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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A study of the ecology and taxonomy of Micromonospora in the natural environment

Mullins, Jane A. January 1993 (has links)
No description available.
2

Fixation of nitrogen by algae and associated organisms in semi- arid soils: identification and characterization of soil organisms /

Cameron, R. E. January 1958 (has links) (PDF)
Thesis (M.S. - Agricultural Chemistry and Soils)--University of Arizona. / Bibliography: leaves 106-129.
3

A characterization of bacteria populations from two sites /

Stanley, Lynn, January 1998 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 161-182). Also available on the Internet.
4

A characterization of bacteria populations from two sites

Stanley, Lynn, January 1998 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 161-182). Also available on the Internet.
5

Karakterizacija bioremedijacionih procesa u zemljištu i podzemnim vodama zagađenim naftom i derivatima na lokalitetu Ratno ostrvo / Characterisation of the bioremediation processes in soil and groundwater contaminated by oil and oil derivatives at the site of Ratno Ostrvo

Rončević Srđan 01 June 2007 (has links)
<p>Predmet izučavanja ove disertacije je pasivna bioremedijacija naftom i derivatima nafte&nbsp;zagađenih podzemnih voda na lokalitetu&nbsp; Ratno ostrvo i pospe&scaron;ivanje procesa&nbsp;<br />bioremedijacije zemlji&scaron;ta i podzemne vode zagađenih naftom i derivatima nafte na&nbsp;laboratorijskom postrojenju u ciljusanacije ugroženog lokaliteta.</p><p>Praćenjem podzemnih voda granične zone izvori&scaron;ta Ratno ostrvo i Rafinerije nafte&nbsp;utvrđeno je da je u podzemnoj vodi granične zone izvori&scaron;ta Ratno ostrvo i Rafinerije&nbsp;nafte Novi Sad prisutan proces pasivnebioremedijacije, odnosno, da na pojavu&nbsp;ugljovodoničnog zagađenja u vodi sredina odgovara povećanjem brojnosti, pre svega,&nbsp;ugljovodonik-osidujućih i lipolitskih bakterija i bakterijske enzimatske aktivnosti, i&nbsp;dolazi do transformacije mineralnih ulja u polarna jedinjenja. U vodi većine praćenih&nbsp;objekata uočene su eksponencijalne i linearne funkcionalne zavisnosti bakterijske&nbsp;brojnosti i fosfatazne aktivnosti od koncentracije ugljovodoničnog zagađenja za&nbsp;koncentracije ukupnih ugljovodonika &lt; 400 &micro;g/l (najče&scaron;će &lt; 200 &micro;g/l). Visok nivo&nbsp;podzemnih voda i prisustvo dela zagađenja u gornjim slojevima zemlji&scaron;ta ukazuje nam&nbsp;na mogućnost primene fitoremedijacije navedenog područja, jer je deo zagađenja&nbsp;dostupan korenskom sistemu.</p><p>Ispitivanjem tehničke bioremedijacije zemlji&scaron;ta i podzemne vode zagađenih naftom i&nbsp;<br />derivatima nafte&nbsp; na laboratorijskom postrojenju utvrđeno je da dolazi do opadanja&nbsp;<br />koncentracije ukupnih ugljovodonika u zemlji&scaron;tu sa 38,2 na 14,6 g/kg i mineralnih ulja&nbsp;sa 27,0 na 10,2 g/kg (62%), &scaron;to se može definisati jednačinom C=C<sub>0</sub>e<sup>-kt</sup>, gde je&nbsp;<br />konstanta brzine degradacije ugljovodonika k=0,0082 dan<sup>-1</sup>. U vodi je prisutan veliki&nbsp;<br />broj karboksilnih kiselinanastalih oksidacijom alkana (C10-19), kao i aromata&nbsp;(benzoeva kiselina, kao i benzaldehid), &scaron;to ukazuje na proces biooksidacije&nbsp;ugljovodonika. Proces rastvaranja i emulgovanja nafte se pospe&scaron;uje uvođenjem&nbsp;recirkulacije vode: određena je jednačina zavisnosti koncentracije ugljovodonika u&nbsp;vodenoj fazi od koncentracije u&nbsp; čvrstoj fazi, zavisno od&nbsp; brzine proticanja:&nbsp;C<sub>voda</sub>=(f<sup>*</sup>v+K<sub>0</sub>)C<sub>zemlja</sub>, gde je koeficijent ispiranja f=1400 s/m, a difuzioni koeficijent&nbsp;K<sub>0</sub>=6<sup>*</sup>10<sup>-4</sup>. Proces ispiranja nafte i derivata sa zemlje značajno utiče na aktivnost&nbsp;mikroorganizama i razgradnju zagađenja. Sa porastom koncentracije ugljovodonika&nbsp;generalno opadaju brojnosti svih ispitivanih grupa bakterija i fosfatazna aktivnost i&nbsp;određene su granične vrednosti tolerancije. Proces ispiranja se &nbsp;mora voditi tako da&nbsp;koncentracija mineralnih ulja u vodenoj fazi netreba da pređe 15-35 mg/l, a kad se&nbsp;postignu koncentracije ugljovodonika manje od 400 &micro;g/l treba prepustiti pasivnoj&nbsp;bioremedijaciji da ukloni zagađenje.</p> / <p>This dissertation investigates the passivebioremediation of groundwater from Ratno&nbsp;Ostrvo contaminated by oil and oil derivatives, and a bench-scale experiment to improve the soil and groundwater bioremediation processes, with the goal of sanatising the effected area.</p><p>During groundwater monitoring of the zone between the Ratno Ostrvo spring and the&nbsp;Novi Sad oil refinery, a passive bioremediation process was observed, whereby, &nbsp;in the hydrocarbons-contaminated water, increased counts of hydrocarbon-oxidising and lipolytic bacteria and increasing bacterial enzyme activity were found, along with the transformation of mineral oils to polar&nbsp; compounds. In water, the majority of the&nbsp;monitoring points displayed either exponential or linear functionalal dependence&nbsp; between bacterial count or phosphatase activity and hydrocarbon concentration, for&nbsp; total hydrocarbon concentrations &lt; 400 &micro;g/l (most often &lt; 200 &micro;g/l). The high groundwater level and the presence of contamination inthe upper soil layers makes possible the application of phytoremediation at the site, as part of the contamination is in the rhyzosphere.</p><p>The bench-scale investigation of bioremediation in soil and groundwater contaminated by oil and oil derivatives yielded decreasing concentrations of total hydrocarbons in the soil from 38.2 to 14.6 g/kg and mineral oils from 27.0 to 10.2 g/kg&nbsp; (62%), which can be described by C=C<sub>0</sub>e<sup>-kt</sup>, where the rate constant of&nbsp; hydrocarbon degradation is k=0.0082 day<sup>-1</sup>.</p><p>In water, a large number of carboxylic acids were present, from the oxidation of&nbsp; alkanes (C10-19) and aromatics (benzoic acid, and also benzaldehyde), which indicates a hydrocarbon biooxidation process. The process of dissolving and emulgating the oil is enhanced by recirculating the water: the linear relation between the concentration of hydrocarbons in the liquid and solid phases was found to be dependent on the flow rate: C<sub>water</sub>=(f<sup>*</sup>v+K<sub>0</sub>)C<sub>soil</sub>, where the rinsing coefficient f=1400 s/m, and the diffusion coefficient K<sub>0</sub>=6 x 10<sup>-4</sup>. The process of rinsing the oil and oil derivatives from the soil significantly influences the microbial activity and the degradation of contaminants. With increasing hydrocarbon concentrations, there was&nbsp; generally decreasing bacterial counts and phosphatase activity, and an upper limit for&nbsp; hydrocarbon tolerance was determined. The rinsing process must becontrolled to&nbsp; ensure the mineral oil concentration in water does not exceed 15-35 mg/l, and once the concentration of hydrocarbons becomes less than 400&micro;g/l, passive bioremediation may be left to complete the degradation.</p>
6

Lignocellulosic materials coated with Trichoderma atroviride SC1 increase its persistency in the soil and impact soil microbiota

Chammem, Hamza 14 April 2022 (has links)
Trichoderma atroviride SC1 (SC1) was isolated from hazelnut wood and it is effective in the biocontrol of soil-borne pathogens. However, its effectiveness decreases as its population declines in the soil over time. To improve its persistency in the soil, lignocellulosic materials (wood pellets) were tested to be used as carriers to sustain the population of SC1 and facilitate its incorporation into the soil. A method was developed to coat wood pellets of fir, beech, and chestnut with a conidial suspension to reach a preset concentration (i.e. 10^4, 10^5, and 10^6 cfu/ g of wood). The growth of SC1 on each type of wood was compared. Chestnut pellets were excluded from further experiments because they had low counts of colony-forming units (cfu) of SC1. Beech pellets were preferred over fir pellets for showing more suitable physicochemical characteristics for soil application. In addition, for the same wood type, increased initial coating concentrations did not impact the final colony counts of SC1 and no significant difference was observed between the counts of 10^4, 10^5, and 10^6 cfu/g of wood at the end of the experiment. The addition of small quantities of nitrogen increased the final cfu on all types of wood pellets. The growth of SC1 on beech pellets was then tested by adding cheap nitrogen sources namely, soy flour, soy protein isolates, and proteins that originated from animal wastes. The best results were obtained with soy protein isolates (1 g/L) and the population of SC1 reached 10^9 cfu/ g of beech wood. Finally, this carrier of coated beech pellets with soy protein isolates was tested in the soil under controlled conditions, in an experimental greenhouse at 25°C and 60% of soil humidity. The pellets were coated to reach a final concentration of 5×10^5 cfu/ g of beech and 10 g of beech coated pellets were mixed with 1 kg of soil in plastic pots to reach the final concentration of 5×10^3 cfu/ g of soil. The carrier increased the bacterial richness and diversity of the soil and decreased the fungal ones. The total Trichoderma population persisted in the first month and then declined after three months with competition from other bacteria such as Massilia spp. and fungi such as Stachybotrys spp. and Mortierella spp.
7

Vliv dominantní dřeviny a zrnitosti substrátu na složení mikrobiálního společenstva studovaného pomocí PLFA / The influence of the dominant trees and grain substrate the composition of the microbial community studied by PLFA

Stachová, Sandra January 2016 (has links)
The aim of the thesis was to analyze soil microbial communities of three ecologically different locations, about 25 years old, forestry reclaimed dumps in the Republic of Poland, namely dumps of brown coal mine Bełchatów and sand mines Piaseczno and Szczakowa. I evaluated the degree of dependence of structure and composition of these communities on various substrate grain sizes and the influence of the dominant tree species. These were stands of birch (Betula pendula), pine (Pinus silvestris), oak (Quercus robur) and alder (Alnus glutinosa). Analysis of soil microbial communities was made by evaluating specific phospholipid fatty acids (PLFA) of microorganisms. It is the most appropriate way to implement the relatively rapid analysis of large numbers of samples, since PLFA are easily extractable and act as biomarkers indicating the presence of a number of different microorganisms (fungi, G- and G + bacteria, Actinobacteria, etc.) and thus allowing a qualitative and quantitative assessment of whole microbial communities. PLFA analysis enables to detect a total concentration of PLFA only in living soil microbial biomass. I analyzed 66 soil samples, 33 from an Oe layer and 33 from an A layer, every in three replications, i.e. three replications were collected at each location below each tree...

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