Vibrio Fisheri Research Articles

Combination of Fenton oxidation and sequencing batch membrane bioreactor for treatment of dry-spun acrylic fiber wastewater

Dry-spun acrylic fiber (DAF) is typically synthesized by the polymerization of acrylonitrile (AN) monomers under high-temperature conditions. DAF manufacturing factories produce DAF polymerization and AN manufacturing wastewaters that are complex, toxic and bio-refractory. In this study, a bench-scale combined Fenton-sequencing batch membrane bioreactor (SBMBR) process was developed for DAF wastewater treatment. Fenton oxidation was used for the pretreatment of DAF polymerization wastewater, with which the COD removal efficiency exceeded 47.0 % under the optimum conditions of H2O2 90.0 mM, Fe2+ 20.0 mM, pH value 3.0, and reaction time 120 min. The pretreatment increased the BOD5/COD ratio of DAF polymerization wastewater from 0.35 to 0.69 and observably decreased the toxicity (assessed with the Vibrio fisheri bacteria light loss) from 92.0 to 32.0 %. As for the biological treatment, the mixture liquor of Fenton effluent and AN manufacturing wastewater was fed to a bench-scale SBMBR system. Under the designed operation conditions, the average COD, NH4 +–N and TN removal efficiencies reached 82.5, 98.4 and 74.6 %, respectively. The final effluent of SBMBR could steadily meet the National Discharge Standard of China of Grade I (GB8978-1996). The polyvinylidene fluoride flat-plate membranes used in this study showed excellent anti-fouling performance throughout the operation period.

Phylogenetic Investigations on the Endosymbiotic Bacteria of Axinella donnani

The present study focuses on the isolation of endosymbiotic bacteria from eight different types of sponges. The sponges were collected from the southern peninsular coast of India and identified as Sigmadocia carnosa, Ircinia fasciculate, Callyspongia diffusa, Zygomycale angulosa, Clathria vulpine, Clathria gorgonids, Phloeodictyon species and Axinella donnani. For the isolation of endosymbionts, the collected sponge species were cultured in three different media such as Nutrient agar media, Zobell marine agar and Zobell marine agar + sponge extracts. The sponge extracts supplemented media produced high bacterial growth than the other media. The sponge A. donnani, recorded the highest bacterial counts. Of which, 13 endosymbiotic bacterial strains (ESB) of A. donnani were screened against common pathogenic bacteria. The strains ESB-3 and ESB-7 were identified to be potential strains exhibiting significant antibacterial property. The antibacterial activity was evaluated through testing against various shrimp pathogens (Vibrio esturiances, Vibrio alginolyticans, Vibrio harvae, Aeromonas hydrophila and Pseudomonas aerogenosa) as well as human pathogens (Streptococcus hemolyticus, Vibrio fisheri, Escherichia coli, Morgenella morgenii, and Bacillus cereus). The strains exhibited significant activity against all the shrimp and human pathogens. The unknown bacterial strain (ESB3 and ESB7) were identified using 16S rRNA gene technique to be Bacillus subtilis, Further, sequencing methodologies verified that the FASTA sequence of ESB3 contains 994 residues and that of ESB7 contains 1023 residues. The result so these findings are presented and elaborately discussed in the following paper.

Degradation and transformation of atrazine under catalyzed ozonation process with TiO2 as catalyst

Degradation of atrazine by heterogeneously catalyzed ozonation was carried out with TiO2 in the form of rutile as the catalyst. Some experimental factors such as catalyst dose, ozone dose and initial concentration of atrazine were investigated for their influence on catalyzed ozonation process. Although atrazine was effectively removed from aqueous solution by catalyzed ozonation process, the mineralization degree only reached 56% at the experimental conditions. Five transformation products were identified by GC/MS analysis. The degradation of atrazine involved de-alkylation, de-chlorination and de-amination. Diaminotriazine and 5-azauracil were the de-chlorinated and de-aminated products, respectively. The evolution of concentration of transformation products during catalyzed ozonation process was compared with uncatalyzed ozonation to show the degradation pathway. Toxicity tests based on the inhibition of the luminescence emitted by Vibrio fisheri indicated the detoxification of atrazine by catalyzed ozonation.

Photosonochemical degradation of butyl-paraben: Optimization, toxicity and kinetic studies

The objective of the present work is to evaluate the potential of a photosonolysis process for the degradation of butyl-paraben (BPB). After 120min of treatment time, high removal of BPB was achieved by the photosonolysis (US/UV) process (88.0±0.65%) compared to the photochemical (UV) and the conventional ultrasonication (US) processes. Several factors such as calorimetric power, treatment time, pH and initial concentration of BPB were investigated. Using a 24 factorial matrix, the treatment time and the calorimetric power are the main parameters influencing the degradation rate of BPB. Subsequently, a central composite design methodology has been investigated to determine the optimal experimental parameters for BPB degradation. The US/UV process applied under optimal operating conditions (at a calorimetric power of 40W during 120min and under pH7) is able to oxidize around 99.2±1.4% of BPB and to record 43.3% of mineralization. During the US/UV process, BPB was mainly transformed into 1 hydroxy BPB, dihydroxy BPB, hydroquinone and 4-hydroxybenzoic acid. Microtox biotests (Vibrio fisheri) showed that the treated effluent was not toxic. The pseudo-first order kinetic model (k=0.0367min−1) described very well the oxidation of BPB.

Identification of intermediates and ecotoxicity assessment during the UV/H2O2 oxidation of azo dye Reactive Orange 16

Degradation of azo dye Reactive Orange 16, a widely used textile dye, was carried out with UV light in the presence of H2O2. The experiments were conducted in the batch mode using low-pressure mercury lamps, emitting at 253.7 nm. Liquid-chromatography tandem mass spectrometry (LC/MS/MS) and high resolution mass spectrometry (FT-ICR) were employed in order to identify some of degradation products as well as to suggest possible degradation pathways. According to the mass spectrum characterization of RO16 dye and MSn fragmentation (up to MS4), its possible fragmentation pattern was proposed. The results revealed that degradation occurred mainly via hydroxylation, cleavage of the C‒S bond between the aromatic ring and the sulfonate group, cleavage of the azo bond, cleavage of the C‒N bond between azo group and naphthalene ring and aromatic ring opening. Toxicity test with marine photobacterium Vibrio Fisheri was performed to consider whether or not the UV/H2O2 treatment of RO16 dye results in the products with enhanced toxicity for aquatic life.

Photoelectrocatalytic degradation of carbamazepine using Ti/TiO2 nanostructured electrodes deposited by means of a pulsed laser deposition process

The objective of the present work is to evaluate the potential of photoelectrocatalytic oxidation (PECO) process using Ti/TiO2 for the degradation of carbamazepine (CBZ). Ti/TiO2 prepared by pulsed laser deposition (PLD) has been used as a photo-catalyst in a photoelectrocatalytic cell. The PLD TiO2 coatings were found to be of anatase structure consisting of nanocrystallites of approximately 15nm in diameter. Factorial and central and extreme composite design methodologies were successively employed to define the optimal operating conditions for CBZ degradation. Several factors such as current intensity, treatment time, pollutant concentration and cathode material were investigated. Using a 24 factorial matrix, the best performance for CBZ degradation (53.5%) was obtained at a current intensity of 0.1 A during 120min of treatment time and when the vitreous carbon (VC) was used at the cathode in the presence of 10mgL−1 of CBZ. Treatment time and pollutant concentration were found to be very meaningful for CBZ removal. The PECO process applied under optimal conditions (at current intensity of 0.3A during 120min in the presence of 10mgL−1 of CBZ with VC at the cathode) is able to oxidize around 73.5% ±2.8% of CBZ and to ensure 21.2%±7.7% of mineralization. During PECO process, CBZ was mainly transformed to acridine and anthranilic acid. Microtox biotests (Vibrio fisheri) showed that the treated – effluent was not toxic. The pseudo-second order kinetic model (k2=6×10−4Lmg−1min−1) described very well the oxidation of CBZ.

Electrochemical treatment of iopromide under conditions of reverse osmosis concentrates – Elucidation of the degradation pathway

Application of reverse osmosis for the reuse of treated wastewater on the one hand offers a way to provide high quality effluent waters. On the other hand reverse osmosis concentrates exhibiting highly concentrated contaminants are produced simultaneously. Electrochemical treatment of those concentrates is regarded as one possible answer to the problem of their disposal into surface waters. Nevertheless, due to the diversity of direct and indirect degradation processes during electrolysis, special care has to be taken about the formation of toxic transformation products (TPs). In this study the electrochemical transformation of the X-ray contrast medium iopromide was investigated as a representative of biologically persistent compounds. For this purpose, anodic oxidation at boron doped diamond as well as cathodic reduction using a platinum electrode were considered. Kinetic analyses revealed a transformation of 100 μM iopromide with first order kinetic constants between 0.6 and 1.6 × 10−4 s−1 at the beginning and a subsequent increase of the reaction order due to the influence of secondary oxidants formed during electrolysis. Mineralization up to 96% was achieved after about 7.5 h. At shorter treatment times several oxidatively and reductively formed transformation products were detected, whereas deiodinated iopromide represented the major fraction. Nevertheless, the latter exhibited negligible toxicological relevance according to tests on vibrio fisheri. Additional experiments utilizing a divided cell setup enabled the elucidation of the transformation pathway, whereas emerging TPs could be identified by means of high resolution mass spectrometry and MSn-fragmentations. During electrolysis the iodine released from Iopromide was found to 90% as iodide and to 10% as iodate even in the open cell experiments, limiting the potential formation of toxic iodo-disinfection by-products. Chlorinated TPs were not found.

Antimicrobial activities of Dilobeia thouarsii Roemer and Schulte, a traditional medicinal plant from Madagascar

The leaves of Dilobeia thouarsii (Roemer and Schulte), a tree that is endemic to Madagascar (Proteaceae), are used in traditional Malagasy medicine to treat bacterial skin infections and wounds. This study investigated the in vitro antibacterial activities of D. thouarsii leaf extracts and identified the bioactive compounds with the aim of providing a scientific basis for its use against skin diseases. Using broth microdilution method for leaf crude extract and its compounds, we investigated inhibition of the growth of Bacillus cereus, Bacillus megaterium, Staphylococcus aureus, Enterococcus faecalis, Vibrio harveyi, Vibrio fisheri, Salmonella Typhimurium, Salmonella antarctica, Escherichia coli, and Klebsiella pneumoniae. The two purified phenolic compounds from leaf ethyl acetate extracts (1, 2) were found to be more active than the crude extract itself. The structure of the two compounds was elucidated by NMR and mass spectrometry: compound 1 was identified as 4-aminophenol and compound 2 as 4-hydroxybenzaldehyde. A marked inhibitory effect (MIC<0.1mg/ml) was found against S. aureus, which is a major agent in skin infections. We observed moderate activities (MIC values of between 0.1 and 0.5mg/ml) for E. faecalis, Vibrio spp., and Bacillus spp. Neither compound was active against Salmonella spp., E. coli and K. pneumoniae (MICs>1mg/ml). To conclude, the high antimicrobial activity of D. thouarsii leaf extracts against S. aureus supports its traditional use to treat skin infections.

Changing Views of the Evolution of Immunity

Changing Views of the Evolution of Immunity

Aqueous chlorination of levofloxacin: Kinetic and mechanistic study, transformation product identification and toxicity

The aim of this study was to gain further insight into the fate of levofloxacin during the chlorination process. First, a kinetic study was thus performed at pH 7.2, 20 °C and in the presence of an excess of total chlorine. A slower apparent removal of levofloxacin (k ∼ 26 M−1 s−1) was noted when sodium thiosulfate was used to stop the chlorination reaction compared to the degradation observed without using a reducing agent (k ∼ 4400 M−1 s−1). The formation of a chlorammonium intermediate which could be converted back into the parent compound through a reaction with thiosulfate was thus expected. This intermediate would result from an initial chlorine attack on the tertiary amine function of levofloxacin. Secondly, four chlorination transformation products were detected by LC/UV/MS analysis. The chemical structures of two of them are proposed. It was suggested that these compounds could come from a secondary reaction of the chlorammonium intermediate on levofloxacin. A reactional pathway is then proposed. Finally, a bioassay using Vibrio fisheri was carried out to study the toxicity pattern during levofloxacin chlorination. An increase in toxicity was observed during chlorination suggesting that the first transformations products formed were more toxic than the parent compound.

Photoelectrocatalytic oxidation of chlortetracycline using Ti/TiO2 photo-anode with simultaneous H2O2 production

This study investigated the photoelectrocatalytic oxidation (PECO) of chlortetracycline (CTC) in aqueous solution using a Ti/TiO2 photocatalyst. The Ti/TiO2 used as photo-anode was prepared by a pulsed laser deposition (PLD) method. The PLD TiO2 coatings were found to have rutile and anatase structures consisting of nano-crystallites of approximately 10nm and 15nm in diameter, respectively. The influence of various parameters such as crystallographic structure of Ti/TiO2, cathode material and pH were evaluated. Experimental results revealed that a current intensity of 0.39A under UV irradiation (245nm) for a period of treatment of 120min was beneficial for CTC oxidation. The initial CTC concentration (25μg/L) could be optimally diminished up to 98.0±0.2% while using a Ti/TiO2 photo-anode having a crystallographic structure of anatase and using vitreous carbon as cathode. Under these conditions, a relatively high mineralization of CTC (67.3±2.15% of TOC removal and 69.3±3.10% of TN removal) was recorded. The initial rate of photoelectrocatalytic degradation of CTC can be well described by the Langmuir–Hinshelwood (L–H) kinetic model (R2=0.9996) with a reaction rate constant of 17.3μg/Lmin. Likewise, microtox (Vibrio fisheri), microalga (Pseudokirchneriella Subcapitata) and Daphnia (Daphnia magna) biotests revealed that the treated – effluent was not toxic compared to the untreated effluent.

Sequential Partial Ozonation for the Treatment of Wastewater Concentrate: Practical Implications From a Conventional and (Eco) Toxicological Perspective

This article compares multi-stage ozonation-biological treatment processes [O3 - Biodegradation - O3 - Biodegradation] and conventional partial ozonation processes [O3 - Biodegradation] for the removal of SCOD and toxicity from a recalcitrant and toxic wastewater concentrate. Both direct (pH 7.5) and advanced (pH 11.5) ozonation are evaluated. Short-term estimation methods for biodegradability (respirometry) and toxicity (30 min Vibrio fisheri luminescence inhibition) are evaluated for their use in process control.

Abstracts of the 17th International Symposium on Bioluminescence and Chemiluminescence ‐ (ISBC 2012)

WARNING : The light-emitting molecular structures responsible for the chemiluminescence and fluorescence phenomena are not necessarily the same!

Traditional antibacterial activity of freshwater microalga Spirulina platensis to aquatic pathogens

The crude ethanol, methanol and aqueous extracts of Spirulina (Spirulina platensis) have been investigated for antibacterial activity using disc diffusion assays against various strains of fish and shellfish pathogens e.g. Pseudomonas putida (ATCC 49128; PP1, PP2), Pseudomonas aeruginosa (ATCC 35032; PA1, PA2), Pseudomonas fluorescens (PF1, PF2), Aeromonas hydrophila (ATCC 49140; AH1, AH2, AH3, AH4), Vibrio alginolyticus (VA), Vibrio anguillarum (VAN), Vibrio fluvialis (VF), Vibrio parahaemolyticus (VP), Vibrio harveyi (VH), Vibrio fisheri (VFS), Edwardsiella tarda and animal isolates of Escherichia coli (O115, O1, O156, O164, O111 and O109). The minimum inhibitory concentrations (MIC) of crude extracts were determined using the tube dilution method. Ethanolic extract showed comparatively higher antibacterial activity (15.66 mm) than that of methanolic and aqueous extract of S. platensis along with their respective MIC values, ranging from 100 to 150 μg mL−1. The aqueous extract had no effective antibacterial activity against the test microorganism. The study suggested that S. platensis may have potential use in aqua feed as an antimicrobial agent of pharmaceutical interest.

Efficiency of butyl rubber sorbent to remove the PAH toxicity

Large amounts of polycyclic aromatic hydrocarbons (PAHs) have been released to the marine environment as a result of oil spills and from other sources including wastewaters, surface runoff, industrial processes, atmospheric deposition, biosynthesis, and natural events such as forest fires. PAHs have been known to affect a variety of biological processes and can be potent cell mutagens/carcinogens and toxic. In this study, PAH toxicity removal was investigated by using a novel macroporous butyl rubber (BR) sorbent. To find out the toxicity removal efficiency of the sorbents, the toxicity tests with Vibrio fisheri (luminescence bacteria) and Phaeodactylum tricornutum (marine algae) were applied to the acenaphthene (Ace) and phenanthrene (Phen) solutions in seawater (Ace: 500– 1000 μg/L; Phen; 100–1000 μg/L) before and after sorbent applications. Additionally, lysosomal stability and filtration rate biomarker techniques were applied to the mussels (Mytilus galloprovincialis) exposed to 1000 μg/L Phen solution and bioaccumulation was measured. The results showed that the toxicity of the PAH solutions decreased 50–100 percent depending on the concentration of the solutions and organisms. Phaeodactylum was found as the most sensitive organism to Phen and Ace. Since the application of BR sorbent removed the Phen from the solution, the bioaccumulated Phen amount in the mussels decreased accordingly.

SENSITIVE QUANTIFICATION OF DICLOFENAC AND IBUPROFEN USING THIN LAYER CHROMATOGRAPHY COUPLED WITH A VIBRIO FISHERI BIOLUMINESCENCE ASSAY

We present a video-densitometric quantification method for the pain killer known as diclofenac and ibuprofen. These non-steroidal anti-inflammatory drugs were separated on cyanopropyl bonded plates using CH2Cl2, methanol, cyclohexane (95 + 5 + 40, v/v) as mobile phase. The quantification is based on a bio-effective-linked analysis using Vibrio fisheri bacteria. Within 10 min a CCD-camera registered the white light of the light-emitting bacteria. Diclofenac and ibuprofen effectively suppressed the bacterial light emission which can be used for quantification within a linear range of 10 to 2000 ng. The detection limit for ibuprofen is 20 ng and the limit of quantification 26 ng per zone. Measurements were carried out using a 16-bit ST-1603ME CCD camera with 1.56 megapixels (from Santa Barbara Instrument Group, Inc., Santa Barbara, USA). The range of linearity covers more than two magnitudes because the extended Kubelka-Munk expression is used for data transformation. The separation method is inexpensive, fast, and reliable.

New biosensors for assessment of environmental toxicity based on marine luminescent bacteria

Sixteen strains of luminescent bacteria of Vibrio and Photobacterium genera were isolated from water of the Azov and Black seas. Two strains prospective for biotesting were genetically identified as Vibrio fisher Ve-9579 and Vibrio fisheri Ve-9580 according to Russian Industrial Microorganism Collection (VKMP) classification and accepted for depositing. The isolated luminescent strains exhibited high individual sensitivity to oil derived products, heavy metal salts, sodium dodecyl sulfate (SDS) and phenol (up to the maximum concentration limit for fishery impoundments). According to EC50, they are ten times more sensitive to heavy metal salts and potassium dichromate and 2-6 times more sensitive to SDSand phenol compared to P. phosphoreum (Cohn) Ford and Escherichia coli C600 (pPLS-5) strains. Using Vibrio fisheri VKMP Ve-9579 and Vibrio fisheri VKMP Ve-9580 as biosensors, we have shown their high sensitivity and efficacy to marine ecosystem toxicity assessment.

Does the actual standard of 0.1 μg/L overestimate or underestimate the risk of plant protection products to groundwater ecosystems?

The present groundwater standard of 0.1 μg/L for plant protection products (PPPs) has been under much debate because an ecotoxicological base is missing. In the present study, groundwater threshold values were calculated for all PPPs currently included in Annex I to Directive 91/414/EEC using three different approaches: (1) first-tier ( Daphnia magna and Vibrio fisheri); (2) species sensitivity distributions, constructed for surrogate freshwater organisms for the truncated groundwater biodiversity; (3) the case-based model PERPEST. For the majority of the PPPs, the trigger value of 0.1 μg/L appears to be sufficiently protective. However, it may not fully protect groundwater life from several insecticides. Implications for the environmental risk assessment of groundwater and recommendations for future research are discussed.

Conventional and (eco) toxicological assessment of batch partial ozone oxidation and subsequent biological treatment of a tank truck cleaning generated concentrate

This paper compares the treatment efficiencies of direct (pH 7.5) and advanced (pH 11.5) partial ozonation followed by biodegradation for the treatment of tank cleaning wastewater concentrate. Both S COD and toxicity removal efficiencies are examined and direct ozonation is found to perform better in combined toxicity and S COD removal. Optimal process performance, i.e. the minimal ozone dosage resulting in a maximal removal of S COD and toxicity in the final effluent, is reached upon reaction of 500 mg O 3/l for both ozonation processes. This ozone dosage results in 60% S COD reduction for direct ozonation and 64% S COD reduction for advanced ozonation. A 79% toxicity reduction was achieved using direct ozonation compared to 53% toxicity reduction for advanced ozonation as measured with the standard Pseudokirchneriella subcapitata algal 72 h growth inhibition test. Short-term methods for biodegradability (respirometry) and toxicity (30 min Vibrio fisheri luminescence inhibition) estimation are evaluated in view of process control. The maximal specific oxygen uptake rate of an activated sludge culture (respirometry) is found to relate to the 5-day biochemical oxygen demand ( S BOD,5) but less to the actual S COD removal during biodegradation. The 30 min Vibrio fisheri luminescence inhibition test is found to be a good short-term estimator for relative changes in toxicity when compared to the standard P. subcapitata algal 72 h growth inhibition test. The 500 mg O 3/l optimal ozone dosage, as determined from P. subcapitata algal 72 h growth inhibition and S COD removal, could be retrieved using short-term methods.

Aquatic Toxicity of Airfield-Pavement Deicer Materials and Implications for Airport Runoff

Concentrations of airfield-pavement deicer materials (PDM) in a study of airport runoff often exceeded levels of concern regarding aquatic toxicity. Toxicity tests on Vibrio fischeri, Pimephales promelas, Ceriodaphnia dubia, and Pseudokirchneriella subcapitata (commonly known as Selenastrum capricornutum) were performed with potassium acetate (K-Ac) PDM, sodium formate (Na-For) PDM, and with freezing-point depressants (K-Ac and Na-For). Results indicate that toxicity in PDM is driven by the freezing-point depressants in all tests except the Vibrio fisheri test for Na-For PDM which is influenced by an additive. Acute toxicity end points for different organisms ranged from 298 to 6560 mg/L (as acetate) for K-Ac PDM and from 1780 to 4130 mg/L (as formate) for Na-For PDM. Chronic toxicity end points ranged from 19.9 to 336 mg/L (as acetate) for K-Ac PDM and from 584 to 1670 mg/L (as formate) for Na-For PDM. Sample results from outfalls at General Mitchell International Airport in Milwaukee, WI (GMIA) indicated that 40% of samples had concentrations greater thanthe aquatic-life benchmarkfor K-Ac PDM. K-Ac has replaced urea during the 1990s as the most widely used PDM at GMIA and in the United States. Results of ammonia samples from airport outfalls during periods when urea-based PDM was used at GMIA indicated that 41% of samples had concentrations exceeding the U.S. Environmental Protection Agency (USEPA) 1-h water-quality criterion. The USEPA 1-h water-quality criterion for chloride was exceeded in 68% of samples collected in the receiving stream, a result of road-salt runoff from urban influence near the airport. Results demonstrate that PDM must be considered to comprehensively evaluate the impact of chemical deicers on aquatic toxicity in water containing airport runoff.