宁波象山海域表层沉积物细菌群落季节性分布特征研究

分别在2013年夏季及2014年冬季采集宁波象山海域7个站位的表层沉积物样品, 利用16S rRNA基因扩增子MiSeq测序技术研究了沉积物细菌群落的季节性分布特征. 研究发现: 宁波象山海域海洋沉积物细菌群落主要由γ-变形菌纲、δ-变形菌纲、酸杆菌门、α-变形菌纲、绿弯菌门和拟杆菌门组成; 沉积物细菌群落的时空分布同时受地理距离、季节和环境理化因子等影响, 其中地理距离占主导地位, 且冬季地理距离对群落的影响更大.     

Enhancement of Antibiotic Activity by 1,8-Naphthyridine Derivatives against Multi-Resistant Bacterial Strains

The search for new antibacterial agents has become urgent due to the exponential growth of bacterial resistance to antibiotics. Nitrogen-containing heterocycles such as 1,8-naphthyridine derivatives have been shown to have excellent antimicrobial properties. Therefore, the purpose of this study was to evaluate the antibacterial and antibiotic-modulating activities of 1,8-naphthyridine derivatives against multi-resistant bacterial strains. The broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of the following compounds: 7-acetamido-1,8-naphthyridin-4(1H)-one and 3-trifluoromethyl-N-(5-chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide. The antibiotic-modulating activity was analyzed using subinhibitory concentrations (MIC/8) of these compounds in combination with norfloxacin, ofloxacin, and lomefloxacin. Multi-resistant strains of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were used in both tests. Although the compounds had no direct antibacterial activity (MIC ≥ 1.024 µg/mL), they could decrease the MIC of these fluoroquinolones, indicating synergism was obtained from the association of the compounds. These results suggest the existence of a structure–activity relationship in this group of compounds with regard to the modulation of antibiotic activity. Therefore, we conclude that 1,8-naphthyridine derivatives potentiate the activity of fluoroquinolone antibiotics against multi-resistant bacterial strains, and thereby interesting candidates for the development of drugs against bacterial infections caused by multidrug resistant strains.     

陆梁油田菌群结构解析及激活后群落变化

 针对新疆陆梁油田呼图壁河组注水井LU3064 注入水,设计一组营养剂激活配方,该配方能够成功乳化原油。经平板计数法、最大或然数计数法（MPN）和理化性质检测发现,激活后注入水菌浓明显增加,表面张力下降37%。采用建立细菌16S rDNA克隆文库方法,对LU3064 注入水、LU3036 采出液、LU3064 激活液细菌进行多样性研究。从克隆文库中随机挑选100 个克隆子测序,并在GenBank 中比对,结果表明,注入水菌群具有高度多样性,优势菌属于Alphaproteobacteria;采出液较地层水菌群结构简单,存在Pseudomonas（假单胞菌属）、Bacillus（芽孢杆菌属）等功能菌属;激活液菌群结构最为单一,仅存在Bacillus（芽孢杆菌属）。Bacillus 在注入水和采出液中均有发现,但都不是优势菌种。该激活剂配方成功激活了可在地层中生长的功能菌属Bacillus。     

Fabrication and Evaluation of Alginate/Bacterial Cellulose Nanocrystals–Chitosan–Gelatin Composite Scaffolds

It is common knowledge that pure alginate hydrogel is more likely to have weak mechanical strength, a lack of cell recognition sites, extensive swelling and uncontrolled degradation, and thus be unable to satisfy the demands of the ideal scaffold. To address these problems, we attempted to fabricate alginate/bacterial cellulose nanocrystals-chitosan-gelatin (Alg/BCNs-CS-GT) composite scaffolds using the combined method involving the incorporation of BCNs in the alginate matrix, internal gelation through the hydroxyapatite-d-glucono-δ-lactone (HAP-GDL) complex, and layer-by-layer (LBL) electrostatic assembly of polyelectrolytes. Meanwhile, the effect of various contents of BCNs on the scaffold morphology, porosity, mechanical properties, and swelling and degradation behavior was investigated. The experimental results showed that the fabricated Alg/BCNs-CS-GT composite scaffolds exhibited regular 3D morphologies and well-developed pore structures. With the increase in BCNs content, the pore size of Alg/BCNs-CS-GT composite scaffolds was gradually reduced from 200 μm to 70 μm. Furthermore, BCNs were fully embedded in the alginate matrix through the intermolecular hydrogen bond with alginate. Moreover, the addition of BCNs could effectively control the swelling and biodegradation of the Alg/BCNs-CS-GT composite scaffolds. Furthermore, the in vitro cytotoxicity studies indicated that the porous fiber network of BCNs could fully mimic the extracellular matrix structure, which promoted the adhesion and spreading of MG63 cells and MC3T3-E1 cells on the Alg/BCNs-CS-GT composite scaffolds. In addition, these cells could grow in the 3D-porous structure of composite scaffolds, which exhibited good proliferative viability. Based on the effect of BCNs on the cytocompatibility of composite scaffolds, the optimum BCNs content for the Alg/BCNs-CS-GT composite scaffolds was 0.2% (w/v). On the basis of good merits, such as regular 3D morphology, well-developed pore structure, controlled swelling and biodegradation behavior, and good cytocompatibility, the Alg/BCNs-CS-GT composite scaffolds may exhibit great potential as the ideal scaffold in the bone tissue engineering field.     

Identification of Bacteria Associated with Post-Operative Wounds of Patients with the Use of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry Approach

The bacterial infection of post-operative wounds is a common health problem. Therefore, it is important to investigate fast and accurate methods of identifying bacteria in clinical samples. The aim of the study was to analyse the use of the MALDI-TOF MS technique to identify microorganism wounds that are difficult to heal. The most common bacteria are Escherichia coli, Staphylococcus spp., and Enterococcus spp. We also demonstrate the effect of culture conditions, such as the used growth medium (solid: Brain Heart Infusion Agar, Mueller Hilton Agar, Glucose Bromocresol Purple Agar, and Vancomycin Resistance Enterococci Agar Base and liquid: Tryptic Soy Broth and BACTEC Lytic/10 Anaerobic/F), the incubation time (4, 6, and 24h), and the method of the preparation of bacterial protein extracts (the standard method based on the Bruker guideline, the Sepsityper method) to identify factors and the quality of the obtained mass spectra. By comparing the protein profiles of bacteria from patients not treated with antibiotics to those treated with antibiotics based on the presence/absence of specific signals and using the UniProt platform, it was possible to predict the probable mechanism of the action of the antibiotic used and the mechanism of drug resistance.     

细菌鞭毛染色制片方法的改进

本文按照细菌鞭毛标本片的染色细菌扣鞭毛结构完整、染色清晰、保存时间长的要求。比较了Ryu氏法扣饺银法。得出饺银法较好的结论。并针对饺银法。对细菌悬液的制备、培养时间的控制以及培养基的种类选择等进行实验,找到适合的鞭毛标本片制备过程以满足鞭毛标本片的染色要求。     

土霉素菌渣活性炭吸附处理低浓度含铬废水

采用活化法制备土霉素菌渣活性炭(菌渣炭),并用于处理低浓度含铬废水。经过组分测定可以看出土霉素菌渣含有较高的挥发分,灰分含量较低;元素分析中C、O元素的含量较高,表明土霉素菌渣含有大量的有机物和菌体蛋白;BET测得菌渣炭的比表面积、孔容和孔径都较大,通过扫描电镜可观察出菌渣炭具有较多的微孔和中孔,有利于对Cr(VI)定的吸附。通过单因素实验确定在初始Cr(VI)浓度为2mg/L时菌渣炭对Cr(VI)的最佳吸附pH、吸附剂投加量、吸附时间分别为4、0.5g/L、 50min, Cr(VI)的最高去除率为96.2%。热力学和动力学分析结果表明菌渣炭对Cr(VI)的吸附符合Freundlich等温吸附模型和准二级动力学模型。菌渣炭的饱和吸附量为17.93 mg/g,对Cr(VI)的吸附速率与吸附剂上未被占据的吸附位点的平方成正比。用1mol/L的HCl对菌渣炭进行洗脱再生,经过4次循环实验Cr(VI)的去除率为77.1%,剩余溶液中Cr(VI)浓度为0.459 mg/L,满足污水综合排放标准0.5 mg/L,菌渣炭的饱和吸附量为2.018 mg/g,表明菌渣炭的再生性能良好。     

杏鲍菇菌糠多糖对小鼠脾指数、脾淋巴细胞增殖及免疫因子的影响

目的 观察杏鲍菇菌糠多糖对小鼠脾指数、脾淋巴细胞增殖及免疫因子的影响。方法 将超声法提取制备的杏鲍菇菌糠多糖与基础饲料混合制成低剂量(200 mg/kg)、中剂量(400 mg/kg)及高剂量(800 mg/kg)三种多糖饲料。用48只KM小鼠,随机分为空白组,杏鲍菇菌糠多糖低、中、高剂量组。连续饲养60 d后,测定小鼠脾指数、脾淋巴细胞增殖和免疫因子IFN-γ、TNF-α及IL-6含量指标。结果 杏鲍菇菌糠多糖组与空白组相比,低剂量组显著提高脾指数(P<0.05),中剂量组能显著提高脾指数和脾淋巴细胞增殖(P<0.05),同时能提高免疫因子TNF-α、IL-6含量(P<0.05);高剂量组能显著提高小鼠的IFN-γ含量(P<0.05),极显著提高小鼠的脾指数、脾淋巴细胞增殖、TNF-α及IL-6含量(P<0.01)。结论 杏鲍菇菌糠多糖对小鼠的脾指数、脾淋巴细胞增殖及免疫因子具有调节作用。     

对氮掺杂二氧化钛抗菌剂中氮元素含量测定的不确定度评定

利用有机元素分析仪,对氮掺杂二氧化钛中氮元素的含量进行了测定,评定了其测量不确定度。分析了测定过程中的不确定度的来源,并对不确定度的各个分量进行了评定,给出了测定结果的合成不确定度和扩展不确定度。结果表明：不确定度可表示为（1.21±0.16）%,k=2,其中校准曲线对不确定度的影响最大。     

超级电容器用细菌纤维素基电极材料

超级电容器由于能提供比电池更高的功率密度,比传统电容器更高的能量密度而备受关注。但目前其应用仍存在能量密度低的问题。碳材料、金属氧化物和导电聚合物是常见的三种超级电容器电极材料,而其中不同形式碳材料是电容器中研究和应用最广泛的电极材料。细菌纤维素是由细菌分泌产生的具有一定纳米级孔径分布的多孔生物材料,具有高强度和模量、高孔隙率、极好的尺寸和热稳定性的特性。以细菌纤维素为原料制备电极材料是近年来超级电容器领域的热点研究方向之一。本文以细菌纤维素基电极材料的种类、制备方法和性能为线索,综述了国内外细菌纤维素基超级电容器电极材料的研究进展,并归纳总结了电极材料最优的形态和制备方法,进一步对该类电极材料的发展趋势进行了展望。