Abstract:
:In this work the question was addressed if in nitrite-oxidizing activated sludge systems the environmental competition between Nitrobacter spp. and Nitrospira spp., which only recently has been discovered to play a role in these systems, is affected by the nitrite concentrations. Two parallel chemostats were inoculated with nitrifying-activated sludge containing Nitrospira and operated under identical conditions. After addition of Nitrobacter to both chemostats, the nitrite concentration in the influent of one of the chemostats was increased such that nitrite peaks in the bulk liquid of this reactor were detected. The other chemostat served as control reactor, which always had a constant nitrite influent concentration. The relative cellular area (RCA) of Nitrospira and Nitrobacter was determined by quantitative fluorescence in situ hybridization (FISH). The nitrite perturbation stimulated the growth of Nitrobacter while in the undisturbed control chemostat Nitrospira dominated. Overall, the results of this experimental study support the hypothesis that Nitrobacter is a superior competitor when resources are abundant, while Nitrospira thrive under conditions of resource scarcity. Interestingly, the dominance of Nitrobacter over Nitrospira, caused by the elevated nitrite concentrations, could not be reverted by lowering the available nitrite concentration to the original level. One possible explanation for this result is that when Nitrobacter is present at a certain cell density it is able to inhibit the growth of Nitrospira. An alternative explanation would be that the length of the experimental period was not long enough to observe an increase of the Nitrospira population.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Nogueira R,Melo LFdoi
10.1002/bit.21004subject
Has Abstractpub_date
2006-09-05 00:00:00pages
169-75issue
1eissn
0006-3592issn
1097-0290journal_volume
95pub_type
杂志文章abstract::The goal of drug delivery is to improve the safety and therapeutic efficacy of drugs. This review focuses on delivery platforms that are either derived from endogenous pathways, long-circulating biomolecules and cells or that piggyback onto long-circulating biomolecules and cells. The first class of such platforms is ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章,评审
doi:10.1002/bit.25307
更新日期:2014-09-01 00:00:00
abstract::The addition of simple inorganic salts to aqueous enzyme solutions prior to lyophilization results in a dramatic activation of the dried powder in organic media relative to enzyme with no added salt. Activation of both the serine protease subtilisin Carlsberg and lipase from Mucor javanicus resulting from lyophilizati...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(sici)1097-0290(19990420)63:2<233::aid-bit
更新日期:1999-04-20 00:00:00
abstract::The thermophilic fungus Sporotrichum cellulophilum was immobilized with nonwoven materials for cellulase production. The cellulose powder concentration in the medium was an important factor controlling cellulase production. When the cellulose powder concentration in the nonwoven materials was more than 4%, cellulase p...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260280814
更新日期:1986-08-01 00:00:00
abstract::To monitor gas reaction rates in animal cell culture at constant dissolved oxygen concentration (DO) and constant pH it was necessary to develop improved control methods. Decoupling of both controllrs was obtained by manipulation of molar fractions of oxygen and carbon dioxide in the gas phase. Two pairs of DO and pH ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260450107
更新日期:1995-01-05 00:00:00
abstract::DNA/polyethylenimine (PEI) polyplexes are an important class of nonviral vectors. Although the conventional preparation method, bulk mixing, is straightforward, the formation of the DNA/PEI polyplexes is not well controlled. This work explores coaxial electrohydrodynamic spraying (EHDS) as a novel, alternative method ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22583
更新日期:2010-03-01 00:00:00
abstract::The production of dry-grind corn ethanol results in the generation of intermediate products, thin and whole stillage, which require energy-intensive downstream processing for conversion into commercial animal feed products. Hydrothermal carbonization of thin and whole stillage coupled with anaerobic digestion was inve...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24924
更新日期:2013-10-01 00:00:00
abstract::The enzymatic synthesis of polyesters from activated diesters and diols has been investigated. Differences between enzymatic synthesis and traditional chemical condensation processes are discussed. The disappearance of monomers during the initial phase of reaction indicates that enzyme has a higher specificity for tra...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19970705)55:1<227::AID-BIT
更新日期:1997-07-05 00:00:00
abstract::In an attempt to extend and intensify the productive periods of bioprocesses, a self-cleaning tangential filtration device was examined. Built into a special-design bioreactor, its cell retention was evaluated for continuous-flow operation with selected examples of bacteria (Escherichia coli), yeasts (Sacharomyces cer...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20888
更新日期:2006-11-05 00:00:00
abstract::In this study, white rot fungus, Polyporus brumalis, was applied to degrade dibutyl phthalate (DBP), a major environmental pollutant. The degradation potential and resulting products were evaluated with HPLC and GC/MS. As DBP concentration increased to 250, 750, and 1,250 microM, the mycelial growth of P. brumalis was...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21333
更新日期:2007-08-15 00:00:00
abstract::Generating stable, high-producing cell lines for recombinant protein production requires an understanding of the potential limitations in the cellular machinery for protein expression. In order to increase our understanding of what makes a stable high producer, we have generated a panel of 17 recombinant monoclonal an...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22158
更新日期:2009-03-01 00:00:00
abstract::Pulses of several nonreacting solutes were fed to a column containing immobilized enzyme catalyst beads. The response curves were recorded, and their first and second moments were determined by numerical integration. From the moment analysis, the void volume, internal porosity, and tortuosity of the support were calcu...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260250707
更新日期:1983-07-01 00:00:00
abstract::Flow visualization using fluorescent microparticles and cell viability investigations are carried out to examine the mechanisms by which cells are seeded into scaffolds driven by surface acoustic waves. The former consists of observing both the external flow prior to the entry of the suspension into the scaffold and t...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22243
更新日期:2009-06-01 00:00:00
abstract::Trichoderma reesei (QM 9414) produced cellulase in continuous culture, on media containing xylose (1%) supplemented with sorbose (0.3%) to induce cellulase production. Maximum cell mass of 4.54 kg/m(3) occurred at pH 4.0 and a dilution rate of 0.0391 h(-1) where residual substrate was 0.43 kg/m(3), but no cellulase wa...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260390808
更新日期:1992-04-05 00:00:00
abstract::The feasibility of continuous production of proteins in chemostat cultures of Bacillus subtilis was investigated. An expression system consisting of the bacterium B. subtilis BR151 carrying plasmid p602/19 was used. The plasmid contains the cat (chioramphenicol acetyltrans-ferase) gene downstream of a strong vegetativ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260470503
更新日期:1995-09-05 00:00:00
abstract::This article provides the analysis on biomass yields and energetic yields of the oleaginous yeasts. The biomass yields of the oleaginous yeasts are consistently lower than nonoleaginous microorganisms, whereas their energetic yields are higher. Data inconsistencies of literature are explained by the variation of energ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260280117
更新日期:1986-01-01 00:00:00
abstract::A novel two-stage bioreactor has been designed for a combined submerged (SF) and solid substrate fermentation (SSF) of wheat straw. The straw was pretreated with steam, and cellulases from the culture fluid of Trichoderma reesei were adsorbed on it for increased bioconvertibility. SSF was conducted in the top part of ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260300219
更新日期:1987-08-05 00:00:00
abstract::This reports on the determination of the overall oxygen transfer coefficient in a mechanically agitated vessel using a randomly pulsed dynamic method. This method consists in exciting the system by randomly switching the inlet gas stream with air or nitrogen with an identical volumetric flow rate. A pseudo-random bina...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260370914
更新日期:1991-04-15 00:00:00
abstract::Two simultaneous fermentations were performed at 26 degrees C with simultaneous inocula using Clostridium saccharoperbutylacetonicum. Fermentation 1 prevented the gas formed by the biomass from escaping the fermentor while 2 allowed the gas formed to escape. Fermentor 1 provided for the production of butanol, acetone,...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260280302
更新日期:1986-03-01 00:00:00
abstract::The kinetics of precipitation of soya protein has been examined in a tubular flow reactor with the precipitants, ammonium sulfate, ethanol, divalent calcium, and sulfuric acid. The precipitate growth profiles obtained in all cases showed the rapid formation of a precipitate phase and the attainment of a final size wit...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260280312
更新日期:1986-03-01 00:00:00
abstract::The G-H loop of foot-and-mouth disease virus is a disordered protrusion of the VP1 protein exposed on the virion surface. This short stretch includes an arginine-glycine-aspartic acid tripeptide, a recognized integrin-binding motif, which is responsible for cell attachment and infection. Eight copies of a peptide repr...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(sici)1097-0290(19980805)59:3<294::aid-bit
更新日期:1998-08-05 00:00:00
abstract::The C-terminal lysine variation is commonly observed in biopharmaceutical monoclonal antibodies. This modification can be important since it is found to be sensitive to the production process. The methods commonly used to probe this charge variation, including IEF, cIEF, ion-exchange chromatography, and LC-MS, were ev...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21855
更新日期:2008-08-15 00:00:00
abstract::Dehydrogenase activity assay of activated sludge using the redox dye 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride (INT) was investigated. INT-dehydrogenase activity (INT-DHA) was directly proportional to INT dosage and inversely proportional to bio-mass concentration over limited ranges. INT dosages...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260280719
更新日期:1986-07-01 00:00:00
abstract::Self-cycling fermentation (SCF), a cyclical, semi-continuous process that induces cell synchrony, was incorporated into a recombinant protein production scheme. Escherichia coli CY15050, a lac(-) mutant lysogenized with temperature-sensitive phage λ modified to over-express β-galactosidase, was used as a model system....
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24492
更新日期:2012-09-01 00:00:00
abstract::Pathway refactoring serves as an invaluable synthetic biology tool for natural product discovery, characterization, and engineering. However, the complicated and laborious molecular biology techniques largely hinder its application in natural product research, especially in a high-throughput manner. Here we report a p...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26309
更新日期:2017-08-01 00:00:00
abstract::Whole cell pyruvate decarboxylase (PDC) from Candida utilis enhanced the enzymatic production of (R)-phenylacetylcarbinol (PAC) in an aqueous/octanol biotransformation compared to the partially purified PDC especially for a lower range of initial activities (0.3-2.5 U/mL). With an initial activity of 1.1 U/mL and at a...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20959
更新日期:2006-08-20 00:00:00
abstract::Plasmid gene product accumulation in a cell population depends on the fraction of plasmid-containing cells and the distribution of single-cell plasmid content. These important population properties have been related to plasmid replication regulation and kinetics and to plasmid segregation rules at the single-cell leve...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260260519
更新日期:1984-05-01 00:00:00
abstract::Mathematical models to describe transcription (Arnold et al. (2001); Biotech Bioeng 72:548-561) and translation (Mehra et al. (2003); Biotech Bioeng 84:822-841) in bacteria are modified in order to improve reaction kinetics and to include the number of polymerase molecules that are active on the DNA, as well as to inc...
journal_title:Biotechnology and bioengineering
pub_type: 评论,信件
doi:10.1002/bit.21065
更新日期:2007-03-01 00:00:00
abstract::The scope in improving enzyme productivities from the cellulose fermentation process is examined in laboratory-scale fermentors. The maximum productivity (30 IU/liter hr) is attained in a continuous-culture process with cell recycle using modified medium containing 0.5% cellulose. Optimum dilution rate and recycle rat...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260210213
更新日期:1979-02-01 00:00:00
abstract::A microarray targeting four sequenced strains in the Dehalococcoides (Dhc) genus was used to analyze gene expression in a robust long-term trichloroethene (TCE)-degrading microbial community (designated ANAS) during feeding cycles that involve conditions of periodic substrate supply. The Dhc transcriptome was examined...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24819
更新日期:2013-05-01 00:00:00
abstract::An examination is made of five methods for obtaining values of the enthalpy of formation of a unit mass of living Escherichia coli K-12 cells. The values obtained by these methods ranged from -88.95 kJ to -99.55 kJ, the gross average being 96.01 kJ, per unit carbon formula weight equivalent of living, hydrated cells. ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260390103
更新日期:1992-01-05 00:00:00