Tag Archives: bacteria

256–269 M. Paiders, A. Gruduls, L. Kalnina, S. Valucka, I. Dimanta, J. Kleperis, and V. Nikolajeva
Biogas and hydrogen production from glycerol by Enterobacter aerogenes and anaerobic microbial communities
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Biogas and hydrogen production from glycerol by Enterobacter aerogenes and anaerobic microbial communities

M. Paiders¹*, A. Gruduls¹, L. Kalnina¹, S. Valucka¹, I. Dimanta¹², J. Kleperis², and V. Nikolajeva¹

¹University of Latvia, Faculty of Biology, Department of Microbiology and Biotechnology, Jelgavas street 1, LV-1004 Riga, Latvia
²University of Latvia, Institute of Solid State Physics, Laboratory of Hydrogen Energy Materials, Kengaraga street 8, LV-1063 Riga, Latvia
*Correspondence: matisspaiders@gmail.com

Abstract:

Biological hydrogen production by anaerobic fermentation of widely available renewable resources is a promising and advantageous area. Using microbiological hydrogen production from crude glycerol biodiesel-derived waste was utilized by obtaining renewable energy carrier. The purpose of this research was to study biogas and hydrogen production by Enterobacter aerogenes MSCL 758 and by natural microbial communities. Growth medium was supplemented with analytical grade, technical grade or crude glycerol. Inoculants from old municipal landfill, manure and lake sludge were also used. Biogas production was analyzed using Automatic Methane Potential Test System II. Part of the experiments were carried out in serum bottles and evolved gases were tested using mass-spectrometry. Fluorescence in situ hybridization was used for bacterial population dynamic determination. Optimal concentration for crude glycerol was found to be six grams per liter. Amount of hydrogen was significantly higher and amount of nitrogen gas was lower in case of analytical grade glycerol usage in comparison to crude glycerol fermentation. E. aerogenes acted in synergy with landfill substrate and manure in biogas production from technical grade and analytical grade glycerol. It was not the case for crude glycerol usage. Addition of E. aerogenes increased overall amount of produced hydrogen. Obtained results showed potential of E. aerogenes for use in bioaugmentation purposes for fermentation of glycerol. Lake sludge inoculum contained microorganisms necessary for the production of hydrogen as well as biogas from glycerol. Clostridia and Gammaproteobacteria were predominant in the inoculum. Cultivable bacteria Bacillus licheniformis, Burkholderia cepacia, Hafnia alvei and unidentified Clostridium species were found to be predominant after six days of fermentation.

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236-254 K. Ritslaid, A. Küüt and J. Olt
State of the Art in Bioethanol Production
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State of the Art in Bioethanol Production

K. Ritslaid¹, A. Küüt² and J. Olt²

¹ Estonian Aviation Academy,
58A Kreutzwaldi Str., EE51014 Tartu, Estonia;
² Institute of Technology, Estonian University of Life Sciences,
56 Kreutzwaldi Str., EE51014 Tartu;
e-mail, arne.kyyt@emu.ee

Abstract:

The objective of the present study is to provide an overview of available literature on problems and potential solutions in bioethanol production. The preparation of an overview of bioethanol as motor fuel requires knowledge of its chemical-physical properties and different production methods. The study points out the most popular opinions and test results to characterise the production of bioethanol. This overview considers potential methods for producing ethanol and production technologies suitable for ethanol as motor fuel, especially most recent achievements in converting carbohydrates into ethanol.

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97-107 E. Bakšienė, A. Ražukas, T.L. Nedzinskienė,O. Salina and J. Repečkienė
Influence of various farming systems on agrochemical indices and amount of microorganisms in Haplic Luvisol
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Influence of various farming systems on agrochemical indices and amount of microorganisms in Haplic Luvisol

E. Bakšienė¹, A. Ražukas¹, T.L. Nedzinskienė¹,O. Salina² and J. Repečkienė²

¹Voke Branch of Lithuanian Institute of Agriculture, Žalioji a. 2, Trakų Vokė,LT-02232 Vilnius; e-mail: eugenija.baksiene@voke.lzi.lt
²Institute of Botany, Žaliųjų Ežerų 49, LT-08406, Vilnius;e-mail: olga.salina@botanika.lt

Abstract:

The article presents data from a study comparing the influence on plant productivity of three different farming systems – ecological, sustainable and chemical – and the use of various plants grown for green manure. Crops were lupine, white mustard and red clover. Calculations of the nutritional content of the soil in the experiments show that various crop rotations (treatments) affect the phosphorus and potassium balance.The data indicate that productivity of plant rotations depends on the plants cultivated andthe applied farming system. In all farming systems, the highest yield was achieved cultivating plants after fertilization with green manure (lupines and white mustard). The results of the experiments show that crop rotations result in negative nitrogen, phosphorus (except in sustainable and chemical farming systems) and potassium balance in the soil.Crop rotations had no effect on the soil acidity and increased total nitrogen and organiccarbon content in the soil. The amount of phosphorus in the soil increased in all farming systems; potassium increased only in the sustainable and chemical farming systems.Data indicating the number of micromycetes, organic and mineral nitrogen assimilatingbacteria in the rizosphere soil of various grown plants are also presented.

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