Sucrose metabolism in Zymomonas mobilis: production and localization of sucrase and levansucrase activities

The sucrase and levansucrase activities of Zymomonas mobilis cells were characterized. The kinetics of production of sucrase activity was growth associated and the activity was constitutively expressed in cells grown on sucrose, glucose, or fructose media. Most of the sucrase activity (about 80%) was soluble and extracellular, while the cellular activity (about 20%) was demonstrated to be mostly membrane bound. The occurrence of sucrase activity in culture medium seemed to result from a secretory mechanism rather than from cell lysis. Like sucrase activity, levansucrase activity was mainly extracellular and was present in fermentations run with the above three carbon sources. These results demonstrated that both sucrase and levansucrase activities were present in cellular and extracellular extracts of cells grown on different sugars. Key words: Zymomonas mobilis, levansucrase, sucrase, localization.

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Semi-pilot production of xanthan gum using nejayote as culture medium substrate

10.21203/rs.3.rs-24096/v1 ◽

2020 ◽

Author(s):

Alonso A. Orozco-Flores ◽

Jesús O. Zúñiga-Sánchez ◽

Maria M. Iracheta-Cárdenas ◽

Ricardo Gomez-Flores ◽

César I. Romo-Sáenz ◽

...

Keyword(s):

Xanthan Gum ◽

Culture Medium ◽

Carbon Sources ◽

Cellular Growth ◽

Cellular Activity ◽

Activity Assay ◽

Reduction Assay ◽

Alternative Culture ◽

Xanthan Production ◽

Mtt Reduction

Abstract Background: Xanthan gum is an industrialized polysaccharide produced by Xanthomonas genus. Alternative carbon sources for Xanthomonas culturing may help reducing its production cost. Nejayote, a residue from maize nixtamalization process, is an alternative culture medium substrate to produce xanthan. In this study, industrial and semi-industrial nejayote alone or in combination with supplements, were tested for xanthan production by Xantomonas campestris (1 × 108 cells/mL inoculum), using YGC medium as control, in 100 mL and 1 L volumes. Cellular growth was determined by the colorimetric MTT reduction assay (OD 540 ). Xanthan pyruvate and acetyl groups from nejayote plus supplement cultures in the bioreactor were evaluated (OD 570). Results: Industrial nejayote steadily produced up to 4 g/L xanthan, as compared with YGC medium control, which increased its production over time up to 9.3 g/L at 96 h. Cellular activity assay revealed that the highest values after 24 h (3.88 and 2.71 OD 540 for YGC and industrial nejayote, respectively). Nejayote supplemented with MgSO4 •7 H2O resulted in the highest xanthan production (10.8 g/L), but low cell growth (3.6 and 1.82 OD 540 for YGC and nejayote plus supplement, respectively), after 96 h of culture. Furthermore, gum yield reached up to 6 g/L and 1.9 OD 540, after 96 h of nejayote plus supplement culture, using a 14 L bioreactor. Xanthan pyruvate and acetyl groups from nejayote plus supplement cultures in the bioreactor resulted in similar amounts (0.107 and 0.130 OD 570 , respectively), compared with a commercial biopolymer (0.148 and 0.127 OD 570 respectively). Conclusions: X. campestris effectively grew and produced industrial-quality xanthan gum in nejayote substrate-containing culture medium, thus providing an inexpensive alternative for bioremediation.

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Measuring microtubule binding kinetics of membrane-bound kinesin motors using supported lipid bilayers

STAR Protocols ◽

10.1016/j.xpro.2021.100691 ◽

2021 ◽

Vol 2 (3) ◽

pp. 100691

Author(s):

Rui Jiang ◽

William O. Hancock

Keyword(s):

Lipid Bilayers ◽

Binding Kinetics ◽

Supported Lipid Bilayers ◽

Microtubule Binding ◽

Membrane Bound ◽

Kinetics Of

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The NADH dehydrogenase of the respiratory chain of Escherichia coli. II. Kinetics of the purified enzyme and the effects of antibodies elicited against it on membrane-bound and free enzyme.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(17)33040-5 ◽

1976 ◽

Vol 251 (19) ◽

pp. 5921-5928

Author(s):

G F Dancey ◽

B M Shapiro

Keyword(s):

Escherichia Coli ◽

Respiratory Chain ◽

Nadh Dehydrogenase ◽

Free Enzyme ◽

Membrane Bound ◽

Kinetics Of

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SHEDDING OF SURFACE PROTEINS BY PORCINE THYROID CELLS

Journal of Endocrinology ◽

10.1677/joe.0.0850245 ◽

1980 ◽

Vol 85 (2) ◽

pp. 245-251 ◽

Cited By ~ 1

Author(s):

A. BRENNAN ◽

P. M. POVEY ◽

B. REES SMITH ◽

R. HALL

Keyword(s):

Cell Surface ◽

Sodium Dodecyl Sulphate ◽

Culture Medium ◽

Cell Metabolism ◽

Sodium Dodecyl ◽

Surface Proteins ◽

Half Time ◽

Thyroid Cells ◽

Peptide Cleavage ◽

Membrane Bound

Isolated porcine thyroid cells were surface-labelled with 125I using the lactoperoxidase technique. Samples of the cells were then cultured and harvested at various intervals for up to 7 days. The labelled proteins remaining on the cells or shed into the culture medium were analysed by electrophoresis on polyacrylamide gels run in sodium dodecyl sulphate. These studies indicated that the several different surface proteins of the thyroid cells were lost from the cell surface at similar rates (half-time of approximately 28 h) as the result, at least in part, of a process which depended on active cell metabolism. In addition, the gel profiles obtained from analysis of both medium and membrane-bound labelled proteins were similar and this suggested that peptide cleavage was not involved in the shedding of the majority of these proteins.

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The kinetics of the flash-induced P515 response in relation to the H+-permeability of the membrane bound ATPase in spinach chloroplasts

Journal of Bioenergetics and Biomembranes ◽

10.1007/bf00744203 ◽

1985 ◽

Vol 17 (4) ◽

pp. 207-216 ◽

Cited By ~ 4

Author(s):

Robert L. A. Peters ◽

Olaf van Kooten ◽

Wim J. Vredenberg

Keyword(s):

Spinach Chloroplasts ◽

Membrane Bound ◽

Kinetics Of

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Steady state kinetics of soluble and membrane-bound mitochondrial ATPase

Biochimica et Biophysica Acta (BBA) - Biomembranes ◽

10.1016/0005-2736(71)90156-8 ◽

1971 ◽

Vol 233 (3) ◽

pp. 580-590 ◽

Cited By ~ 64

Author(s):

Gordon G. Hammes ◽

David A. Hilborn

Keyword(s):

Steady State ◽

Mitochondrial Atpase ◽

Steady State Kinetics ◽

Membrane Bound ◽

Kinetics Of

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Kinetics of mucopolysaccharide and glycoprotein synthesis by chick embryo chondrocytes. Effect of D-glucose concentration in the culture medium.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(20)81846-8 ◽

1976 ◽

Vol 251 (20) ◽

pp. 6210-6217

Author(s):

J J Kim ◽

H E Conrad

Keyword(s):

Chick Embryo ◽

Glucose Concentration ◽

Culture Medium ◽

Glycoprotein Synthesis ◽

Kinetics Of

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Improvement of the Culture Medium for the Dichlorvos-Ammonia (DV-AM) Method to Selectively Detect Aflatoxigenic Fungi in Soil

Toxins ◽

10.3390/toxins10120519 ◽

2018 ◽

Vol 10 (12) ◽

pp. 519 ◽

Cited By ~ 1

Author(s):

Kimiko Yabe ◽

Haruna Ozaki ◽

Takuya Maruyama ◽

Keisuke Hayashi ◽

Yuki Matto ◽

...

Keyword(s):

Culture Medium ◽

Agar Medium ◽

Carbon Sources ◽

Tween 80 ◽

Selective Medium ◽

Selective Detection ◽

Aflatoxigenic Fungi ◽

Aspergillus Nomius ◽

Rhizopus Sp ◽

Triton X

The dichlorvos-ammonia (DV-AM) method is a simple but sensitive visual method for detecting aflatoxigenic fungi. Here we sought to develop a selective medium that is appropriate for the growth of aflatoxigenic fungi among soil mycoflora. We examined the effects of different concentrations of carbon sources (sucrose and glucose) and detergents (deoxycholate (DOC), Triton X-100, and Tween 80) on microorganisms in soils, using agar medium supplemented with chloramphenicol. The results demonstrated that 5–10% sucrose concentrations and 0.1–0.15% DOC concentrations were appropriate for the selective detection of aflatoxigenic fungi in soil. We also identified the optimal constituents of the medium on which the normal rapid growth of Rhizopus sp. was completely inhibited. By using the new medium along with the DV-AM method, we succeeded in the isolation of aflatoxigenic fungi from non-agricultural fields in Fukui city, Japan. The fungi were identified as Aspergillus nomius based on their calmodulin gene sequences. These results indicate that the new medium will be useful in practice for the detection of aflatoxigenic fungi in soil samples including those from non-agricultural environments.

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Re-evaluation of Mature Seed-derived Callusing and Regeneration Potential of Nine Orchardgrass (Dactylis golomerata L.) Cultivars

Plant Tissue Culture and Biotechnology ◽

10.3329/ptcb.v17i2.3240 ◽

1970 ◽

Vol 17 (2) ◽

pp. 193-207 ◽

Cited By ~ 2

Author(s):

Sang-Hoon Lee ◽

Nagib Ahsan ◽

Ki-Won Lee ◽

Dong-Gi Lee ◽

Iftekhar Alam ◽

...

Keyword(s):

Key Words ◽

Callus Induction ◽

Plant Tissue ◽

Genotypic Variation ◽

Carbon Sources ◽

Mature Seed ◽

Regeneration Potential ◽

Efficient Regeneration ◽

N6 Medium ◽

Mature Seeds

A suitable callus induction and efficient regeneration protocol for orchardgrass (Dactylis golomerata L.) was developed. It consisted of 3 mg/l 2,4-D + 0.1 mg/l BA + 1 g/l CH + 300 mg/l L-proline + 40 mg/l L-cysteine + 30 g/l sucrose in MS showed the highest percentage of callus induction. Maltose exhibited better in regeneration than other types of carbon sources. Highest (71%) regeneration was obtained from N6 medium containing 1 mg/l 2,4-D + 3 mg/l BA + 1 g/l CH + 300 mg/l L-proline + 40 mg/l L-cysteine + 30 g/l maltose. Among the nine cultivars of orchardgrass (Dactylis golomerata L.), genotypic variation was observed in both callus induction and regeneration. Overall callus induction and regeneration rates were 23 - 73 and 17 - 71%, respectively. Key words: Dactylis golomerata, Orchardgrass, Mature seeds, Additives, Regeneration, Maltose. D.O.I. 10.3329/ptcb.v17i2.3240 Plant Tissue Cult. & Biotech. 17(2): 193-207, 2007 (December)

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