Mechanism of rhamnolipid promoting the degradation of polycyclic aromatic hydrocarbons by gram-positive bacteria-Enhance transmembrane transport and electron transfer.

In this study, the Gram-positive bacterium Bacillus licheniformis T5 was utilized to investigate the impact of rhamnolipid on cell membrane and cell wall, as well as enzyme activity and electron transfer rate within cells. Results indicated that at the optimal concentration of rhamnolipid (200 mg/L), the cell membrane protein and cell wall peptidoglycan content of T5 decreased significantly. Infrared spectrum analysis and ultrastructure observations confirmed these findings, revealing noticeable changes in cell morphology in the presence of rhamnolipid.

Simultaneous biodegradation of phenolics and petroleum hydrocarbons from semi-coking wastewater: Construction of bacterial consortium and their metabolic division of labor.

Phenols and petroleum hydrocarbons were the main contributors to COD in semi-coking wastewater, and their removal was urgent and worthwhile. The microbial strains were selected to construct microbial community for the wastewater treatment. The concentration of phenols was decreased from 2450 ± 1.

Toxicity evaluation of the metabolites derived from the degradation of phenanthrene by one of a soil ubiquitous PAHs-degrading strain Rhodococcus qingshengii FF.

Rhodococcus qingshengii strain FF is a soil ubiquitous strain that has a high polycyclic aromatic hydrocarbons (PAHs) biodegradation capability. In this work, phenanthrene was used as a PAH model compound. The accumulated pattern of the metabolites of phenanthrene by strain FF was investigated, and their toxicity to Vibrio fischeri, effect on microbiota diversity of farmland soil and influence on seed of wheat were evaluated.

A novel Ca indicator for long-term tracking of intracellular calcium flux.

The major drawback of using Fluo-4 AM is that it requires an organic anion transporter inhibitor, such as probenecid, to prevent leakage. This can hinder the studies that require extended monitoring time and longer cellular retention. To address the issue, a novel Ca indicator, Calbryte 520 AM, was developed.

Optimization and characterization of rhamnolipid production by Pseudomonas aeruginosa NY3 using waste frying oil as the sole carbon.

Yield and cost are two major factors limiting the widespread use of rhamnolipids (RLs). In the present study, waste frying oil (WFO) was used as the sole carbon source to produce environmentally friendly RLs by Pseudomonas aeruginosa NY3. The Plackett-Burman design (PBD) and Box-Behnken design (BBD) methods were used to maximize the production yield of RL.

Immobilization of Rhodococcus qingshengii strain FF on the surface of polyethylene and its adsorption and biodegradation of mimic produced water.

Low pH and high salinity characteristic of produced water (PW) posed a big challenge for the direct biological treatment. The immobilization of R. qingshengii strain FF, which degraded petroleum effectively under low pH, and application of immobilized R.

Homogeneously catalytic oxidation of phenanthrene by the reaction of extracellular secretions of pyocyanin and Nicotinamide Adenine Dinucleotide.

Application of biological methods on polycyclic aromatic hydrocarbons (PAHs) treatment is always limited by its low degradation efficiency. In this work, a catalytic oxidation pathway of phenanthrene resulted by extracellular secretions of P. aeruginosa NY3 was proposed.

A highly selective fluorescent probe for the intracellular measurement of magnesium ion.

Magnesium ion (Mg) plays an important role in various biological processes. All the commercial indicators available share a common drawback, i.e.

Establishment and application of a novel fluorescence-based analytical method for the rapid detection of viable bacteria in different samples.

A rapid method for readily detecting the total numbers of viable bacterial cells in numerous samples (including surface water, solid inoculants, and soil samples) is reported using a newly developed hand-held fluorometer and a fluorescent dye Calcein UltraGreen™ AM. Compared to the traditional plate counting method that requires 48 hours of cultivation, the newly established method does not require any incubation time, making the detection method faster and more convenient. The portable rapid detection fluorometer has a wide dynamic range of relative fluorescence intensity from 45 to 30 133.

Biological treatment of high salinity and low pH produced water in oilfield with immobilized cells of P. aeruginosa NY3 in a pilot-scale.

Produced water (PW) in oilfield, as the largest waste streams in the oil and gas production, has posed a huge threat to the ecosystem. In this work, an environmentally friendly and recyclable biofilms have been developed for treating PW. We discovered that the cells of P.

Evidences of extracellular abiotic degradation of hexadecane through free radical mechanism induced by the secreted phenazine compounds of P. aeruginosa NY3.

The aim of this work was to investigate the effects of secreted extracellular phenazine compounds (PHCs) on the degradation efficiency of alkanes by P. aeruginosa NY3. Under aerobic conditions, the PHCs secreted by P.

Fluorescent real-time quantitative measurements of intracellular peroxynitrite generation and inhibition.

Peroxynitrite (ONOO), a strong oxidant species, is produced by the reaction of nitric oxide (NO) and superoxide (O) radicals. It plays an important role as a biological regulator in numbers of physiological and pathological processes. In this study, we developed fluorescence-based real-time quantitative measurements to detect intracellular ONOO.

New violet-excitable reagents for multicolor flow applications.

We have recently added three new fluorophores-BD Horizon™ V450, BD Horizon V500, and BD Horizon V550 (V450, V500, and V550; BD Biosciences, San Jose, CA) to our existing AmCyan product, forming a group of four violet-excitable dyes from which we have produced functional antibody conjugates. These conjugates, with emission maxima that range from 450 to 535 nm, are compatible with multilaser flow cytometry (FCM) and can be used for polychromatic FCM in three-color or two-color combinations; in fact, V500 fills a spectral opening that has thus far not been exploited by other manufacturers of FCM reagents. We here report that conjugates based on BD Horizon dyes performed well within a useful sensitivity range, established by testing a representative group of violet-excitable FCM reagents currently available, and that V500 has better compatibility with FITC in multicolor applications than does AmCyan.

3-Carboxy-6-chloro-7-hydroxycoumarin: a highly fluorescent, water-soluble violet-excitable dye for cell analysis.

In our search for new violet-excitable dyes with improved photophysical and photochemical properties, we examined several halogen-substituted hydroxycoumarins and found that chlorinated derivatives are at least as bright as their fluorinated analogs. A monochlorinated hydroxycoumarin was found to have a high quantum yield (approximately 0.98), and human leucocyte-specific monoclonal antibodies (CD3, CD4, and CD45) conjugated with this dye exhibited reliable performance in flow cytometry assays.

A novel fluorogenic coumarin substrate for monitoring acid phosphatase activity at low pH environment.

This article described the synthesis and application of 6-chloro-8-fluoro-4-methylumbelliferone phosphate (CF-MUP) in analyzing acid phosphatase activity. Compared to the existing MUP, the new coumarin phosphate, CF-MUP, demonstrateed much higher sensitivity and was more robust for detecting the activity of acid phosphatase than the classic substrate 4-methylumbelliferone phosphate (MUP). The product of enzyme reaction, 6-chloro-8-fluoro-4-methylumbelliferone (CF-MU) possesses strong fluorescence at approximately 450 nm with low pKa (4.

Real-time and high throughput monitoring of cAMP in live cells using a fluorescent membrane potential-sensitive dye.

Adenosine-3',5'-cyclic monophosphate (cAMP) conveys the signals from G-protein coupled receptors (GPCRs) and regulates a variety of downstream cellular events. However, there are few robust assays available for measuring cAMP in live cells. Most of the existing cAMP assays require cell lysis and/or have relatively low throughput.

N-DEVD-N'-morpholinecarbonyl-rhodamine 110: novel caspase-3 fluorogenic substrates for cell-based apoptosis assay.

A novel caspase-3 substrate N-Ac-DEVD-N'-MC-R110, which is a fluorogenic substrate cleavable in a single step, has been prepared. It has a significantly higher enzyme turnover rate and sensitivity for detecting caspase-3 activity both in solution and living cells than existing fluorogenic substrates.

Fluorescent sodium ion indicators based on the 1,7-diaza-15-crown-5 system.

A series of novel sodium ion-sensitive fluorescent reagents suitable for biological applications is described. The chelator nitrogen atom substituents affect the selectivity and affinity of cation binding, while the nature of the fluorophore determines the type of fluorescent response to metal ion chelation.

Fluorescence detection and quantitation of recombinant proteins containing oligohistidine tag sequences directly in sodium dodecyl sulfate-polyacrylamide gels.

Two fluorophore-nitrilotriacetic acid conjugates, Pro-Q Sapphire 365 and Pro-Q Sapphire 488 oligohistidine gel stains, have been developed for the fluorescence detection of fusion proteins containing oligohistidine tags directly in sodium dodecyl sulfate polyacrylamide gels, without the requirement for electroblotting, reporter enzymes or secondary detection reagents. Pro-Q Sapphire 365 oligohistidine gel stain exhibits bright-blue fluorescence (emission maximum = 450 nm) when illuminated with UV-A or UV-B light from a standard ultraviolet transilluminator. Pro-Q Sapphire 488 oligohistidine gel stain exhibits bright-green fluorescence (emission maximum = 515 nm) when illuminated with visible light from a laser-based gel scanner equipped with a 470 nm second-harmonic generation (SHG) or 488 nm argon-ion laser source.