蔬菜专用发酵乳酸菌菌体高密度培养基优化的研究

本文对从泡菜中筛选到乳酸菌编号为NGU0101进行了菌体高密度培养基优化的研究。通过单因子试验研究了不同碳源、氮源及缓冲磷酸盐对乳酸菌培养的影响,并且采用了L₉（3⁴）正交试验法确定培养基。     

鳗弧菌pEIB1质粒缺失株MVAV6201的筛选和三价铁源供给的优化

以鳗弧菌Vibrio anguiUarum MVM425(01型)为出发菌株,通过变温培养诱变筛选得到pEIB1质粒缺失株MVAV6201。通过与野生株MVM425的摇瓶培养对比发现,Fe^3 营养的摄取是质粒缺失株MVAV6201生长的瓶颈。MVAV6201对Fe^3 的吸收有赖于外界Fe^3 营养的供给形式。柠檬酸铁铵能有效增强MVAV6201对三价铁营养的吸收,促进菌体细胞的生长。柠檬酸铁铵饱和浓度为0．4mmol／L。     

致病性鳗弧菌金属蛋白酶基因克隆及序列分析

从我国山东沿海发病的鲈鱼（Lateolabrax japonicus）分离到一株致病性鳗弧菌（Vibrio anguillarum）W-1，该菌的胞外蛋白酶活性为4226u/ml，部分纯化的胞外蛋白酶对海水养殖大菱鲆鱼有一定的毒性。应用PCR扩增，从鳗弧菌W-1染色体DNA扩增出一条长约1.925kb的特异性PCR产物，DNA序列分析表明：克隆的片段含有完整的金属蛋白酶基因阅读框，编码611个氨基酸残基的蛋白质，该金属蛋白酶基因与一株致病性鳗弧菌蛋白酶基因的核苷酸及氨基酸序列同源性为100%，而与解蛋白弧菌（V.proteolyticus)、创作弧菌（V.vulnificus）、霍乱弧菌（V.cholerae)、斑点气单胞菌（Aeromonas punctata），嗜水气单胞菌（Aeromonas hydrophila）的氨基酸序列同源性分别为73%、70%、69%、53%、51%。     

海洋聚磷菌 Halomonas YSR-3 的除磷特性研究

用改变培养条件的方法对海洋聚磷菌Halomonas YSR-3 的生长和除磷特性进行了研究.研究结果表明,无磷培养时,该菌菌体不能生长;用磷酸钾盐作为磷源时,菌体生长较好,形成多聚磷酸盐的菌体比例较高;较适合YSR-3菌体生长和多聚磷酸盐形成的磷源是 KH2PO4,较适磷浓度为1 mmol/L.pH 的变化影响菌株的生长、多聚磷酸盐形成和除磷效果.pH 值为5时,菌体的数量几乎不增加(△OD480为0.013),体内多聚磷酸盐和培养基中磷含量变化不大;pH 值为6、7和8时,菌体生长良好(△OD480分别为1.529、1.539和1.497),95%以上的菌体内形成多聚磷酸盐,培养基中磷含量明显下降.YSR-3在不同培养基中除磷量和除磷率不同.在高磷培养基中除磷量为0.7 mmol/L(磷含量由1.84mmol/L降到1.14 mmol/L),除磷率为37.5%;在低磷培养基中除磷量为0.02 mmol/L(磷含量由0.028 mmol/L降到0.008 mmol/L),除磷率为72.2%.     

氮源和初始NaHCO3浓度对转Tα1基因聚球藻7942生长与表达的影响

研究了氮源和初始NaHCO3浓度对转基因聚球藻7942生长与胸腺素α1表达的影响。结果表明：最适的氮源为NaNO3，NaNO3浓度低于1g／L时，增加NaNO3浓度能提高藻细胞的生长和表达，但1～2．5g／LiNaNO3对转基因聚球藻7942生长与表达没有明显的影响。最适的初始NaHCO3浓度为8．0g／L。生长在8．0g／L初始NaHCO3浓度培养基中藻细胞密度和胸腺素α1最大表达能力分别为BG-11培养基中的1．94倍和2．01倍。     

细胞培养用温度敏感凝胶的合成与性能研究

用丙烯酸（ARc）对壳聚糖（CS）进行化学改性，合成反应中问体壳聚糖衍生物CS-ARc，进一步合成不同配比的CS-ARc与N-异丙基丙烯酰胺（NIPA）的共聚凝胶P（CS-AAc-NIPA），通过红外光谱和元素分析等表征了产物的结构和组成，并研究了P（CS—ARc-NIPA）凝胶在水中和细胞培养基中的溶胀性能．结果表明共聚凝胶在水中和培养基中均显示较好的温度敏感性．对P（CS-ARc-NIPA）共聚凝胶进行细胞培养研究发现，其表面可成功种植成纤维细胞（L929），细胞贴附生长情况良好，表明材料具有很好的细胞相容性．当环境温度降低后，共聚凝胶发生疏水．亲水变化，导致其表面细胞自动脱附，从而避免了使用酶解法脱附细胞造成的细胞功能损伤．’     

溶藻弧菌脂多糖单克隆抗体的制备、鉴定及初步应用

用细菌颗粒性抗原多次免疫Balb/c小鼠，首次制备了一株鱼类病原溶藻弧菌VAF01的LPS的单克隆抗体4D5。4D5识别VAF01和VAF02（另一株病原溶藻弧菌）的LPS的核心多糖抗原。除了与测试的溶藻弧菌发生免疫识别外，4D5还与解蛋白弧菌，哈维氏弧菌，灿烂弧菌和海藻施万氏菌发生免疫交叉反应，但不与副溶血弧菌，鳗弧菌，嗜水气单菌等发生交叉反应。用温和高碘酸氧化法对LPS处理后，VAF01和LPS不再与4D5识别，VAF02上的LPS与4D5的反应部分减弱，推测VAF01及VAF02的LPS有不同的组分和结构。用抑制ELISA法半定量检测溶藻弧菌培养上清的LPS，测得培养48小时LPS释放量不超过57μg/ml，大大低于使鱼类致死所需的LPS的剂量。     

鳗弧菌灭活疫苗对海水养殖大菱鲆的免疫预防研究

福尔马林灭活的鳗弧菌疫苗分别以浸泡、注射接种的方式对海水养殖大菱鲆鱼苗进行免疫 ,定期检测血清中特异性抗体。 4周后用鳗弧菌悬液 (3.7× 1 0 8cfu/ml) 0 .2ml腹腔注射感染免疫鱼。结果表明 ,灭活鳗弧菌疫苗用 2种方式免疫后都能刺激大菱鲜产生特异性免疫反应。其中注射免疫组在 1周后即可产生特异抗体 ,在 6周内一直呈上升趋势 ,最高达 1 2 2 8.8,免疫 4周后人工感染后的免疫保护力为 91 .70 %。浸泡免疫组在 3周后才产生抗体凝集价 ,凝集抗体效价最高 36 ,免疫保护力为 33.30 %。     

利用遗传算法优化透明质酸发酵培养基

运用遗传算法对透明质酸(HA)产生菌--马链球菌兽瘟亚种ATCC 39920发酵培养基的6种组份进行了优化研究.每个长度为36位的染色体编码一种培养基配方,以HA产量为适应度函数值对其进行评价.经过4代的进化,各参数的取值范围收敛于最优区域.最终以40个实验样本完成了6种培养基成分、64个浓度水平的优化选择.优化后的培养基的构成为:葡萄糖44.0g/L,酵母膏5.2g/L,蛋白胨8.4g/L,牛肉膏9.8g/L,KH2PO41.45g/L,MgSO42.8g/L.采用优化培养基的HA产量达0.395g/L,较原培养基提高了31.2%,生产成本也大幅度降低.     

应用间接ELISA技术快速检测花鲈病原菌-鳗弧菌

以花鲈（Lateolabrax japonicus)弧菌病的病原菌－鳗弧菌（Vibrio auguillarum)W-1为抗原,制备兔抗血清;利用辣根过氧化酶标记的羊抗兔血清（HRP－IgG)为酶标二抗,建立了检测鳗弧菌的间接ELISA快速检测法。结果表明,应用间接ELISA技术检测鳗弧菌有较高的灵敏度,最低的检测量为10^5个／ml,即10^4个／孔。同时交叉反应表明其具有较高的特异性。对46份人工感染后的花鲈组织样品,包括肌肉、鳃、肠、肝、肾等组织的检测表明,阳性检测率为76．1％。     

集胞藻6803在封闭式光生物反应器中的混合营养培养

采用摇瓶和封闭式光生物反应器进行了蓝藻基因工程常用宿主系统集胞藻Syne-chocystis 6803的混合营养培养研究,在摇瓶中对集胞藻6803利用有机碳源特性进行研究的结果表明,光照是集胞藻6803利用葡萄糖的必需条件,混合营养培养是集胞藻6803的最佳培养方式,以葡萄糖为基质在2.5L封闭式光生物反应器中经过58.5h的混合营养培养,集胞藻6803的藻细胞密度和平均生长速度分别达到2.50g/L和1.01g/L/d,分别是光自养培养同期的9倍和11倍,这表明封闭式光生物反应器混合营养培养方式在促进集胞藻6803生长上有显著作用。     

酵母表达的重组草鱼生长激素对鲤鱼的促生长效应

通过发酵罐放大培养,优化发酵参数,提高了重组草鱼生长激素在酵母中的表达量。以含重组草鱼生长激素的酵母裂解物投喂鱼苗,实验组鱼体重的增加显著高于对照组,体长的亦高于对照组。鱼体生化组成分析表明：投喂转草鱼生长激素基因酵母裂解物能显著提高鱼体的干物质和蛋白含量,并降低鱼体脂肪酸含量。     

海洋鱼类资源的可持续利用和海洋鱼类科学技术的研究方向

积极实施海洋鱼类的增殖与养殖是海洋鱼类资源合理开发和可持续利用的基本措施和有效途径。因此，建立和提高海洋鱼类增殖与养殖的新技术，是近年来海洋生物技术的重要研究领域之一。海洋鱼类的生殖内分泌生理学、生长与发育生物学、免疫学、分子生物学等是海洋鱼类增殖与养殖的理论基础；系统深入地开展这些学科的基础研究和应用基础研究，成为当前海洋鱼类科学技术的前沿和主要发展方向。     

DF-3絮凝剂产生菌培养条件的优化

从花园土壤中筛选到一株有絮凝能力的菌株编号为DF-3,在温度为30℃,通气量（以摇床转速表示）为160r／min时通过实验确定DF-3的最佳培养条件：初始pH为8;20g／L果糖和5g／L葡萄糖为碳源;0．3g／L蛋白胨,0．5g／L酵母膏,0．5g／L尿素和0．2g／L（NH4）2SO4为最佳氮源;无机盐为2g／LKH2PO4,5g／L K2HPO4和0．1g／L NaCl。在这种条件下培养36小时所产微生物絮凝剂对高岭土悬浊液的絮凝率超过90％。     

Response surface optimization of electrochemical treatment of textile dye wastewater

The electrochemical treatment of textile dye wastewater containing Levafix Blue CA, Levafix Red CA and Levafix Yellow CA reactive dyes was studied on iron electrodes in the presence of NaCl electrolyte in a batch electrochemical reactor. The wastewater was synthetically prepared in relatively high dye concentrations between 400mg/L and 2000mg/L. The electrochemical treatment of textile dye wastewater was optimized using response surface methodology (RSM), where current density and electrolyte concentration were to be minimized while dye removal and turbidity removal were maximized at 28 degrees C reaction temperature. Optimized conditions under specified cost driven constraints were obtained for the highest desirability at 6.7mA/cm(2), 5.9mA/cm(2) and 5.4mA/cm(2) current density and 3.1g/L, 2.5g/L and 2.8g/L NaCl concentration for Levafix Blue CA, Levafix Red CA and Levafix Yellow CA reactive textile dyes, respectively.     

Batch growth kinetics of an indigenous mixed microbial culture utilizing m-cresol as the sole carbon source

An indigenous mixed microbial culture, isolated from a sewage treatment plant located in Guwahati was used to study biodegradation of m-cresol in batch shake flasks. m-Cresol concentration in the growth media was varied from 100mg/L to 900mg/L. The degradation kinetics was found to follow a three-half-order model at all initial m-cresol concentrations with regression values greater than 0.97. A maximum observed specific degradation rate of 0.585h(-1) was observed at 200mg/L m-cresol concentration in the medium. In the range of m-cresol concentrations used in the study, specific growth rate of the culture and specific degradation rates were observed to follow substrate inhibition kinetics. These two rates were fitted to kinetic models of Edward, Haldane, Luong, Han-Levenspiel, and Yano-Koga that are used to explain substrate inhibition on growth of microbial culture. Out of these models Luong and Han-Levenspiel models fitted the experimental data best with lowest root mean square error values. Biokinetic constants estimated from these two models showed good potential of the indigenous mixed culture in degrading m-cresol in wastewaters.     

Co-metabolic degradation of bensulfuron-methyl in laboratory conditions

The present study deals with the degradation of bensulfuron-methyl by microorganisms cultured with different sources of carbon, nitrogen and phosphorus. Addition of carbon source accelerated the degradation of bensulfuron-methyl under co-metabolism process. Sodium lactate was the best carbon source for the degradation of bensulfuron-methyl, compared to other carbon sources studied, and the degradation ratio of bensulfuron-methyl reached 79.5%, whereas only 34.6 and 29.7% were removed in the presence of glucose and sucrose, respectively. Supplement of nitrogen source also enhanced degradation of bensulfuron-methyl. However, no significant differences were observed in the loss of bensulfuron-methyl between organic nitrogen and inorganic source. Phosphate buffer was supplemented into the media to maintain neutral conditions for the advantage of the strain growth since increase in pH value was observed. An orthogonal array design was applied to arrange main factors singled out for investigating the influence of factor and interaction between them on the degradation of bensulfuron-methyl. Statistical analysis showed that the concentration of sodium lactate, bensulfuron-methyl and inoculum size were the main effects, and the interaction of sodium lactate and bensulfuron-methyl was of statistical significance.     

Statistical factor-screening and optimization in slurry phase bioremediation of 2,4,6-trinitrotoluene contaminated soil

Since slurry phase bioremediation is a promising treatment for recalcitrant compounds such as 2,4,6-trinitrotoluene (TNT), a statistical study was conducted for the first time to optimize TNT removal (TR) in slurry phase. Fractional factorial design method, 2(IV)(7-3), was firstly adopted and four out of the seven examined factors were screened as effective. Subsequently, central composite design and response surface methodology were employed to model and optimize TR within 15 days. A quadratic model (R(2) = 0.9415) was obtained, by which the optimal values of 6.25 g/L glucose, 4.92 g/L Tween 80, 20.23% (w/v) slurry concentration and 5.75% (v/v) inoculum size were estimated. Validation experiments at optimal factor levels resulted in 95.2% TR, showing a good agreement with model prediction of 96.1%. Additionally, the effect of aeration rate (0-4 vvm) on TR was investigated in a 1-liter bioreactor. Maximum TR of 95% was achieved at 3 vvm within 9 days, while reaching the same removal level in flasks needed 15 days. This reveals that improved oxygen supply in bioreactor significantly reduces bioremediation time in comparison with shake flasks.     

Biodegradation of p-nitrophenol by Rhodococcus sp. CN6 with high cell surface hydrophobicity

Rhodococcus sp. CN6, isolated from a pesticide industry's effluent-sediment, was able to completely degrade and utilize 100mg/L p-nitrophenol (PNP) as the sole carbon, nitrogen and energy sources for growth in the minimal salt media (MSM) within 12h. To study the applicability of the strain for bioremediation of PNP, its degradation potential was examined in the presence of different supplemented carbon and nitrogen sources in MSM with 100mg/L PNP. Dextrin was experienced as the best supplemented carbon source used by the strain CN6 during degrading PNP. Addition of ammonium nitrate could also increase the PNP degradation rate. Preliminary studies on the surface characters of Rhodococcus sp. CN6 were undertaken for the sake of exploring its high efficiency on the degradation of PNP. Microbial adherence to hydrocarbons (MATH) assays illuminated that the strain CN6 was of higher hydrophobicity while grown on higher concentration of PNP. The results suggested that the strain CN6 could be used as a potential and efficient PNP degrader for the bioremediation of contaminated sites.