藏期间保鲜效果的影响,以‘莱克西’蓝莓为试材,采后2 h内入预冷库,装入气调箱并对其进行0.5、1.0、1.5μL/L 1-MCP处理,冷链车运输96 h后入冰温库（（-0.5±0.3）℃）贮藏,每10 d测定蓝莓的品质指标、生理指标和挥发性成分。结果表明：MAP结合3种浓度1-MCP处理均能延缓蓝莓果实硬度的下降,保持相对较高的花色苷、VC、可溶性固形物、可滴定酸含量,抑制呼吸峰值和乙烯生成速率。利用SPSS主成分分析得出各处理的保鲜效果排序为：MAP+1.0μL/L 1-MCP>MAP+1.5μL/L 1-MCP>MAP+0.5μL/L 1-MCP>MAP。在蓝莓贮藏过程中醛类（52.34%～86.13%）和萜类（7.26%～32.44%）是其主要挥发性成分,MAP+1.0μL/L 1-MCP处理的蓝莓果实能保持较高的醛类物质和萜类物质相对含量。综上,MAP结合1.0μL/L1-MCP处理对蓝莓的保鲜效果最佳。     

不同修饰模式高岭土的表征及对CrO42-的吸附

为了研究不同修饰模式高岭土对CrO_4~(2-)的吸附效果,并分析外界条件对CrO_4~(2-)吸附效果的影响,采用DTAB(十二烷基三甲基溴化铵,简写为DT)分别对15%、30%和60%BS-12(十二烷基二甲基甜菜碱,简写为BS)高岭土进行复配修饰,探索不同BS-12和BS+DT复配修饰模式高岭土的表面特征及其对CrO_4~(2-)的吸附特征,并对比不同p H值和温度条件下的吸附差别。结果表明:高岭土经BS-12和BS+DT修饰后,TOC含量均表现为疏水修饰模式疏水修饰和离子交换共存模式离子交换模式;不同修饰模式高岭土层间距d001无显著变化,但相比原土(CK)均增大;不同修饰模式高岭土的比表面积SBET随疏水修饰的增强而减小。BS+DT修饰高岭土对CrO_4~(2-)的吸附量均比CK和BS-12修饰的土高,Henry模型拟合证明疏水修饰模式高岭土对CrO_4~(2-)保持着良好的吸附能力,且随着疏水修饰比例的增强,土样对于CrO_4~(2-)的结合能力增强。温度范围10~30℃内,CK对CrO_4~(2-)吸附量增加5%以上,不同BS-12修饰土的吸附量增加了1.4%~3.7%。15%、30%和60%BS+DT复配修饰土对CrO_4~(2-)吸附量降低了5.4%~7.2%。p H值在4~10范围内,随着p H值增大,各修饰土样对CrO_4~(2-)的吸附量均逐渐减小。     

大豆基木材胶粘剂的制备及热压工艺研究

应用环氧大豆油(ESO)、硼酸溶液对大豆分离蛋白(SPI)进行改性,制备了环保的大豆基木材胶粘剂.考察了ESO用量、硼酸浓度对蛋白胶粘剂胶合强度和耐水性能的影响,研究了热压工艺对胶粘剂性能的影响.结果表明:最佳反应条件为反应温度为65℃,SPI和ESO用量分别为10g和12 g,硼酸浓度为1.0％,水为100 mL;在热压温度为150℃,压力1.5 MPa,热压时间1.5 min/mm条件下,对杨木的拉伸剪切拉伸强度达到2.2 MPa,耐湿拉伸强度达到1.86 MPa,符合木材胶粘剂的要求;红外光谱证明ESO与SPI发生了改性反应.     

转cry1Ie基因抗虫玉米IE09S034种植对田间大型土壤动物多样性的影响

选取我国具有自主知识产权的转cry1Ie基因抗虫玉米IE09S034,利用手捡法和巴氏罐诱捕法,以群落组成、群落结构、优势类群种群动态为参数,研究转基因玉米IE09S034对田间大型土壤动物多样性的影响。研究结果表明,转基因玉米IE09S034较非转基因对照综31,对田间大型土壤动物的群落组成、物种丰富度、Shannon-Wiener多样性指数、Pielou均匀度指数以及优势类群种群动态等均无显著影响,可初步认定转基因抗虫玉米IE09S034对田间大型土壤动物无安全性风险。