0000000000287380
AUTHOR
Ilze Dimanta
Changes in freshwater sediment microbial populations during fermentation of crude glycerol
This work was supported by the Latvian Council of Science , project NN-CARMA, project No. lzp-2018/1-0194.
Testsistēmas izveide baktēriju ūdeņraža producēšanas spējas novērtēšanai.
Ūdeņraža gāzi var iegūt fermentācijas procesā, baktērijām sadalot organiskas vielas anaerobos apstākļos. Tālākai izmantošanai ūdeņradi šādās sistēmās ievāc no gāzes fāzes, kur tas izdalās no baktēriju kultivēšanu vides. Lai optimizētu ūdeņraža iegūšanu, nepieciešams izsekot ūdeņraža veidošanās procesam šķidrajā fāzē. Darba gaitā izveidotas un darbībā pārbaudītas vairākas laboratorijas testsistēmas, lai novērtētu ūdeņraža veidošanos enterobaktēriju barotnē, kā arī noformulēti ieteikumi šo sistēmu pilnveidošanai. Ūdeņraža producēšanai izmantots Escherichia coli celms, kuru lieto kā references kultūru ūdens sanitārajā analīzē. Izšķīdušā ūdeņraža mērījumiem izmantoti Klarka tipa elektrodi – mik…
Influence of the initial acidification step on biogas production and composition
Laboratory-scale experiments were carried out to evaluate the effect of initial acidification of feedstock consisting of different components on biogas production and composition. Feedstock containing different agricultural wastes, biomass, and microorganisms was collected from five full-scale biogas plants. Two continuously stirred tank reactors were used. The fermentation temperature was 37 °C. The pH value was adjusted to 6.0 in the first reactor at the beginning of the experiment, and an initial pH value of 7.0 was implemented after 48 H. The second reactor was used as a control reactor with a constant pH of 7.0. The experiment lasted a total of 7 days. In the reactors, the gas phase wa…
Hydrogen-producingEscherichia colistrains overexpressing lactose permease: FT-IR analysis of the lactose-induced stress
The lactose permease gene (lacY) was overexpressed in the septuple knockout mutant of Escherichia coli, previously engineered for hydrogen production from glucose. It was expected that raising the lactose transporter activity would elevate the intracellular lactose concentration, inactivate the lactose repressor, induce the lactose operon, and as a result stimulate overall lactose consumption and conversion. However, overexpression of the lactose transporter caused a considerable growth delay in the recombinant strain on lactose, resembling to some extent the "lactose killing" phenomenon. Therefore, the recombinant strain was subjected to selection on lactose-containing media. Selection on …
Solution to Urban Air Pollution – Carbon Free Transport
Abstract The analysis of the results of long-term air quality monitoring in Riga is presented, which shows that in city centre throughout the measurement time (2004-2014) according to the guidelines defined by the European Union directives and Latvian laws the limits of small particles PM10 and nitrogen dioxide (NO2) are exceeded. From the nature of appearance of pollution and from the research of morphology and composition of fine dust particles it was concluded that in the city centre where the monitoring was performed the main air pollutants are caused by internal combustion engine vehicles. The measures to reduce air pollution performed by two Action Programs (2004-2009; 2011-2015) of t…
Analysis of the Role of the Latvian Natural Gas Network for the use of Future Energy Systems: Hydrogen from Res
The research has been funded by the Ministry of Economics of the Republic of Latvia, project “Trends, Challenges and Solutions of Latvian Gas Infrastructure Development (LAGAS)”, project No. VPP EM-INFRA-2018/1-0003.
Jēlglicerīna, laktozes izmantošana bio-ūdeņraža iegūšanai ar anaerobām mikroorganismu kultūrām un ūdeņraža savākšana no fermentācijas barotnes ar metālhifrīdiem
Elektroniskā versija nesatur pielikumus
Metal hydride alloys for storing hydrogen produced by anaerobic bacterial fermentation
Abstract This study reports on hydrogen sorption from bacterial fermentation media with powdered palladium (Pd) and alloys (LaNi5, AB5, and AB2) that are capable of forming hydrides. Mass changes of the powders after incubation in fermentation media were measured by differential thermogravimetry. Composition and concentrations of the gases accumulated during fermentation and absorbed by Pd or the alloys were analyzed by mass spectrometry. The results demonstrated that hydrogen (H2) was absorbed and stored by powdered Pd and alloys directly from nutritional broth. The best sorption was obtained with Pd, followed by alloys AB5 and AB2. Scanning electron microscopy revealed that bacteria were …