Bioconversion of AHX to AOH by resting cells of Burkholderia contaminans CH-1

Upgrading of biomass derived 5-hydroxymethylfurfural (HMF) has attracted considerable interest recently. A new highly HMF-tolerant strain of Burkholderia contaminans NJPI-15 was isolated in this study, and the biocatalytic reduction of HMF into 2,5-bis(hydroxymethyl)furan (BHMF) using whole cells was reported. Co-substrate was applied to improve the BHMF yield and selectivity of this strain as well as HMF-tolerant level. The catalytic capacity of the cells can be substantially improved by Mn2+ ion. The strain exhibited good catalytic performance at a pH range of 6.0–9.0 and a temperature range of 25°C–35°C. In addition, 100 mM HMF could be reduced to BHMF by the B. contaminans NJPI-15 resting cells in presence of 70 mM glutamine and 30 mM sucrose, with a yield of 95%. In the fed-batch strategy, 656 mM BHMF was obtained within 48 h, giving a yield of 93.7%. The reported utilization of HMF to produce BHMF is a promising industrially sound biocatalytic process.

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Ultrastructure of Melosira resting cell rejuvenation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010011355x ◽

1984 ◽

Vol 42 ◽

pp. 734-735

Author(s):

C. E. M. Bourne ◽

L. Sicko-Goad

Keyword(s):

Electron Microscopy ◽

Lake Michigan ◽

Light And Electron Microscopy ◽

Resting Cells ◽

Planktonic Diatoms ◽

Resting Cell ◽

Vegetative Survival ◽

Cytological Changes ◽

Recent Attention ◽

Freshwater Diatom

Much recent attention has been focused on vegetative survival forms of planktonic diatoms and other algae. There are several reports of extended vegetative survival of the freshwater diatom Melosira in lake sediments. In contrast to those diatoms which form a morphologically distinct resistant spore, Melosira is known to produce physiological resting cells that are indistinguishable in outward morphology from actively growing cells.We used both light and electron microscopy to document and elucidate the sequence of cytological changes during the transition from resting cells to actively growing cells in a population of Melosira granulata from Douglas Lake, Michigan sediments collected in mid-July of 1983.

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Exemplar Abstract for Burkholderia contaminans Vanlaere et al. 2009 emend. Depoorter et al. 2020.

The NamesforLife Abstracts ◽

10.1601/ex.13250 ◽

2003 ◽

Author(s):

Charles Thomas Parker ◽

Kara Mannor ◽

George M Garrity

Keyword(s):

Burkholderia Contaminans

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Responses to Ecopollutants and Pathogenization Risks of Saprotrophic Rhodococcus Species

Pathogens ◽

10.3390/pathogens10080974 ◽

2021 ◽

Vol 10 (8) ◽

pp. 974

Author(s):

Irina B. Ivshina ◽

Maria S. Kuyukina ◽

Anastasiia V. Krivoruchko ◽

Elena A. Tyumina

Keyword(s):

Survival Strategies ◽

Complex Life Cycle ◽

Anthropogenic Pressure ◽

Resting Cells ◽

Organic Substrates ◽

Negative Effects ◽

Anthropogenic Pollutants ◽

Rhodococcus Species ◽

Wide Range ◽

Rigid Cell Wall

Under conditions of increasing environmental pollution, true saprophytes are capable of changing their survival strategies and demonstrating certain pathogenicity factors. Actinobacteria of the genus Rhodococcus, typical soil and aquatic biotope inhabitants, are characterized by high ecological plasticity and a wide range of oxidized organic substrates, including hydrocarbons and their derivatives. Their cell adaptations, such as the ability of adhering and colonizing surfaces, a complex life cycle, formation of resting cells and capsule-like structures, diauxotrophy, and a rigid cell wall, developed against the negative effects of anthropogenic pollutants are discussed and the risks of possible pathogenization of free-living saprotrophic Rhodococcus species are proposed. Due to universal adaptation features, Rhodococcus species are among the candidates, if further anthropogenic pressure increases, to move into the group of potentially pathogenic organisms with “unprofessional” parasitism, and to join an expanding list of infectious agents as facultative or occasional parasites.

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Glucose metabolism in resting cells ofCandida albicans as studied by13C NMR

Experimental Mycology ◽

10.1016/0147-5975(91)90030-h ◽

1991 ◽

Vol 15 (3) ◽

pp. 279-282 ◽

Cited By ~ 1

Author(s):

Osamu Shimokawa ◽

Keiichi Kawano ◽

Hiroaki Nakayama

Keyword(s):

Glucose Metabolism ◽

Resting Cells ◽

Ofcandida Albicans

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Inhibition of Escherichia coli Trimethylamine-N-oxide Reductase by Food Preservatives1

Journal of Food Protection ◽

10.4315/0362-028x-45.3.241 ◽

1982 ◽

Vol 45 (3) ◽

pp. 241-243 ◽

Cited By ~ 2

Author(s):

M. KRUK ◽

J. S. LEE

Keyword(s):

Escherichia Coli ◽

Benzoic Acid ◽

Sorbic Acid ◽

Reductase Activity ◽

Resting Cells ◽

E Coli

Trimethylamine-N-oxide (TMA-O) reductase activity of resting cells of Escherichia coli was inhibited by tetrasodium ethylenediaminetetraacetate (Na4EDTA), benzoic acid (BA and methylparaben (MP). The 50% inhibitory concentrations of Na4EDTA, BA and MP were 20.2, 1.2 and 32.4 mM, respectively. BA at pH 6.5 or below most effectively inhibited the TMA-O reductase. Sorbic acid (SA), up to 0.70 mM, had no effect on TMA-O reductase activity, but SA inhibited the growth and subsequent TMA production in E. coli at or above 0.3S mM.

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Protein phosphatase inhibitors okadaic acid and calyculin A alter cell shape and F-actin distribution and inhibit stimulus-dependent increases in cytoskeletal actin of human neutrophils

Blood ◽

10.1182/blood.v80.11.2911.2911 ◽

1992 ◽

Vol 80 (11) ◽

pp. 2911-2919 ◽

Cited By ~ 46

Author(s):

P Kreienbuhl ◽

H Keller ◽

V Niggli

Keyword(s):

Okadaic Acid ◽

Human Neutrophils ◽

Resting Cells ◽

Calyculin A ◽

Chemotactic Peptide ◽

Phosphatase Inhibitors ◽

Protein Phosphatase Inhibitors ◽

Actin Localization ◽

Shape Changes

Abstract The phosphatase inhibitors okadaic acid and calyculin A were found to elicit or to modify several neutrophil responses, suggesting that dephosphorylation plays a regulatory role. The concentrations of okadaic acid (> or = 1 mumol/L) that were effective on neutrophil functions (shape changes and marginal stimulation of pinocytosis) were shown to stimulate the incorporation of 32PO4 into many neutrophil proteins several-fold. Calyculin A was effective at 50-fold lower concentrations. In the presence of the inhibitors, the cells exhibited a nonpolar shape and the polarization response induced by chemotactic peptide was inhibited. Both phosphatase inhibitors also induced the association of F-actin with the cell membrane. A steady-state phosphatase activity is thus involved in maintaining shape and F-actin localization of resting cells. Inhibitors alone had no significant effect on the amount of cytoskeleton-associated actin. The increase in cytoskeletal actin observed at 30 minutes of stimulation with phorbol ester or 5 to 30 minutes of stimulation with chemotactic peptide, however, was abolished by okadaic acid or calyculin A, suggesting an important role of a phosphatase. In contrast, the early increase in cytoskeleton-associated actin observed at 1 minute of stimulation with peptide was not affected. This finding indicates that the increased association of actin with the cytoskeleton in the early and the later stages of neutrophil activation may be mediated by different signalling pathways.

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Enhanced Arsenic Accumulation in Engineered Bacterial Cells Expressing ArsR

Applied and Environmental Microbiology ◽

10.1128/aem.70.8.4582-4587.2004 ◽

2004 ◽

Vol 70 (8) ◽

pp. 4582-4587 ◽

Cited By ~ 112

Author(s):

Jan Kostal ◽

Rosanna Yang ◽

Cindy H. Wu ◽

Ashok Mulchandani ◽

Wilfred Chen

Keyword(s):

Cell Growth ◽

Environmental Protection Agency ◽

Arsenic Removal ◽

Fusion Partner ◽

Resting Cells ◽

Bacterial Cells ◽

High Affinity ◽

Affinity Ligand ◽

Arsenic Accumulation ◽

Severe Reduction

ABSTRACT The metalloregulatory protein ArsR, which offers high affinity and selectivity toward arsenite, was overexpressed in Escherichia coli in an attempt to increase the bioaccumulation of arsenic. Overproduction of ArsR resulted in elevated levels of arsenite bioaccumulation but also a severe reduction in cell growth. Incorporation of an elastin-like polypeptide as the fusion partner to ArsR (ELP153AR) improved cell growth by twofold without compromising the ability to accumulate arsenite. Resting cells overexpressing ELP153AR accumulated 5- and 60-fold-higher levels of arsenate and arsenite than control cells without ArsR overexpression. Conversely, no significant improvement in Cd2+ or Zn2+ accumulation was observed, validating the specificity of ArsR. The high affinity of ArsR allowed 100% removal of 50 ppb of arsenite from contaminated water with these engineered cells, providing a technology useful to comply with the newly approved U.S. Environmental Protection Agency limit of 10 ppb. These results open up the possibility of using cells overexpressing ArsR as an inexpensive, high-affinity ligand for arsenic removal from contaminated drinking and ground water.

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NADPH-dependent reduction of 2,6-dichlorophenol-indophenol by the phagocytic vesicles of pig polymorphonuclear leucocytes

Biochemical Journal ◽

10.1042/bj2100577 ◽

1983 ◽

Vol 210 (2) ◽

pp. 577-581 ◽

Cited By ~ 24

Author(s):

H Wakeyama ◽

K Takeshige ◽

S Minakami

Keyword(s):

Oxidation Rate ◽

Cetyltrimethylammonium Bromide ◽

Reductase Activity ◽

Tween 20 ◽

Polymorphonuclear Leucocytes ◽

Resting Cells ◽

Low Concentrations ◽

Km Value ◽

Nadph Oxidation

NADPH-dependent 2,6-dichlorophenol-indophenol (DCIP) reductase activity in the homogenate of phagocytosing pig polymorphonuclear leucocytes was twice that of the resting cells and the activity in the phagocytic vesicles corresponded to the activity increment due to phagocytosis. The apparent Km value of the reductase activity in the vesicles for NADPH was 30 microM, which is similar to that of the NADPH-dependent superoxide (O2-) formation. Increasing the DCIP reductase activity by increasing the DCIP concentration caused a decrease in the O2- –forming activity, the NADPH oxidation rate being constant and independent of the dye concentration. p-Chloromercuribenzoate and cetyltrimethylammonium bromide at low concentrations inhibited the O2- –forming activity of the vesicles without inhibiting the DCIP reductase. Quinacrine inhibited both O2- formation and DCIP reduction. The DCIP reductase activity could be extracted with a mixture of deoxycholate and Tween-20, which extracts the O2- –forming activity. The reductase activity in the extract was enhanced 2-fold by the addition of FAD, and its apparent Km was 0.085 microM. These results indicate that the NADPH-dependent DCIP reductase activity of the phagocytic vesicles is catalysed by a flavin-containing component of the O2- –forming system.

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Analysis with specific polyclonal antiserum indicates that the E1A-associated 300-kDa product is a stable nuclear phosphoprotein that undergoes cell cycle phase-specific modification.

Molecular and Cellular Biology ◽

10.1128/mcb.11.11.5389 ◽

1991 ◽

Vol 11 (11) ◽

pp. 5389-5397 ◽

Cited By ~ 64

Author(s):

P Yaciuk ◽

E Moran

Keyword(s):

Cell Cycle ◽

Cell Function ◽

Rat Kidney ◽

Sodium Dodecyl ◽

Polyclonal Antiserum ◽

Cell Protein ◽

Cycle Phase ◽

Resting Cells ◽

Kidney Cells ◽

Nuclear Phosphoprotein

Binding of a 300-kDa host cell protein (p300) is tightly correlated with the ability of the adenovirus E1A products to induce quiescent baby rat kidney cells to proliferate. We have generated rabbit polyclonal antibodies against p300 to characterize this protein further. We have found p300 to be a nuclear phosphoprotein that is actively synthesized in both quiescent and proliferating baby rat kidney cells. In partially purified mitotic cell populations, we observe a form of p300 with decreased electrophoretic mobility in sodium dodecyl sulfate-polyacrylamide gels that shares a nearly identical partial proteolytic digest pattern with p300. The slower-migrating form of p300 is greatly reduced by treating immune complexes with potato acid phosphatase. The relative stability and presence of p300 even in resting cells suggests that p300 has a basal cell function, but the appearance of differentially modified forms during the cell cycle suggests the possibility that p300 function is modulated specifically in growing cells.

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