Isolation from coastal sea water and characterization of bacterial strains involved in non-ionic surfactant degradation

A bacterial community degrading branched alkylphenol ethoxylate (APE) was selected from coastal sea water intermittently polluted by urban sewage. This community degraded more than 99% of a standard surfactant, TRITON X 100, but I.R. analysis of the remaining compound showed the accumulation of APE₂ (alkylphenol with a two units length ethoxylated chain) which seemed very recalcitrant to further biodegradation. Twenty-five strains were isolated from this community, essentially Gram negative and were related to Pseudomonas, Oceanospirillum or Deleya genera. Among these strains, only four were able to degrade APE_9–10 (TRITON X 100). They were related to the Pseudomonas genus and were of marine origin. Pure cultures performed with these strains on TRITON X 100 gave APE₅ and APE₄ as end products. These products were further degraded to APE2 by two other strains unable to degrade the initial surfactant.     

The Clara cell and pulmonary surfactant: A study using selective chemical ablation

Administration of 3-hydroxymethylfuran-N-ethylcarbamate (HFC) to female hamsters via the jugular vein under pentobarbitone anaesthetic at 20 mg per kg body weight produced pronounced necrosis of the Clara cells without apparent morphological effect on other cell types as judged by transmission electron microscope examination. The surfactant material recoverable by minimal lavage followed by purification by sucrose gradient ultracentrifugation increased, reaching a maximum around 48 h after treatment. At this time static pressure/volume measurements on isolated lungs indicated an increase in airway surface compliance. Lavageable surfactant phospholipid composition was examined by ³¹P nuclear magnetic resonance (n.m.r.). The distribution of phospholipids between the various classes was unchanged by HFC treatment. No change in the total lung surfactant pool size was seen. These results are discussed in relation to the possible roles of the Clara cell in influencing airway surfactant levels.     

Influence of extracellular matrix and collagen components on alveolar type 2 cell morphology and function

Summary The effects of various extracellular matrices and collagenous components on the morphology, growth, and function of cultured alveolar type 2 cells is examined. Cells grown on an endothelial matrix (EC) showed the greatest adherence, some cell division, and spreading to reach confluence sooner than cells grown on an epithelial matrix or on various types of collagen. The attenuated cells from all cultures were not true type 1 cells because, on trypsinization, they detached as sheets, reverted immediately to a cuboidal shape held together by junctional complexes, and showed an apparently normal content of lamellar bodies. The greatest synthesis of disaturated phosphatidylcholine (DSPC) was seen in cells grown on EC soon after confluence, but all cultures showed reduced but equal levels of DSPC-DNA by Day 4. This occured whether cells were attenuated or cuboidal in shape. The results suggest that some component(s) of the endothelial matrix at the alveolar basement membrane facilitates epithelial cell growth. However, over longer culture periods the matrix preparations had little effect on type 2 cell proliferation whereas function diminished. This suggests that maintenance of these cells as normal type 2 cells or their further differentiation to the type 1 form requires some additional cell derived factor(s). This research was supported by grants from the Medical Research Council of Canada and the Council for Tobacco Research, U.S.A., Inc.     

Synthesis and reactivity of cationic bipyridine tungsten(0) and molybdenum(0) nitrosyl complexes

A variety of Group 6 mono bipyridine (bpy) complexes were prepared, and substitution reactions of [(bpy)(MeIm)M(CO)₂(NO)]PF₆ complexes (MeIm = 1-methylimidazole, M = W or Mo) were investigated. Nitrosylation of complexes having the general formula (bpy)(L)M(CO)₃ (L = a variable ligand) gave cationic complexes of the form [(bpy)(L)M(CO)₂(NO)]PF₆. The structure of [(bpy)(MeIm)W(CO)₂(NO)]PF₆ was confirmed by single-crystal X-ray diffractometry. [(bpy)(MeIm)M(CO)₂(NO)]PF₆ complexes undergo facile substitutions with mono-, tri- and tetra-dentate ligands, yielding di- or mono-carbonyl mononitrosyl complexes. The structures of [(bpy)(PMe₃)₂W(CO)(NO)]PF₆ and [(dien)(PMe₃)W(CO)(NO)]PF₆ (dien = diethylenetriamine) were determined by X-ray diffraction.     

Evaluation of intra-amniotic surfactant administration for lung maturation in preterm sheep

We aimed to evaluate the effects of intra-amniotic surfactant administration on alveolar lecithin/sphingomyelin ratio, density of type II pneumocytes, and fetal lung function in preterm merino sheep. Pregnant ewes at 119 days gestation either received 200 mg intra-amniotic surfactant (n=4) or saline solution (n=4). After 24 h, the lambs were delivered by hysterotomy and mechanically ventilated. Lecithin/sphingomyelin ratios in alveolar fluid, inflating pressure–volume relationships, and type II pneumocyte counts in histological specimens were compared among the groups. All of the lambs completed the protocol. Mean lecithin/sphingomyelin ratio increased significantly in amniotic (p=0.03) and alveolar fluid (p=0.03) samples of surfactant-treated animals. Lung function in terms of pressure–volume curves did not differ between two groups. Type II pneumocyte density tended to be higher (p=0.057) after intra-amniotic surfactant administration. Single-dose treatment with intra-amniotic surfactant seems to improve amniotic and alveolar lecithin/sphingomyelin ratio questionably by increasing alveolar type II cells. Pressure–volume relationships from inflation of the lungs might be unaltered with intra-amniotic surfactant treatment.     

阴阳离子表面活性剂对无花果叶中有效成分提取工艺优化及初步功能评价

对阴阳离子复配型表面活性剂联合微波辅助提取无花果叶中有效活性物质的实验条件进行了设计和工艺参数的优化，最终的结果如下：1%（w/v）阴阳离子复配型表面活性剂，提取温度40℃，提取时间10 min，液固比30：1 mL·g^-1。在上述优化的条件下补骨脂素及佛手柑内酯的平均提取率分别为15.37和3.59 mg·g^-1。通过将利用表面活性剂辅助提取与常规水溶液提取获得的无花果叶粗提物进行对比发现，加入了表面活性剂的溶液抗氧化能力有明显增强，同时无花果叶主要物质的降解也得到显著的抑制，对植物中天然有效目标产物的绿色高效提取以及功能评价具有十分重要的理论指导意义。     

Chiroptical properties of lecithin reverse micelles and organogels

The ultraviolet absorbance and circular dichroism (CD) spectra of lecithin reverse micelles and gels were investigated in order to establish whether the formation of these noncovalent macromolecular aggregates, which was induced by the addition of water to solutions of lecithin in organic solvents, was accompanied by specific spectroscopic changes. Systems containing the synthetic short-chain lecithins, 1,2-hexanoyl-, 1,2-diheptanoyl-, 1,2-dioctanoyl-, and 1,2-dinonaoyl-sn-glycero-3-phosphatidylcholines were used as models for the long-chain lecithins, soybean phosphatidylcholine and palmitoyl-oleoyl-phosphatidylcholine. All the molecules studied had asymmetric centres, formed reverse micelles under appropriate conditions, and, while both the long-chain lecithins also formed gels, none of the short-chain molecules did. As well as having CD spectra that were simpler to interpret, spectroscopic observations on solutions of the short-chain lecithins could be carried out over a large water content range. The ester chromophore of these compounds was shown to be highly sensitive to variation in both the solvent environment and the temperature, and components of both direct solvent effects and conformational change upon the addition of water were detected in the spectra. The spectra of the longer chain lecithins were complicated by the presence of double bonds although, here again, it was found that significant changes occurred as the water content increased, as monitored by the ester chromophore. However, no specific effect that could be ascribed to gelation alone was detected. The overall picture that emerged was that the ester chromophore of anhydrous micelles gave rise to a specific negative band in the CD spectrum (λ_max ≈ 210 nm) whereas a positive CD signal (λ_max ≈ 233 nm) was associated with the same chromophore in filled (i.e., hydrated) micelles. The two signals correspond to two different conformational states of the lecithin molecule, the hydrated state being not only more conformationally restricted but also providing a less polar environment for the ester groups, while the addition of water to the system shifts the conformational equilibrium. These observations have been interpreted as showing that only a limited range of lecithin conformation is compatible with the formation of the micellar structure and that it is this constraint, together with those introduced by the overall geometry of the aggregated state, that gives rise to the changes observed in the CD spectrum.     

离子及表面活性剂对蜡状芽孢杆菌S1发酵的影响

APS是一种由新近分离的蜡状芽孢杆菌（Bacillus cereus）菌株S1分泌产生的新型抗真菌环状多肽。研究了不同的离子对菌株S1发酵生产APS的影响，结果表明，阳离子如K^ ,Na^ ,Al^3 对S1产素APS的产生有促进作用，而Ca^2 ,Fe^2 ,Mg^2 表现出抑制作用，有离子中H2PO4^-,HPO^2-4，对产素的产生具有较强的抑制作用，其它阴离子表现出中性作用，在S1发酵的过程，加入浓度为0．2％－0．8％Tween20和10－100u/mL的青霉素G能够增加APS的效价。     

Extraction of lactic acid with colloidal liquid aphrons and comparison of their toxicities with solvents without surfactant on the viability of Lactobacillus rhamnosus

Colloidal liquid aphrons (CLAs) are surfactant-stabilized solvent droplets which have recently been explored for predispersed solvent extraction (PDSE). We have compared the equilibrium distribution of lactic acid with solvent alone and with CLAs. In spite of the short contact time in the PDSE process with CLAs, there was little difference in equilibrium distribution with solvent alone. The toxicity of extractants and diluents on Lactobacillus rhamnosus was measured for in situ extraction. Long chain alcohols such as 1-octanol and 1-decanol were less toxic among diluents. CLAs reduced the toxicity of solvents on Lactobacillus rhamnosus.     

Physiological role of phosphatidylcholine in the Pseudomonas putida A ATCC 12633 response to tetradecyltrimethylammonium bromide and aluminium

Aims:  To evaluate the effect of tetradecyltrimethylammonium bromide (TTAB) and aluminium stresses on the phospholipid (PL) composition of Pseudomonas putida A ATCC 12633.
Methods and Results:  Pseudomonas putida were grown with TTAB in the presence or absence of AlCl₃, and the PL composition was analysed. The presence of TTAB resulted in an increase in phosphatidylglycerol and phosphatidic acid levels (6- and 20-fold, respectively) with respect to the levels in cells grown without the surfactant. With AlCl₃, phosphatidylcholine (PC) increased (threefold) and cell-free extracts contained approximately threefold more phosphatidylcholine synthase activities than extracts without AlCl₃, indicating that the PC level is dependent upon activation of this enzyme.
Conclusions:  The negative charges of the headgroups of PL are the primary membrane-associated factors for the response to TTAB. PC are involved in cellular responses to binding Al³⁺ and should be viewed as a temporary reservoir of available Al³⁺ to allow a more efficient utilization of TTAB by Ps. putida .
Significance and Impact of the Study:  The changes in the PL of Ps. putida in the presence of TTAB and AlCl₃ indicate that different responses are utilized by bacteria to maintain optimal PL composition in the presence of such environmental pollutants.