Exposure of Metal Oxide Nanoparticles on the Bioluminescence Process of and Recombinant Strains.

Comparison of the effects of metal oxide nanoparticles (NPs; CuO, NiO, ZnO, TiO, and AlO) on different bioluminescence processes was evaluated using two recombinant ( and ) strains of with same inducer exposure. Different sensitivities and responses were observed according to the type of NPs and recombinant strains. EC values were determined.

Comparisons of the Effect of Different Metal Oxide Nanoparticles on the Root and Shoot Growth under Shaking and Non-Shaking Incubation, Different Plants, and Binary Mixture Conditions.

We evaluated the toxicity of five metal oxide nanoparticles (NPs) in single or binary mixtures based on root and shoot growth of two plant species under non-shaking and shaking conditions. The effects of NPs on root and shoot growth differed depending on the NP type, incubation condition, and plant type. The half maximal effective concentration (EC) of NPs based on root growth were significantly lower, by 2.

Evaluation of the Effects of Particle Sizes of Silver Nanoparticles on Various Biological Systems.

Seven biological methods were adopted (three bacterial activities of bioluminescence, enzyme, enzyme biosynthetic, algal growth, seed germination, and root and shoot growth) to compare the toxic effects of two different sizes of silver nanoparticles (AgNPs). AgNPs showed a different sensitivity in each bioassay. Overall, the order of inhibitory effects was roughly observed as follows; bacterial bioluminescence activity ≈ root growth > biosynthetic activity of enzymes ≈ algal growth > seed germination ≈ enzymatic activity > shoot growth.

Comparative Effects of Particle Sizes of Cobalt Nanoparticles to Nine Biological Activities.

The differences in the toxicity of cobalt oxide nanoparticles (Co-NPs) of two different sizes were evaluated in the contexts of the activities of bacterial bioluminescence, - gene, enzyme function and biosynthesis of β-galactosidase, bacterial gene mutation, algal growth, and plant seed germination and root/shoot growth. Each size of Co-NP exhibited a different level of toxicity (sensitivity) in each biological activity. No revertant mutagenic ratio (greater than 2.

Toxic Effects of Metal Oxide Nanoparticles Based on the Enzymatic Activity and Biosynthesis of -Galactosidase Using a Mutant Strain of .

The effects of six metal oxide nanoparticles (MO-NPs) on the activity and biosynthesis of an enzyme (-galactosidase) were examined using a mutant strain of . Different sensitivities were observed according to the type of NP and metabolic process. The toxic effects on enzyme activity were significantly greater than on biosynthesis (p < 0.

Ecotoxicity evaluation of Cu- and Fe-CNT complexes based on the activity of bacterial bioluminescence and seed germination.

The toxic effects of the composites of Fe and Cu with different percentages of CNTs were examined based on the activity of bacterial bioluminescence and seed germination. In terms of the EC values, the toxic effects of Cu on bacterial bioluminescence and seed germination were approximately 2 and 180 times greater than that of Fe, respectively. The toxicity increased with increasing CNT content in the Cu-CNT mixtures for both organisms, whereas opposite results were observed with Fe-CNT mixtures.

Influence of Incubation Conditions on the Nanoparticles Toxicity Based on Seed Germination and Bacterial Bioluminescence.

The effects of the modified incubation conditions of a conventional bioassay on the toxicity of partially soluble nanoparticles (NPs) were evaluated based on the activity of seed germination and bacterial bioluminescence. Different levels of toxicity were observed for seed germination (CuO > ZnO > NiO) and bacterial bioluminescence (ZnO > CuO > NiO). The NP inhibition of seed germination increased strongly under modified incubation conditions: sample volume from 5 mL to 10 mL, shaking from none to 70 rpm, and working vessel from a Petri dish (+/− filter paper) to an Erlenmeyer flask (no filter paper).

Toxicity Evaluation of Individual and Mixtures of Nanoparticles Based on Algal Chlorophyll Content and Cell Count.

The toxic effects of individual and binary mixtures of five metal oxide nanoparticles (NPs) were evaluated based on changes in two endpoints of algal growth: the cell count and chlorophyll content. Various effects were observed according to the concentration tested and type of NPs, and there were no significant differences in findings for the two endpoints. In general, ZnO NPs caused the greatest inhibition of algal growth, and Fe₂O₃ NPs the least.

Evaluation of the Effects of Nanoparticle Mixtures on Brassica Seed Germination and Bacterial Bioluminescence Activity Based on the Theory of Probability.

Effects of binary mixtures of six metal oxide nanoparticles (NPs; 54 combinations) on the activities of seed germination and bacterial bioluminescence were investigated using the theory of probability. The observed toxicities of various NPs combinations were compared with the theoretically expected toxicities, calculated based on individual NPs toxicities. Different sensitivities were observed depending on the concentrations and the types of NPs.

Application of the freeze-dried bioluminescent bioreporter Pseudomonas putida mt-2 KG1206 to the biomonitoring of groundwater samples from monitoring wells near gasoline leakage sites.

This study examined the applicability of a freeze-dried bioluminescent bioreporter, Pseudomonas putida mt-2 KG1206 (called KG1206), to the biomonitoring of groundwater samples. Samples were collected from the monitoring wells of gas station tanks or old pipeline leakage sites in Korea. In general, the freeze-dried strain in the presence of pure inducer chemicals showed low bioluminescence activity and a different activity order compared with that of the subcultured strain.

Effects of properties of metal-contaminated soils on bacterial bioluminescence activity, seed germination, and root and shoot growth.

This study examined the effects of several factors (metal contents and soil properties) on bacterial bioluminescence activity, seed germination and root/shoot growth of Lactuca in metal-contaminated soils. Each bioassay showed different sensitivities to extractants of soil samples. Average sensitivities of the bioassay were in the following order: root growth > bioluminescence ≥ shoot growth ≥ seed germination.

Interactive Effects of Metal Mixtures on Seed Germination and Bioluminescence Activities based on the Theory of Probabilities.

The interactive effects of metal mixtures on seed germination (36 combinations) and bacterial bioluminescence (60 combinations) activities were investigated based on the theory of probabilities. Observed effects were compared with expected effects, which were calculated based on single metal activities. Different responses and sensitivities were observed depending on the types and concentrations of mixture metals as well as the organisms tested.

Effects of Monotypic and Binary Mixtures of Metal Oxide Nanoparticles on Microbial Growth in Sandy Soil Collected from Artificial Recharge Sites.

The potential effects of monotypic and binary metal oxide nanoparticles (NPs, ZnO, NiO, Co₃O₄ and TiO₂) on microbial growth were evaluated in sandy soil collected from artificial recharge sites. Microbial growth was assessed based on adenosine triphosphate (ATP) content, dehydrogenase activity (DHA), and viable cell counts (VCC). Microbial growth based on ATP content and VCC showed considerable differences depending on NP type and concentration, whereas DHA did not significantly change.

Effects of binary mixtures of inducers (toluene analogs) and of metals on bioluminescence induction of a recombinant bioreporter strain.

This paper investigated the effects of binary mixtures of bioluminescence inducers (toluene, xylene isomers, m-toluate) and of metals (Cu, Cd, As(III), As(V), and Cr) on bioluminescence activity of recombinant (Pm-lux) strain KG1206. Different responses and sensitivities were observed depending on the types and concentrations of mixtures of inducers or metals. In the case of inducer mixtures, antagonistic and synergistic modes of action were observed, whereas metal mixtures showed all three modes of action.

Toxic effects of nanoparticles on bioluminescence activity, seed germination, and gene mutation.

The potential environmental toxicities of several metal oxide nanoparticles (NPs; CuO, TiO2, NiO, Fe2O3, ZnO, and Co3O4) were evaluated in the context of bioluminescence activity, seed germination, and bacterial gene mutation. The bioassays exhibited different sensitivities, i.e.

Joint effects of heavy metal binary mixtures on seed germination, root and shoot growth, bacterial bioluminescence, and gene mutation.

This investigation was to assess the joint effects of metal binary mixtures on seed germination, root and shoot growth, bacterial bioluminescence, and gene mutation based on the one toxic unit (1 TU) approach. Different sensitivities and orders of toxicity of metal mixtures were observed among the bioassays. In general, mostly additive or antagonistic effects were observed, while almost no synergistic effects by the binary metal mixtures in all bioassays.

Evaluation of the toxic effects of arsenite, chromate, cadmium, and copper using a battery of four bioassays.

The sensitivities of four different kinds of bioassays to the toxicities of arsenite, chromate, cadmium, and copper were compared. The different bioassays exhibited different sensitivities, i.e.

Application of stimulating agents on the immobilized bioluminescence strain Pseudomonas putida mt-2 KG1206, preserved by deep-freezing, for the convenient biomonitoring.

This study was conducted to develop methods for the application of an immobilized bioluminescence strain (KG1206), preserved by deep-freezing (DF), for the monitoring of contaminated environments. The immobilized cells, preserved by DF, required approximately 2 hr for reconstitution of their activity. A large reduction in bioluminescence was observed due to the DF process; 0.

Bioassessments of anaerobically decomposing organic refuse in laboratory lysimeters with and without leachate recycling and pH adjustment.

In this paper, various microbial characteristics of degrading refuse in three lysimeters were compared to bioassess the operating conditions with and without leachate recycling and pH adjustment. Laboratory lysimeters with leachate recycling produced more gas and took less time to reach the highest methane percentage than a lysimeter without leachate recycling. Generally, lysimeters with leachate recycling showed high ATP (adenosine triphosphate) contents in the leachate.

The use of bioluminescence stimulant on the immobilized strain, P. putida mt-2 KG1206, with toluene analog inducers and environmental samples.

This study was conducted to investigate the applicability of the stimulant conditions for the bioluminescence activity of a recombinant strain of Pseudomonas putida, mt-2 KG1206, when immobilized using alginate polymer. The bioluminescence activity of the immobilized strain was generally approximately three to five times lower than the subcultured strain, and the activity was observed to slowly decrease. These facts may have been caused by several factors, such as the low biomass and the time required for diffusion into the entrapped biomass.

Conditions required for the stimulation of bioluminescence activity of the genetically engineered bacteria, P. putida mt-2 KG1206, preserved by deep-freezing.

Herein the conditions required for the stimulation of bioluminescence activity in a genetically engineered strain of Pseudomonas putida mt-2 KG1206, containing the intact TOL plasmid and a constructed plasmid with the P(m)-lux gene, are reported upon. Both sodium lactate (SL) and potassium nitrate (KNO(3)) were able to stimulate the bioluminescence activity, but a greater increase was observed with nitrogen amendment. This selected stimulant was then tested on reconstituted cells that had been preserved by deep-freezing and mixed with pure inducer solution or groundwater samples.

Microbial characteristics associated with six different organic wastes undergoing anaerobic decomposition in batch vial conditions.

In this study, the biodegradation characteristics of six plant-based wastes were compared in anaerobic batch vial systems. The highest gas accumulation and methane (CH4) concentrations (approximately 70%) were observed in samples containing copy paper, newspaper and box paper materials, whereas the lowest were observed in samples containing wood and leaves. In samples containing steamed rice and fruit, the methanogenic activity was inhibited, which resulted in acid accumulation.

Peroxidase-mediated oxidative coupling of 1-naphthol: characterization of polymerization products.

The oxidative polymerization of 1-naphthol was investigated in the presence of horseradish peroxidase (HRP). Naphthol polymerization products (NPP) were characterized for their relative polarity using octanol--water partitioning experiments and reverse-phase high pressure liquid chromatography, for structure using size exclusion chromatography and liquid chromatography-mass spectrometry (LC/MS), and for ecotoxicity using inhibition of bacterial bioluminescence. Peroxidase addition resulted in the production of soluble and insoluble NPP.