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Ying Yong Sheng Tai Xue Bao ; 25(9): 2563-8, 2014 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-25757306


Mangrove wetland ecosystem in Quanzhou Bay in Fujian Province is newly restored with a regular semidiurnal tide. Soil CO2 concentration in the mangrove soil was determined by Li-840 portable gas analyzer, and periodic characteristics of soil CO2 emission was investigated. The soil CO2 flux in the wetland soil was relatively small because the mangrove was young. The change trends of soil CO2 concentration and flux with time were consistent in Kandelia obovate and Aegiceras corniculatum communities in the intertidal periods. The CO2 concentration and flux in the wetland soil were 557.08-2211.50 µmol · mol(-1) and -0.21-0.40 µmol · m(-2) · s(-1), respectively. The average CO2 flux in the wetland soil was 0.26 µmol · mol(-1) · s(-1) in the intertidal of morning and evening tides (early intertidal) and -0.01 µmol · m(-2) · s(-1) in the intertidal of evening and morning tides (late intertidal), respectively. At the same time after the tide, the concentration and flux of CO2 in the mangrove soil in early intertidal was higher than that in late intertidal. In early intertidal, the relationship between the flux and instantaneous concentration of CO2 in the wetland soil was expressed as a bell-shaped curve, and CO2 flux increased first and then decreased with the increasing CO2 concentration, which was in conformity with Gaussian distribution.

Dióxido de Carbono/análise , Solo/química , Áreas Alagadas , Baías , China , Rhizophoraceae
Bioresour Technol ; 136: 176-81, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23567679


This study investigated the anaerobic decolorization of the dye mixture containing methyl orange (MO) and naphthol green B (NGB) by Shewanella oneidensis MR-1. S. oneidensis MR-1 showed a strong ability to decolorize the dye mixture. MO was easier to get the electrons and inhibited the reduction of NGB, despite of its lower redox potential than NGB. The Mtr respiratory pathway played an important role in this process. Meantime, addition of extracellular electron shuttles accelerated the decolorization. Those results suggest that the decolorization capacity of S. oneidensis MR-1 is associated with the electricity production. The operating parameters, such as electron acceptors, temperature, and pH, were also investigated in this study. Thus, this work may facilitate a better understanding of the extensive nonspecific reduction capacity of exoelectrogens and is beneficial for promoting their application in bioremediation.

Compostos Azo/metabolismo , Corantes/metabolismo , Eletricidade , Compostos Férricos/metabolismo , Naftalenossulfonatos/metabolismo , Shewanella/metabolismo , Anaerobiose/efeitos dos fármacos , Biodegradação Ambiental/efeitos dos fármacos , Cor , Elétrons , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Redes e Vias Metabólicas/genética , Mutação/genética , Riboflavina/farmacologia , Shewanella/efeitos dos fármacos , Espectrofotometria Ultravioleta , Temperatura
Artigo em Inglês | MEDLINE | ID: mdl-16511191


Oligoribonucleases are essential components of RNA and DNA metabolism and close homologues of genes encoding them are found not only in prokaryotes but also in a wide range of eukaryotes, including yeast and humans. Inactivation of the oligoribonuclease gene (orn) can result in cellular lethality. Despite their important biological function, they have been studied little from a structural point of view. In this report, the cloning, expression, crystallization and preliminary X-ray analysis of XC847, a DEDDh-type 3'-5' oligoribonuclease from the plant pathogen Xanthomonas campestris pv. campestris, a Gram-negative bacterium causing major worldwide disease of cruciferous crops, is described. The XC847 crystals diffracted to a resolution of at least 2.1 A. They are tetragonal and belong to space group P4(3)2(1)2, with unit-cell parameters a = b = 67.5, c = 89.8 A. One molecule is present per asymmetric unit.

Exorribonucleases/química , Xanthomonas campestris/enzimologia , Motivos de Aminoácidos , Clonagem Molecular , Cristalografia por Raios X , DNA/química , Eletroforese em Gel de Poliacrilamida , RNA/química , Difração de Raios X