Wyniki wyszukiwania - BazTech

1

Research on the effects of rare earth combined contamination on soil microbial diversity and enzyme activity

Jiang Ying, Wang Xuemei, Chen Yunzhu, Nengzi Lichao

Ecological Chemistry and Engineering. S

|

2022

|

Vol. 29, nr 2

227--236

EN

Soil microorganisms and soil enzyme activities are important indexes to evaluate soil status. The soil pollution status was evaluated by measuring the physical and chemical properties and heavy metal content of rare earth combined contaminated soil around the Maoniuping old mining area and tailings ponds in different seasons, and measuring the number and diversity of microorganisms and the soil enzyme activities of the arable soil microecology. This research shows that the physical and chemical properties of farmland soil in old mining areas and tailings ponds in different seasons are significantly different, the concentration of rare earth combined contamination in old mines is greater than that in the tailings area, and the changes in the concentration of rare earth combined contamination cause significant changes in soil microecology. Rare earth combined contamination inhibits fungal and bacterial vital activities and promotes the growth of actinomycetes; reduces the sensitivity of sucrase to heavy metal contamination, promotes the activity of phosphatase, and the effect on urease is that of “promotion at low concentration and inhibition at high concentration”; and reduces the community’s ability to use carbon sources and, as a result, the community species are rare and distributed unevenly and the community structure is simple. These results indicate that rare earth combined contamination is potentially harmful to soil microorganisms, which can provide a theoretical basis for the ecological restoration of farmland soil in mining areas.

2

Morphology analysis and microbial diversity in novel anaerobic baffled reactor treating recycled paper mill wastewater

Zwain Haider M., Al-Marzook Farah A., Nile Basim K., Jeddoa Zuhair Mohammed Ali, Atallah Aqeel H., Dahlan Irvan, Hassan Waqed Hammed

Archives of Environmental Protection

|

2021

|

Vol. 47, no. 4

9--17

EN

The profile of microbial diversity in a NABR digesting RPMW was investigated using phylogenetic analysis of partial 16S rRNA sequences by a neighbor-joining-tree, supported by microbial morphology analysis by SEM. The results showed that microorganism inside NABR consisted of dominant Bacillus (25 strains) and Bacterium (1 strain) which were isolated from the settled sludge at the bottom of the reactor, whilst Bacillus (2 strains), Pseudomonas (2 strain) and Chryseobacterium (2 strain) were isolated from the biofilm formed on the packing material. It revealed that the microbial community strains, function, and structure changed simultaneously throughout the reactor system. The microscopic results showed rich biofacies, while the dominant microorganisms have various morphologies in every compartment of the system. It consisted of a long rod-shaped and filamentous bacterium composed majorly of bacilli of different sizes. Although the study successfully analyzed the microbial diversity and morphology in the system, the microbial communities reported in this study were different from other similar studies. This may be caused by the application of a culture-based technique that usually provides limited information due to the number of barely cultivated or uncultured strains.

3

Microbial diversity of sewage sludge

Błaszczyk K., Krzyśko-Łupicka T.

Proceedings of ECOpole

|

2013

|

Vol. 7, No. 2

461--466

EN

Sewage sludge may be a cluster of different groups of microorganisms, including potential pathogenic, therefore processing of sludge should be conducted in a manner that protects workers and the environment from the sanitary risks. The aim of the study was to assess quantitatively and qualitatively the microbial diversity of the municipal sewage sludge, from the food industry and from the coke after the treatment, with the addition of flocculant and/or lime. Research material consisted of samples taken directly from the wastewater treatment plant. Quantitative and qualitative assessment of mesophilic and psychrophilic bacteria, yeasts, filamentous fungi and potentially pathogenic microorganisms was performed by a culture method. Techniques for treatment sewage sludge towards their hygenisation and reduce the amount of sediment by supporting flocculants and/or liming affect the quantitative and qualitative microorganisms composition. In the studied sewage sludge dewatered using a flocculant, with the exception of sediments from the food industry, there was the highest total number of microorganisms, both meso- and psychrophilic bacteria, yeast, filamentous fungi and potentially pathogenic bacteria. However, in the sediments of the food industry increase in the number of bacteria was observed only after simultaneous application of liming. Among the isolated microorganisms, depending on the origin of the sludge there was a domination of gram negative rods, with the exception of coke sediments without a flocculant. The municipal and from the food industry sediments were dominated by fungi: Aspergillus niger and Cladosporium sp., in coke sediments Aspergillus amstelodami, Paecilomyces javanicus and Acremonium sp. In these latter was also observed the greatest diversity of yeasts.

PL

Osady ściekowe mogą być skupiskiem różnych grup mikroorganizmów, w tym potencjalnie chorobotwórczych, dlatego ich przeróbka powinna być prowadzona w sposób chroniący pracowników i środowisko przed zagrożeniem sanitarnym. Celem badań była mikrobiologiczna ocena ilościowa i jakościowa osadów ściekowych komunalnych i pochodzących z przemysłu spożywczego oraz koksowni po przeróbce z dodatkiem flokulantu i/lub wapna palonego. Materiał badawczy stanowiły próbki pobrane bezpośrednio z oczyszczalni ścieków. Ocenę ilościową i jakościową bakterii mezofilnych i psychrofilnych, drożdży, grzybów strzępkowych oraz mikroorganizmów potencjalnie chorobotwórczych przeprowadzono metodą hodowlaną. Techniki przeróbki osadów ściekowych w kierunku ich higienizacji oraz zmniejszenia ilości osadów poprzez wspomaganie flokulantami i/lub wapnowanie miały wpływ na skład ilościowy i jakościowy mikroorganizmów. W badanych osadach ściekowych odwadnianych flokulantem, z wyjątkiem osadów z przemysłu spożywczego, występowała najwyższa ogólna liczba mikroorganizmów, zarówno bakterii mezo-, jak i psychrofilnych, drożdży i grzybów strzępkowych oraz bakterii potencjalnie chorobotwórczych. Natomiast w osadach przemysłu spożywczego wzrost liczebności bakterii obserwowano dopiero po równoczesnym zastosowaniu wapnowania. Wśród wyizolowanych mikroorganizmów, w zależności od pochodzenia osadu ściekowego, stwierdzono dominację pałeczek gram-ujemnych z wyjątkiem osadów koksowniczych bez flokulantu. W osadach komunalnych i pochodzenia spożywczego dominowały grzyby: Aspergillus niger oraz Cladosporium sp., a w osadach koksowniczych Aspergillus amstelodami, Paecilomyces javanicus i Acremonium sp. W tych ostatnich obserwowano również największą różnorodność drożdży.

4

The effect of some technological parameters on the diversity of immobilized microorganisms

Zielińska M., Cydzik-Kwiatkowska A., Wojnowska-Baryła I.

Archives of Environmental Protection

|

2009

|

Vol. 35, no. 1

45-53

EN

The effect of hydraulic retention time (HRT) and internal circulation capacity (q(.) on microbial diversity of immobilized biomass in the porous ceramic carrier was determined. The bioreactor, operating at HRT of 70 and 60 min, and with q(, in the range of 20-70 dm-'-h"1, was employed for the removal of organic compounds from municipal wastewater. Microbial diversity was estimated on the basis of RISA patterns using the Shannon-Wiener index (H'). At HRT of 70 min, H' lowered from 2.48 š 0.14 to 2.13 š 0.23 as q(. was increased from 20 to 60 dm'-h"1. At HRT of 60 min, an increase in q(. from 40 to 70 dm'-h"1 resulted in H' drop from 2.41 š 0.13 to 2.08 š0.19. At every HRT the highest efficiency of removal of organic compounds was obtained at the lowest value of qc and the highest biomass diversity.

PL

Celem pracy było określenie wpływu hydraulicznego czasu zatrzymania (HRT) i wydajności cyrkulacji wewnętrznej (q_c) na różnorodność mikroorganizmów w biomasie unieruchomionej w porowatym nośniku ceramicznym. Bioreaktor, wykorzystywany do usuwania związków organicznych ze ścieków komunalnych, był eksploatowany przy HRT 70 i 60 min oraz q_c, w zakresie 20-70 dm^33h^-1. Różnorodność mikroorganizmów była określana na podstawie wzorów RISA przy użyciu indeksu Shannona-Wienera (H'). Przy HRT równym 70 min, II' obniżył się z 2,48 š 0,14 do 2,13 š 0,23 ze wzrostem q(. z 20 do 60 dm-'-lv1. Przy HRT 60 min, zwiększenie qt. z 40 do 70 dm^3h^-1 spowodowało spadek II' z 2,41 š 0,13 do 2,08 š 0,19. Przy każdej wartości HRT, najwyższą efektywność usuwania związków organicznych uzyskano przy najniższej wartości q_c. i najwyższej bioróżnorodności.

5

Biodiversity of freshwater microorganisms - achievements, problems, and perspectives

Weisse Thomas

Polish Journal of Ecology

|

2006

|

Vol. 54, nr 4

633-652

EN

The extent and significance of the diversity of freshwater microbes is at present controversially debated. Until 1980 it was assumed that there are no freshwater-specific bacteria and that the total number of bacterial species is low. The advent of molecular tools over the last ten years revealed that there is a bacterial freshwater assemblage which is phylogenetically different from soil and marine bacteria; secondly, it became obvious that the total number of cultured bacterial species ([similar to] 5900) underestimates bacterial diversity by several orders of magnitude. The current debate centres on 1) how to define a bacterial species and 2) if there is a microbial biogeography. The latter relates to the issue of ubiquity and cosmopolitanism, which is controversially discussed primarily in relation to eukaryotic microorganisms, namely ciliates. Although solid evidence is scarce, many microbial ecologists assume, in accordance with Baas Becking's famous 70-year old dictum - "everything is everywhere, the environment selects" - that freshwater microorganisms are easily dispersed and, therefore, potentially cosmopolitan. This review focuses on the often neglected second part of Baas Becking's metaphor. Evidence is accumulating rapidly that the environment does not simply act as a filter sensu Gleason's individualistic concept for widely dispersed microbes. Rather, prokaryotic and eukaryotic microorganisms have adapted to their specific habitat and perform better in this environment than newly invading congeners. There is an enormous ecophysiological diversity among closely related freshwater microbes which is neither obvious at the morphospecies level nor at the level of evolutionarily conserved genes, such as the small ribosomal RNA gene. Although this large diversity has been demonstrated for various groups of bacteria and protists, there is currently no measure available to compare microbial biodiversity across prokaryotic and eukaryotic domains. The current challenge is to link genetic divergence to ecophysiological diversity in the major taxa.