scholarly journals Effect of Addition of Tryptophan on Aggregation of Apo-α-Lactalbumin Induced by UV-Light

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1577
Author(s):  
Zichen Zhao ◽  
Renjie Li ◽  
Mahesha M. Poojary ◽  
Søren B. Nielsen ◽  
Marianne N. Lund
Keyword(s):  
Uv Light ◽  
Bond Cleavage ◽  
Aerobic Condition ◽  
Amino Acid Residues ◽  
Exchange Reactions ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Induced Aggregation ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

UV-B illumination facilitates aggregation of alpha-lactalbumin (α-LA) by intramolecular disulfide bond cleavage followed by intermolecular thiol-disulfide exchange reactions. However, long term exposure to UV-B illumination may induce undesired oxidative modifications of amino acid residues in the protein. The purpose of this study was to examine the effect of UV-induced aggregation of apo-α-LA (a calcium-depleted form of α-LA) under aerobic and anaerobic conditions and by addition of tryptophan (Trp) as a photosensitizer. The addition of Trp to apo-α-LA illuminated under anaerobic conditions facilitated the highest level of free thiol release and disulfide-mediated aggregation as compared to without addition of Trp under both anaerobic and aerobic conditions. Addition of Trp under aerobic condition resulted in the lowest level of free thiols and disulfide-mediated aggregation and the aerobic conditions caused oxidation of the free Trp with formation of kynurenine and 5-hydroxy-Trp. Minor levels of the Trp oxidation product, 3-hydroxy-kynurenine (2% converted from Trp), was formed in apo-α-LA with added Trp under both aerobic and anaerobic conditions after UV-B treatment.

Oxygen concentration affects frequency and range of transconjugants for the incompatibility (Inc) P-1 and P-7 plasmids pBP136 and pCAR1

2020 ◽  
Vol 85 (4) ◽  
pp. 1005-1015
Author(s):  
Kentaro Ochi ◽  
Maho Tokuda ◽  
Kosuke Yanagiya ◽  
Chiho Suzuki-Minakuchi ◽  
Hideaki Nojiri ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Anaerobic Condition ◽  
Environmental Samples ◽  
Aerobic Condition ◽  
Recipient Strain ◽  
Donor Strain ◽  
Anaerobic Conditions ◽  
Filter Mating ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

ABSTRACT The frequency of transconjugants were compared for the incompatibility (Inc) P-1 and P-7 plasmids pBP136 and pCAR1 under aerobic and anaerobic conditions. Filter mating assays were performed with one donor strain and one recipient strain using different donors of Pseudomonas and recipient strains, including Pseudomonas, Pantoea, and Buttiauxella. Under anaerobic condition, frequencies of transconjugants for both plasmids were 101-103-fold lower than those under aerobic condition regardless of whether aerobically or anaerobically grown donors and recipients were used. To compare the transconjugant ranges under aerobic and anaerobic conditions, conjugation was performed between the donor of pBP136 and recipient bacteria extracted from environmental samples. Several transconjugants were uniquely obtained from each aerobic or anaerobic condition. Our findings indicate that a plasmid can differently spread among bacteria depending on the oxygen concentrations of the environment.

PRODUCTION AND PROPERTIES OF 2,3-BUTANEDIOL: VII. FERMENTATION OF WHEAT BY AEROBACILLUS POLYMYXA UNDER AEROBIC AND ANAEROBIC CONDITIONS

1946 ◽  
Vol 24f (1) ◽  
pp. 1-11 ◽  
Author(s):  
G. A. Adams
Keyword(s):  
Carbon Dioxide ◽  
Anaerobic Fermentation ◽  
Anaerobic Conditions ◽  
Mechanical Agitation ◽  
Fermentation Time ◽  
Aerobic Conditions ◽  
Ethanol Formation ◽  
Time Required ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Aeration by mechanical agitation of 15% wheat mash fermented by Aerobacillus polymyxa inhibited the formation of 2,3-butanediol and particularly of ethanol. Aeration of similar mashes by passage of finely dispersed air or oxygen at the rate of 333 ml. per minute per litre of mash increased the rate of formation and yield of 2,3-butanediol but inhibited ethanol formation. However, the over-all time required for the completion of fermentation was not shortened from the usual 72 to 96 hr. required for unaerated mashes. There was no evidence of a shift from fermentative to oxidative dissimilation. Under aerobic conditions, the final butanediol–ethanol ratio was approximately 3:1. Anaerobic conditions, as produced by the passage of nitrogen or hydrogen through the mash, increased the rate of formation of both butanediol and ethanol and shortened the fermentation time to about 48 hr. Under these conditions, the butanediol–ethanol ratio was reduced to about 1.3:1.0. Carbon dioxide gave a butanediol–ethanol ratio resembling that of anaerobic fermentation but did not reduce fermentation time.

scholarly journals In vivo cycling of the Escherichia coli transcription factor FNR between active and inactive states

Microbiology ◽  
2005 ◽  
Vol 151 (12) ◽  
pp. 4063-4070 ◽  
Author(s):  
David P. Dibden ◽  
Jeffrey Green
Keyword(s):  
Escherichia Coli ◽  
De Novo ◽  
Oxygen Availability ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Fnr Protein ◽  
Transcription Regulators ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

FNR proteins are transcription regulators that sense changes in oxygen availability via assembly–disassembly of [4Fe–4S] clusters. The Escherichia coli FNR protein is present in bacteria grown under aerobic and anaerobic conditions. Under aerobic conditions, FNR is isolated as an inactive monomeric apoprotein, whereas under anaerobic conditions, FNR is present as an active dimeric holoprotein containing one [4Fe–4S] cluster per subunit. It has been suggested that the active and inactive forms of FNR are interconverted in vivo, or that iron–sulphur clusters are mostly incorporated into newly synthesized FNR. Here, experiments using a thermo-inducible fnr expression plasmid showed that a model FNR-dependent promoter is activated under anaerobic conditions by FNR that was synthesized under aerobic conditions. Immunoblots suggested that FNR was more prone to degradation under aerobic compared with anaerobic conditions, and that the ClpXP protease contributes to this degradation. Nevertheless, FNR was sufficiently long lived (half-life under aerobic conditions, ∼45 min) to allow cycling between active and inactive forms. Measuring the abundance of the FNR-activated dms transcript when chloramphenicol-treated cultures were switched between aerobic and anaerobic conditions showed that it increased when cultures were switched to anaerobic conditions, and decreased when aerobic conditions were restored. In contrast, measurement of the abundance of the FNR-repressed ndh transcript under the same conditions showed that it decreased upon switching to anaerobic conditions, and then increased when aerobic conditions were restored. The abundance of the FNR- and oxygen-independent tatE transcript was unaffected by changes in oxygen availability. Thus, the simplest explanation for the observations reported here is that the FNR protein can be switched between inactive and active forms in vivo in the absence of de novo protein synthesis.

scholarly journals Incubation Studies on Exchangable Zn for Varying Levels of added Zn Under Aerobic and Anaerobic Conditions in Grey Terrace Soils, Non Calcarious Floodplain Soils and Calcarious Floodplain Soils

2013 ◽  
Vol 9 (1-2) ◽  
pp. 9-15 ◽  
Author(s):  
KH Talukder ◽  
IU Ahmed ◽  
MS Islam ◽  
MS Islam ◽  
M Asaduzzaman ◽  
...  
Keyword(s):  
Anaerobic Condition ◽  
Early Stage ◽  
Aerobic Condition ◽  
Anaerobic Conditions ◽  
Floodplain Soil ◽  
Zinc Fractions ◽  
Floodplain Soils ◽  
Soil Zn ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Fractions studies were done to know how the zinc applied to different soils was distributed in to various fractions when the soils incubated under aerobic and anaerobic condition. The added zinc provided significant increase in exchangeable Zn both under aerobic and anaerobic conditions although anaerobic condition gave lower results than aerobic condition. The higher results were obtained at early stage of incubation and it gradually reduced as the incubation period proceeded to 90 days. These results showed all most similar trends for all the soils under study. In general, added zinc showed significantly higher results to the different fractions of soil Zn both under anaerobic and aerobic incubation with very few exceptions. The highest amount of added Zn (12 kg/ha) always produced greater results than the lower doses. Only exchangeable Zn was found higher in the 1st measurement at 15 DAI then gradually decreased but in other cases, gradual increase in zinc fractions was seen as the incubation study proceed to longer duration provided with very few exceptions. In many cases, the exchangeable-Zn found higher only at 15 DAI but sharply reduced at 30 DAI. In general, the Gray Terrace Soil produced the highest results followed by Non Calcareous Gray Floodplain and the lowest results were observed in Dark Grey Floodplain & Brown Floodplain Soil. DOI: http://dx.doi.org/10.3329/jsf.v9i1-2.14643 J. Sci. Foundation, 9(1&2): 9-15, June-December 2011

The energy metabolism of adult Haemonchus contortus, in vitro

Parasitology ◽  
1978 ◽  
Vol 77 (3) ◽  
pp. 255-271 ◽  
Author(s):  
P. F. V. Ward ◽  
N. S. Huskisson
Keyword(s):  
Energy Metabolism ◽  
Haemonchus Contortus ◽  
Aerobic Incubation ◽  
Anaerobic Conditions ◽  
Physically Active ◽  
Aerobic Conditions ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

SummaryA comparison was made of the major excretory products when adult Haemonchus contortus worms were incubated with D-[U-14C]glucose under aerobic and anaerobic conditions. Catabolites measured were propan-1-ol, acetate, n-propionate and CO2 and the only major difference was that nearly twice as much CO2 both in terms of quantity and radioactivity was excreted under aerobic than anaerobic conditions. The worms were also much more physically active under aerobic conditions. When worms were incubated under aerobic conditions with increasing amounts of fluoroacetate their CO2 production was progressively reduced to the anaerobic level. Their movement and their ability to clump together was also progressively reduced. After aerobic incubation with fluoroacetate and D-[U-14C]g1ucose the quantity and radioactivity of citrate within worms increased greatly. When worms were similarly incubated anaerobically no increase in citrate occurred, no radioactivity was associated with the citrate and the worms appeared physically unaffected. When worms were incubated aerobically with fluoro[1-14C]acetate they produced radioactive fluorocitrate.

scholarly journals Diverse effects of nitric oxide reductase NorV on Aeromonas hydrophila virulence-associated traits under aerobic and anaerobic conditions

2019 ◽  
Vol 50 (1) ◽  
Author(s):  
Jin Liu ◽  
Yuhao Dong ◽  
Nannan Wang ◽  
Shuiyan Ma ◽  
Chengping Lu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Aeromonas Hydrophila ◽  
Dependent Manner ◽  
Nitric Oxide Reductase ◽  
Wild Type ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Significant Difference ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Abstract NorV has been known to be an anaerobic nitric oxide reductase associated with nitric oxide (NO) detoxification. Recently, we showed that the norV gene of Aeromonas hydrophila was highly upregulated after co-culturing with Tetrahymena thermophila. Here, we demonstrated that the transcription and expression levels of norV were upregulated in a dose-dependent manner after exposure to NO under aerobic and anaerobic conditions. To investigate the roles of norV in resisting predatory protists and virulence of A. hydrophila, we constructed the norV gene-deletion mutant (ΔnorV). Compared to the wild type, the ΔnorV mutant showed no significant difference in growth at various NO concentrations under aerobic conditions but significantly stronger NO-mediated growth inhibition under anaerobic conditions. The deletion of norV exhibited markedly decreased cytotoxicity, hemolytic and protease activities under aerobic and anaerobic conditions. Also, the hemolysin co-regulated protein (Hcp) in the ΔnorV mutant showed increased secretion under aerobic conditions but decreased secretion under anaerobic conditions as compared to the wild-type. Moreover, the inactivation of norV led to reduced resistance to predation by T. thermophila, decreased survival within macrophages and highly attenuated virulence in zebrafish. Our data indicate a diverse role for norV in the expression of A. hydrophila virulence-associated traits that is not completely dependent on its function as a nitric oxide reductase. This study provides insights into an unexplored area of NorV, which will contribute to our understanding of bacterial pathogenesis and the development of new control strategies for A. hydrophila infection.

scholarly journals ATTENUATION OF HEAVY METALS IN SEDIMENTS OF THE BONNY ESTUARY, NIGERIA: THE ROLE OF OXYGEN

2013 ◽  
Vol 9 (1) ◽  
pp. 1810-1821
Author(s):  
Dr. Dike Henry Ogbuagu ◽  
Dagogo Eras Dinney
Keyword(s):  
Pearson Correlation ◽  
Aerobic Condition ◽  
Significant Heterogeneity ◽  
Anaerobic Conditions ◽  
Student’S T ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions ◽  
Student’S T Test ◽  
Analyze Data

Sediments of the Bonny Estuary, which is repository to pollutants from various industrial and shipment activities in its catchment was investigated for rate of natural attenuation of toxic metals (Cd, Mn, Cr, Pb, Cu, Ni, Fe) under aerobic and anaerobic conditions. Samples were collected with pre-grab sampler from seabed, sieved in the laboratory and monitored under aerobic and anaerobic conditions. After incubation at 18°C, harvests were made on days 1, 14, 28 and 42 and levels of the metals determined spectrophotometrically. Variation plots, ANOVA, Means plots, Student’s t-test and Pearson correlation (r) were used to analyze data. Concentration reductions were higher in aerobic condition in the order Cu(15.5%)> Cd(11.4%)> Fe(8.0%)>Mn(5.7%)> Cr(4.4%)> Ni(4.2%)>Pb(3.9%) than in anaerobic condition which was in the order Cu(7.5%)> Cd(7.4%)>Pb(2.4%)>Mn/Cr(1.8% each)> Fe(0.9%)> Ni(0.5%). There was significant heterogeneity in metals reductions (Sig. F=0.000) on all the harvest days, especially of Cu, Pb and Fe at P<0.05. Attenuation of Mn also differed markedly between the aerobic and anaerobic conditions (Sig. t=0.005) at the 95% confidence interval. pH influenced the attenuation of Ni (r=0.766) and Fe (r=0.795) (P<0.05) as well as Cd (r=0.968), Cr (r=0.861), Pb (r=0.989) and Cu (r=0.950) (P<0.01). Results indicate that rate of attenuation was slow and slightly enhanced by oxygenation.

Evaluation of the effects of nanoscale zero-valent iron (nZVI) dispersants on intrinsic biodegradation of trichloroethylene (TCE)

2014 ◽  
Vol 69 (11) ◽  
pp. 2357-2363 ◽  
Author(s):  
Y. C. Chang ◽  
S. C. Huang ◽  
K. F. Chen
Keyword(s):  
Zero Valent Iron ◽  
Adverse Impact ◽  
Tween 20 ◽  
Anaerobic Conditions ◽  
Sorbitan Monolaurate ◽  
Aerobic Conditions ◽  
Microcosm Study ◽  
Nanoscale Zero Valent Iron ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

In this study, the biodegradability of nanoscale zero-valent iron (nZVI) dispersants and their effects on the intrinsic biodegradation of trichloroethylene (TCE) were evaluated. Results of a microcosm study show that the biodegradability of three dispersants followed the sequence of: polyvinyl alcohol-co-vinyl acetate-co-itaconic acid (PV3A) &gt; polyoxyethylene (20) sorbitan monolaurate (Tween 20) &gt; polyacrylic acid (PAA) under aerobic conditions, and PV3A &gt; Tween 20 &gt; PAA under anaerobic conditions. Natural biodegradation of TCE was observed under both aerobic and anaerobic conditions. No significant effects were observed on the intrinsic biodegradation of TCE under aerobic conditions with the presence of the dispersants. The addition of PAA seemed to have a slightly adverse impact on anaerobic TCE biodegradation. Higher accumulation of the byproducts of anaerobic TCE biodegradation was detected with the addition of PV3A and Tween 20. The diversity of the microbial community was enhanced under aerobic conditions with the presence of more biodegradable PV3A and Tween 20. The results of this study indicate that it is necessary to select an appropriate dispersant for nZVI to prevent a residual of the dispersant in the subsurface. Additionally, the effects of the dispersant on TCE biodegradation and the accumulation of TCE biodegrading byproducts should also be considered.

Is Polymer Retention Different Under Anaerobic vs. Aerobic Conditions?

SPE Journal ◽  
2016 ◽  
Vol 22 (02) ◽  
pp. 431-437 ◽  
Author(s):  
Hao Wan ◽  
R. S. Seright
Keyword(s):  
Dissolved Oxygen ◽  
Polymer Solutions ◽  
Dynamic Tests ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Static Tests ◽  
Dynamic Methods ◽  
Polymer Retention ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Summary This paper examines whether retention of partially hydrolyzed polyacrylamide (HPAM) is different under anaerobic vs. aerobic conditions. Both static (mixing with loose sand) and dynamic methods (corefloods) were used to determine HPAM retention. There are both advantages and disadvantages associated with determining polymer retention with static tests vs. dynamic tests and with aerobic vs. anaerobic conditions. From static-retention measurements, polymer-adsorption values on pure silica sand or Berea sandstone were small, and they showed little difference between experiments conducted aerobically or anaerobically. For both aerobic and anaerobic conditions, HPAM retention increased significantly with increased pyrite or siderite content. Static retention under anaerobic conditions ranged from 45 to 75 µg/g with 1% of either pyrite or siderite to 137–174 µg/g for 10% pyrite or siderite to 1161–1249 µg/g for 100% pyrite or siderite. If iron minerals are present, the most representative polymer-retention results are obtained (for both static and dynamic tests) if conditions are anaerobic. Retention values (from static measurements) under aerobic conditions were commonly twice those determined under anaerobic conditions. If iron minerals are present and retention tests are performed under aerobic conditions, total organic carbon (TOC) or some similar method should be used for polymer detection. Viscosity detection of polymer may provide retention values that are too high (because oxidative degradation can be misinterpreted as polymer retention). For a broad range of siderite content, retention from static tests did not depend on whether dissolved oxygen was present. However, for a broad range of pyrite content, HPAM retention was significantly lower in the absence of dissolved oxygen than under aerobic conditions. These results may be tied to iron solubility. When polymer solutions were mixed with 100% pyrite over the course of 12 hours, 360–480 ppm of iron dissolved into polymer solutions under both aerobic and anaerobic conditions, whereas with 100% siderite, only 0.0–0.6 ppm of iron dissolved. If dynamic methods (i.e., corefloods) are used to determine polymer retention under aerobic conditions, flow rates should be representative of the field application. Rates that are too high lead to underestimation of polymer retention. With 10% pyrite, dynamic retention was 211 µg/g at 6 ft/D vs. 43.2 µg/g at 30 ft/D. In contrast, retention values were fairly consistent (40.6–47.8 µg/g) between 6 and 33 ft/D under anaerobic conditions.

THE FERMENTATION OF D-ALLOSE AND D-GLUCOSE BY AEROBACTER AEROGENES

1955 ◽  
Vol 1 (7) ◽  
pp. 473-478 ◽  
Author(s):  
H. A. Altermatt ◽  
F. J. Simpson ◽  
A. C. Neish
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Methyl Groups ◽  
Carboxyl Group ◽  
Hexose Monophosphate ◽  
Anaerobic Conditions ◽  
Aerobacter Aerogenes ◽  
Aerobic Conditions ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Aerobacter aerogenes rapidly ferments D-allose-1-C14 and D-alIose-2-C14 under aerobic and anaerobic conditions to give products labelled in the same manner as those obtained from similar fermentations of D-glucose-1-C14 and D-glucose-2-C14. The lactic acid, acetic acid, ethanol, and 2,3-butanediol obtained from the sugars labelled in carbon-1 contained C14 in the methyl groups. From the sugars labelled in carbon-2, A. aerogenes produced lactic acid, ethanol, and 2,3-butanediol labelled in the carbinol groups and acetic acid labelled in the carboxyl group. The results agree with the hypothesis that both sugars are fermented under anaerobic conditions by the Embden–Meyerhof–Parnas route. This route is also of major importance under aerobic conditions where little sugar appears to be dissimilated via the hexose monophosphate shunt.

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