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Investigation of carbon catabolite repression in Clostridium beijerinckii NCIMB 8052
No full textSummary in English.Includes bibliographical references.The substrate basis for the industrial acetone-butanol-ethanol (ABE) fermentations, has been agricultural products rich in starch or sucrose, and employed taxonomically distinct amylolytic and saccharolytic solventogenic clostridial strains respectively. There is evidence to suggest that the utilization of these substrates is subject to carbon catabolite repression. In Gram-positive bacteria, carbon catabolite repression is controlled by a global regulatory mechanism, central to which is an imperfect palindromic sequence, the cre element, which is recognized by a protein of the GalR-LacI family, the CcpA protein. A ccpA homologue, regA, has been previously identified in C. acetobutylicum NCP262 and successfully complemented a B. subtilis ccpA mutant strain. The sucrose operon from C. beijerinckii NCIMB 8052, scrARBK, has been characterised at the physiological and genetic levels with the ScrR repressor found to negatively auto-regulate the operon
Glucose Uptake in <i>Clostridium beijerinckii</i> NCIMB 8052 and the Solvent-Hyperproducing Mutant BA101
No full textABSTRACT
Glucose uptake and accumulation by
Clostridium beijerinckii
BA101, a butanol hyperproducing mutant, were examined during various stages of growth. Glucose uptake in
C. beijerinckii
BA101 was repressed 20% by 2-deoxyglucose and 25% by mannose, while glucose uptake in
C. beijerinckii
8052 was repressed 52 and 28% by these sugars, respectively. We confirmed the presence of a phosphoenolpyruvate (PEP)-dependent phosphotransferase system (PTS) associated with cell extracts of
C. beijerinckii
BA101 by glucose phosphorylation by PEP. The PTS activity associated with
C. beijerinckii
BA101 was 50% of that observed for
C. beijerinckii
8052.
C. beijerinckii
BA101 also demonstrated lower PTS activity for fructose and glucitol. Glucose phosphorylation by cell extracts derived from both
C. beijerinckii
BA101 and 8052 was also dependent on the presence of ATP, a finding consistent with the presence of glucokinase activity in
C. beijerinckii
extracts. ATP-dependent glucose phosphorylation was predominant during the solventogenic stage, when PEP-dependent glucose phosphorylation was dramatically repressed. A nearly twofold-greater ATP-dependent phosphorylation rate was observed for solventogenic stage
C. beijerinckii
BA101 than for solventogenic stage
C. beijerinckii
8052. These results suggest that
C. beijerinckii
BA101 is defective in PTS activity and that
C. beijerinckii
BA101 compensates for this defect with enhanced glucokinase activity, resulting in an ability to transport and utilize glucose during the solventogenic stage.
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Examination of Glucose Transport in Clostridium Beijerinckii NCIMB 8052 and the Solvent Hyper-Producing Mutant BA101
No full text89 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2003.Glucose uptake and accumulation by Clostridium beijerinckii BA101, a butanol hyper-producing mutant was examined during various stages of growth. Glucose uptake in C. beijerinckii BA101 was repressed 20% by 2-deoxyglucose (2-DG) and 25% by mannose, while glucose uptake in C. beijerinckii 8052 was repressed 52% and 28% by these sugars, respectively. We confirmed the presence of a phosphoenolpyruvate (PEP) dependent phosphotransferase system (PTS) associated with cell-free extracts of C. beijerinckii BA101 by glucose phosphorylation by PEP. The PTS activity associated with C. beijerinckii BA101 was 50% of that observed for C. beijerinckii 8052. C. beijerinckii BA101 also demonstrated lower PTS activity for fructose and glucitol. Glucose phosphorylation by cell-free extracts derived from both C. beijerinckii BA101 and 8052 was also dependent on the presence of ATP, consistent with the presence of glucokinase activity in C. beijerinckii extracts. ATP-dependent glucose phosphorylation was predominant during the solventogenic stage when PEP-dependent glucose phosphorylation was dramatically repressed. A nearly two-fold greater ATP-dependent phosphorylation rate was observed for solventogenic stage C. beijerinckii BA101 than for solventogenic stage C. beijerinckii 8052. These results suggest that C. beijerinckii BA101 is defective in PTS activity and that C. beijerinckii BA101 compensates for this defect with enhanced glucokinase activity resulting in an ability to transport and utilize glucose during the solventogenic stage. Glucose uptake by both acidogenic and solventogenic stage C. beijerinckii BA 101 was inhibited by proton conductors, ATPase inhibitors and non-PTS substrates in contrast with what was observed for acidogenic stage C. beijerinckii 8052. However, it was observed that these compounds were also potent inhibitors of glucose uptake by solventogenic C. beijerinckii 8052. ATP-dependent glucose phosphorylation was dramatically induced during solventogenic stage when PEP-dependent glucose phosphorylation was decreased. Approximately a two-fold greater ATP-dependent phosphorylation rate was observed during all growth stages for C. beijerinckii BA101 versus C. beijerinckii 8052. These results suggest that an alternative glucose transport mechanism is present in C. beijerinckii other than PTS, which is predominant during the solventogenic stage. The alternative transport mechanism together with enhanced glucokinase activity may allow C. beijerinckii BA101 to more completely utilize glucose in spite of a defective PTS being associated with this strain.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD
Examination of Glucose Transport in Clostridium Beijerinckii NCIMB 8052 and the Solvent Hyper-Producing Mutant BA101
No full textGlucose uptake and accumulation by Clostridium beijerinckii BA101, a butanol hyper-producing mutant was examined during various stages of growth. Glucose uptake in C. beijerinckii BA101 was repressed 20% by 2-deoxyglucose (2-DG) and 25% by mannose, while glucose uptake in C. beijerinckii 8052 was repressed 52% and 28% by these sugars, respectively. We confirmed the presence of a phosphoenolpyruvate (PEP) dependent phosphotransferase system (PTS) associated with cell-free extracts of C. beijerinckii BA101 by glucose phosphorylation by PEP. The PTS activity associated with C. beijerinckii BA101 was 50% of that observed for C. beijerinckii 8052. C. beijerinckii BA101 also demonstrated lower PTS activity for fructose and glucitol. Glucose phosphorylation by cell-free extracts derived from both C. beijerinckii BA101 and 8052 was also dependent on the presence of ATP, consistent with the presence of glucokinase activity in C. beijerinckii extracts. ATP-dependent glucose phosphorylation was predominant during the solventogenic stage when PEP-dependent glucose phosphorylation was dramatically repressed. A nearly two-fold greater ATP-dependent phosphorylation rate was observed for solventogenic stage C. beijerinckii BA101 than for solventogenic stage C. beijerinckii 8052. These results suggest that C. beijerinckii BA101 is defective in PTS activity and that C. beijerinckii BA101 compensates for this defect with enhanced glucokinase activity resulting in an ability to transport and utilize glucose during the solventogenic stage. Glucose uptake by both acidogenic and solventogenic stage C. beijerinckii BA 101 was inhibited by proton conductors, ATPase inhibitors and non-PTS substrates in contrast with what was observed for acidogenic stage C. beijerinckii 8052. However, it was observed that these compounds were also potent inhibitors of glucose uptake by solventogenic C. beijerinckii 8052. ATP-dependent glucose phosphorylation was dramatically induced during solventogenic stage when PEP-dependent glucose phosphorylation was decreased. Approximately a two-fold greater ATP-dependent phosphorylation rate was observed during all growth stages for C. beijerinckii BA101 versus C. beijerinckii 8052. These results suggest that an alternative glucose transport mechanism is present in C. beijerinckii other than PTS, which is predominant during the solventogenic stage. The alternative transport mechanism together with enhanced glucokinase activity may allow C. beijerinckii BA101 to more completely utilize glucose in spite of a defective PTS being associated with this strain.Made available in DSpace on 2015-09-25T21:09:59Z (GMT). No. of bitstreams: 2
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Previous issue date: 2003Embargo set by: Seth Robbins for item 84964
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only89 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2003
Genetic and Physiological Characterization of Clostridium Beijerinckii BA101 and NCIMB 8052
No full text136 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1999.The addition of sodium acetate in MP2 medium was also able to stabilize solvent production by C. beijerinckii BA101, a hypersolvent producing mutant derived from NCIMB 8052. Moreover, BA101 demonstrated a greater increase in solvent production than NCIMB 8052 when acetate was added into MP2 medium. During the exponential growth phase, the specific activities of CoA transferase, acetoacetate decarboxylase and butyraldehyde dehydrogenase were higher in BA101 than in NCIMB 8052. mRNA expression levels of the sol operon were also elevated during the exponential and early stationary growth phases in BA101. The increased phosphotransbutyrylase activity, as a result of elevated ptb-buk operon expression, resulted in enhanced butyrate production by BA101 during the early exponential phase, which was offset by the elevated acid reassimilation due to an increase in CoA transferase activity. The results indicate that an increase in expression of the sol operon and, consequently, activities of associated enzymes may be, in part, responsible for enhanced solvent production by BA101 relative to NCIMB 8052.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD
Enhanced phenolic compounds tolerance response of Clostridium beijerinckii NCIMB 8052 by inactivation of Cbei_3304
No full textAbstract Background Phenolic compounds generated in hydrolysis of lignocellulosic materials are major limiting factors for biological production of solvents by Clostridia, but it lacks the attention on the study of adaptation or resistance mechanisms in response to phenolic compounds. Results Gene Cbei_3304, encoding a hypothetical membrane transport protein, was analyzed by bioinformatic method. After insertional inactivation of the functionally uncertain gene Cbei_3304 in Clostridium beijerinckii NCIMB 8052, resulted in enhanced phenolic compounds tolerance. Compared to the parent strain C. beijerinckii NCIMB 8052, evaluation of toxicity showed the recombination stain C. beijerinckii 3304::int had a higher level of tolerance to four model phenolic compounds of lignocellulose-derived microbial inhibitory compounds. A comparative transcriptome analysis showed that the genes were involved in membrane transport proteins (ABC and MFS family) and were up-regulated expression after disrupting gene Cbei_3304. Additionally, the adaptation of C. beijerinckii NCIMB 8052 in response to non-detoxified hemicellulosic hydrolysate was improved by disrupting gene Cbei_3304. Conclusion Toxicity evaluation of lignocellulose-derived phenolic compounds shows that Cbei_3304 plays a significant role in regulating toxicities tolerance for ABE fermentation by C. beijerinckii, and the adaptation of non-detoxified hemicellulosic hydrolysate is significantly improved after inactivation of Cbei_3304 in wild-type strain C. beijerinckii NCIMB 8052. It provided a potential strategy for generating high inhibitor tolerance strains for using lignocellulosic materials to produce solvents by clostridia in this study
Genome sequence of Clostridium beijerinckii NCIMB 8052 spoIIE mutant
No full textA Clostridium beijerinckii NCIMB 8052 SpoIIE deficient mutant was engineered through a CRISPR cas9 method. A 2.379 kb fragment was removed from the spoIIE coding sequence. The SpoIIE mutant strain produced solvent and did not sporulate. Its genome was sequenced to confirm the gene disruption and screen for SNPs
Genetic and Physiological Characterization of Clostridium Beijerinckii BA101 and NCIMB 8052
No full textThe addition of sodium acetate in MP2 medium was also able to stabilize solvent production by C. beijerinckii BA101, a hypersolvent producing mutant derived from NCIMB 8052. Moreover, BA101 demonstrated a greater increase in solvent production than NCIMB 8052 when acetate was added into MP2 medium. During the exponential growth phase, the specific activities of CoA transferase, acetoacetate decarboxylase and butyraldehyde dehydrogenase were higher in BA101 than in NCIMB 8052. mRNA expression levels of the sol operon were also elevated during the exponential and early stationary growth phases in BA101. The increased phosphotransbutyrylase activity, as a result of elevated ptb-buk operon expression, resulted in enhanced butyrate production by BA101 during the early exponential phase, which was offset by the elevated acid reassimilation due to an increase in CoA transferase activity. The results indicate that an increase in expression of the sol operon and, consequently, activities of associated enzymes may be, in part, responsible for enhanced solvent production by BA101 relative to NCIMB 8052.Made available in DSpace on 2015-09-25T21:10:17Z (GMT). No. of bitstreams: 2
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Previous issue date: 1999Embargo set by: Seth Robbins for item 85019
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only136 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1999
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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