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F.J. Avelar P. Martínez-Pereda F. Thalasso R. Rodríguez-Vázquez F.J. Esparza-García 《Biotechnology letters》2001,23(14):1115-1118
Wastewater treatment using laboratory scale waste stabilisation ponds enriched with activated sludge was studied. After enrichment, the efficiency of these ponds under high organic loading rates (i.e., up to 2800kg CODha–1day–1) reached a maximum COD removal rate of 970kg CODha–1day–1, which is from 2 to 10 times more than commonly reported values, and suggests that enrichment is an effective method to improve stabilisation ponds. 相似文献
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The application of bioflocs technology to protect brine shrimp (Artemia franciscana) from pathogenic Vibrio harveyi 总被引:2,自引:0,他引:2
R. Crab A. Lambert T. Defoirdt P. Bossier W. Verstraete 《Journal of applied microbiology》2010,109(5):1643-1649
Aims: To study the potential biocontrol activity of bioflocs technology. Methods and Results: Glycerol‐grown bioflocs were investigated for their antimicrobial and antipathogenic properties against the opportunistic pathogen Vibrio harveyi. The bioflocs did not produce growth‐inhibitory substances. However, bioflocs and biofloc supernatants decreased quorum sensing‐regulated bioluminescence of V. harveyi. This suggested that the bioflocs had biocontrol activity against this pathogen because quorum sensing regulates virulence of vibrios towards different hosts. Interestingly, the addition of live bioflocs significantly increased the survival of gnotobiotic brine shrimp (Artemia franciscana) larvae challenged to V. harveyi. Conclusions: Bioflocs grown on glycerol as carbon source inhibit quorum sensing‐regulated bioluminescence in V. harveyi and protect brine shrimp larvae from vibriosis. Significance and Impact of the Study: The results presented in this study indicate that in addition to water quality control and in situ feed production, bioflocs technology could help in controlling bacterial infections within the aquaculture pond. 相似文献
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Extracellular polymeric substances (EPS) of microbial origin are a complex mixture of biopolymers comprising polysaccharides,
proteins, nucleic acids, uronic acids, humic substances, lipids, etc. Bacterial secretions, shedding of cell surface materials,
cell lysates and adsorption of organic constituents from the environment result in EPS formation in a wide variety of free-living
bacteria as well as microbial aggregates like biofilms, bioflocs and biogranules. Irrespective of origin, EPS may be loosely
attached to the cell surface or bacteria may be embedded in EPS. Compositional variation exists amongst EPS extracted from
pure bacterial cultures and heterogeneous microbial communities which are regulated by the organic and inorganic constituents
of the microenvironment. Functionally, EPS aid in cell-to-cell aggregation, adhesion to substratum, formation of flocs, protection
from dessication and resistance to harmful exogenous materials. In addition, exopolymers serve as biosorbing agents by accumulating
nutrients from the surrounding environment and also play a crucial role in biosorption of heavy metals. Being polyanionic
in nature, EPS forms complexes with metal cations resulting in metal immobilization within the exopolymeric matrix. These
complexes generally result from electrostatic interactions between the metal ligands and negatively charged components of
biopolymers. Moreover, enzymatic activities in EPS also assist detoxification of heavy metals by transformation and subsequent
precipitation in the polymeric mass. Although the core mechanism for metal binding and / or transformation using microbial
exopolymer remains identical, the existence and complexity of EPS from pure bacterial cultures, biofilms, biogranules and
activated sludge systems differ significantly, which in turn affects the EPS-metal interactions. This paper presents the features
of EPS from various sources with a view to establish their role as central elements in bioremediation of heavy metals. 相似文献
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