scholarly journals Factors Influencing the Bacterial Bioremediation of Hydrocarbon Contaminants in the Soil: Mechanisms and Impacts

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Gessesse Kebede ◽  
Tekle Tafese ◽  
Ebrahim M. Abda ◽  
M. Kamaraj ◽  
Fassil Assefa
Keyword(s):  
Environmental Pollution ◽  
Polyaromatic Hydrocarbons ◽  
Abiotic Factors ◽  
Hydrocarbon Biodegradation ◽  
Key Factors ◽  
Hydrophobic Compounds ◽  
Degradative Enzymes ◽  
Bacterial Biodegradation ◽  
Ph Range ◽  
Major Factors

The discharge of hydrocarbons and their derivatives to environments due to human and/or natural activities cause environmental pollution (soil, water, and air) and affect the natural functioning of an ecosystem. To minimize or eradicate environmental pollution by hydrocarbon contaminants, studies showed strategies including physical, chemical, and biological approaches. Among those strategies, the use of biological techniques (especially bacterial biodegradation) is critically important to remove hydrocarbon contaminants. The current review discusses the insights of major factors that enhance or hinder the bacterial bioremediation of hydrocarbon contaminants (aliphatic, aromatic, and polyaromatic hydrocarbons) in the soil. The key factors limiting the overall hydrocarbon biodegradation are generally categorized as biotic factors and abiotic factors. Among various environmental factors, temperature range from 30 to 40°C, pH range from 5 to 8, moisture availability range from 30 to 90%, carbon/nitrogen/phosphorous (C/N/P; 100:20:1) ratio, and 10–40% of oxygen for aerobic degradation are the key factors that show positive correlation for greatest hydrocarbon biodegradation rate by altering the activities of the microbial and degradative enzymes in soil. In addition, the formation of biofilm and production of biosurfactants in hydrocarbon-polluted soil environments increase microbial adaptation to low bioavailability of hydrophobic compounds, and genes that encode for hydrocarbon degradative enzymes are critical for the potential of microbes to bioremediate soils contaminated with hydrocarbon pollutants. Therefore, this review works on the identification of factors for effective hydrocarbon biodegradation, understanding, and optimization of those factors that are essential and critical.

scholarly journals Person - job fi t and the work commitment of IT Personnel

2016 ◽  
Vol 26 (2) ◽  
pp. 218 ◽  
Author(s):  
Therasa C. ◽  
C. Vijayabanu
Keyword(s):  
Regression Analysis ◽  
Principal Component ◽  
Attrition Rate ◽  
P Value ◽  
Work Commitment ◽  
Key Factors ◽  
Coeffi Cients ◽  
Work Autonomy ◽  
Major Factors ◽  
The Impact

Introduction: There have been given a much higher importance to employee commitment and retention since India is experiencing the highest attrition rate globally Economic Times, 2015. Hence, considering the factors of Person-job fi t to interpret the impact towards work commitment is very well essential, especially in the current scenario. Work Commitment is a vital element in any organization which has outstanding impact on productivity and functioning and hence it is very much vital to have a committed workforce which is necessary in this competitive environment and tight labour market. In the same way, there is considerable amount of evidence that if P-J fi t is high then it will have a direct impact on organization commitment also. Person-job fi t is the compatibility between person’s competency and abilities and the requirements of the job Zheng et al.2. If there exists a mismatch between person-job fi t then the consequences might result in poor work commitment, low job satisfaction and extremely lower involvement in the job. Objective: This study analyzed the key factors that contribute to Person- job compatibility among IT workers and also analyzed the relationship and impact of Person- job compatibility towards work commitment. Methods: Exploratory Factor Analysis (EFA) was used to fi lter the key factors initially, followed by a linear regression technique to determine the impact of Person- job compatibility factors in work commitment on a sample of 300 employees. EFA used Principal Component analysis for extraction and Promax for rotation. Finally regression analysis was carried out to predict the work commitment through statistically significant person-job compatibility variables. Results: The impact of person-job compatibility on work commitment was studied through regression analysis and it imply that for every unit increase in HR Policy, a 0.52 (unstandardised coeffi cients) increase in work commitment is predicted and it has been turned out as a most impacting variable to predict work commitment. The coeffi cients for Relationship (B =.330, sig =.000), HR Policies (B =.519, sig =.000), Pay and Benefi ts (B =.386, sig =.000) and Employee Growth (B =.290, sig =.001) were statistically significant, since its p-value is .000 which is smaller than .05. The coeffi cients for Work Autonomy (B =.154, sig = .081) was not statistically signifi cant, since its p-value is 0.081 which is greater than.05. Conclusion: The major factors responsible for creating work commitment among IT employees are Relationship, HR Policies and strategies, Pay and benefi ts, Work autonomy and Employee growth. The most contributing regressors which accounts for creating work commitment are HR policies, Pay and benefi ts, Employee growth and work autonomy.

scholarly journals ESTIMATION OF NUMBERS OF COLIFORM BACTERIAL AS WATER QUALITY INDICATOR IN KEPAHIANG DISTRICT RIVERS, BENGKULU PROVINCE

2021 ◽  
Vol 7 (2) ◽  
pp. 154-163
Author(s):  
Sipriyadi Sipriyadi ◽  
Risky Hadi Wibowo ◽  
Welly Darwis
Keyword(s):  
Water Quality ◽  
Fecal Coliform ◽  
Abiotic Factors ◽  
Total Coliform ◽  
Household Waste ◽  
Most Probable Number ◽  
Abiotic Factor ◽  
Probable Number ◽  
Quality Water ◽  
Ph Range

Coliform is a group of microbes that are used as indicators of water quality. Water pollution is generally caused by pathogenic microbes from feces, household waste, and industrial activity waste. This study aimed to estimate the total number of coliform contamination in several rivers in Kepahiang Regency, namely Tebat Monok (TM), Sempiyang (SPY), Penanjung Panjang (PP), Embong Ijok (EI) Air Langkap(ALK), and Air Belimbing (ABB).  Total coliform and Fecal coliform tests were carried out using the Most Probable Number (MPN) method on Lactose Broth, Brillian Green Lactose Bile Broth and pour plates on Eosin Methylene Blue Agar media. Measurement of abiotic factors was on temperature and pH parameters. The test results of total coliform showed that 6 rivers contained total coliform under the Class II river water quality standards with a range of 1210/100 mL– 4310/100 mL and 2 rivers that were contaminated with Fecal coliform, TM and ALK, have the content of 1500/100 mL and 1700 / 100 mL. The results of the measurement of the abiotic factor, the river pH range was 7.4 - 8.2. The lowest temperature was 25oC in SPY river and the highest temperature was 26 oC on the TM, PP, EI, ALK, and ABB rivers.

scholarly journals Four Factors that will shape the Future of Work

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Michal Beno
Keyword(s):  
Technological Progress ◽  
Environmental Changes ◽  
Key Factors ◽  
Future Of Work ◽  
Technological Advances ◽  
The Future ◽  
Recent Developments ◽  
Diverse World ◽  
Major Factors ◽  
Complex Activities

The future of work is shaped by technological progress, globalisation and glocalisation, and societal and institutional change. As a result of recent developments, a diverse world of work with significant differences in working conditions by industry and occupation will develop, with a focus on creative, interactive and more complex activities with essential skills. At the same time, demands on companies with regard to innovation and flexibility are growing. To understand the future of work, we believe it is essential to explore four major factors that will impact on the future of work: 1) Technological progress, IT platforms, the sharing and knowledge economy; 2) Demographic, social and environmental changes; 3) Globalisation and glocalisation; and 4) Labour flexibility. Our aim is to gain a better understanding of the dynamics of the future of work by examining these four key factors that influence today’s labour market, because this market is agile, since people can work anywhere at any time. In summary, seeing automation as synonymous with job losses is not correct. We contend that it is a mistake to believe that globalisation and technological advances lead to a reduction in the demand for human employees. However, it is possible that the opposing viewpoints of those who agree and those who disagree with this opinion are causing a polarisation of the workforce. Changes in our society, such as the constantly evolving demography, as well as environmental issues and ICT, have an influence on the way we work, and when, how and where we work.

scholarly journals The development of food preferences: anatomical and genetic determinants, important factors of taste development in children

2020 ◽  
Vol 3 (2) ◽  
pp. 119-125
Author(s):  
I.N. Zakharova ◽  
◽  
Yu.A. Dmitrieva ◽  
E.B Machneva ◽  
A.N. Tsutsaeva ◽  
...  
Keyword(s):  
Child Nutrition ◽  
Food Preferences ◽  
Current Data ◽  
Gustatory System ◽  
Key Factors ◽  
Genetic Determinants ◽  
Factors Affecting ◽  
Ancient Times ◽  
Major Factors

Since ancient times, scientists and philosophers were interested in the sense of taste, the mechanisms of its development, anatomical structures responsible for taste, and its importance. Currently, it is clear that food preferences are the main determinant of the development of nutrition and food behavior. Food preferences begin to develop in the early childhood and retain throughout the life. Therefore, inculcating correct nutritional behavior with respect to healthy food is a promising approach to improve the quality of diet being one of the key factors affecting human health. This article addresses current data on morphology, genetics, embryology, and ontogeny of gustatory system as well as major factors affecting the development of food preferences in a child. Most of these factors are modified ones, therefore, the aim of this review is to draw the attention of pediatricians since this is pediatrician who makes evidence-based recommendations on child nutrition and provides adequate feeding strategy.Keywords: genetics, food preferences, taste, taste receptors, children, smell, ontogeny, tongue, baby food, healthy lifestyle.For citation: Zakharova I.N., Dmitrieva Yu.A., Machneva E.B., Tsutsaeva A.N. The development of food preferences: anatomical and genetic determinants, important factors of taste development in children. Russian Journal of Woman and Child Health. 2020;3(2):119–125. DOI: 10.32364/2618-8430-2020-3-2-119-125.

scholarly journals Enhancement of Solubilization and Biodegradation of Polyaromatic Hydrocarbons by the Bioemulsifier Alasan

1999 ◽  
Vol 65 (6) ◽  
pp. 2697-2702 ◽  
Author(s):  
T. Barkay ◽  
S. Navon-Venezia ◽  
E. Z. Ron ◽  
E. Rosenberg
Keyword(s):  
Polyaromatic Hydrocarbons ◽  
Physicochemical Characterization ◽  
Aqueous Solubility ◽  
Physical Interaction ◽  
Hydrophobic Compounds ◽  
Enhanced Solubility ◽  
Potential Applications ◽  
Hydrophobic Nature ◽  
Aqueous Solubilities

ABSTRACT Alasan, a high-molecular-weight bioemulsifier complex of an anionic polysaccharide and proteins that is produced by Acinetobacter radioresistens KA53 (S. Navon-Venezia, Z. Zosim, A. Gottlieb, R. Legmann, S. Carmeli, E. Z. Ron, and E. Rosenberg, Appl. Environ. Microbiol. 61:3240–3244, 1995), enhanced the aqueous solubility and biodegradation rates of polyaromatic hydrocarbons (PAHs). In the presence of 500 μg of alasan ml−1, the apparent aqueous solubilities of phenanthrene, fluoranthene, and pyrene were increased 6.6-, 25.7-, and 19.8-fold, respectively. Physicochemical characterization of the solubilization activity suggested that alasan solubilizes PAHs by a physical interaction, most likely of a hydrophobic nature, and that this interaction is slowly reversible. Moreover, the increase in apparent aqueous solubility of PAHs does not depend on the conformation of alasan and is not affected by the formation of multimolecular aggregates of alasan above its saturation concentration. The presence of alasan more than doubled the rate of [14C]fluoranthene mineralization and significantly increased the rate of [14C]phenanthrene mineralization bySphingomonas paucimobilis EPA505. The results suggest that alasan-enhanced solubility of hydrophobic compounds has potential applications in bioremediation.

Enhanced Hydrocarbon Biodegradation by a Newly Isolated Bacillus subtilis Strain

2004 ◽  
Vol 59 (3-4) ◽  
pp. 205-208 ◽  
Author(s):  
Nelly Christova ◽  
Borjana Tuleva ◽  
Boryana Nikolova-Damyanova
Keyword(s):  
Surface Tension ◽  
Bacillus Subtilis ◽  
Hydrocarbon Biodegradation ◽  
Subtilis Strain ◽  
Emulsifying Activity ◽  
Hydrophobic Compounds ◽  
High Concentrations ◽  
Rhamnolipid Biosurfactant ◽  
Hydrocarbon Substrates ◽  
Soluble Substrate

The relation between hydrocarbon degradation and biosurfactant (rhamnolipid) production by a new Bacillus subtilis 22BN strain was investigated. The strain was isolated for its capacity to utilize n-hexadecane and naphthalene and at the same time to produce surfaceactive compound at high concentrations (1.5 -2.0 g l-1). Biosurfactant production was detected by surface tension lowering and emulsifying activity. The strain is a good degrader of both hydrocarbons used with degradability of 98.3 ± 1% and 75 ± 2% for n-hexadecane and naphthalene, respectively. Measurement of cell hydrophobicity showed that the combination of slightly soluble substrate and rhamnolipid developed higher hydrophobicity correlated with increased utilization of both hydrocarbon substrates. To our knowledge, this is the first report of Bacillus subtilis strain that degrades hydrophobic compounds and at the same time produces rhamnolipid biosurfactant.

scholarly journals Predictive Factors for the Suppression of Fusarium Wilt of Tomato in Plant Growth Media

2004 ◽  
Vol 94 (10) ◽  
pp. 1094-1101 ◽  
Author(s):  
Celia Borrero ◽  
M. Isabel Trillas ◽  
José Ordovás ◽  
Julio C. Tello ◽  
Manuel Avilés
Keyword(s):  
Fusarium Wilt ◽  
Control Measures ◽  
Growth Media ◽  
Cellulolytic Bacteria ◽  
Key Factors ◽  
Glucosidase Activity ◽  
Oligotrophic Bacteria ◽  
Predictive Variables ◽  
Physiological Profiles ◽  
Ph Range

Fusarium wilts are economically important diseases for which there are no effective chemical control measures. However, biological control and fertility management are becoming efficient alternatives for controlling this disease. Growth media formulated with composts that are able to suppress Fusarium wilt of tomato provide a control system that integrates both strategies. The aim of this study was to predict Fusarium wilt suppression of growth media using abiotic and biotic variables. Grape marc compost was the most effective medium used to suppress Fusarium wilt. Cork compost was intermediate, and light peat and expanded vermiculite were the most conducive growth media. The growth media evaluated were in a pH range of 6.26 to 7.97. Both composts had high β-glucosidase activity. When pH and β-glucosidase activity were taken into account as predictive variables, more than 91% of the variation in severity of Fusarium wilt was explained. This relationship illustrates the effect of nutrient availability and the degree of microbiostasis, two key factors in this pathosystem. Microbial populations involved in suppressiveness were cellulolytic and oligotrophic actinomycetes, fungi, and the ratios cellulolytic actinomycetes/cellulolytic bacteria, oligotrophic bacteria/copiotrophic bacteria, and oligotrophic actinomycetes/oligotrophic bacteria. Based on community level physiological profiles, different community structures were evident among growth media evaluated.

scholarly journals Travelling and COVID-19: A Mathematical Model

2020 ◽  
Author(s):  
Sankha Banerjee
Keyword(s):  
Mathematical Model ◽  
Transmission Dynamics ◽  
High Rate ◽  
Key Factors ◽  
Population Dispersal ◽  
Proposed Model ◽  
Disease Spreading ◽  
Major Factors ◽  
Transmission Of Disease ◽  
Critical Limits

Abstract A non-linear mathematical model is proposed to study the impacts of travelling in human-human transmission of COVID- 19.Two different regions are considered and transmission dynamics of COVID-19 dissemination in two regions caused by travelling from one region to other and infection during travel are discussed.Besides contacts between susceptible and infected population of a region off the travel,transmission of disease due to contacts during travel is also considered.The proposed model is analysed using stability theory of ordinary differential equation and feasibility of qualitative results ia checked through numerical simulations.From obtained results,it is shown that travelling and population dispersal can aggravate disease spreading in each region.It is also inferred that rate of travelling and rate of contacts during travel and off the travel can ease the disease to take endemic form and for high rates,it may become pandemic. Further numerical calculations are performed and critical limits of the major factors enhancing spreading of disease.It is revealed that when the rates goes higher than their corresponding critical limits,disease may not be controlled due to high infection.It is also imparted that when the rates are high, disease can only be controlled with high rate of quarantine.Also approximate time or stability is evaluated for maximum as well as minimum rates of key parameters.The results obtained by analyzing the model recommends that for early stability of endemic situation, key factors must be kept as minimum as possible within estimated limits and quarantining infected class to control the transmission of disease.

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