生物表面活性剂的研究进展及工业应用

生物表面活性剂是由微生物代谢时产生的一种具有表面活性的化学物质，同时含有亲水和疏水部分。生物表面活性剂具有降低液体、固体和气体不同界面间表面张力的能力，并表现出乳化、润湿、分散、增溶、去污等多种特性。此外，它在抗黏附和抗菌活性方面也具有显著的潜力。与化学表面活性剂相比，生物表面活性剂具有表面活性高、耐盐耐酸、毒性低、生物兼容性好、可生物降解等优点，在食品、石油、环境、制药、农业、化妆品、洗涤剂等行业均有良好的应用前景。该文介绍了生物表面活性剂的分类和物理化学性质，并讨论了不同的表征技术及其在各个领域的应用。     

生物质表面活性剂研究现状及展望

介绍了天然表面活性剂、改性生物质表面活性剂、生物表面活性剂等特性,综述了生物质表面活性剂的种类、研究现状和发展,认为生物质表面活性剂凭借其良好的表面活性和无毒绿色特性,将展现出宽广的应用前景.     

生物表面活性剂的研究进展

生物表面活性剂是一类新型环保的表面活性剂,除了具备化学合成表面活性剂的表面活性外,还具有毒性低、可生物降解、应用领域广泛等优点。文中综述了生物表面活性剂的类型、结构、性能及其在日化、纺织和环境工程等领域中的应用,为其在纺织领域中的应用提供参考依据。     

Gemini表面活性剂(一)

Gemini表面活性剂由于其独特的结构,而具有优异的表面活性.其临界胶束浓度（CMC）较传统表面活性剂低数百倍,不仅应用浓度可大幅降低,而且具有传统表面活性剂不具备的性能.文中介绍了Gemini表面活性剂的研发现状,分子结构特点及表面行为,以及其优良性能.根据Gemini表面活性剂的性能,可将其分为阳离子型、阴离子型、非离子型和两性离子型,并详细阐述了合成、性能和应用.     

磺酸盐Gemini表面活性剂的研究进展

与传统的表面活性剂相比,Gemini型表面活性剂分子具有特殊结构,因此表现出独特性能。简述了近几年来磺酸盐Gemini表面活性剂的合成方法与性能,发现该类双子型表面活性剂具有较高的表面活性以及在复配体系中具有更强的协同作用,最后展望了磺酸盐Gemini表面活性剂在各个领域上的应用。     

Gemini表面活性剂及其合成与应用

Gemini表面活性剂由于独特的性能、优异的表面活性，它的临界胶束浓度cwc以及降低表面张力的效率均较传统表面活性剂低数百倍，不仅应用浓度大幅刚氏，而且具有传统表面活性剂不具备的性能，被誉为新一代的表面活性剂，成为表面活性剂研究开发的热点，目前正期待着大规模工业化生产．     

Gemini表面活性剂的研究进展及应用

Gemini表面活性剂是一类含有双疏水基双亲水基的新型表面活性剂,表面活性高,临界胶束浓度低,Krafft点低,因此在增溶、杀菌、制备新材料等方面具有广阔的应用前景。本文综述了Gemini表面活性剂的研究进展、性能及应用,指出了今后的发展趋势。     

Gemini表面活性剂的研究进展及应用

Gemini表面活性剂是一类含有双疏水基双亲水基的新型表面活性剂,表面活性高,临界胶束浓度低,Krafft点低,因此在增溶、杀菌、制备新材料等方面具有广阔的应用前景.本文综述了Gemini表面活性剂的研究进展、性能及应用,指出了今后的发展趋势.     

Gemini表面活性剂在制革工业中的应用

Gemini表面活性剂是一种新型的表面活性剂,它具有高表面活性、超低界面张力、强协同效应等特性。从Gem-ini表面活性剂的结构、性质、分类及其合成方法等方面进行了介绍,就其在制革工序中的应用进展进行了综述,并对其在制革工业中的应用前景进行了展望。     

表面活性剂在苹果罐头生产中的应用

在传统的苹果罐头生产中,通常采用机械去皮或手工去皮方法,致使原料消耗较大,单位成本较高,本文采用复合表面活性剂去皮,大大减少了原料消耗,降低了成本,从而也提高了生产效率,增加了经济效益,同时采用多种表面活性剂复合应用是表面活性应用的新发展,也为表面活性剂在食品工业中的应用开阔了新路。     

Surfactin 抑制乳中大肠杆菌O157 活性研究

本研究采用牛津杯法和倍比稀释法测定大肠杆菌O157对Surfactin(生物表面活性素)的敏感性,并通过检测对大肠杆菌O157 生长曲线、杀菌率、杀菌动力学的影响探讨Surfactin 对大肠杆菌O157 的杀菌特点,最后测定了Surfactin 对鲜乳中大肠杆菌O157 的杀菌效果。结果表明,大肠杆菌O157 对Surfactin 敏感性较高,其最小抑菌浓度(MIC)为25μg/ml,Surfactin 不仅具有抑制大肠杆菌O157 的作用,还具有明显的杀菌效果。2MIC Surfactin 作用于鲜乳介质中的大肠杆菌48h 后,大肠杆菌不被检出。     

纳米纤维的技术进展

本文简单介绍了纳米纤维的定义、特点和应用 ,主要讨论了纳米纤维的制备方法 ,包括传统纺丝方法(如 :静电纺丝法、复合纺丝法和分子喷丝板法 )的改进以及新兴的生物合成法和化学合成法     

Identification of induced acidification in iron-enriched cultures of Bacillus subtilis during biosurfactant fermentation

Bacillus subtilis is able to synthesize a lipopeptide biosurfactant (known as surfactin), which is one of the most effective biosurfactants available. In our previous study, B. subtilis ATCC 21332 was used to produce surfactant and it was found that the addition of iron at an appropriate amount significantly improved the biosurfactant production. However, it also showed that excess addition of iron led to a sharp decrease in pH of the culture and surfactin in the broth disappeared rapidly once the pH fell below 5.0. This study reveals that the disappearance of surfactin at the acidic pH was due to the precipitation of surfactin triggered by the accumulation of extracellular acidic metabolites. The acidic material was isolated and purified from the broth and was characterized by GC-MS and IR spectroscopy. The results of GC-MS and IR analysis show that the molecular weight and molecular structure of the acidic metabolite resembled those of phthalic anhydride.     

The production of surfactin during the fermentation of cheonggukjang by potential probiotic Bacillus subtilis CSY191 and the resultant growth suppression of MCF-7 human breast cancer cells

Bacillus subtilis CSY191, the potential probiotics and surfactin-like compound producer, was isolated from doenjang (Korean traditional fermented soybean paste).The survival rate of this strain appeared to be the 58.3% under artificial gastric conditions after 3 h at pH 3.0. Surfactin was purified from the strain CSY191. Three potential surfactin isoforms were detected, with protonated masses of m/z 1030.7, 1044.7, and 1058.71. These different structures were detected in combination with Na⁺, K⁺ and Ca²⁺ ions by MALDI-TOF mass spectrometry. Upon 500 MHz ¹H NMR analysis, the surfactin isoforms had identical amino acids (GLLVDLL) and hydroxy fatty acids (of 13-15 carbons in length). The MTT assay showed that surfactin inhibited growth of MCF-7 human breast cancer cells in a dose-dependent manner, with an IC₅₀ of approximately 10 μg/ml at 24 h. Additionally, the surfactin contents, during cheonggukjang fermentation with strain CSY191, increased from 0.3 to 48.2 mg/kg over 48 h of fermentation, while the level of anticancer activity increased from 2.6- to 5.1-fold.     

响应面法优化枯草芽孢杆菌表面活性素的发酵工艺

为提高枯草芽孢杆菌FHYB201030的表面活性素生产能力,本文以枯草芽孢杆菌FHYB201030为试验菌株,CPC-BTB（氯化十六烷基吡啶-溴百里酚蓝）值为考核指标,利用单因素实验、Plackett-Burman试验、最陡爬坡试验和响应面试验进行优化,筛选出产表面活性素的最优发酵条件。Plackett-Burman试验筛选出对表面活性素产量影响显著的因素为温度、乳糖、谷氨酸（Glu）,采用最陡爬坡设计和Box-Behnken中心组合设计三因素三水平试验,计算得到表面活性素产量最高的培养基成分为乳糖25 g/L、酪蛋白10 g/L、牛肉膏3 g/L、蛋白胨10 g/L、NaCl 5 g/L、Mn2+ 0.5 mmol/L、Glu 2.5 g/L;最佳培养条件为温度40 ℃、转速200 r/min、装液量30%（体积比）。在上述发酵条件下,枯草芽孢杆菌FHYB201030表面活性素的产量为0.48 mg/mL,较优化前的0.35 mg/mL提高34.56%。研究结果为提高表面活性素生产水平奠定良好的基础。     

脂肽类生物表面活性剂Surfactin的乳化性

采用白金板法对Surfactin的表面活性进行研究,并用浊度法和离心法对其乳化性进行研究。结果表明：Surfactin的临界胶束浓度为9.03×10－5 mol/L,可将水的表面张力由73.98 mN/m降至最低27.48 mN/m。在浓度为1×10－3～1.2×10－2 mol/L的NaCl溶液中,Surfactin溶液的表面张力随盐浓度升高逐渐降低并最终稳定在34 mN/m;Surfactin在121 ℃处理20 min后,其表面张力仍能保持在37.10 mN/m;在pH值为2～12范围内,其表面活性稳定并良好;表明Surfactin具有较强的NaCl浓度、温度、pH值的耐受性。浊度法测得Surfactin亲水亲油平衡（hydrophilelipophilic balance,HLB）值为14,对所需HLB值为12～16的油相乳化性能良好。     

Surfactin作为表面活性剂对O/W型藻油DHA乳状液物理和氧化稳定性的影响

以Surfactin作为表面活性剂制备藻油二十二碳六烯酸(docosahexaenoic acid,DHA)乳状液并研究其稳定性。研究发现,水相为质量分数0.8%的Surfactin溶液,在不添加助表面活性剂和其他添加剂的条件下,制备水包油型藻油DHA乳状液,在4℃和37℃条件下保存相比其他表面活性剂具有良好的物理稳定性,在浊度、粒径、Zeta电位和流变学角度与Tween-80-丙三醇等表面活性剂制备的藻油DHA乳状液相比均有显著差异(P0.05),Surfactin藻油DHA乳状液在各方面均优于其他表面活性剂的藻油DHA乳状液。在高温处理和常温贮存过程中,Surfactin藻油DHA乳状液的氧化稳定性也十分优良,在37℃贮存60 d乳状液过氧化值始终处于较低水平,仅为(1.635±0.202)meq/kg。     

贝莱斯芽孢杆菌1-3产表面活性素的纯化、鉴定及表征

从口腔离体牙样品中筛选得到1株具有抑菌作用的贝莱斯芽孢杆菌（Bacillus velezensis）1-3。通过硫酸铵沉淀、分子筛层析、薄层层析和基质辅助激光解析电离-飞行时间质谱检测,确定具有抑菌活性的物质是含有14～16个C的环状脂肽Surfactin,其分子质量分别为1 030.642、1 044.660 Da和1 058.677 Da。通过对分离纯化Surfactin的特征研究,结果表明其具有表面活性剂的功能,对食品加工、医疗卫生、畜禽养殖中常见的病原菌具有抑制作用,其中对单核细胞性李斯特菌（Listeria monocytogenes）ATCC 19115的最小抑菌浓度可达4 μg/mL。Surfactin对小鼠红细胞在有效抑菌浓度范围内未显示溶血性,且具有良好的热稳定性（20～100℃）和广泛的pH值（2.0～10.0）适应性,表明其在食品加工、医疗卫生和畜牧养殖中具有良好的应用潜能。     

枯草芽孢杆菌ATCC2233产生表面活性素的研究

薄层导一性分析结果表明枯草芽孢杆菌ＡＴＣＣ２２３３能够产生Ｓｕｒｆａｃｔｉｎ,生长曲线表明菌体生长和产Ｓｕｒｆａｃｔｉｎ的过程不同步。透明圈测定结果表明产Ｓｕｒｆａｃｔｉｎ的最适温度为３７℃,最适ｐＨ为７．０。Ｓｕｒｆａｃｔｉｎ能够显著降低水－空气之间的表面张力,且具有对热稳定的特性。     

Production of polysaccharide and surfactin by Bacillus subtilis ATCC 6633 using rehydrated whey powder as the fermentation medium

The aim of this research was to assess the amounts of polysaccharide and surfactin produced by Bacillus subtilis ATCC 6633 in rehydrated whey powder (RWP) as the growth medium. One-day-old cultures of B. subtilis (～4.6 log cfu/mL) were inoculated into 100mL of 10, 15, or 20% (wt/vol) RWP and incubated at 30°C for 72 h. To analyze the effects of lactose and protein on polysaccharide and surfactin production, 6 RWP solutions containing different levels of lactose and protein were also used as media. The number of vegetative cells and spores, pH, viscosity, and the concentration of lactose were determined at 0, 24, 48, or 72 h of fermentation. The levels of polysaccharide and surfactin produced after 72 h of fermentation were measured using HPLC and the phenol-sulfuric acid method, respectively. During 72 h of fermentation, B. subtilis populations increased from 4.6 to 10.54, 9.82, and 9.67 log(10) cfu/mL in 10, 15, and 20% RWP, respectively. The number of B. subtilis spores in 10% RWP increased from 3.91 to 4.72 log(10) cfu/mL after 48 and 72 h of fermentation, respectively. The increased level of lactose or protein in RWP did not significantly change the vegetative growth. After 72h of fermentation, the pH of RWP decreased from 5.70 to 4.99 with a slight increase in viscosity. Polysaccharide levels in 10, 15, and 20% RWP after fermentation were 513.6, 613.5, and 768.3mg/L, respectively, with B. subtilis producing 0.18 to 0.29 g/L of surfactin after 72 h of fermentation. The polysaccharide or surfactin production was not changed significantly by addition of protein or lactose to RWP. These results indicate that RWP is a good fermentation substrate for surfactin and polysaccharide production.