scholarly journals Effects of Dichloroethene Isomers on the Induction and Activity of Butane Monooxygenase in the Alkane-Oxidizing Bacterium “Pseudomonas butanovora”

2005 ◽  
Vol 71 (10) ◽  
pp. 6054-6059 ◽  
Author(s):  
D. M. Doughty ◽  
L. A. Sayavedra-Soto ◽  
D. J. Arp ◽  
P. J. Bottomley
Keyword(s):  
Gene Expression ◽  
Lactic Acid ◽  
Organic Acids ◽  
The Other ◽  
Reporter Strain ◽  
Negative Effects ◽  
Intact Cells ◽  
Pseudomonas Butanovora ◽  
Butane Monooxygenase

ABSTRACT We examined cooxidation of three different dichloroethenes (1,1-DCE, 1,2-trans DCE, and 1,2-cis DCE) by butane monooxygenase (BMO) in the butane-utilizing bacterium “Pseudomonas butanovora.” Different organic acids were tested as exogenous reductant sources for this process. In addition, we determined if DCEs could serve as surrogate inducers of BMO gene expression. Lactic acid supported greater rates of oxidation of the three DCEs than the other organic acids tested. The impacts of lactic acid-supported DCE oxidation on BMO activity differed among the isomers. In intact cells, 50% of BMO activity was irreversibly lost after consumption of ∼20 nmol mg protein−1 of 1,1-DCE and 1,2-trans DCE in 0.5 and 5 min, respectively. In contrast, a comparable loss of activity required the oxidation of 120 nmol 1,2-cis DCE mg protein−1. Oxidation of similar amounts of each DCE isomer (∼20 nmol mg protein−1) produced different negative effects on lactic acid-dependent respiration. Despite 1,1-DCE being consumed 10 times faster than 1,2,-trans DCE, respiration declined at similar rates, suggesting that the product(s) of oxidation of 1,2-trans DCE was more toxic to respiration than 1,1-DCE. Lactate-grown “P. butanovora” did not express BMO activity but gained activity after exposure to butane, ethene, 1,2-cis DCE, or 1,2-trans DCE. The products of BMO activity, ethene oxide and 1-butanol, induced lacZ in a reporter strain containing lacZ fused to the BMO promoter, whereas butane, ethene, and 1,2-cis DCE did not. 1,2-trans DCE was unique among the BMO substrates tested in its ability to induce lacZ expression.

Synergistic Antilisterial Effects of Mixtures of Lysozyme and Organic Acids

2016 ◽  
Vol 79 (12) ◽  
pp. 2184-2189 ◽  
Author(s):  
MYEONGGEUN OH ◽  
JOONGJAE LEE ◽  
YOONHWA JEONG ◽  
MISOOK KIM
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Citric Acid ◽  
Organic Acids ◽  
Succinic Acid ◽  
Malic Acid ◽  
Synergistic Effects ◽  
The Other ◽  
Food Preservative ◽  
Time Kill

ABSTRACT We investigated the synergistic effects of lysozyme combined with organic acids to inhibit the growth of Listeria monocytogenes. The antilisterial effects of the combination of lysozyme and acetic acid, citric acid, lactic acid, malic acid, or succinic acid were evaluated using the checkerboard method and time-kill assay. The MIC was 25,000 mg/liter for lysozyme, 625 mg/liter for acetic acid, and 1,250 mg/liter for the other acids. The MBC was 10,000 mg/liter for all of the tested organic acids. The combination of lysozyme and each organic acid showed synergistic effects via the checkerboard method; however, the time-kill assay showed synergistic effects for only three combinations of 1,250 mg/liter lysozyme with succinic acid (312 and 625 mg/liter) or malic acid (625 mg/liter). The results of this study indicate that the combination of lysozyme and malic acid or succinic acid can be effectively used as a food preservative to control L. monocytogenes.

scholarly journals Product Repression of Alkane Monooxygenase Expression in Pseudomonas butanovora

2006 ◽  
Vol 188 (7) ◽  
pp. 2586-2592 ◽  
Author(s):  
D. M. Doughty ◽  
L. A. Sayavedra-Soto ◽  
D. J. Arp ◽  
P. J. Bottomley
Keyword(s):  
Chain Length ◽  
Growth Medium ◽  
Transcriptional Activity ◽  
Propane Oxidation ◽  
Regulatory Mechanisms ◽  
Reporter Strain ◽  
Pseudomonas Butanovora ◽  
Alkane Monooxygenase ◽  
Butane Monooxygenase

ABSTRACT Physiological and regulatory mechanisms that allow the alkane-oxidizing bacterium Pseudomonas butanovora to consume C2 to C8 alkane substrates via butane monooxygenase (BMO) were examined. Striking differences were observed in response to even- versus odd-chain-length alkanes. Propionate, the downstream product of propane oxidation and of the oxidation of other odd-chain-length alkanes following β-oxidation, was a potent repressor of BMO expression. The transcriptional activity of the BMO promoter was reduced with as little as 10 μM propionate, even in the presence of appropriate inducers. Propionate accumulated stoichiometrically when 1-propanol and propionaldehyde were added to butane- and ethane-grown cells, indicating that propionate catabolism was inactive during growth on even-chain-length alkanes. In contrast, propionate consumption was induced (about 80 nmol propionate consumed · min−1 · mg protein−1) following growth on the odd-chain-length alkanes, propane and pentane. The induction of propionate consumption could be brought on by the addition of propionate or pentanoate to the growth medium. In a reporter strain of P. butanovora in which the BMO promoter controls β-galactosidase expression, only even-chain-length alcohols (C2 to C8) induced β-galactosidase following growth on acetate or butyrate. In contrast, both even- and odd-chain-length alcohols (C3 to C7) were able to induce β-galactosidase following the induction of propionate consumption by propionate or pentanoate.

scholarly journals Evidence for Involvement of Copper Ions and Redox State in Regulation of Butane Monooxygenase in Pseudomonas butanovora

2008 ◽  
Vol 190 (8) ◽  
pp. 2933-2938 ◽  
Author(s):  
D. M. Doughty ◽  
E. G. Kurth ◽  
L. A. Sayavedra-Soto ◽  
D. J. Arp ◽  
P. J. Bottomley
Keyword(s):  
Phosphate Buffer ◽  
Copper Ions ◽  
Galactosidase Activity ◽  
Reporter Strain ◽  
Mineral Salts ◽  
Anoxic Conditions ◽  
Repressive Effect ◽  
Pseudomonas Butanovora ◽  
Reporter Strains ◽  
Butane Monooxygenase

ABSTRACT Pseudomonas butanovora possesses an alcohol-inducible alkane monooxygenase, butane monooxygenase (BMO), that initiates growth on C2-C9 alkanes. A lacZ transcriptional reporter strain, P. butanovora bmoX::lacZ, in which the BMO promoter controls the expression of β-galactosidase activity, was used to show that 1-butanol induced the BMO promoter in the presence or absence of O2 when lactate-grown, BMO-repressed cells were washed free of lactate and incubated in NH4Cl-KNa phosphate buffer. In contrast, when lactate-grown cells of the reporter strain were incubated in phosphate buffer containing the mineral salts of standard growth medium, 1-butanol-dependent induction was significantly repressed at low O2 (1 to 2% [vol/vol]) and totally repressed under anoxic conditions. The repressive effect of the mineral salts was traced to its copper content. In cells exposed to 1% (vol/vol) O2, CuSO4 (0.5 μM) repressed 1-butanol-dependent induction of β-galactosidase activity. Under oxic conditions (20% O2 [vol/vol]), significantly higher concentrations of CuSO4 (2 μM) were required for almost complete repression of induction in lactate-grown cells. A combination of the Cu2+ reducing agent Na ascorbate (100 μM) and CuSO4 (0.5 μM) repressed the induction of β-galactosidase activity under oxic conditions to the same extent that 0.5 μM CuSO4 alone repressed it under anoxic conditions. Under oxic conditions, 2 μM CuSO4 repressed induction of the BMO promoter less effectively in butyrate-grown cells of the bmoX::lacZ strain and of an R8-bmoX::lacZ mutant reporter strain with a putative BMO regulator, BmoR, inactivated. Under anoxic conditions, CuSO4 repression remained highly effective, regardless of the growth substrate, in both BmoR-positive and -negative reporter strains.

scholarly journals Co-Cultivation of Sake Yeast and Kocuria Isolates From the Sake Brewing Process

2021 ◽  
Author(s):  
Momoka Terasaki ◽  
Airu Inoue ◽  
Saki Yoshida ◽  
Masato Yamada ◽  
Hiroshi Toda ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Citric Acid ◽  
Organic Acids ◽  
Succinic Acid ◽  
Aspergillus Oryzae ◽  
Microbial Population ◽  
Ethanol Concentration ◽  
Living Cells ◽  
The Other ◽  
Brewing Process

Abstract Kocuria isolates collected from the sake brewing process have inhabited the Narimasa Sake Brewery in Toyama, Japan. To investigate the effect of these actinobacterial isolates on the growth and metabolism of sake yeast, co-cultivation of sake yeast and Kocuria isolates was performed in a medium containing tryptone, glucose, and yeast extract (TGY), and a solution containing koji (steamed rice covered with Aspergillus oryzae) and glucose. In the TGY medium, the ethanol concentration and the number of living cells of each microorganism were measured. In the koji solution, the concentrations of ethanol and organic acids (citric acid, lactic acid, and succinic acid) were measured. The results showed that in TGY media, the growth of each Kocuria isolate in the co-culture of the two Kocuria isolates was similar to that in each monoculture. However, the growth of both Kocuria isolates was inhibited in the co-cultures of sake yeast and Kocuria isolates. On the other hand, the growth and ethanol productivity of sake yeast did not differ between its monoculture and co-cultures with Kocuria isolates. In the koji solution, although the concentration of succinic acid did not differ between the monocultures of sake yeast and co-cultures with Kocuria isolates, the concentrations of citric acid and lactic acid were different, indicating that Kocuria isolates affected the microbial population and/or sake yeast metabolism, but the effects were not identical between the two isolates. This strongly suggests that bacteria inhabiting a sake brewery influence the flavor of sake products of the brewery.

Development and regional planning within the decentralized administrative frame: case study (the Jordanian Experiment)

2018 ◽  
Vol 1 (2) ◽  
pp. 60-72
Author(s):  
Mansour Safran
Keyword(s):  
Regional Planning ◽  
The Other ◽  
Negative Effects ◽  
Administrative Procedures ◽  
The Way

This aims to review and analyze the Jordanian experiment in the developmental regional planning field within the decentralized managerial methods, which is considered one of the primary basic provisions for applying and success of this kind of planning. The study shoed that Jordan has passed important steps in the way for implanting the decentralized administration, but these steps are still not enough to established the effective and active regional planning. The study reveled that there are many problems facing the decentralized regional planning in Jordan, despite of the clear goals that this planning is trying to achieve. These problems have resulted from the existing relationship between the decentralized administration process’ dimensions from one side, and between its levels which ranged from weak to medium decentralization from the other side, In spite of the official trends aiming at applying more of the decentralized administrative policies, still high portion of these procedures are theoretical, did not yet find a way to reality. Because any progress or success at the level of applying the decentralized administrative policies doubtless means greater effectiveness and influence on the development regional planning in life of the residents in the kingdom’s different regions. So, it is important to go a head in applying more steps and decentralized administrative procedures, gradually and continuously to guarantee the control over any negative effects that might result from Appling this kind of systems.   © 2018 JASET, International Scholars and Researchers Association

Reparação óssea no implante dental

2020 ◽  
Vol 12 (45) ◽  
pp. 63-66
Author(s):  
Halim Nagem Filho ◽  
Reinaldo Francisco Maia ◽  
Reinaldo Missaka ◽  
Nasser Hussein Fares
Keyword(s):  
Gene Expression ◽  
Titanium Surface ◽  
Close Contact ◽  
The Other ◽  
Main Function ◽  
Indirect Interaction ◽  
M2 Macrophages ◽  
Activated Macrophages ◽  
M1 Macrophages ◽  
High Production

The osseointegration is the stable and functional union between the bone and a titanium surface. A new bone can be found on the surface of the implant about 1 week after its installation; the bone remodeling begins between 6 and 12 weeks and continues throughout life. After the implant insertion, depending on the energy of the surface, the plasma fluid immediately adheres, in close contact with the surface, promoting the adsorption of proteins and inducing the indirect interaction of the cells with the material. Macrophages are cells found in the tissues and originated from bone marrow monocytes. The M1 macrophages orchestrate the phagocytic phase in the inflammatory region and also produce inflammatory cytokines involved with the chronic inflammation and the cleaning of the wound and damaged tissues from bacteria. On the other hand, alternative-activated macrophages (M2) are activated by IL-10, the immune complex. Its main function consists on regulating negatively the inflammation through the secretion of the immunosuppressant IL-10. The M2 macrophages present involvement with the immunosuppression, besides having a low capacity for presenting antigens and high production of cytokines; these can be further divided into M2a, M2b, and M2c, based on the gene expression profile.

scholarly journals Analysis of the Mechanism by Which Glucose Inhibits Maltose Induction of MAL Gene Expression in Saccharomyces

Genetics ◽  
2000 ◽  
Vol 154 (1) ◽  
pp. 121-132
Author(s):  
Zhen Hu ◽  
Yingzi Yue ◽  
Hua Jiang ◽  
Bin Zhang ◽  
Peter W Sherwood ◽  
...  
Keyword(s):  
Gene Expression ◽  
Glucose Repression ◽  
Protein A ◽  
The Other ◽  
Maltose Permease ◽  
Inducer Exclusion ◽  
Glucose Inhibition ◽  
Independent Mechanism ◽  
Mal Genes

Abstract Expression of the MAL genes required for maltose fermentation in Saccharomyces cerevisiae is induced by maltose and repressed by glucose. Maltose-inducible regulation requires maltose permease and the MAL-activator protein, a DNA-binding transcription factor encoded by MAL63 and its homologues at the other MAL loci. Previously, we showed that the Mig1 repressor mediates glucose repression of MAL gene expression. Glucose also blocks MAL-activator-mediated maltose induction through a Mig1p-independent mechanism that we refer to as glucose inhibition. Here we report the characterization of this process. Our results indicate that glucose inhibition is also Mig2p independent. Moreover, we show that neither overexpression of the MAL-activator nor elimination of inducer exclusion is sufficient to relieve glucose inhibition, suggesting that glucose acts to inhibit induction by affecting maltose sensing and/or signaling. The glucose inhibition pathway requires HXK2, REG1, and GSF1 and appears to overlap upstream with the glucose repression pathway. The likely target of glucose inhibition is Snf1 protein kinase. Evidence is presented indicating that, in addition to its role in the inactivation of Mig1p, Snf1p is required post-transcriptionally for the synthesis of maltose permease whose function is essential for maltose induction.

scholarly journals Hardening Properties of Cheeses by Latilactobacillus curvatus PD1 Isolated from Hardened Cheese-Ddukbokki Rice Cake

2021 ◽  
Vol 9 (5) ◽  
pp. 1044
Author(s):  
Jeong A Kim ◽  
Geun Su Kim ◽  
Se Mi Choi ◽  
Myeong Seon Kim ◽  
Do Young Kwon ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Acid Production ◽  
Lactobacillus Casei ◽  
Leuconostoc Mesenteroides ◽  
The Other ◽  
Rice Cake ◽  
Two Samples ◽  
High Protease Activity

Hardening of cheese is one of major issues that degrade the quality of Home Meal Replacement (HMR) foods containing cheese such as Cheese-ddukbokki rice cake (CD, stir-fried rice cakes with shredded cheese). The quality of cheese, such as pH, proteolytic, and flavor properties, depends on various lactic acid bacteria (LAB) used in cheese fermentation. The hardening of cheese is also caused by LAB. In this study, various LAB strains were isolated from CD samples that showed rapid hardening. The correlation of LAB with the hardening of cheese was investigated. Seven of the CD samples with different manufacturing dates were collected and tested for hardening properties of cheese. Among them, strong-hardening of cheese was confirmed for two samples and weak-hardening was confirmed for one sample. All LAB in two strong-hardening samples and 40% of LAB in one weak-hardening sample were identified as Latilactobacillus curvatus. On the other hand, most LAB in normal cheese samples were identified as Leuconostoc mesenteroides and Lactobacillus casei. We prepared cheese samples in which L. curvatus (LC-CD) and L. mesenteroides (LM-CD) were most dominant, respectively. Each CD made of the prepared cheese was subjected to quality test for 50 days at 10 °C. Hardening of cheese with LC-CD dominant appeared at 30 days. However, hardening of cheese with LM-CD dominant did not appear until 50 days. The pH of the LC-CD was 5.18 ± 0.04 at 30 days, lower than that of LM-CD. The proteolytic activity of LC-CD sample was 2993.67 ± 246.17 units/g, higher than that of LM-CD sample (1421.67 ± 174.5 units/g). These results indicate that high acid production and high protease activity of L. curvatus might have caused hardening of cheese.

scholarly journals Are Honey Bees at Risk from Microplastics?

Toxics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 109
Author(s):  
Yahya Al Naggar ◽  
Markus Brinkmann ◽  
Christie M. Sayes ◽  
Saad N. AL-Kahtani ◽  
Showket A. Dar ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gut Microbiota ◽  
Honey Bees ◽  
Rural Areas ◽  
Aquatic Systems ◽  
Wide Spread ◽  
Negative Effects ◽  
Potential Threat ◽  
Persistent Pollutants ◽  
Research Questions

Microplastics (MPs) are ubiquitous and persistent pollutants, and have been detected in a wide variety of media, from soils to aquatic systems. MPs, consisting primarily of polyethylene, polypropylene, and polyacrylamide polymers, have recently been found in 12% of samples of honey collected in Ecuador. Recently, MPs have also been identified in honey bees collected from apiaries in Copenhagen, Denmark, as well as nearby semiurban and rural areas. Given these documented exposures, assessment of their effects is critical for understanding the risks of MP exposure to honey bees. Exposure to polystyrene (PS)-MPs decreased diversity of the honey bee gut microbiota, followed by changes in gene expression related to oxidative damage, detoxification, and immunity. As a result, the aim of this perspective was to investigate whether wide-spread prevalence of MPs might have unintended negative effects on health and fitness of honey bees, as well as to draw the scientific community’s attention to the possible risks of MPs to the fitness of honey bees. Several research questions must be answered before MPs can be considered a potential threat to bees.

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