scholarly journals Soil biotest results using Azotobacter bacteria: interpretation problems and possible solutions

2021 ◽  
Vol 4 (3) ◽  
Author(s):  
A. A. Danilova ◽  
A. A. Petrov
Keyword(s):  
Microbial Community ◽  
Coal Mining ◽  
Soil Aggregates ◽  
Well Being ◽  
Processing Plant ◽  
Arable Soils ◽  
Glucose Response ◽  
Undisturbed Soil ◽  
Glucose Addition ◽  
Summer Fallow

The aim of the study. The Azotobacter genus is a well-known bioassay for testing the soil environment quality. A large number of these bacteria is considered as evidence of the ecological well-being of a soil. However, a high number of these microorganisms was found in disturbed ecosystems, which means there is a problem of how to interpret the results of the biotest. Therefore the aim of the study was to clarify the causes of this problem and suggest a possible way to solve it. Location and objects of the study. The study was conducted in West Siberia (Russia) in the Priobskoe plateau (54°53'13.5"N, 82°59'36.7E"). Leached сhernozem with different content of organic matter (mortmass) was studied under the following treatments: 1) permanent fallow, 2) wheat cultivation, annual removal of straw from the field + summer fallow, 3) wheat + left straw + summer fallow, 4) wheat +left straw + green manure fallow, 5) grassland. The content of N-NO3, respectively, was equal to 50, 10, 15, 5, 0 mg/kg. Another object was a site at the mining and processing plant "Denisovsky" in South Yakutia (Russia) (56°46'20.23"N, 124°51'06.95"E). Abandoned for a long time (30 years) after coal mining spoils were studied in two variants: without plants and with well-developed vegetation cover. Total SOC content was 1.8 and 5.7%, N – 0.3 and 0.4 %, respectively. Methodology. The direct sowing of single soil aggregates onto the N-free medium containing glucose as C-source was used to cultivate Azotobacter. Glucose (10 mg/g soil) was added to the soil to activate Azotobacter growth. A live culture of bacteria was introduced into the soil at a dose of 1 ml/g to check the viability of Azotobacter in experimental soils. Main results. The status of the microbial community in situ was observed on microbial landscapes obtained by exposing slides in the undisturbed soil for 30 days. The overgrowth of soil lumps in the specified range of options was 0–80–40–0–0% and after glucose addition – 100–80–80–0%. The activation of Azotobacter growth after glucose addition was inversely proportional to the C: N ratio (between the mortmass and the mineral nitrogen). Live Azotobacter culture under grassland developed 2.5 times slower in comparison with the fallow. Similar patterns were found in the study of the soils developed on the coal mining spoils. Activation of Azotobacter growth by glucose (response to stress) was more pronounced in soils with apparently less favorable environment for bacteria. Conclusion. The reason behind misleading interpretation of Azotobacter biotest results was that the original purpose of the test was to assess fertility of arable soils. This role of the indicator bacterium was previously underestimated. It is known that the arable soil belongs to the category of disturbed ones, and the abundance of Azotobacter may indicate instability in the microbial community of the soil. To expand the capabilities of the biotest, the authors propose to supplement the test with a procedure for evaluating the Azotobacter growth response to experimental stress, e.g. C-substrate addition.

Are Economic Sanctions against North Korea Effective? Assessing Nighttime Light in 25 Major Cities

2021 ◽  
Vol 94 (3) ◽  
pp. 464-492
Author(s):  
Sung Hyun Son ◽  
Joonmo Cho
Keyword(s):  
Growth Rate ◽  
Coal Mining ◽  
North Korea ◽  
Economic Sanctions ◽  
Well Being ◽  
Capital City ◽  
Calibration Process ◽  
Nighttime Light ◽  
Negative Growth ◽  
Economic Well Being

This study analyzes the effects of the economic sanctions against North Korea since 2016 on the economic well-being of North Korean cities. As a proxy for economic well-being, we use nighttime light (NTL), which we estimate from 1992 to 2019 through an inter-calibration process for DMSP/OLS and SNPP/VIIRS. We found that NTL in North Korea was getting brighter up until 2009, but that the growth rate of total NTL in 25 major North Korean cities began to decrease from 2016. The decline in the NTL growth rate of Pyongyang, the capital city, as well as in cities bordering China and in self-regenerating cities, was relatively slight. By contrast, the declines in the NTL growth rate of coal-mining cities and inland cities without sufficient production bases were greater than those in other cities, and some cities experienced negative growth in 2019. Cities in regions relying on coal mining have traditionally accounted for a large portion of North Korea's exports, and since these cities have been heavily affected by sanctions, coal mining could become a vulnerable sector, which would threaten North Korea's economic well-being.

scholarly journals ANALYSIS OF THE EFFICIENCY IN THE STRUCTURE OF FUNCTIONAL CONDITIONS IN COMMUNICATION WITH SOCIAL-PSYCHOLOGICAL QUALITIES OF WATCH EMPLOYEES OF THE MINING AND PROCESSING PLANT

2018 ◽  
Vol 97 (2) ◽  
pp. 149-155 ◽  
Author(s):  
Irina A. Porokhina ◽  
T. S. Voytekhovich ◽  
N. N. Simonova
Keyword(s):  
Shift Work ◽  
Right Hemisphere ◽  
Well Being ◽  
Professional Activity ◽  
Processing Plant ◽  
Social Psychological ◽  
Shift Workers ◽  
Professional Activities ◽  
Functional States ◽  
The Right

The authors prove the relevance of the study of the effectiveness of professional activities of employees in relation to personal characteristics and functional states in extreme conditions, especially in conditions of the shift work in the Far North. The purpose of the study was to analyze the interrelationship between the efficiency of professional activities of shift workers in a mining and processing factory with their social and psychological qualities and functional states during the shift-work period. Study group: 41 shift workers of the mining and processing factory of one of the diamondiferous deposits of the Arkhangelsk region. Methods of research included the psychological testing, set of psychophysiological techniques. The research show the social-psychological characteristics of the personality such as an evaluation of others as an etalon of oneself, moderate severity of altruistic type of attitude towards people, desire to achieve results in their activities at an average level, ability to control one’s feelings and emotions to be important for the effectiveness of the professional activity of shift specialists. The states of high effective workers are estimated at the level of the norm according to the indices of well-being and mood, the activity is estimated below the norm. The states of high-performance workers are also characterized by heteronomy and a strong degree of predominance of the right hemisphere. Average effective workers have a setting for the result at a level above the average, developed the ability to control one’s feelings, responsibility towards people. The states arising in the course of the labor activity, average-effective workers are estimated to be on average higher than the group of highly efficient workers. They are more autonomous and have a small degree of predominance of the right hemisphere. Employees, judged by experts as average-effective, resort to the use of the adaptation strategy for the emergency job, highly effective workers use economical strategy.

Nematodes and microbial community affect the sizes and turnover rates of organic carbon pools in soil aggregates

2018 ◽  
Vol 119 ◽  
pp. 22-31 ◽  
Author(s):  
Yuji Jiang ◽  
Haiyan Qian ◽  
Xiaoyue Wang ◽  
Lijun Chen ◽  
Manqiang Liu ◽  
...  
Keyword(s):  
Microbial Community ◽  
Organic Carbon ◽  
Soil Aggregates ◽  
Carbon Pools ◽  
Turnover Rates

scholarly journals Fecal Microbiotas of Indonesian and New Zealand Children Differ in Complexity and Bifidobacterial Taxa during the First Year of Life

2019 ◽  
Vol 85 (19) ◽  
Author(s):  
Blair Lawley ◽  
Anna Otal ◽  
Kit Moloney-Geany ◽  
Aly Diana ◽  
Lisa Houghton ◽  
...  
Keyword(s):  
New Zealand ◽  
Microbial Community ◽  
Early Life ◽  
Cultural Influences ◽  
Well Being ◽  
Rural Setting ◽  
First Year ◽  
Natural Ecosystem ◽  
Content Type ◽  
First Year Of Life

ABSTRACT The biological succession that occurs during the first year of life in the gut of infants in Western countries is broadly predictable in terms of the increasing complexity of the composition of microbiotas. Less information is available about microbiotas in Asian countries, where environmental, nutritional, and cultural influences may differentially affect the composition and development of the microbial community. We compared the fecal microbiotas of Indonesian (n = 204) and New Zealand (NZ) (n = 74) infants 6 to 7 months and 12 months of age. Comparisons were made by analysis of 16S rRNA gene sequences and derivation of community diversity metrics, relative abundances of bacterial families, enterotypes, and cooccurrence correlation networks. Abundances of Bifidobacterium longum subsp. infantis and B. longum subsp. longum were determined by quantitative PCR. All observations supported the view that the Indonesian and NZ infant microbiotas developed in complexity over time, but the changes were much greater for NZ infants. B. longum subsp. infantis dominated the microbiotas of Indonesian children, whereas B. longum subsp. longum was dominant in NZ children. Network analysis showed that the niche model (in which trophic adaptation results in preferential colonization) of the assemblage of microbiotas was supported in Indonesian infants, whereas the neutral (stochastic) model was supported by the development of the microbiotas of NZ infants. The results of the study show that the development of the fecal microbiota is not the same for infants in all countries, and they point to the necessity of obtaining a better understanding of the factors that control the colonization of the gut in early life. IMPORTANCE This study addresses the microbiology of a natural ecosystem (the infant bowel) for children in a rural setting in Indonesia and in an urban environment in New Zealand. Analysis of DNA sequences generated from the microbial community (microbiota) in the feces of the infants during the first year of life showed marked differences in the composition and complexity of the bacterial collections. The differences were most likely due to differences in the prevalence and duration of breastfeeding of infants in the two countries. These kinds of studies are essential for developing concepts of microbial ecology related to the influence of nutrition and environment on the development of the gut microbiota and for determining the long-term effects of microbiological events in early life on human health and well-being.

scholarly journals Plant-derived coumarins shape the composition of an Arabidopsis synthetic root microbiome

2019 ◽  
Vol 116 (25) ◽  
pp. 12558-12565 ◽  
Author(s):  
Mathias J. E. E. E. Voges ◽  
Yang Bai ◽  
Paul Schulze-Lefert ◽  
Elizabeth S. Sattely
Keyword(s):  
Microbial Community ◽  
Systematic Approach ◽  
Potential Role ◽  
Microbial Community Composition ◽  
Alkaline Soils ◽  
Arable Soils ◽  
Specialized Metabolites ◽  
Community Shifts ◽  
Root Microbiome

The factors that contribute to the composition of the root microbiome and, in turn, affect plant fitness are not well understood. Recent work has highlighted a major contribution of the soil inoculum in determining the composition of the root microbiome. However, plants are known to conditionally exude a diverse array of unique secondary metabolites, that vary among species and environmental conditions and can interact with the surrounding biota. Here, we explore the role of specialized metabolites in dictating which bacteria reside in the rhizosphere. We employed a reduced synthetic community (SynCom) of Arabidopsis thaliana root-isolated bacteria to detect community shifts that occur in the absence of the secreted small-molecule phytoalexins, flavonoids, and coumarins. We find that lack of coumarin biosynthesis in f6′h1 mutant plant lines causes a shift in the root microbial community specifically under iron deficiency. We demonstrate a potential role for iron-mobilizing coumarins in sculpting the A. thaliana root bacterial community by inhibiting the proliferation of a relatively abundant Pseudomonas species via a redox-mediated mechanism. This work establishes a systematic approach enabling elucidation of specific mechanisms by which plant-derived molecules mediate microbial community composition. Our findings expand on the function of conditionally exuded specialized metabolites and suggest avenues to effectively engineer the rhizosphere with the aim of improving crop growth in iron-limited alkaline soils, which make up a third of the world’s arable soils.

scholarly journals Phytate and Microbial Suspension Amendments Increased Soybean Growth and Shifted Microbial Community Structure

2021 ◽  
Vol 9 (9) ◽  
pp. 1803
Author(s):  
Bulbul Ahmed ◽  
Jean-Baptiste Floc’h ◽  
Zakaria Lahrach ◽  
Mohamed Hijri
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Bacterial Community ◽  
Indicator Species ◽  
Mycorrhizal Fungi ◽  
Rrna Gene ◽  
Soybean Plant ◽  
Trichoderma Spp ◽  
Undisturbed Soil ◽  
Microbial Suspension

Phytate represents an organic pool of phosphorus in soil that requires hydrolysis by phytase enzymes produced by microorganisms prior to its bioavailability by plants. We tested the ability of a microbial suspension made from an old growth maple forest’s undisturbed soil to mineralize phytate in a greenhouse trial on soybean plants inoculated or non-inoculated with the suspension. MiSeq Amplicon sequencing targeting bacterial 16S rRNA gene and fungal ITS was performed to assess microbial community changes following treatments. Our results showed that soybean nodulation and shoot dry weight biomass increased when phytate was applied to the nutrient-poor substrate mixture. Bacterial and fungal diversities of the root and rhizosphere biotopes were relatively resilient following inoculation by microbial suspension; however, bacterial community structure was significantly influenced. Interestingly, four arbuscular mycorrhizal fungi (AMF) were identified as indicator species, including Glomus sp., Claroideoglomus etunicatum, Funneliformis mosseae and an unidentified AMF taxon. We also observed that an ericoid mycorrhizal taxon Sebacina sp. and three Trichoderma spp. were among indicator species. Non-pathogenic Planctobacteria members highly dominated the bacterial community as core and hub taxa for over 80% of all bacterial datasets in root and rhizosphere biotopes. Overall, our study documented that inoculation with a microbial suspension and phytate amendment improved soybean plant growth.

Introduction

2016 ◽  
Author(s):  
Joseph D. Witt
Keyword(s):  
Elementary School ◽  
Coal Mining ◽  
Labor Unions ◽  
Processing Plant ◽  
Preparation Process ◽  
Coal Preparation ◽  
Political Pressure ◽  
Earthen Dam ◽  
Mountaintop Removal ◽  
Strip Mine

In the summer of 2009, I participated in a rally against mountaintop removal coal mining in Appalachia. The rally was held on the grounds of Marsh Fork Elementary, a school situated between the Coal River and Route 3 in Raleigh County, West Virginia. Sitting immediately below a slurry impoundment (a giant reservoir of toxic coal sludge produced by the coal preparation process and retained by an earthen dam), Marsh Fork Elementary also sat at the center of many debates surrounding the safety and justness of mountaintop removal. Activists cited increased health problems for Marsh Fork students due to their proximity to an active strip mine, such as abnormally high rates of asthma, and worried about the potentially disastrous consequences of any stresses or failures in the earthen dam retaining the slurry. The nearby mine and processing plant were owned and operated at the time by Massey Energy, one of the most controversial coal companies in the region. It was led by Don Blankenship, an outspoken and active opponent of labor unions and environmental regulations. Both Blankenship and his company were frequent targets for environmentalist outrage, and for his part, Blankenship seldom passed an opportunity to denounce “tree huggers” and others who, so he claimed, would destroy the jobs of hard-working Appalachian miners. In 2012 a new elementary school was built several miles from the original site, thanks to donations and ongoing political pressure; but in June 2009 these issues remained unsettled....

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