Enhanced production of cellulose in Komagataeibacter xylinus by preventing insertion of IS element into cellulose synthesis gene

2020 ◽  
Vol 156 ◽  
pp. 107527 ◽  
Author(s):  
Dong Hoon Hur ◽  
Hong-Soon Rhee ◽  
Jae Hyung Lee ◽  
Woo Yong Shim ◽  
Tae Yong Kim ◽  
...  
Keyword(s):  
Cellulose Synthesis ◽  
Is Element ◽  
Enhanced Production ◽  
Komagataeibacter Xylinus

scholarly journals Missense mutations in a transmembrane domain of the Komagataeibacter xylinus BcsA lead to changes in cellulose synthesis

2019 ◽  
Author(s):  
Luis Salgado ◽  
Silvia Blank ◽  
Reza Alipour Moghadam Esfahani ◽  
Janice L. Strap ◽  
Dario Bonetta
Keyword(s):  
Transmembrane Domain ◽  
Bacterial Species ◽  
Industrial Applications ◽  
Forward Genetics ◽  
Site Directed Mutagenesis ◽  
Cellulose Synthesis ◽  
Missense Mutations ◽  
Cellulose Biosynthesis ◽  
Phenotypic Analysis ◽  
Komagataeibacter Xylinus

Abstract Background Cellulose is synthesized by an array of bacterial species. Komagataeibacter xylinus is the best characterized as it produces copious amounts of the polymer extracellularly. Despite many advances in the past decade, the mechanisms underlying cellulose biosynthesis are not completely understood. Elucidation of these mechanisms is essential for efficient cellulose production in industrial applications. Results In an effort to gain a better understanding of cellulose biosynthesis and its regulation, cellulose crystallization was investigated in K. xylinus mutants resistant to an inhibitor of cellulose I formation, pellicin. Through the use of forward genetics and site-directed mutagenesis, A449T and A449V mutations in the K. xylinus BcsA protein were found to be important for conferring high levels of pellicin resistance. Phenotypic analysis of the bcsAA449T and bcsAA449V cultures revealed that the mutations affect cellulose synthesis rates and that cellulose crystallinity is affected in wet pellicles but not dry ones. Conclusions A449 is located in a predicted transmembrane domain of the BcsA protein suggesting that the structure of the transmembrane domain influences cellulose crystallization either by affecting the translocation of the nascent glucan chain or by allosterically altering protein-protein interactions.

scholarly journals Enhanced Production of Bacterial Cellulose in Komagataeibacter xylinus Via Tuning of Biosynthesis Genes with Synthetic RBS

2020 ◽  
Vol 30 (9) ◽  
pp. 1430-1435 ◽  
Author(s):  
Dong Hoon Hur ◽  
Woo Sung Choi ◽  
Tae Yong Kim ◽  
Sang Yup Lee ◽  
Jin Hwan Park ◽  
...  
Keyword(s):  
Bacterial Cellulose ◽  
Enhanced Production ◽  
Komagataeibacter Xylinus

scholarly journals Missense mutations in a transmembrane domain of the Komagataeibacter xylinus BcsA lead to changes in cellulose synthesis

2019 ◽  
Author(s):  
Luis Salgado ◽  
Silvia Blank ◽  
Reza Alipour Moghadam Esfahani ◽  
Janice L. Strap ◽  
Dario Bonetta
Keyword(s):  
Transmembrane Domain ◽  
Bacterial Species ◽  
Industrial Applications ◽  
Forward Genetics ◽  
Site Directed Mutagenesis ◽  
Cellulose Synthesis ◽  
Missense Mutations ◽  
Cellulose Biosynthesis ◽  
Phenotypic Analysis ◽  
Komagataeibacter Xylinus

Abstract Background Cellulose is synthesized by an array of bacterial species. Komagataeibacter xylinus is the best characterized as it produces copious amounts of the polymer extracellularly. Despite many advances in the past decade, the mechanisms underlying cellulose biosynthesis are not completely understood. Elucidation of these mechanisms is essential for efficient cellulose production in industrial applications. Results In an effort to gain a better understanding of cellulose biosynthesis and its regulation, cellulose crystallization was investigated in K. xylinus mutants resistant to an inhibitor of cellulose I formation, pellicin. Through the use of forward genetics and site-directed mutagenesis, A449T and A449V mutations in the K. xylinus BcsA protein were found to be important for conferring high levels of pellicin resistance. Phenotypic analysis of the bcsAA449T and bcsAA449V cultures revealed that the mutations affect cellulose synthesis rates and that cellulose crystallinity is affected in wet pellicles but not dry ones. Conclusions A449 is located in a predicted transmembrane domain of the BcsA protein suggesting that the structure of the transmembrane domain influences cellulose crystallization either by affecting the translocation of the nascent glucan chain or by allosterically altering protein-protein interactions.

scholarly journals Missense mutations in a transmembrane domain of the Komagataeibacter xylinus BcsA lead to changes in cellulose synthesis

2019 ◽  
Author(s):  
Luis Salgado ◽  
Silvia Blank ◽  
Reza Alipour Moghadam Esfahani ◽  
Janice L. Strap ◽  
Dario Bonetta
Keyword(s):  
Transmembrane Domain ◽  
Bacterial Species ◽  
Industrial Applications ◽  
Forward Genetics ◽  
Site Directed Mutagenesis ◽  
Cellulose Synthesis ◽  
Missense Mutations ◽  
Cellulose Biosynthesis ◽  
Phenotypic Analysis ◽  
Komagataeibacter Xylinus

Abstract Background Cellulose is synthesized by an array of bacterial species. Komagataeibacter xylinus is the best characterized as it produces copious amounts of the polymer extracellularly. Despite many advances in the past decade, the mechanisms underlying cellulose biosynthesis are not completely understood. Elucidation of these mechanisms is essential for efficient cellulose production in industrial applications. Results In an effort to gain a better understanding of cellulose biosynthesis and its regulation, cellulose crystallization was investigated in K. xylinus mutants resistant to an inhibitor of cellulose I formation, pellicin. Through the use of forward genetics and site-directed mutagenesis, A449T and A449V mutations in the K. xylinus BcsA protein were found to be important for conferring high levels of pellicin resistance. Phenotypic analysis of the bcsAA449T and bcsAA449V cultures revealed that the mutations affect cellulose synthesis rates and that cellulose crystallinity is affected in wet pellicles but not dry ones. Conclusions A449 is located in a predicted transmembrane domain of the BcsA protein suggesting that the structure of the transmembrane domain influences cellulose crystallization either by affecting the translocation of the nascent glucan chain or by allosterically altering protein-protein interactions.

scholarly journals Missense mutations in a transmembrane domain of the Komagataeibacter xylinus BcsA lead to changes in cellulose synthesis

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Luis Salgado ◽  
Silvia Blank ◽  
Reza Alipour Moghadam Esfahani ◽  
Janice L. Strap ◽  
Dario Bonetta
Keyword(s):  
Transmembrane Domain ◽  
Bacterial Species ◽  
Industrial Applications ◽  
Forward Genetics ◽  
Site Directed Mutagenesis ◽  
Cellulose Synthesis ◽  
Missense Mutations ◽  
Cellulose Biosynthesis ◽  
Phenotypic Analysis ◽  
Komagataeibacter Xylinus

Abstract Background Cellulose is synthesized by an array of bacterial species. Komagataeibacter xylinus is the best characterized as it produces copious amounts of the polymer extracellularly. Despite many advances in the past decade, the mechanisms underlying cellulose biosynthesis are not completely understood. Elucidation of these mechanisms is essential for efficient cellulose production in industrial applications. Results In an effort to gain a better understanding of cellulose biosynthesis and its regulation, cellulose crystallization was investigated in K. xylinus mutants resistant to an inhibitor of cellulose I formation, pellicin. Through the use of forward genetics and site-directed mutagenesis, A449T and A449V mutations in the K. xylinus BcsA protein were found to be important for conferring high levels of pellicin resistance. Phenotypic analysis of the bcsAA449T and bcsAA449V cultures revealed that the mutations affect cellulose synthesis rates and that cellulose crystallinity is affected in wet pellicles but not dry ones. Conclusions A449 is located in a predicted transmembrane domain of the BcsA protein suggesting that the structure of the transmembrane domain influences cellulose crystallization either by affecting the translocation of the nascent glucan chain or by allosterically altering protein-protein interactions.

scholarly journals Missense mutations in a transmembrane domain of the Komagataeibacter xylinus BcsA lead to changes in cellulose synthesis

2019 ◽  
Author(s):  
Luis Salgado ◽  
Silvia Blank ◽  
Reza Alipour Moghadam Esfahani ◽  
Janice L. Strap ◽  
Dario Bonetta
Keyword(s):  
Transmembrane Domain ◽  
Bacterial Species ◽  
Industrial Applications ◽  
Forward Genetics ◽  
Site Directed Mutagenesis ◽  
Cellulose Synthesis ◽  
Missense Mutations ◽  
Cellulose Biosynthesis ◽  
Phenotypic Analysis ◽  
Komagataeibacter Xylinus

Abstract Background Cellulose is synthesized by an array of bacterial species. Komagataeibacter xylinus is the best characterized as it produces copious amounts of the polymer extracellularly. Despite many advances in the past decade, the mechanisms underlying cellulose biosynthesis are not completely understood. Elucidation of these mechanisms is essential for efficient cellulose production in industrial applications. Results In an effort to gain a better understanding of cellulose biosynthesis and its regulation, cellulose crystallization was investigated in K. xylinus mutants resistant to an inhibitor of cellulose I formation, pellicin. Through the use of forward genetics and site-directed mutagenesis, A449T and A449V mutations in the K. xylinus BcsA protein were found to be important for conferring high levels of pellicin resistance. Phenotypic analysis of the bcsAA449T and bcsAA449V cultures revealed that the mutations affect cellulose synthesis rates and that cellulose crystallinity is affected in wet pellicles but not dry ones. Conclusions A449 is located in a predicted transmembrane domain of the BcsA protein suggesting that the structure of the transmembrane domain influences cellulose crystallization either by affecting the translocation of the nascent glucan chain or by allosterically altering protein-protein interactions.

Single molecule optical diffraction: A tool for understanding the structure of triple stranded left-hand helical cellulose

1989 ◽  
Vol 47 ◽  
pp. 1024-1025
Author(s):  
George C. Ruben ◽  
William Krakow
Keyword(s):  
Single Molecule ◽  
Helical Structure ◽  
Optical Diffraction ◽  
Maximum Diameter ◽  
Primary Cell Wall ◽  
Cellulose Synthesis ◽  
Left Hand ◽  
Left Handed ◽  
Freeze Dried ◽  
Diffraction Patterns

Tobacco primary cell wall and normal bacterial Acetobacter xylinum cellulose formation produced a 36.8±3Å triple-stranded left-hand helical microfibril in freeze-dried Pt-C replicas and in negatively stained preparations for TEM. As three submicrofibril strands exit the wall of Axylinum , they twist together to form a left-hand helical microfibril. This process is driven by the left-hand helical structure of the submicrofibril and by cellulose synthesis. That is, as the submicrofibril is elongating at the wall, it is also being left-hand twisted and twisted together with two other submicrofibrils. The submicrofibril appears to have the dimensions of a nine (l-4)-ß-D-glucan parallel chain crystalline unit whose long, 23Å, and short, 19Å, diagonals form major and minor left-handed axial surface ridges every 36Å.The computer generated optical diffraction of this model and its corresponding image have been compared. The submicrofibril model was used to construct a microfibril model. This model and corresponding microfibril images have also been optically diffracted and comparedIn this paper we compare two less complex microfibril models. The first model (Fig. 1a) is constructed with cylindrical submicrofibrils. The second model (Fig. 2a) is also constructed with three submicrofibrils but with a single 23 Å diagonal, projecting from a rounded cross section and left-hand helically twisted, with a 36Å repeat, similar to the original model (45°±10° crossover angle). The submicrofibrils cross the microfibril axis at roughly a 45°±10° angle, the same crossover angle observed in microflbril TEM images. These models were constructed so that the maximum diameter of the submicrofibrils was 23Å and the overall microfibril diameters were similar to Pt-C coated image diameters of ∼50Å and not the actual diameter of 36.5Å. The methods for computing optical diffraction patterns have been published before.

Structural aspects of tracheary element differentiation in suspension cultures of Zinnia elegans

1989 ◽  
Vol 47 ◽  
pp. 768-769
Author(s):  
C. H. Haigler ◽  
A. W. Roberts
Keyword(s):  
Tracheary Element ◽  
Vesicle Fusion ◽  
Zinnia Elegans ◽  
Cellulose Synthesis ◽  
Tracheary Elements ◽  
Animal Cells ◽  
Mesophyll Cells ◽  
Fixation Techniques ◽  
Localized Patterns ◽  
Structural Aspects

Tracheary elements, the water-conducting cells in plants, are characterized by their reinforced walls that became thickened in localized patterns during differentiation (Fig. 1). The synthesis of this localized wall involves abundant secretion of Golgi vesicles that export preformed matrix polysaccharides and putative proteins involved in cellulose synthesis. Since the cells are not growing, some kind of endocytotic process must also occur. Many researchers have commented on where exocytosis occurs in relation to the thickenings (for example, see), but they based their interpretations on chemical fixation techniques that are not likely to provide reliable information about rapid processes such as vesicle fusion. We have used rapid freezing to more accurately assess patterns of vesicle fusion in tracheary elements. We have also determined the localization of calcium, which is known to regulate vesicle fusion in plant and animal cells.Mesophyll cells were obtained from immature first leaves of Zinnia elegans var. Envy (Park Seed Co., Greenwood, S.C.) and cultured as described previously with the following exceptions: (a) concentration of benzylaminopurine in the culture medium was reduced to 0.2 mg/l and myoinositol was eliminated; and (b) 1.75ml cultures were incubated in 22 x 90mm shell vials with 112rpm rotary shaking. Cells that were actively involved in differentiation were harvested and frozen in solidifying Freon as described previously. Fractures occurred preferentially at the cell/planchet interface, which allowed us to find some excellently-preserved cells in the replicas. Other differentiating cells were incubated for 20-30 min in 10(μM CTC (Sigma), an antibiotic that fluoresces in the presence of membrane-sequestered calcium. They were observed in an Olympus BH-2 microscope equipped for epi-fluorescence (violet filter package and additional Zeiss KP560 barrier filter to block chlorophyll autofluorescence).

Activation of cytochrome c to a peroxidase compound I-type intermediate by H2O2: relevance to redox signalling in apoptosis

2004 ◽  
Vol 71 ◽  
pp. 97-106 ◽  
Author(s):  
Mark Burkitt ◽  
Clare Jones ◽  
Andrew Lawrence ◽  
Peter Wardman
Keyword(s):  
Cytochrome C ◽  
Hydroxyl Radical ◽  
Redox Regulation ◽  
Chemotherapeutic Agents ◽  
Tyrosyl Radical ◽  
Compound I ◽  
Definitive Evidence ◽  
Enhanced Production ◽  
Physico Chemical

The release of cytochrome c from mitochondria during apoptosis results in the enhanced production of superoxide radicals, which are converted to H2O2 by Mn-superoxide dismutase. We have been concerned with the role of cytochrome c/H2O2 in the induction of oxidative stress during apoptosis. Our initial studies showed that cytochrome c is a potent catalyst of 2′,7′-dichlorofluorescin oxidation, thereby explaining the increased rate of production of the fluorophore 2′,7′-dichlorofluorescein in apoptotic cells. Although it has been speculated that the oxidizing species may be a ferryl-haem intermediate, no definitive evidence for the formation of such a species has been reported. Alternatively, it is possible that the hydroxyl radical may be generated, as seen in the reaction of certain iron chelates with H2O2. By examining the effects of radical scavengers on 2′,7′-dichlorofluorescin oxidation by cytochrome c/H2O2, together with complementary EPR studies, we have demonstrated that the hydroxyl radical is not generated. Our findings point, instead, to the formation of a peroxidase compound I species, with one oxidizing equivalent present as an oxo-ferryl haem intermediate and the other as the tyrosyl radical identified by Barr and colleagues [Barr, Gunther, Deterding, Tomer and Mason (1996) J. Biol. Chem. 271, 15498-15503]. Studies with spin traps indicated that the oxo-ferryl haem is the active oxidant. These findings provide a physico-chemical basis for the redox changes that occur during apoptosis. Excessive changes (possibly catalysed by cytochrome c) may have implications for the redox regulation of cell death, including the sensitivity of tumour cells to chemotherapeutic agents.

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