贻贝中有机氯残留的气相色谱分析

建立了贻贝中有机氯农药残留的气相色谱法,方法检测限：666为0．315×10^-3mg／kg,DDT为4．60×10^-3mg／kg,分别添加5．0×10^-3、10．0×10^-3和50．0×10^-3mg／kg三个浓度水平加标回收范围为82．6—108％,RSD为1．03—7．84％。该方法具备较高的灵敏度和准确度,适合实验室分析。     

电子束辐照对蚌肉的保鲜效果

为探究电子束辐照对蚌肉保鲜效果及品质的影响,对0~9 kGy不同剂量电子束辐照处理的蚌肉进行冰藏试验。结果表明:电子束辐照处理能减少蚌肉中的菌落总数,延缓挥发性盐基氮(TVB-N)值的增加。1、3、5、7和9 kGy剂量的电子束辐照处理的蚌肉货架期分别延长了6、10、12、13和13 d。但5~9 kGy剂量辐照对感官评价、菌落总数、TVB-N及货架期的影响差距不大。电子束辐照在一定程度上加速蚌肉脂肪氧化,且电子束辐照剂量越大,硫代巴比妥酸值(TBA)上升越快,最大值越大。同时7~9 kGy剂量电子束辐照后蚌肉中各类氨基酸的含量有不同程度的降低。综合考虑,5 kGy剂量电子束辐照处理对蚌肉的保鲜效果较优。     

海洋低温酶酶解贻贝的动力学研究

用海洋低温碱性蛋白酶在温度30℃、pH为10.00条件下,对贻贝肉蛋白进行酶解。用相关的动力学模型推导公式与实验相结合,研究其酶解机制。结果表明:在反应过程中存在着酶失活现象,以及底物存在着促进反应进行和抑制酶活性的双重作用;得到的水解度动力学方程及水解速率方程,结果表明酶催化水解速率随水解进程呈指数递减;失活常数k_d=13.989 min^-1;动力学模型计算值与实验值平均相对偏差为5.80%,此结果说明该动力学模型与实验测量结果有很高的吻合性。     

Antioxidative activity of a low molecular weight peptide derived from the sauce of fermented blue mussel, Mytilus edulis

In order to identify nutraceutical functions of fermented fish and shellfish sauces, which are highly appreciated in food products in South-East Asia, the antioxidative activity of fermented blue mussel sauce (FBMS) was investigated. The blue mussel was fermented with 25% NaCl (w/w) at 20±0.5 °C for 12 months and the fermented sauce was passed bimonthly through a 40-mesh sieve, desalted using an electrodialyzer, and then lyophilized. The antioxidative activity of FBMSs was investigated and compared with that of a natural antioxidant, -tocopherol standing as a reference. Using consecutive chromatographic methods, the antioxidative peptide with a molecular mass of 620 Da was purified from 6-month-fermented sauce, and its sequence of the peptide was FGHPY. In addition, 64.8 M of the purified peptide could scavenge 89.5% of hydroxyl radical in radical scavenging assay using electron spin resonance spectroscopy.     

A Mussel‐Inspired Persistent ROS‐Scavenging,Electroactive, and Osteoinductive Scaffold Based on Electrochemical‐Driven In Situ Nanoassembly

Conductive polymers are promising for bone regeneration because they can regulate cell behavior through electrical stimulation; moreover, they are antioxidative agents that can be used to protect cells and tissues from damage originating from reactive oxygen species (ROS). However, conductive polymers lack affinity to cells and osteoinductivity, which limits their application in tissue engineering. Herein, an electroactive, cell affinitive, persistent ROS‐scavenging, and osteoinductive porous Ti scaffold is prepared by the on‐surface in situ assembly of a polypyrrole‐polydopamine‐hydroxyapatite (PPy‐PDA‐HA) film through a layer‐by‐layer pulse electrodeposition (LBL‐PED) method. During LBL‐PED, the PPy‐PDA nanoparticles (NPs) and HA NPs are in situ synthesized and uniformly coated on a porous scaffold from inside to outside. PDA is entangled with and doped into PPy to enhance the ROS scavenging rate of the scaffold and realize repeatable, efficient ROS scavenging over a long period of time. HA and electrical stimulation synergistically promote osteogenic cell differentiation on PPy‐PDA‐HA films. Ultimately, the PPy‐PDA‐HA porous scaffold provides excellent bone regeneration through the synergistic effects of electroactivity, cell affinity, and antioxidative activity of the PPy‐PDA NPs and the osteoinductivity of HA NPs. This study provides a new strategy for functionalizing porous scaffolds that show great promise as implants for tissue regeneration.     

Facile Fabrication of Mussel‐Inspired Multifunctional Polymeric Membranes with Remarkable Anticoagulant,Antifouling, and Antibacterial Properties

Herein, a facile one‐step surface modification technique of coating functional biopolymer conjugated mussel‐inspired catechol (CA) onto substrate is applied to confer polyethersulfone (PES) membranes with remarkable blood compatibility, antifouling property, and antibacterial property, respectively. CA conjugated poly(2‐acrylamido‐2‐methylpropanesulfonic acid) (PAMPS), poly(sulfobetaine methacrylate) (PSBMA), and poly(methacryloxyethyltrimethyl ammonium chloride) are synthesized via free radical polymerization in the presence of CA, and simultaneously coated onto PES membrane surface. The surface chemical compositions, surface zeta‐potential convince the successful preparation of the modified PES membranes. PAMPS‐coated membrane exhibits excellent blood compatibility, especially anticoagulation property; PSBMA‐coated membrane displays excellent antifouling property and blood compatibility; meanwhile, PDMC‐coated membrane shows robust bactericidal property. In general, this work demonstrates that the mussel‐inspired surface modification protocol provides a facile and versitile method to confer the substrate with excellent blood compatibility, antifouling property, and antibacterial property, respectively, which has great potential for multibiomedical applications, such as blood purification, hemodialysis, and organ implantation.     

海洋产蛋白酶细菌发酵液防污活性研究

传统的防污剂对海洋环境造成严重污染,随着环保意识的增强以及相关规定的制订,各国竞相开展新型无毒防污剂的研究。本文以海洋产蛋白酶菌株发酵产物为活性物质,研究蛋白酶粗提物对污损生物硅藻(navicula sp.)和贻贝(mytilus edulis)附着行为的影响。结果表明,所研究菌株的发酵液对硅藻(navicula sp.)和贻贝(mytilus edulis)的附着有明显抑制作用。贻贝(mytilus edulis)毒性实验显示,细菌发酵液对贻贝无毒。因此,海洋微生物蛋白酶产生菌粗酶提取物可以作为环保型防污功能添加剂。     

响应面法优化微波辅助提取贻贝蛋白的工艺研究

研究微波对中性蛋白酶水解贻贝蛋白条件的影响,探讨了在一定的微波功率/时间,加酶量、酶解温度和时间对蛋白质回收率的影响。单因素实验先确定因素水平,再通过响应面确定最佳的工艺条件,酶解条件分别是时间为118.8min,加酶量为0.754%,微波功率为189.7W,温度分别为46.9℃,该条件下得到的最大蛋白质回收率为74.83%。     

Assessment of the biosorption kinetic and thermodynamic for the removal of safranin dye from aqueous solutions using calcined mussel shells

Calcined mussel shells have been used as new low cost and eco-friendly biosorbent for the removal of safranin as cationic dye from aqueous solutions by biosorption technique. Batch mode experiments were conducted using various parameters such as pH, contact time, biosorbent amount and safranin concentration. Removal efficiency of safranin by the calcined mussel shells attained 87.56% using 200 mg of biosorbent and 150 mg/L as safranin concentration and for a pH above 9.2. Four kinetic models are used, pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion for the design and the optimization treatment. The kinetic analysis showed that the pseudo-second-order model had the best fit to the experimental data. Biosorption isotherms were also investigated using Langmuir, Freundlich and Temkin models. The experimental data fitted very well with both Langmuir and Freundlich isotherm models. Thermodynamic biosorption processes were found to be spontaneous, endothermic. The Gibbs energy ΔG° decreased from −1.956 kJ/mol to −2.456 kJ/mol with increase in temperature from 298 K to 313 K indicating a increase in feasibility of biosorption at higher temperature. Accordingly, calcined mussel shells were shown to be a very efficient, eco-friendly and low cost biosorbent and a promising alternative for removal dyes from aqueous solutions.