A comparison between ethanol and methanol as carbon sources for denitrification

1994 ◽  
Vol 30 (6) ◽  
pp. 83-90 ◽  
Author(s):  
Magnus Christensson ◽  
Ewa Lie ◽  
Thomas Welander
Keyword(s):  
Growth Rate ◽  
Carbon Source ◽  
Pure Culture ◽  
Carbon Sources ◽  
Culture Studies ◽  
Adaptation Time ◽  
Synthetic Media ◽  
Short Time

Ethanol and methanol were compared for their performance as carbon sources for denitrification. The study was carried out in two chemostats, operated in parallel on synthetic media containing ethanol and methanol respectively as carbon sources. In addition, pure culture studies were performed on one ethanol- and one methanol-utilizing denitrifier. Ethanol was found to be considerably more readily available as a carbon source for denitrification than was methanol. An efficient denitrification with ethanol was established in a short time, while denitrification with methanol required a substantial adaptation time and never showed the same stability as denitrification with ethanol. The growth rate of denitrifiers with ethanol as carbon source was 2–3 times higher than with methanol. The amount of COD required to denitrify a certain amount of nitrate was somewhat lower for ethanol (3.85 g/gN) than for methanol (4.45 g/gN) in the continuous experiments, while it was considerably higher for ethanol (6.1 g/gN) than for methanol (4.1 g/gN) in pure culture batch cultivations.

scholarly journals Screening of local wild-type Xanthomonas spp. for xanthan biosynthesis using media with different carbon sources

2021 ◽  
Vol 26 (4) ◽  
pp. 2800-2807
Author(s):  
IDA ZAHOVIĆ ◽  
JELENA DODIĆ ◽  
SINIŠA MARKOV ◽  
JOVANA GRAHOVAC ◽  
MILA GRAHOVAC ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Carbon Source ◽  
Carbon Sources ◽  
Wild Type ◽  
Biotechnological Production ◽  
Aerobic Conditions ◽  
Pepper Leaves ◽  
Synthetic Media ◽  
Selection Of

In this study the screening of different Xanthomonas strains, isolated from infected crucifers and pepper leaves, for xanthan biosynthesis on semi-synthetic media containing different carbon sources was performed. The success of xanthan biosynthesis was estimated based on xanthan concentration in media and its molecular weight. Glucose and glycerol were investigated as carbon sources in a quantity of 20.0 g/L. Xanthan biosynthesis by different Xanthomonas isolates on two different cultivation media was carried out in Erlenmeyer flasks under aerobic conditions for 168 h. According to the obtained results selection of the carbon source, producing strain and their combination have a statistically significant effect on xanthan quantity and quality. The results obtained in this study indicate that local wild-type Xanthomonas strains isolated from pepper leaves have a great potential for application in biotechnological production of good-quality xanthan on glycerol-based media.

scholarly journals Metabolic phenotyping of marine heterotrophs on refactored media reveals diverse metabolic adaptations and lifestyle strategies

2022 ◽  
Author(s):  
Elena Jean Forchielli ◽  
Daniel Jonathan Sher ◽  
Daniel Segre
Keyword(s):  
Carbon Source ◽  
Species Interactions ◽  
Heterotrophic Bacteria ◽  
Carbon Sources ◽  
Phylogenetic Distance ◽  
Marine Biomass ◽  
Glyoxylate Metabolism ◽  
Nutritional Needs ◽  
Metabolic Heterogeneity ◽  
Synthetic Media

Microbial communities, through their metabolism, drive carbon cycling in marine environments. These complex communities are composed of many different microorganisms including heterotrophic bacteria, each with its own nutritional needs and metabolic capabilities. Yet, models of ecosystem processes typically treat heterotrophic bacteria as a "black box", which does not resolve metabolic heterogeneity nor address ecologically important processes such as the successive modification of different types of organic matter. Here we directly address the heterogeneity of metabolism by characterizing the carbon source utilization preferences of 63 heterotrophic bacteria representative of several major marine clades. By systematically growing these bacteria on 10 media containing specific subsets of carbon sources found in marine biomass, we obtained a phenotypic fingerprint that we used to explore the relationship between metabolic preferences and phylogenetic or genomic features. At the class level, these bacteria display broadly conserved patterns of preference for different carbon sources. Despite these broad taxonomic trends, growth profiles correlate poorly with phylogenetic distance or genome-wide gene content. However, metabolic preferences are strongly predicted by a handful of key enzymes that preferentially belong to a few enriched metabolic pathways, such as those involved in glyoxylate metabolism and biofilm formation. We find that enriched pathways point to enzymes directly involved in the metabolism of the corresponding carbon source and suggest potential associations between metabolic preferences and other ecologically-relevant traits. The availability of systematic phenotypes across multiple synthetic media constitutes a valuable resource for future quantitative modeling efforts and systematic studies of inter-species interactions.

Effect of carbon source on Phenobarbital metabolism by Rhizopus stolonifer

2010 ◽  
Vol 3 (2) ◽  
pp. 1022-1027
Author(s):  
Kavitha K ◽  
Asha S ◽  
Hima Bindu T.V.L ◽  
Vidyavathi M
Keyword(s):  
Carbon Source ◽  
High Performance ◽  
Carbon Sources ◽  
In Vitro Models ◽  
Rhizopus Stolonifer ◽  
Safety And Efficacy ◽  
Alternative Systems ◽  
Toxicological Studies ◽  
Microbial Model

The safety and efficacy of a drug is based on its metabolism or metabolite formed. The metabolism of drugs can be studied by different in vitro models, among which microbial model became popular. In the present study, eight microbes were screened for their ability to metabolize phenobarbital in a manner comparable to humans with a model to develop alternative systems to study human drug metabolism. Among the different microbes screened, a filamentous fungi Rhizopus stolonifer metabolized phenobarbital to its metabolite which is used for further pharmacological and toxicological studies. The transformation of phenobarbital was identified by high- performance liquid chromatography (HPLC). Interestingly, Rhizopus stolonifer sample showed an extra metabolite peak at 3.11min. compared to its controls. The influence of different carbon sources in media used for growth of fungus, on metabolite production was studied, to find its effect in production of metabolite as the carbon source may influence the growth of the cell.

scholarly journals Denitrification Control in a Recirculating Aquaculture System—A Simulation Study

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1306
Author(s):  
Pedro Almeida ◽  
Laurent Dewasme ◽  
Alain Vande Wouwer
Keyword(s):  
Carbon Source ◽  
Carbon Sources ◽  
Aquatic Organisms ◽  
Operating Conditions ◽  
Toxic Substances ◽  
Recirculating Aquaculture System ◽  
Treatment Technology ◽  
Tuning Method ◽  
Recirculating Aquaculture ◽  
Aquaculture System

The recirculating aquaculture system (RAS) is a land-based water treatment technology, which allows for farming aquatic organisms, such as fish, by reusing the water in the production (often less than 5%). This technology is based on the use of filters, either mechanical or biological, and can, in principle, be used for any species grown in aquaculture. Due to the low recirculation rate, ammonia accumulates in the system and must be converted into nitrate using nitrification reactors. Although less toxic for fish, nitrate can also be further reduced into nitrogen gas by the use of denitrification biofilters which may create several issues, such as incomplete denitrification, resulting in toxic substances, such as nitrite and nitric oxide, or a waste of carbon source in excess. Control of the added quantity of carbon source in the denitrification biofilter is then mandatory to keep nitrate/nitrite concentrations under toxic levels for fish and in accordance with local effluent regulations, and to reduce costs related to wasted organic carbon sources. This study therefore investigates the application of different control methodologies to a denitrification reactor in a RAS. To this end, a numerical simulator is built to predict the RAS behavior and to allow for the comparison of different control approaches, in the presence of changes in the operating conditions, such as fish density and biofilter removal efficiency. First, a classical proportional-integral-derivative (PID) controller was designed, based on an SIMC tuning method depending on the amount of ammonia excreted by fish. Then, linearizing and cascade controllers were considered as possible alternatives.

scholarly journals The carbon source-dependent pattern of antimicrobial activity and gene expression in Pseudomonas donghuensis P482

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marta Matuszewska ◽  
Tomasz Maciąg ◽  
Magdalena Rajewska ◽  
Aldona Wierzbicka ◽  
Sylwia Jafra
Keyword(s):  
Gene Expression ◽  
Antimicrobial Activity ◽  
Carbon Source ◽  
Reference Genes ◽  
Plant Pathogens ◽  
Plant Protection ◽  
Carbon Sources ◽  
Unknown Compound ◽  
Fungal Plant Pathogens ◽  
The Impact

AbstractPseudomonas donghuensis P482 is a tomato rhizosphere isolate with the ability to inhibit growth of bacterial and fungal plant pathogens. Herein, we analysed the impact of the carbon source on the antibacterial activity of P482 and expression of the selected genes of three genomic regions in the P482 genome. These regions are involved in the synthesis of pyoverdine, 7-hydroxytropolone (7-HT) and an unknown compound (“cluster 17”) and are responsible for the antimicrobial activity of P482. We showed that the P482 mutants, defective in these regions, show variations and contrasting patterns of growth inhibition of the target pathogen under given nutritional conditions (with glucose or glycerol as a carbon source). We also selected and validated the reference genes for gene expression studies in P. donghuensis P482. Amongst ten candidate genes, we found gyrB, rpoD and mrdA the most stably expressed. Using selected reference genes in RT-qPCR, we assessed the expression of the genes of interest under minimal medium conditions with glucose or glycerol as carbon sources. Glycerol was shown to negatively affect the expression of genes necessary for 7-HT synthesis. The significance of this finding in the light of the role of nutrient (carbon) availability in biological plant protection is discussed.

scholarly journals Maintenance of Mitochondrial Morphology Is Linked to Maintenance of the Mitochondrial Genome in Saccharomyces cerevisiae

Genetics ◽  
2002 ◽  
Vol 162 (3) ◽  
pp. 1147-1156 ◽  
Author(s):  
Theodor Hanekamp ◽  
Mary K Thorsness ◽  
Indrani Rebbapragada ◽  
Elizabeth M Fisher ◽  
Corrine Seebart ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Mitochondrial Dna ◽  
Carbon Sources ◽  
Mitochondrial Morphology ◽  
Yeast Saccharomyces Cerevisiae ◽  
Slow Growth Rate ◽  
Dna Migration ◽  
Mitochondrial Dna Stability ◽  
Extragenic Suppressors

Abstract In the yeast Saccharomyces cerevisiae, certain mutant alleles of YME4, YME6, and MDM10 cause an increased rate of mitochondrial DNA migration to the nucleus, carbon-source-dependent alterations in mitochondrial morphology, and increased rates of mitochondrial DNA loss. While single mutants grow on media requiring mitochondrial respiration, any pairwise combination of these mutations causes a respiratory-deficient phenotype. This double-mutant phenotype allowed cloning of YME6, which is identical to MMM1 and encodes an outer mitochondrial membrane protein essential for maintaining normal mitochondrial morphology. Yeast strains bearing null mutations of MMM1 have altered mitochondrial morphology and a slow growth rate on all carbon sources and quantitatively lack mitochondrial DNA. Extragenic suppressors of MMM1 deletion mutants partially restore mitochondrial morphology to the wild-type state and have a corresponding increase in growth rate and mitochondrial DNA stability. A dominant suppressor also suppresses the phenotypes caused by a point mutation in MMM1, as well as by specific mutations in YME4 and MDM10.

Development of mutants of Gliocladium virens tolerant to benomyl

1990 ◽  
Vol 36 (7) ◽  
pp. 484-489 ◽  
Author(s):  
G. C. Papavizas ◽  
D. P. Roberts ◽  
K. K. Kim
Keyword(s):  
Carbon Source ◽  
Type Strain ◽  
Wild Type Strain ◽  
Carbon Sources ◽  
Sclerotium Rolfsii ◽  
Wild Type ◽  
Gliocladium Virens ◽  
Rhizosphere Competence ◽  
Filter Paper Cellulase ◽  
Type Strains

Aqueous suspensions of conidia of Gliocladium virens strains Gl-3 and Gl-21 were exposed to both ultraviolet radiation and ethyl methanesulfonate. Two mutants of Gl-3 and three of Gl-21 were selected for tolerance to benomyl at 10 μg∙mL−1, as indicated by growth and conidial germination on benomyl-amended potato dextrose agar. The mutants differed considerably from their respective wild-type strains in appearance, growth habit, sporulation, carbon-source utilization, and enzyme activity profiles. Of 10 carbon sources tested, cellobiose, xylose, and xylan were the best for growth, galactose and glucose were intermediate, and arabinose, ribose, and rhamnose were poor sources of carbon. The wild-type strains and the mutants did not utilize cellulose as the sole carbon source for growth. Two benomyl-tolerant mutants of Gl-3 produced less cellulase (β-1,4-glucosidase, carboxymethylcellulase, filter-paper cellulase) than Gl-3. In contrast, mutants of Gl-21 produced more cellulase than the wild-type strain. Only Gl-3 provided control of blight on snapbean caused by Sclerotium rolfsii. Wild-type strain Gl-21 and all mutants from both strains were ineffective biocontrol agents. Key words: Gliocladium, benomyl tolerance, Sclerotium, rhizosphere competence.

scholarly journals Comparison of clinical acinetobacter strains using a carbon source growth assay

1990 ◽  
Vol 104 (3) ◽  
pp. 443-453 ◽  
Author(s):  
L. Dijkshoorn ◽  
A. Van Ooyen ◽  
W. C. J. Hop ◽  
M. Theuns ◽  
M. F. Michel
Keyword(s):  
Cluster Analysis ◽  
Carbon Source ◽  
Univariate Analysis ◽  
Carbon Sources ◽  
Protein Profiles ◽  
Growth Data ◽  
Epidemiological Factors ◽  
Growth Assay ◽  
Growth Profiles ◽  
Related Pattern

SUMMARYA quantitative carbon source growth assay, comprising ten carbon sources, was used to compare acinetobacter strains from three hospitals. The strains had been obtained during episodes of increased prevalence of isolations and were, for each hospital, assumed to be epidemiologically related. This assumption was supported by the electrophoretic protein profiles of the strains. Univariate analysis of growth data showed significant differences between strains from the three hospitals. Moreover, cluster analysis revealed that the major pattern in the data was related to the epidemiological origin of the strains. Exceptions to the epidemic-related pattern were observed. Thus, apart from epidemiological factors, other factors might contribute to carbon source growth profiles of the strains. It is concluded that the carbon growth assay may be useful to distinguish roughly between acinetobacter strains from different sites of origin. Further studies are required to analyse additional factors which influence carbon source growth of strains.

Regulation of yeast COX6 by the general transcription factor ABF1 and separate HAP2- and heme-responsive elements

1992 ◽  
Vol 12 (5) ◽  
pp. 2302-2314
Author(s):  
J D Trawick ◽  
N Kraut ◽  
F R Simon ◽  
R O Poyton
Keyword(s):  
Transcription Factor ◽  
Carbon Source ◽  
Protein Binding ◽  
Glucose Repression ◽  
Protein Complexes ◽  
Carbon Sources ◽  
Major Protein ◽  
Mobility Shift ◽  
Gel Mobility Shift ◽  
In Cells

Transcription of the Saccharomyces cerevisiae COX6 gene is regulated by heme and carbon source. It is also affected by the HAP2/3/4 transcription factor complex and by SNF1 and SSN6. Previously, we have shown that most of this regulation is mediated through UAS6, an 84-bp upstream activation segment of the COX6 promoter. In this study, by using linker scanning mutagenesis and protein binding assays, we have identified three elements within UAS6 and one element downstream of it that are important. Two of these, HDS1 (heme-dependent site 1; between -269 and -251 bp) and HDS2 (between -228 and -220 bp), mediate regulation of COX6 by heme. Both act negatively. The other two elements, domain 2 (between -279 and -269 bp) and domain 1 (between -302 and -281 bp), act positively. Domain 2 is required for optimal transcription in cells grown in repressing but not derepressing carbon sources. Domain 1 is essential for transcription per se in cells grown on repressing carbon sources, is required for optimal transcription in cells grown on a derepressing carbon source, is sufficient for glucose repression-derepression, and is the element of UAS6 at which HAP2 affects COX6 transcription. This element contains the major protein binding sites within UAS6. It has consensus binding sequences for ABF1 and HAP2. Gel mobility shift experiments show that domain 1 binds ABF1 and forms different numbers of DNA-protein complexes in extracts from cells grown in repressing or derepressing carbon sources. In contrast, gel mobility shift experiments have failed to reveal that HAP2 or HAP3 binds to domain 1 or that hap3 mutations affect the complexes bound to it. Together, these findings permit the following conclusions: COX6 transcription is regulated both positively and negatively; heme and carbon source exert their effects through different sites; domain 1 is absolutely essential for transcription on repressing carbon sources; ABF1 is a major component in the regulation of COX6 transcription; and the HAP2/3/4 complex most likely affects COX6 transcription indirectly.

A Simple Statistical Theory for Grain Growth in Materials.

1990 ◽  
Vol 209 ◽  
Author(s):  
P. Mulheran ◽  
J.H. Harding
Keyword(s):  
Growth Rate ◽  
Monte Carlo ◽  
Statistical Theory ◽  
Stochastic Model ◽  
Grain Growth ◽  
Three Dimensional ◽  
Monte Carlo Procedure ◽  
Short Time ◽  
2D And 3D ◽  
Good Agreement

A Monte Carlo procedure has been used to study the ordering of both two and three dimensional (2d and 3d) Potts Hamiltonians, further to the work of Anderson et al. For the 3d lattice, the short time growth rate is found to be much slower than previously reported, though the simulated microstructure is in agreement with the earlier studies. We propose a new stochastic model that gives good agreement with the simulations.

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