scholarly journals Xylanase production using fruit waste as cost effective carbon source from thermo-tolerant Bacillus megaterium

2014 ◽  
Vol 8 (38) ◽  
pp. 3463-3470 ◽  
Author(s):  
Abdul Wahid Abdul Kareem Rafid ◽  
Khushk Imrana ◽  
Aqeel Bhutto Muhammad ◽  
Abdul Sattar Qureshi ◽  
Ahmed Ayyaz
Keyword(s):  
Carbon Source ◽  
Bacillus Megaterium ◽  
Cost Effective ◽  
Xylanase Production ◽  
Fruit Waste

Cost-effective upgrading of the Arnsberg WWTP by post denitrification with a moving bed system

2000 ◽  
Vol 41 (9) ◽  
pp. 123-130
Author(s):  
N. Jardin ◽  
L. Rath ◽  
A. Sabin ◽  
F. Schmitt ◽  
D. Thöle ◽  
...  
Keyword(s):  
Carbon Source ◽  
Biological Process ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Cost Effective ◽  
Benefit Analysis ◽  
Moving Bed ◽  
Trickling Filters ◽  
Sludge Hydrolysis ◽  
Effective Integration

On the basis of a cost-benefit analysis it was decided to expand the Arnsberg WWTP by a multistage biological process which allows for cost-effective integration of the existing facilities. Carbon removal will then be accomplished in a high-loaded activated sludge stage for which the existing primary clarifier is to be reconstructed. The existing trickling filters will be used for nitrification during a midterm period and will be replaced later on either by a moving bed system or by new trickling filters. Line 3 of the existing secondary clarifiers will be reconstructed and used for post denitrification in a moving bed system. The carbon needed for denitrification will be provided by means of sludge hydrolysis and the use of an external carbon source.

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

mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
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.

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