Chemical structure, surface properties and biological activities of the biosurfactant produced by Pseudomonas aeruginosa LBI from soapstock

Pseudomonas aeruginosa LBI isolated from petroleum-contaminated soil produced rhamnolipids (RL(LBI)) when cultivated on soapstock as the sole carbon source. HPLC-MS analysis of the purified culture supernatant identified 6 RL homologues (%): R(2) C(10) C(10) 28.9; R(2) C(10) C(12:1) 23.0; R(1) C(10) C(10) 23.4; R(2) C(10) C(12) 11.3; R(2) C(10) C(12) 7.9; R(2) C(10) C(12) 5.5. To assess the potential antimicrobial activity of the new rhamnolipid product, RL(LBI), its physicochemical properties were studied. RL(LBI) had a surface tension of 24 mN m(-1) and an interfacial tension of 1.31 mN m(-1); the cmc was 120 mg l(-1). RL(LBI) produced stable emulsions with hydrocarbons and vegetable oils. This product showed good antimicrobial behaviour against bacteria: MIC for Bacillus subtilis, Staphylococcus aureus and Proteus vulgaris was 8 mg l(-1), for Streptococcus faecalis 4 mg l(-1), and for Pseudomonas aeruginosa 32 mg l(-1). RL(LBI) was active against phytopathogenic fungal species, MIC values of 32 mg l(-1) being found against Penicillium, Alternaria, Gliocadium virens and Chaetonium globosum. Due to its physicochemical properties and antimicrobial behaviour, RL(LBI) could be used in bioremediation treatment and in the food, cosmetic and pharmaceutical industries.     

In Vivo Gene Transfer to the Mouse Nasal Cavity Mucosa Using a Stable Cationic Lipid Emulsion

We evaluate a new cationic emulsion as a mucosal gene carrier and elucidate the relationship between the transfection efficiency and the stability of the carrier/DNA complex. A cationic lipid emulsion was formulated with soybean oil and 1,2-dioleoyl-sn-glycero-3-trimethylammonium-propane (DOTAP) as major components and was used to transfer genes to the epithelial cells of the mouse nasal cavity via intranasal instillation. Correlation between the transfection efficiency and the stability of the carrier/DNA complex was investigated by measuring the carrier size changes and by observing the degree of DNA protection against DNase I digestion in the presence of heparin. The cationic emulsion showed at least 3 times better transfection activity than the liposomal carriers in nasal mucosae. The cationic emulsion was stable in the presence of heparin whereas the liposomal carriers became very unstable. Unlike DNA in liposome/DNA complexes, DNA in the emulsion/DNA complex was resistant to heparin exchange and DNase I digestion. The cationic emulsion was more effective in delivering DNA to nasal mucosae than commercially available liposomal carriers. The transfection activities of the lipid carriers in nasal cavity mucosae are in agreement with the stability of the lipid carriers and their complexes with DNA.     

Applying geographic information systems and remote sensing for water quality assessment of mangrove forest

The study of environmental conditions is one of the most important measures in the field of reforestation. The present study was undertaken to assess the environmental status of the mangrove forest of Alibaug, Maharashtra, India with respect to different sixteen physicochemical parameters of water using Geographical information system (GIS) for rehabilitation, conservation and development of the destructed area of the mangrove forest. The Base map of study area was prepared using topographic map and the remote sensing data of Landsat 7 ETM + for spatial analysis. The distributions of water pollutants were assigned using a GIS approach of Inverse Distance Weighted (IDW). The results showed that the amounts of EC, COD, hardness, O&G, Cl^?, Na⁺, Ca^2 +, Mg^2 +, NO₃^? and PO₄^3? are higher than the normal ranges in mangrove forest due to natural processes and human activity, industrial and domestic wastewater disposal, oil spillage and agricultural runoff which all eventually affect the water quality of mangrove forest of Alibaug. To identify the areas within the normal ranges of 16 studied parameter, suitability map of water was prepared through an integration of 16 suitability maps of the studied parameters. The suitability map of water classified the water to six classes of suitability in order of moderate > moderate to high > low to moderate > high > low suitable. The areas with classes of 1 and 2 were suitable for the protective measures. Classes 3 and 4 were suitable for replantation and restoration of native mangrove species as well as local communities' cooperation in the participatory protection measures. The areas of classes 5 and 0 need to be designed an urgent management and mitigation plan to reduce impact of human activities. The result of the study also proves the use of GIS as a powerful tool in addressing assessment and monitoring programs of the water quality in the mangrove ecosystems.     

极大螺旋藻多糖IPⅡA、IPⅡB的理化特性及抗肿瘤活性研究

极大螺旋藻（Ｓｐｉｒｕｌｉｎａｍａｘｉｍａ）经碱性热水抽提,酶解和Ｓｅｖａｇ法结合脱蛋白,醇沉淀得胞内多糖ＩＰⅠ．ＩＰⅠ经ＤＥ－５２和ＤＥＡＥ－ＳｅｐｈａｄｅｘＡ－２５柱层析得到组分多糖ＩＰⅡＡ和ＩＰⅡＢ,糖含量分别为７４．９％和６８．４％,ＩＰⅡＡ分子量为１．３×１０６,ＩＰⅡＢ分子量为５．０×１０５．以完全酸水解、薄层层析、气相层析、红外光谱、核磁共振氢谱对二者进行化学结构分析,证明均为酸性杂多糖;ＩＰⅡＡ糖苷键为α型,ＩＰⅡＢ中同时存在α和β型糖苷键．离体条件下,ＩＰⅠ与血癌细胞ＨＬ６０和Ｕ９３７分别共同培养,半固体琼脂培养法检测,结果表明,ＩＰⅠ对二者的作用具有选择性,同时ＩＰⅠ的促进和抑制作用均表现出一般药物所具有的剂量效应．     

温度对胸腺激素理化性质和生物活性的影响

为探讨胸腺激素耐受的最高温度,将胸腺因子Ｄ、胸腺素和胸腺肽加热至１２１℃、１２５℃、１３０℃,直至１９０℃１５ｍｉｎ。结果：加热１４０℃以下１５ｍｉｎ,其色泽、澄明度、紫外吸收峰、旋光度、ＰＨ值、蛋白质含量、相对比移值和活性玫瑰花形成率,与未加热样品比较,均无明显变化;加热至１５０℃以上,上述指标除紫外吸收峰外,余均显著改变。结果表明,胸腺因子Ｄ、胸腺素和胸腺肽能耐受１４０℃１５ｍｉｎ。     

HBV整合片段对人PCNA基因启动子的调控

Ｈ７Ｃ是从一例肝癌组织中克隆得到的ＨＢＶ整合片段,其中保留有ｐｒｅＳ２基因的启动子及Ｃ端缺失的ｐｒｅＳ／Ｓ蛋白的阅读框架,我们用共转染方法研究了该整合片段地增殖细胞核抗原启动子的影响。结合表明在ＨｅｐＧ２细胞中,含有上述ＨＢＶ整合片段ＤＮＡ的质粒ＰＫＳＨ７Ｃ－ＨｐａＩ能以剂量依赖方式激活ＰＣＮＡ启动子。对ＳＶ４０启动子而言,ＰＣＮＡ启动子有１－２倍的更高激活。而破坏ｐｒｅＳ／Ｓ表达的两个亚克隆ＰＫ     

Comparison of frog albumins with those of other vertebrates

Summary Serum albumin was purified from two frog species (Rana pipiens andR. catesbeiana) and compared by several physical, chemical and immunological techniques with the purified albumins of a reptile, a bird and three mammals. Although the frog albumins proved to be very similar to those of other vertebrates in physical and chemical properties, no immunological relationship was detected in direct precipitin and complement fixation tests. The absence of an immunological relationship between frog albumins and those of other vertebrates is expected because other evidence indicates that albumin evolves very rapidly. Fossil evidence indicates that the lineage leading to frogs separated from those leading to other vertebrates so long ago that we should expect frog albumins to have become more than 40% different in amino acid sequence from those of other vertebrates and thus to exhibit no cross reactivity in direct precipitin or complement fixation tests.     

Hexane Extract of Echinops spinosissimus Turra subsp. spinosus from Tunisia: A Potential Source of Acetylated Sterols – Investigation of its Biological Activities

The hexane extract of Echinops spinosissimus Turra subsp. spinosus flower heads was analyzed for its fatty acid and sterol composition. Its physicochemical characteristics were also studied. The saponification, iodine and peroxide values were determined as 255 mg KOH/g, 42.57 g I₂/100 g and 110 m equiv. O₂/kg of oil, respectively. The oleic (C18:1; 61.14%), palmitic (C16:0; 21.36%) and linoleic (C18:2; 10.45%) acids were the dominant fatty acids. This extract was also found to contain high levels of β‐sitosterol and stigmasterol (44.97% and 34.95% of total sterols, respectively). On the other hand, the identification of terpenoid compounds was investigated by using GC/MS, which revealed fourteen major terpenoids mainly taraxasterol, lupeol, pseudotaraxasterol, lup‐22(29)‐en‐3‐yl acetate, taraxasteryl acetate, α‐amyrin, β‐amyrin, pseudotaraxasteryl acetate, hop‐20(29)‐en3‐β‐ol, α‐amirenone, along with β‐sitosterol and stigmasterol. Moreover, we have evaluated the in vitro antibacterial and antifungal activities of the unsaponifiable matter and a fraction isolated from this extract. These activities were conducted using the diffusion disc methods and broth microdilution assay. The resulted fraction from this extract showed the highest antibacterial activity with significant minimum inhibitory concentrations (MIC) values 125.0 μg/ml against Staphylococcus aureus, Micrococcus luteus and Bacillus cereus. However, it did exhibit no substantial antifungal activity.     

Synthesis and evaluation of Quinoline-3-carbonitrile derivatives as potential antibacterial agents

New quinoline-3-carbonitrile derivatives were synthesized and evaluated for their potential antibacterial behavior. Compounds were obtained by a one-pot multicomponent reaction of appropriate aldehyde, ethyl cyanoacetate, 6-methoxy-1,2,3,4-tetrahydro-naphthalin-1-one and ammonium acetate. Structures were established by different physical and spectroscopic techniques. The molecular geometry, vibration frequencies, HOMO–LUMO energy gap, molecular hardness (g), ionization energy (IE), electron affinity (EA), and total energy of these compounds was assessed by DFT studies, employing DFT/RB3LYP method. Preliminary antibacterial studies using both Gram-positive and Gram-negative bacterial strains and cytotoxicity studies on mammalian cells revealed their promising antibacterial activity, without causing any severe host toxicity. All the compounds (QD1-QD5) in this study obeyed the ‘Lipinski’s Rule of Five’ with logP values <5 and HBA <10, hydrogen bond donor’s <5. The most active compound QD4 showed good interaction with the target DNA gyrase; target enzyme for quinoline class of antibiotics, which reveals its probable mechanism of action. Results of all these studies establish these compounds as important scaffolds with broad-spectrum antibacterial activity with no off-target toxicity. Having lower band gap energy of 3.40 eV and a low lying LUMO for compound QD4, this compound may be a valuable starting point for the development of quinoline-3-carbonitrile based broad-spectrum antibacterial agents.     

Progress in physicochemical parameters of microalgae cultivation for biofuel production

Microalgae have been exploited for biofuel generation in the current era due to its enormous energy content, fast cellular growth rate, inexpensive culture approaches, accumulation of inorganic compounds, and CO₂ sequestration. Currently, research is ongoing towards the advancement of the microalgae cultivation parameters to enhance the biomass yield. The main objective of this study was to delineate the progress of physicochemical parameters for microalgae cultivation such as gaseous transfer, mixing, light demand, temperature, pH, nutrients and the culture period. This review demonstrates the latest research trends on mass transfer coefficient of different microalgae culturing reactors, gas velocity optimization, light intensity, retention time, and radiance effects on microalgae cellular growth, temperature impact on chlorophyll production, and nutrient dosage ratios for cellulosic metabolism to avoid nutrient deprivation. Besides that, cultivation approaches for microalgae associated with mathematical modeling for different parameters, mechanisms of microalgal growth rate and doubling time have been elaborately described. Along with that, this review also documents potential lipid-carbohydrate-protein enriched microalgae candidates for biofuel, biomass productivity, and different cultivation conditions including open-pond cultivation, closed-loop cultivation, and photobioreactors. Various photobioreactor types, the microalgae strain, productivity, advantages, and limitations were tabulated. In line with microalgae cultivation, this study also outlines in detail numerous biofuels from microalgae.