Complete reductive dechlorination of tetrachloroethene to ethene by anaerobic microbial enrichment culture developed from sediment.

A mixed, anaerobic microbial enrichment culture, AMEC-4P, was developed that uses lactate as the electron donor for the reductive dechlorination of tetrachloroethene (PCE) to ethene. AMEC-4P consistently and completely converted 2 mM PCE to cis-1,2-dichloroethene (cis-DCE) within 13 days, and the intermediate, cis-DCE, was then completely dechlorinated to ethene after 130 days. Dechlorination rates for PCE to cis-DCE, cis-DCE to VC, and VC to ethene were 243, 27, and 41 μmol/l/day, respectively.

Diversity and abundance of ammonia-oxidizing bacteria in activated sludge treating different types of wastewater.

The diversity and abundance of ammonia-oxidizing bacteria (AOB) in activated sludge were compared using PCR-DGGE and real-time PCR assays. Activated sludge samples were collected from five different types of wastewater treatment plants (WWTPs) mainly treating textile, paper, food and livestock wastewater or domestic sewage. The composition of total bacteria determined by PCR-DGGE was highly diverse between the samples, whereas the community of AOB was similar across all the investigated activated sludge.

Transgenic poplar expressing Arabidopsis NDPK2 enhances growth as well as oxidative stress tolerance.

Nucleoside diphosphate kinase 2 (NDPK2) is known to regulate the expression of antioxidant genes in plants. Previously, we reported that overexpression of Arabidopsis NDPK2 (AtNDPK2) under the control of an oxidative stress-inducible SWPA2 promoter in transgenic potato and sweetpotato plants enhanced tolerance to various abiotic stresses. In this study, transgenic poplar (Populus alba × Poplus glandulosa) expressing the AtNDPK2 gene under the control of a SWPA2 promoter (referred to as SN) was generated to develop plants with enhanced tolerance to oxidative stress.

Cyanobactericidal effect of Rhodococcus sp. isolated from eutrophic lake on Microcystis sp.

A bacterium, which was observed in all cultivations of Microcystis sp., was isolated and designated as Rhodococcus sp. KWR2.

Differential responses of sweetpotato peroxidases to heavy metals.

Oxidative stress is one of the major causes of damage in plants exposed to different types of environmental stress, including heavy metals. Accumulation of heavy metals in plants can disrupt many cellular functions and plant growth. To assess the contribution of oxidative stress to heavy metal toxicity in plants, young sweetpotato plants (Ipomoea batatas) were treated with increasing concentrations of Cd, Cu and Zn, and grown in half Murashige and Skoog nutrient solution culture.

Enhanced tolerance to methyl viologen-induced oxidative stress and high temperature in transgenic potato plants overexpressing the CuZnSOD, APX and NDPK2 genes.

Oxidative stress is a major threat for plants exposed to various environmental stresses. Previous studies found that transgenic potato plants expressing both copper zinc superoxide dismutase (CuZnSOD) and ascorbate peroxidase (APX) (referred to as SSA plants), or nucleoside diphosphate kinase 2 (NDPK2) (SN plants), showed enhanced tolerance to methyl viologen (MV)-induced oxidative stress and high temperature. This study aimed to develop transgenic plants that were more tolerant of oxidative stress by introducing the NDPK2 gene into SSA potato plants under the control of an oxidative stress-inducible peroxidase (SWPA2) promoter to create SSAN plants.

Surface solubilization of phenanthrene by surfactant sorbed on soils with different organic matter contents.

The effect of sorbed surfactant on the distribution of hydrophobic organic compounds (HOCs) during soil washing was investigated using a mathematical model. Phenanthrene (PHE) as an HOC and Triton X-100 (TX100) as a nonionic surfactant were used with two soils with low (SS) and high (BS) organic matter contents. The available carbon fraction (f(A,soil)(*)) after surfactant sorption was determined from surfactant coverage by measuring soil surface area using a methylene blue method.

Simultaneous expression of choline oxidase, superoxide dismutase and ascorbate peroxidase in potato plant chloroplasts provides synergistically enhanced protection against various abiotic stresses.

Plants synthesize compatible solutes such as glycinebetaine (GB) in response to abiotic stresses. To evaluate the synergistic and protective effect of GB, transgenic potato plants expressing superoxide dismutase (SOD) and ascorbate peroxidase (APX) targeting to chloroplasts (referred to as SSA plants) were retransformed with a bacterial choline oxidase (codA) gene to synthesize GB in chloroplast in naturally occurring non-accumulator potato plants (including SSA) under the control of the stress-inducible SWPA2 promoter (referred to as SSAC plants). GB accumulation resulted in enhanced protection of these SSAC plants and lower levels of H(2)O(2) compared with SSA and non-transgenic (NT) plants after methyl viologen (MV)-mediated oxidative stress.

Exogenous sucrose utilization and starch biosynthesis among sweet potato cultivars.

Three sweetpotato cultivars were investigated for their starch content and amylose/amylopectin ratio. Ym starch contains 87.2% amylopectin and 12.

Microbial community structure in hexadecane- and naphthalene-enriched gas station soil.

Shifts in the activity and diversity of microbes involved in aliphatic and aromatic hydrocarbon degradation in contaminated soil were investigated. Subsurface soil was collected from a gas station that had been abandoned since 1995 owing to ground subsidence. The total petroleum hydrocarbon content of the sample was approximately 2,100 mg/kg, and that of the soil below a gas pump was over 23,000 mg/kg.

Characterization of full-length enriched expressed sequence tags of dehydration-treated white fibrous roots of sweetpotato.

Sweetpotato (Ipomoea batatas (L). Lam.) is relatively tolerant to unfavorable growth conditions such as drought, yet has not been exploited to provide a better understanding of the molecular basis of drought stress tolerance.

Sudden failure of biological nitrogen and carbon removal in the full-scale pre-denitrification process treating cokes wastewater.

A full-scale pre-denitrification process treating cokes wastewater containing toxic compounds such as phenols, cyanides and thiocyanate has shown good performance in carbon and nitrogen removal. However, field operators have been having trouble with its instability without being able to identify the causes. To clarify the main cause of these sudden failures of the process, comprehensive studies were conducted on the pre-denitrification process using a lab-scale reactor system with real cokes wastewater.

Monitoring bacterial population dynamics using real-time PCR during the bioremediation of crude-oil-contaminated soil.

We evaluated the activity and abundance of the crude oil- degrading bacterium Nocardia sp. H17-1 during bioremediation of oil-contaminated soil, using real-time PCR. The total petroleum hydrocarbon (TPH) degradation rate constants (k) of the soils treated with and without H17-1 were 0.

Comparison of several methods for effective lipid extraction from microalgae.

Various methods, including autoclaving, bead-beating, microwaves, sonication, and a 10% NaCl solution, were tested to identify the most effective cell disruption method. The total lipids from Botryococcus sp., Chlorella vulgaris, and Scenedesmus sp.

Selection of microalgae for lipid production under high levels carbon dioxide.

To select microalgae with a high biomass and lipid productivity, Botryococcus braunii, Chlorella vulgaris, and Scenedesmus sp. were cultivated with ambient air containing 10% CO(2) and flue gas. The biomass and lipid productivity for Scenedesmus sp.

Effect of initial glucose concentrations on carbon material and energy balances in hydrogen-producing Clostridium tyrobutyricum JM1.

The carbon metabolism of newly isolated Clostridium tyrobutyricum JM1 was investigated at varying initial glucose concentrations (27.8-333.6mM).

Molecular characterization of the sweet potato peroxidase SWPA4 promoter which responds to abiotic stresses and pathogen infection.

Previously, the swpa4 peroxidase gene has been shown to be inducible by a variety of abiotic stresses and pathogenic infections in sweet potato (Ipomoea batatas). To elucidate its regulatory mechanism at the transcriptional level under various stress conditions, we isolated and characterized the promoter region (2374 bp) of swpa4 (referred to as SWPA4). We performed a transient expression assay in tobacco protoplasts with deletions from the 5'-end of SWPA4 promoter fused to the beta-glucuronidase (GUS) reporter gene.

Removal of cationic heavy metal from aqueous solution by activated carbon impregnated with anionic surfactants.

To increase their capacity to adsorb heavy metals, activated carbons were impregnated with the anionic surfactants sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), or dioctyl sulfosuccinate sodium (DSS). Surfactant-impregnated activated carbons removed Cd(II) at up to 0.198 mmol g(-1), which was more than an order of magnitude better than the Cd(II) removal performance of activated carbon without surfactant (i.

The effects of pH on carbon material and energy balances in hydrogen-producing Clostridium tyrobutyricum JM1.

The effects of pH on hydrogen fermentation of glucose by newly isolated H(2)-producing bacterium Clostridium tyrobutyricum JM1 were investigated in batch cultivations. The changes of carbon material and energy balances by pH conditions provided useful information for understanding and interpreting the regulatory system of the microorganism, and for optimization of a desired product, in this case, molecular hydrogen. The most probable metabolic pathways of C.

Enhanced abiotic reduction of Cr(VI) in a soil slurry system by natural biomaterial addition.

Among various plant-based natural biomaterials, pine bark was chosen as an efficient biomaterial capable of removing toxic Cr(VI) from aqueous solution. XPS spectra indicated that Cr(VI) was abiotically reduced to Cr(III) in both liquid and solid phases. The Cr(VI)-reducing capacity of pine bark was determined as 545 (+/-1.

Synergistic effects of sequential treatment with methyl jasmonate, salicylic acid and yeast extract on benzophenanthridine alkaloid accumulation and protein expression in Eschscholtzia californica suspension cultures.

To develop an optimal bioprocess for secondary metabolite production and explain the bioprocess at the molecular level, we examine the synergistic effects of sequential treatment with methyl jasmonate (MJ), salicylic acid (SA) and yeast extract (YE) on benzophenanthridine alkaloid accumulation and protein expression in Eschscholtzia californica suspension cultures. Serial treatment of MJ, SA and YE at 24h intervals enhanced the accumulation of dihydrosanguinarine (2.5 times) and sanguinarine (5.

Mathematical evaluation of activated carbon adsorption for surfactant recovery in a soil washing process.

The performances of various soil washing processes, including surfactant recovery by selective adsorption, were evaluated using a mathematical model for partitioning a target compound and surfactant in water/sorbent system. Phenanthrene was selected as a representative hazardous organic compound and Triton X-100 as a surfactant. Two activated carbons that differed in size (Darco 20-40 mesh and >100 mesh sizes) were used in adsorption experiments.

Molecular cloning of peroxidase cDNAs from dehydration-treated fibrous roots of sweetpotato and their differential expression in response to stress.

Three peroxidase (POD) cDNAs were isolated from dehydration-treated fibrous roots of sweetpotato (Ipomoea batatas) plant via the screening of a cDNA library, and their expressions were assessed to characterize functions of each POD in relation to environmental stress. Three PODs were divided into two groups, designated the basic PODs (swpb4, swpb5) and the anionic PODs (swpa7), on the basis of the pI values of mature proteins. Fluorescence microscope analysis indicated that three PODs are secreted into the extracellular space.

Differential induction of protein expression and benzophenanthridine alkaloid accumulation in Eschscholtzia californica suspension cultures by methyl jasmonate and yeast extract.

Methyl jasmonate (MJ) and yeast extract (YE) induce protein expression and benzophenanthridine alkaloid accumulation in Eschscholtzia californica suspension cell cultures. One hundred microM MJ primarily induced dihydrosanguinarine 509.0+/-7.