海洋真菌Fy-04生长特性及产抑菌物质

对从海泥中筛选到的1株海洋真菌Fy-04的生长特性及产抑菌物质的培养条件进行了初步研究.结果表明,海洋真菌Fy-04耐盐度2g/100mL,培养基初始pH值6.0～7.0,在基础发酵培养基中生长达到生长高峰时间72h～96h,产抑菌物质高峰时间72h.在优化条件下,菌株Fy-04产抑菌物质抑菌效果,对金黄色葡萄球菌抑菌圈直径34.1mm,对大肠埃希氏菌抑菌圈直径23.7mm.     

海洋鱼油的生产与应用

全面回顾了国内外海洋鱼油生产与应用的历史与现状,指出海洋鱼油作为二十碳五烯酸(EPA)、二十二碳六烯酸(DHA)等ω-3多不饱和脂肪酸的重要来源,正在饲料、食品以及药品等领域展示其良好的应用前景.     

产琼胶酶菌株NBRC102603发酵条件优化及酶的分离纯化

通过正交试验对产琼胶酶海洋菌株NBRC102603发酵条件进行了优化,优化得到的发酵产酶条件为:蛋白胨浓度5.0 g/L、酵母膏浓度1.25 g/L、琼胶浓度4.0 g/L、装瓶量100 mL、接种量1%、转速150 r/min,28℃下发酵48 h后酶活力达到58.94 U/mL,比未优化前提高了2.08倍。经纯化得到琼胶酶A和琼胶酶B,琼胶酶A纯化倍数为17.29倍,酶比活力为870.51 U/mg;琼胶酶B纯化倍数为16.65倍,酶比活力为838.39 U/mg。纯化后琼胶酶经SDS-PAGE检测,显示为单一条带,其相对分子质量酶A约为83.6 ku、酶B约为36.8 ku。     

微生物转谷氨酰胺酶生产菌的“神舟四号”飞船搭载育种研究——搭载前地面育种试验(I)

结合“神舟四号”无人飞船的试验条件和具体搭载要求 ,对转谷氨酰胺酶生产菌株Streptomycessp .WZFF .L -M 1(酶活 1.74U/mL)的孢子和菌丝体以 1 甲基 3硝基 1 亚硝基胍 (NTG)分别进行多种地面模拟比较性的诱变育种试验 ,发现诱变处理后菌落的形态变异等特征与产酶能力相关 ,经初筛和复筛的菌种驯化选育 ,获得具优异性能的突变菌株 ,酶活得到了明显提高     

大孔树脂D380固定化橄榄绿链霉菌E-86来源木聚糖酶的研究

选择有代表性的 1 4种吸附和离子交换树脂进行了橄榄绿链霉菌E 86来源的木聚糖酶固定化试验 ,筛选出固定化效果较好的 72 4和D3 80两种树脂 ;对含伯氨基的离子交换树脂D3 80采用戊二醛进行交联固定化 ,研究了其固定化条件。结果表明 ,戊二醛浓度为1 % ,处理 3 0min ,加酶量为 0 8～ 1mL ,酶液pH 5 8,2 5℃ ,5～ 1 0h固定化处理效果最好 ,获得的固定化酶活力可达 64U/ g(载体 )。     

海洋细菌Bacillus sp.H-TP2岩藻多糖酶的生产和酶学性质

研究了海洋细菌Bacillussp H TP2液态发酵生产岩藻多糖酶的条件 ,并对酶学性质进行了初步探讨。主要包括氮源、碳源、起始pH、温度、盐浓度和添加物等对产酶的影响。培养基组成为 :岩藻多糖 3g/L、尿素 5g/L、NH4 NO32g/L、CaCl2 ·2H2 O 0 0 5g/L、MgSO4 ·7H2 O 2g/L、Na2 HPO40 5g/L、葡萄糖 0 4g/L、蛋白胨 4g/L。菌种在 2 0℃ ,起始pH 7 0 ,1 2 5倍海水盐度下 ,培养 2 4h ,酶活力可以达到 1 2 9IU/mL。另外 ,该酶的最适反应温度为 5 0℃ ,最适反应pH为 6 5。     

Microencapsulation of Oils: A Comprehensive Review of Benefits,Techniques, and Applications

Microencapsulation is a process of building a functional barrier between the core and wall material to avoid chemical and physical reactions and to maintain the biological, functional, and physicochemical properties of core materials. Microencapsulation of marine, vegetable, and essential oils has been conducted and commercialized by employing different methods including emulsification, spray‐drying, coaxial electrospray system, freeze‐drying, coacervation, in situ polymerization, melt‐extrusion, supercritical fluid technology, and fluidized‐bed‐coating. Spray‐drying and coacervation are the most commonly used techniques for the microencapsulation of oils. The choice of an appropriate microencapsulation technique and wall material depends upon the end use of the product and the processing conditions involved. Microencapsulation has the ability to enhance the oxidative stability, thermostability, shelf‐life, and biological activity of oils. In addition, it can also be helpful in controlling the volatility and release properties of essential oils. Microencapsulated marine, vegetable, and essential oils have found broad applications in various fields. This review describes the recognized benefits and functional properties of various oils, microencapsulation techniques, and application of encapsulated oils in various food, pharmaceutical, and even textile products. Moreover, this review may provide information to researchers working in the field of food, pharmacy, agronomy, engineering, and nutrition who are interested in microencapsulation of oils.     

X射线检测海水鱼片中鱼刺

通过X光机设备参数优化、鱼刺分布规律总结及冷冻结合X光机技术3 个方面对X射线检测鱼刺效果进行研究。结果表明,大部分海产鱼片产品的最优检测参数为：电压范围30～45 kV、电流范围3 000～6 000 μA、亮度范围4～6;通过鱼刺分布规律总结,鱼片在冷冻状态下鱼刺的检出率均高于解冻状态下鱼刺检出率,且冷冻状态下人工读X射线图判断鱼刺更接近于实际情况。通过X光机设备参数优化、鱼刺分布规律总结的学习及冷冻结合X光机技术可改善图像质量和提高残留鱼刺检出率,改善水产品加工企业X光机检测人员的视觉感受并一定程度上解决海水冷冻鱼片产品鱼刺残留问题。     

海洋环境中假单胞菌对聚氨酯清漆涂层分解的影响

目的 研究在海洋环境中假单胞菌对聚氨酯清漆涂层分解作用的影响。方法 将聚氨酯清漆涂层样品分别浸泡于无菌海水与含假单胞菌的海水中,对浸泡环境不同的样品利用电化学阻抗谱（EIS）评价涂层防腐性能,使用扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）,观察对比涂层的表面形貌,并表征其分子结构变化。结果 1 h~35 d时,在无菌海水及假单胞菌海水中,样品Nyquist图的容抗弧直径以及Bode图的低频端阻抗模量均减小。与此同时,假单胞菌海水中浸泡样品的Nyquist图容抗弧直径与Bode图低频端阻抗模量的减小量明显大于无菌海水中的减小量。无菌海水浸泡的等效电路在1~48 h时为1个时间常数,5~35 d时增加为2个时间常数;假单胞菌海水浸泡的等效电路在1~48 h时只有1个时间常数,5~29 d时为2个时间常数,35 d时增加为3个时间常数。浸泡36 h时,无菌海水中浸泡样品的涂层电阻值为8.23× 107 Ω?cm2,而假单胞菌海水中样品的涂层电阻为5.14×107 Ω?cm2;至35 d时,无菌海水中样品的涂层电阻降为5.61×106 Ω?cm2,假单胞菌海水中样品的涂层电阻降至7.03×105 Ω?cm2。假单胞菌海水中样品的涂层电阻在36 h~35 d的减小量明显大于无菌海水中的减小量。由SEM结果可以观察到,浸泡30 d后,无菌海水中浸泡样品的表面光滑完整,而在含假单胞菌海水中的样品表面附着了大量细胞及其代谢产生的生物膜,并出现了大量微孔与粉化痕迹。通过FTIR结果可以发现,浸泡在假单胞菌海水中的样品的N—H和醚基中的C—O含量明显比无菌海水中浸泡的样品要低。结论 电化学结果表明,假单胞菌显著降低了涂层的腐蚀抗性,并导致了涂层的分解。SEM和FTIR的分析结果证明,假单胞菌通过破坏聚氨酯分子中的N—H和醚基中的C—O,造成了涂层的分解。     

A New Clearance Design Method for Reciprocating Fuel Pumps of Medium-Speed Diesel Engines

A new clearance design method is proposed for a reciprocating fuel pump. Structural and hydrodynamic lubrication analyses were conducted to design the clearance of the pump, and the former was used to evaluate the clearance reduction due to the deformation that results from applying maximum supply pressure. The reduction in the maximum clearance was used as the limit of the design, and the two-dimensional Reynolds equation is used to evaluate the lubrication characteristics of the pump with variations in the viscosity and clearance. The optimal clearance in the pump must be separately designed in both the stem and the head because the lubrication characteristics and the deformation patterns of the two parts are different. The validity of the numerical model was then verified by determining that the position of the wear was also similar to that of the minimum film thickness. Moreover, a rig test system was also used to verify the clearance of the proposed design method.