scholarly journals Pantoea ananatis Converts MBOA to 6-Methoxy-4-nitro-benzoxazolin-2(3H)-one (NMBOA) for Cooperative Degradation with its Native Root Colonizing Microbial Consortium

2018 ◽  
Vol 13 (10) ◽  
pp. 1934578X1801301 ◽  
Author(s):  
Margot Schulz ◽  
Diana Hofmann ◽  
Dieter Sicker ◽  
Lothar Hennig ◽  
Vadim Schütz ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Microbial Growth ◽  
Microbial Consortium ◽  
Abutilon Theophrasti ◽  
Lepidium Sativum ◽  
Negative Effects ◽  
Pantoea Ananatis ◽  
Unusual Position ◽  
Czapek Medium ◽  
Native Root

6-Methoxy-benzoxazolin-2(3 H)-one (MBOA) is a degradation product derived from 2,4-Dihydroxy-7-methoxy-2 H-1,4-benzoxazin-3(4 H)-one (DIMBOA), one of the bioactive compounds found e.g., in maize. Here we present hitherto unknown 6-methoxy-4-nitro-benzoxazolin-2(3 H)-one (NMBOA) produced in Czapek medium by Pantoea ananatis (Enterobacteriaceae). P. ananatis is a member of a microbial consortium dominated by the zygomycete Actinomucor elegans, which was isolated from roots of Abutilon theophrasti. NMBOA was identified by NMR spectra and HR-ESI-MS analyses, revealing an unusual position of the nitro group at C-4. Nitration of MBOA initiates the degradation of the compound that is almost completed within three days by the entire consortium and isolated P. ananatis. The yeast Papiliotrema baii, another member of the consortium, is unable to degrade NMBOA but stored it at the surface of its polysacchararide capsule. NMBOA has negative effects on microbial growth in liquid medium whereas seedlings of Brassica oleracea var. gongylodes L. (kohlrabi) or Lepidium sativum (cress) are not impaired up to 500 μM. Degradation via nitration may be important to understand the behavior of microbial species and effects of microbiomes when exposed to MBOA.

scholarly journals Pb(II) Bio-Removal, Viability, and Population Distribution of an Industrial Microbial Consortium: The Effect of Pb(II) and Nutrient Concentrations

2020 ◽  
Vol 12 (6) ◽  
pp. 2511
Author(s):  
Carla Hörstmann ◽  
Hendrik G. Brink ◽  
Evans M.N. Chirwa
Keyword(s):  
Klebsiella Pneumoniae ◽  
Microbial Growth ◽  
Microbial Consortium ◽  
Population Distribution ◽  
Active Species ◽  
Sem Analysis ◽  
Nutrient Concentrations ◽  
Local Alignment ◽  
Factors Affecting ◽  
Search Tool

This study presents the effect of aqueous Pb(II) and nutrient concentrations on the Pb(II)-removal, biomass viability, active species identities, and population distribution of an industrial Pb(II) resistant microbial consortium. The studied consortium has previously shown to be highly effective at precipitating Pb(II) from solution. At all conditions tested (80 and 500 ppm Pb(II), and varying nutrients conditions) it was found that circa 50% of Pb(II) was removed within the first 3 h, with the absence of any visual changes, followed by a slower rate of Pb(II) removal accompanied by the formation of a dark precipitate. The Pb(II) removal was found to be independent of microbial growth, while growth was observed dependent on the concentration of Pb(II), nutrients, and nitrates in the system. SEM analysis indicated viable bacilli embedded in precipitate. These findings indicate that precipitation occurs on the surface of the biomass as opposed to an internal excretion mechanism. BLAST (Basic Local Alignment Search Tool) results indicated Klebsiella pneumoniae as the active species responsible for Pb(II) bioprecipitation for both the 80 and 500 ppm isolated colonies, while a diverse population distribution of organisms was observed for the streak plate analyses. A quicker microbial generation rate was observed than what was expected for Klebsiella pneumoniae, indicating that the overall consortial population contributed to the growth rates observed. This study provided insights into the factors affecting Pb(II) bio-removal and bioprecipitation by the investigated industrially obtained consortium, thereby providing invaluable knowledge required for industrial application.

scholarly journals Use of Stochastic Models To Assess the Effect of Environmental Factors on Microbial Growth

2005 ◽  
Vol 71 (5) ◽  
pp. 2355-2364 ◽  
Author(s):  
José Miguel Ponciano ◽  
Frederik P. J. Vandecasteele ◽  
Thomas F. Hess ◽  
Larry J. Forney ◽  
Ronald L. Crawford ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Microbial Growth ◽  
Ecological Model ◽  
Growth Curves ◽  
Growth Dynamics ◽  
Negative Effects ◽  
Data Set ◽  
Experimental Treatments ◽  
Time Required ◽  
Extensive Experimental Data

ABSTRACT We present a novel application of a stochastic ecological model to the study and analysis of microbial growth dynamics as influenced by environmental conditions in an extensive experimental data set. The model proved to be useful in bridging the gap between theoretical ideas in ecology and an applied problem in microbiology. The data consisted of recorded growth curves of Escherichia coli grown in triplicate in a base medium with all 32 possible combinations of five supplements: glucose, NH4Cl, HCl, EDTA, and NaCl. The potential complexity of 25 experimental treatments and their effects was reduced to 22 as just the metal chelator EDTA, the presumed osmotic pressure imposed by NaCl, and the interaction between these two factors were enough to explain the variability seen in the data. The statistical analysis showed that the positive and negative effects of the five chemical supplements and their combinations were directly translated into an increase or decrease in time required to attain stationary phase and the population size at which the stationary phase started. The stochastic ecological model proved to be useful, as it effectively explained and summarized the uncertainty seen in the recorded growth curves. Our findings have broad implications for both basic and applied research and illustrate how stochastic mathematical modeling coupled with rigorous statistical methods can be of great assistance in understanding basic processes in microbial ecology.

EDTA as a chelating agent in quantitative 1H-NMR of biologically important ions

2021 ◽  
Author(s):  
Emmanuel Mathuthu ◽  
Angelique Janse van Rensburg ◽  
Dean Du Plessis ◽  
Shayne Mason
Keyword(s):  
1H Nmr ◽  
Conformational Changes ◽  
Nmr Spectra ◽  
A Priori ◽  
Chelating Agent ◽  
1H Nmr Spectra ◽  
Negative Effects ◽  
Cellular Mechanisms ◽  
Ph Range ◽  
Spectral Patterns

Biologically important ions (Ca, K, Mg, Fe, and Zn) play major roles in numerous biological processes, with their homeostatic balance being necessary for the maintenance of cellular mechanisms. Sudden and severe loss in homeostasis of just one biologically important ion can cause cascading negative effects. Being able to quickly, accurately and reliably quantify biologically important ions in human bio-fluid samples is something that has been sorely lacking within the field of metabolomics. 1H-NMR is a well-known analytical platform in metabolomics but ions are invisible on 1H-NMR spectra. The foundation of our investigation was based upon a priori knowledge that free EDTA produce two clear single peaks on 1H-NMR spectra, and that EDTA chelated to different ions produce unique 1H-NMR spectral patterns due to 3D conformational changes in the chemical structure of chelated-EDTA and varying degrees of electronegativity. The aim of this study was to develop and test a 1H-NMR-based method, with application specifically to the field of metabolomics, to quantify biologically important ions within the physiological pH range of 6.50-7.50 using EDTA as a chelating agent. Our method produced linear, accurate, precise and repeatable results for Ca, Mg and Zn; however, K and Fe did not chelate with EDTA

Undesirable Effects of Goal Setting on Perceived Fairness, Commitment, and Unethical Behavior

2018 ◽  
Vol 62 (2) ◽  
pp. 97-107 ◽  
Author(s):  
Nina Keith
Keyword(s):  
Goal Setting ◽  
Unethical Behavior ◽  
The United States ◽  
Goal Commitment ◽  
Management Technique ◽  
Long Term Effects ◽  
Perceived Fairness ◽  
Negative Effects ◽  
Positive Effects ◽  
And Performance

Abstract. The positive effects of goal setting on motivation and performance are among the most established findings of industrial–organizational psychology. Accordingly, goal setting is a common management technique. Lately, however, potential negative effects of goal-setting, for example, on unethical behavior, are increasingly being discussed. This research replicates and extends a laboratory experiment conducted in the United States. In one of three goal conditions (do-your-best goals, consistently high goals, increasingly high goals), 101 participants worked on a search task in five rounds. Half of them (transparency yes/no) were informed at the outset about goal development. We did not find the expected effects on unethical behavior but medium-to-large effects on subjective variables: Perceived fairness of goals and goal commitment were least favorable in the increasing-goal condition, particularly in later goal rounds. Results indicate that when designing goal-setting interventions, organizations may consider potential undesirable long-term effects.

The Effect of Suicide-Related Internet Use on Users’ Mental Health

Crisis ◽  
2013 ◽  
Vol 34 (5) ◽  
pp. 348-353 ◽  
Author(s):  
Hajime Sueki
Keyword(s):  
Mental Health ◽  
Young Adults ◽  
Suicidal Ideation ◽  
Internet Use ◽  
Panel Study ◽  
Psychological Effects ◽  
The Internet ◽  
Negative Effects ◽  
Suicide Methods ◽  
Internet Users

Background: Previous studies have shown that suicide-related Internet use can have both negative and positive psychological effects. Aims: This study examined the effect of suicide-related Internet use on users’ suicidal ideation, depression/anxiety tendency, and loneliness. Method: A two-wave panel study of 850 Internet users was conducted via the Internet. Results: Suicide-related Internet use (e.g., browsing websites about suicide methods) had negative effects on suicidal ideation and depression/anxiety tendency. No forms of suicide-related Internet use, even those that would generally be considered positive, were found to decrease users’ suicidal ideation. In addition, our results suggest that the greater the suicidal ideation and feelings of depression and loneliness of Internet users, the more they used the Internet. Conclusion: Since suicide-related Internet use can adversely influence the mental health of young adults, it is necessary to take measures to reduce their exposure to such information.

Searching Online for Methods of Suicide

Crisis ◽  
2020 ◽  
pp. 1-8
Author(s):  
Christian Ulrich Eriksen ◽  
Flemming Konradsen ◽  
Thilde Vildekilde
Keyword(s):  
Content Analysis ◽  
English Language ◽  
Significant Proportion ◽  
Background Information ◽  
Access To Information ◽  
Online Content ◽  
Negative Effects ◽  
Search Terms ◽  
Methods Of Suicide

Abstract. Background: Information on methods of suicide is available online, and access to information on methods of suicide appears to contribute to a small but significant proportion of suicides. There is limited documentation of how methods of suicide are being profiled, as well as what content exists in other languages than English. Aim: We aimed to analyze and compare how methods of suicide are profiled on Danish and English-language websites. Method: We applied a categorization and content analysis of websites describing methods of suicide. Sites were retrieved by applying widely used Danish and English-language search terms. Results: A total of 136 English-language websites and 106 Danish-language websites were included for analysis. Websites were more often categorized as prevention or support sites, academic or policy sites, and against suicide sites than dedicated suicide sites (i.e., pro-suicide sites), or information sites. However, information on methods of suicide was available, and 20.1% and 8.9% of the English and Danish-language sites, respectively, suggested that a particular method of suicide was quick, easy, painless, or certain to result in death. Limitations: Only one author coded and analyzed all websites. A further operationalization of the content analysis checklist is warranted to increase reliability. Conclusion: The websites primarily had a prevention or anti-suicide focus, but information on methods of suicide was available, requiring an increased focus on how to diminish the negative effects of harmful online content.

Effectiveness of Programs for the Prevention of Child Sexual Abuse

2020 ◽  
Vol 25 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Amaia Del Campo ◽  
Marisalva Fávero
Keyword(s):  
United States ◽  
Sexual Abuse ◽  
New Zealand ◽  
Critical Analysis ◽  
Prevention Programs ◽  
The United States ◽  
Sexual Abuse Prevention ◽  
Negative Effects ◽  
The United Kingdom ◽  
Methodological Considerations

Abstract. During the last decades, several studies have been conducted on the effectiveness of sexual abuse prevention programs implemented in different countries. In this article, we present a review of 70 studies (1981–2017) evaluating prevention programs, conducted mostly in the United States and Canada, although with a considerable presence also in other countries, such as New Zealand and the United Kingdom. The results of these studies, in general, are very promising and encourage us to continue this type of intervention, almost unanimously confirming its effectiveness. Prevention programs encourage children and adolescents to report the abuse experienced and they may help to reduce the trauma of sexual abuse if there are victims among the participants. We also found that some evaluations have not considered the possible negative effects of this type of programs in the event that they are applied inappropriately. Finally, we present some methodological considerations as critical analysis to this type of evaluations.

If I Had Something to Add, I Would

2020 ◽  
Vol 19 (2) ◽  
pp. 86-96
Author(s):  
Isaac A. Lindquist ◽  
Emily E. Adams ◽  
Joseph A. Allen
Keyword(s):  
Job Attitudes ◽  
Negative Effects ◽  
Meeting Effectiveness ◽  
And Behavior ◽  
Attitudes And Behavior

Abstract. Most employees participate in workplace meetings, and their experiences in meetings can vary greatly, which can lead to positive or negative effects on both job attitudes and behavior. In this study, we examined the effect that a meeting attendee’s competence in the meeting topic had on their participation in the meeting and their perception of meeting effectiveness. Results indicated those with higher levels of competence in the meeting topic were more likely to participate and through participation found their meeting more effective; this relationship was stronger when employee dissent in the meetings was high. Leaders should ensure that those who are present in a meeting are competent in the topic of the meeting and encourage them to participate.

The More Control, the Better?

2014 ◽  
Vol 26 (2) ◽  
pp. 81-91 ◽  
Author(s):  
Jeeyun Oh ◽  
Mun-Young Chung ◽  
Sangyong Han
Keyword(s):  
Mixed Design ◽  
Negative Effects ◽  
Story Structure ◽  
Content Type ◽  
High User ◽  
User Control ◽  
Rigorous Research ◽  
Control Versus ◽  
The Media ◽  
The Impact

Despite of the popularity of interactive movie trailers, rigorous research on one of the most apparent features of these interfaces – the level of user control – has been scarce. This study explored the effects of user control on users’ immersion and enjoyment of the movie trailers, moderated by the content type. We conducted a 2 (high user control versus low user control) × 2 (drama film trailer versus documentary film trailer) mixed-design factorial experiment. The results showed that the level of user control over movie trailer interfaces decreased users’ immersion when the trailer had an element of traditional story structure, such as a drama film trailer. Participants in the high user control condition answered that they were less fascinated with, absorbed in, focused on, mentally involved with, and emotionally affected by the movie trailer than participants in the low user control condition only with the drama movie trailer. The negative effects of user control on the level of immersion for the drama trailer translated into users’ enjoyment. The impact of user control over interfaces on immersion and enjoyment varies depending on the nature of the media content, which suggests a possible trade-off between the level of user control and entertainment outcomes.

Feeling Like a Burden

2020 ◽  
Vol 51 (4) ◽  
pp. 219-238
Author(s):  
James H. Wirth ◽  
Ashley Batts Allen ◽  
Emily M. Zitek
Keyword(s):  
Negative Affect ◽  
Poor Performance ◽  
Self Esteem ◽  
Social Consequences ◽  
Social Costs ◽  
Negative Outcomes ◽  
Negative Effects ◽  
Self Compassion

Abstract. We examined the negative outcomes, particularly social costs that result when a person harms their group by performing poorly, and whether self-compassion could buffer against these negative outcomes. In Studies 1 and 2, participants performed poorly and harmed their group or performed equal to their group. Harmful poor-performing participants felt more burdensome, experienced more negative affect, felt more ostracized, anticipated more exclusion, and felt lowered self-esteem than equal-performing participants. Studies 3 and 4 disentangled poor performance from harming a group. Poor-performing participants either harmed the group or caused no harm. Harmful poor-performing participants felt more burdensome and anticipated more exclusion, indicating the additional social consequences of a harmful poor performance over a non-harmful performance. Across studies, trait self-compassion was associated with reduced negative effects.

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