Transient responses of Wickerhamia sp. yeast continuous cultures to qualitative changes in carbon source supply: induction and catabolite repression of α-amylase synthesis

The effect of carbon source on the levels of three (1 → 3)-β-glucanases and a (1 → 6)-β-glucanase in the culture filtrates of the filamentous fungus Acremonium persicinum was investigated. All four enzymes were produced during growth of the fungus on (1 → 3)-, (1 → 6)-, and (1 → 3)(1 → 6)-β-glucans as well as β-linked oligoglucosides. However, only one (1 → 3)-β-glucanase and the (1 → 6)-β-glucanase were detected during growth on a range of other carbon sources including glucose, carboxymethylcellulose, and the α-glucan pullulan. The presence of glucose in the medium markedly decreased the production of all four glucanases, although the concentration required to effect complete repression of enzyme levels varied for the different enzymes. Similar repressive effects were also observed with sucrose, fructose, and galactose. The most likely explanations for these observations are that the synthesis of the (1 → 6)-β-glucanase and one of the (1 → 3)-β-glucanases is controlled by carbon catabolite repression, while the remaining two (1 → 3)-β-glucanases are inducible enzymes subject to carbon catabolite repression.Key words: (1 → 3)-β-glucanase, (1 → 6)-β-glucanase, Acremonium persicinum, regulation of synthesis, fungal β-glucanases.

Download Full-text

Regulation ofAspergillus nidulansCreA-Mediated Catabolite Repression by the F-Box Proteins Fbx23 and Fbx47

mBio ◽

10.1128/mbio.00840-18 ◽

2018 ◽

Vol 9 (3) ◽

Cited By ~ 15

Author(s):

Leandro José de Assis ◽

Mevlut Ulas ◽

Laure Nicolas Annick Ries ◽

Nadia Ali Mohamed El Ramli ◽

Ozlem Sarikaya-Bayram ◽

...

Keyword(s):

Carbon Source ◽

Aspergillus Nidulans ◽

Ubiquitin Ligase ◽

Catabolite Repression ◽

Carbon Catabolite Repression ◽

26S Proteasome ◽

Xylanase Production ◽

Content Type ◽

Regulatory Pathways ◽

Ubiquitin Ligase Complex

ABSTRACTThe attachment of one or more ubiquitin molecules by SCF (Skp–Cullin–F-box) complexes to protein substrates targets them for subsequent degradation by the 26S proteasome, allowing the control of numerous cellular processes. Glucose-mediated signaling and subsequent carbon catabolite repression (CCR) are processes relying on the functional regulation of target proteins, ultimately controlling the utilization of this carbon source. In the filamentous fungusAspergillus nidulans, CCR is mediated by the transcription factor CreA, which modulates the expression of genes encoding biotechnologically relevant enzymes. Although CreA-mediated repression of target genes has been extensively studied, less is known about the regulatory pathways governing CCR and this work aimed at further unravelling these events. The Fbx23 F-box protein was identified as being involved in CCR and the Δfbx23mutant presented impaired xylanase production under repressing (glucose) and derepressing (xylan) conditions. Mass spectrometry showed that Fbx23 is part of an SCF ubiquitin ligase complex that is bridged via the GskA protein kinase to the CreA-SsnF-RcoA repressor complex, resulting in the degradation of the latter under derepressing conditions. Upon the addition of glucose, CreA dissociates from the ubiquitin ligase complex and is transported into the nucleus. Furthermore, casein kinase is important for CreA function during glucose signaling, although the exact role of phosphorylation in CCR remains to be determined. In summary, this study unraveled novel mechanistic details underlying CreA-mediated CCR and provided a solid basis for studying additional factors involved in carbon source utilization which could prove useful for biotechnological applications.IMPORTANCEThe production of biofuels from plant biomass has gained interest in recent years as an environmentally friendly alternative to production from petroleum-based energy sources. Filamentous fungi, which naturally thrive on decaying plant matter, are of particular interest for this process due to their ability to secrete enzymes required for the deconstruction of lignocellulosic material. A major drawback in fungal hydrolytic enzyme production is the repression of the corresponding genes in the presence of glucose, a process known as carbon catabolite repression (CCR). This report provides previously unknown mechanistic insights into CCR through elucidating part of the protein-protein interaction regulatory system that governs the CreA transcriptional regulator in the reference organismAspergillus nidulansin the presence of glucose and the biotechnologically relevant plant polysaccharide xylan.

Download Full-text

Expression of the Pseudomonas putida OCT Plasmid Alkane Degradation Pathway Is Modulated by Two Different Global Control Signals: Evidence from Continuous Cultures

Journal of Bacteriology ◽

10.1128/jb.185.16.4772-4778.2003 ◽

2003 ◽

Vol 185 (16) ◽

pp. 4772-4778 ◽

Cited By ~ 46

Author(s):

M. Alejandro Dinamarca ◽

Isabel Aranda-Olmedo ◽

Antonio Puyet ◽

Fernando Rojo

Keyword(s):

Carbon Source ◽

Pseudomonas Putida ◽

Catabolite Repression ◽

Degradation Pathway ◽

Independent Effect ◽

Physiological Status ◽

Carbon Limitation ◽

Alkane Degradation ◽

Global Control ◽

Ubiquinol Oxidase

ABSTRACT Expression of the genes of the alkane degradation pathway encoded in the Pseudomonas putida OCT plasmid are subject to negative and dominant global control depending on the carbon source used and on the physiological status of the cell. We investigated the signals responsible for this control in chemostat cultures under conditions of nutrient or oxygen limitation. Our results show that this global control is not related to the growth rate and responds to two different signals. One signal is the concentration of the carbon source that generates the repressing effect (true catabolite repression control). The second signal is influenced by the level of expression of the cytochome o ubiquinol oxidase, which in turn depends on factors such as oxygen availability or the carbon source used. Since under carbon limitation conditions the first signal is relieved but the second signal is not, we propose that modulation mediated by the cytochrome o ubiquinol oxidase is not classical catabolite repression control but rather a more general physiological control mechanism. The two signals have an additive, but independent, effect, inhibiting induction of the alkane degradation pathway.

Download Full-text

Intracellular adenosine triphosphate and cyclic adenosine 3′,5′-monophosphate concentrations during derepression of actinomycin biosynthesis

Canadian Journal of Microbiology ◽

10.1139/m82-207 ◽

1982 ◽

Vol 28 (12) ◽

pp. 1396-1399 ◽

Cited By ~ 2

Author(s):

S. Chatterjee ◽

L. C. Vining

Keyword(s):

Carbon Source ◽

Adenosine Triphosphate ◽

Catabolite Repression ◽

Antibiotic Production ◽

Carbon Source Utilization ◽

Streptomyces Antibioticus ◽

Cell Extracts

Measurements of adenosine triphosphate and of cyclic adenosine 3′,5′-monophosphate in the mycelium of Streptomyces antibioticus during growth in a medium containing a mixture of glucose and galactose showed no marked changes in concentration during the period when glucose was exhausted and the synthesis of actinomycin began. Thus, these nucleotides do not appear to have a role in mediating catabolite repression of either carbon source utilization or antibiotic production in this organism. Since no NADP-glucohydrolase activity was detected in cell extracts, this enzyme is also excluded from apossible role in regulating actinomycin biosynthesis.

Download Full-text

Effect of deregulation of repressor-specific carbon catabolite repression on carbon source consumption in Escherichia coli

Applied Biological Chemistry ◽

10.1186/s13765-021-00627-0 ◽

2021 ◽

Vol 64 (1) ◽

Author(s):

Hyeon Jeong Seong ◽

Yu-Sin Jang

Keyword(s):

Escherichia Coli ◽

Carbon Source ◽

Catabolite Repression ◽

Sole Carbon Source ◽

Carbon Catabolite Repression ◽

Cell Factory ◽

Essential Information ◽

E Coli ◽

Marine Biomass ◽

Galactose Utilization

AbstractEscherichia coli has been used as a host to construct the cell factory for biobased production of chemicals from renewable feedstocks. Because galactose is found in marine biomass as a major component, the strategy for galactose utilization in E. coli has been gained more attention. Although galactose and glucose co-fermentation has been reported using the engineered E. coli strain, few reports have covered fermentation supplemented with galactose as a sole carbon source in the mutant lacking the repressor-specific carbon catabolite repression (CCR). Here, we report the effects of the deregulation of the repressor-specific CCR (galR− and galS−) in fermentation supplemented with galactose as a sole carbon source, using the engineered E. coli strains. In the fermentation using the galR− and galS− double mutant (GR2 strain), an increase of rates in sugar consumption and cell growth was observed compared to the parent strain. In the glucose fermentation, wild-type W3110 and its mutant GR2 and GR2PZ (galR−, galS−, pfkA−, and zwf−) consumed sugar at a higher rate than those values obtained from galactose fermentation. However, the GR2P strain (galR−, galS−, and pfkA−) showed no difference between fermentations using glucose and galactose as a sole carbon source. This study provides essential information for galactose fermentation using the CCR-deregulated E. coli strains.

Download Full-text

Regulation of Cellulase Synthesis in Batch and Continuous Cultures of Clostridium thermocellum

Journal of Bacteriology ◽

10.1128/jb.187.1.99-106.2005 ◽

2005 ◽

Vol 187 (1) ◽

pp. 99-106 ◽

Cited By ~ 92

Author(s):

Zhang Percival Yi-Heng ◽

Lee R. Lynd

Keyword(s):

Dilution Rate ◽

Substrate Concentration ◽

Catabolite Repression ◽

Clostridium Thermocellum ◽

Peptide Sequence ◽

Enzyme Linked Immunosorbent Assay ◽

Limited Growth ◽

Continuous Cultures ◽

Batch Cultures ◽

Batch Growth

ABSTRACT Regulation of cell-specific cellulase synthesis (expressed in milligrams of cellulase per gram [dry weight] of cells) by Clostridium thermocellum was investigated using an enzyme-linked immunosorbent assay protocol based on antibody raised against a peptide sequence from the scaffoldin protein of the cellulosome (Zhang and Lynd, Anal. Chem. 75:219-227, 2003). The cellulase synthesis in Avicel-grown batch cultures was ninefold greater than that in cellobiose-grown batch cultures. In substrate-limited continuous cultures, however, the cellulase synthesis with Avicel-grown cultures was 1.3- to 2.4-fold greater than that in cellobiose-grown cultures, depending on the dilution rate. The differences between the cellulase yields observed during carbon-limited growth on cellulose and the cellulase yields observed during carbon-limited growth on cellobiose at the same dilution rate suggest that hydrolysis products other than cellobiose affect cellulase synthesis during growth on cellulose and/or that the presence of insoluble cellulose triggers an increase in cellulase synthesis. Continuous cellobiose-grown cultures maintained either at high dilution rates or with a high feed substrate concentration exhibited decreased cellulase synthesis; there was a large (sevenfold) decrease between 0 and 0.2 g of cellobiose per liter, and there was a much more gradual further decrease for cellobiose concentrations >0.2 g/liter. Several factors suggest that cellulase synthesis in C. thermocellum is regulated by catabolite repression. These factors include: (i) substantially higher cellulase yields observed during batch growth on Avicel than during batch growth on cellobiose, (ii) a strong negative correlation between the cellobiose concentration and the cellulase yield in continuous cultures with varied dilution rates at a constant feed substrate concentration and also with varied feed substrate concentrations at a constant dilution rate, and (iii) the presence of sequences corresponding to key elements of catabolite repression systems in the C. thermocellum genome.

Download Full-text

Catabolite repression-resistant mutants of Bacillus subtilis

Canadian Journal of Microbiology ◽

10.1139/m79-202 ◽

1979 ◽

Vol 25 (11) ◽

pp. 1283-1287 ◽

Cited By ~ 16

Author(s):

I. Takahashi

Keyword(s):

Bacillus Subtilis ◽

Carbon Source ◽

Catabolite Repression ◽

Minimal Medium ◽

Carbon Sources ◽

Close Relation ◽

Selection Technique ◽

Source Studies ◽

Resistant Mutants ◽

Simple Selection

Mutants of Bacillus subtilis that are able to sporulate under the condition of catabolite repression were isolated by a simple selection technique. The mutants used in the present study were able to grow normally on minimal medium with ammonium sulphate as the nitrogen source and glucose as the carbon source. Studies carried out with these mutants show that there is no close relation between catabolite repression of an inducible enzyme, acetoin dehydrogenase, and that of sporulation. Certain mutants are able to sporulate in the presence of all the carbon sources tested but some mutants are resistant only to the carbon source used in isolation. It is suggested that several metabolic steps may be affected in catabolite repression of sporulation.

Download Full-text

Accumulation of untranslated lactose-specific messenger ribonucleic acid during catabolite repression in Escherichia coli

Biochemical Journal ◽

10.1042/bj1220219 ◽

1971 ◽

Vol 122 (2) ◽

pp. 219-224 ◽

Cited By ~ 4

Author(s):

M. Aboud ◽

M. Burger

Keyword(s):

Escherichia Coli ◽

Carbon Source ◽

Cyclic Amp ◽

Direct Effect ◽

Ribonucleic Acid ◽

Catabolite Repression ◽

Mrna Accumulation ◽

Messenger Ribonucleic Acid ◽

K 12 ◽

Specific Mrna

When Escherichia coli K-12 Hfr.H was induced to synthesize β-galactosidase in the presence of glucose, an untranslated lactose-specific mRNA (lac-mRNA), protected from decay, was found to accumulate progressively within the cells. The lac-mRNA accumulation was unaffected by the carbon source on which the cells had been grown before the induction. The amount of the lac-mRNA available for translation was affected by catabolite repression and 3′:5′-cyclic AMP, but it remained unclear whether this was a direct effect on the formation of the lac-mRNA or a consequence of the effect on its translation.

Download Full-text