Author, institution: Dalia Čižeikienė, Kaunas University of Technology
Science area, field: Technological Sciences, Chemical Engineering
The Doctoral Dissertation is available at the library of Kaunas University of Technology (K. Donelaičio St. 20, Kaunas).
Scientific Supervisor:
Prof. Dr. Habil. Gražina JUODEIKIENĖ (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T).
Dissertation Defense Board of Chemical Engineering Science Field:
Prof. Dr. Jolanta LIESIENĖ (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T) – Chairperson;
Dr. Ina JASUTIENĖ (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T);
Assoc. Prof. Dr. Rima KLIMAVIČIŪTĖ (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T);
Prof. Dr. Mindaugas MALAKAUSKAS (Academy of Veterinary of Lithuanian University of Health Sciences, Agricultural Sciences, Veterinary Medicine – 02A);
Assoc. Prof. Dr. Vytautas RUZGAS (Lithuanian Research Centre for Agriculture and Forestry, Institute of Agriculture, Agricultural Sciences, Agronomy – 01A).
Annotation:
The aim of the thesis was to determinate the antimicrobial and phytase activities of lactic acid bacteria (LAB) isolated from sourdough and to assess the use opportunities of bacteriocins producing LAB in order to reduce biological pollution of summer wheat grain seeds in the organic farming and in order to increase the nutritional value and safety of bakery products. Antimicrobial activity of bacteriocins producing LAB against the microorganism of grain seeds and causing food spoilage was determinate. The influence of nutrients of media and fermentation conditions on antimicrobial activity of bacteriocins like inhibitory substances was evaluated. LAB with phytase activities from industrial sourdough were isolated, genetically identified and assessed their phytase activity (intracellular and extracellular); as well as phytase activity of LAB that produce bacteriocins were evaluated. The usability of selected LAB with phytase activity by imitating the environment pH of the digestive tract, in order to increase the biologically available minerals from whole-grain wheat bread was assessed. For expanding the scope for the use of these LAB’s in organic farming for reduction of biological pollution of the wheat grain seeds new bioproducts were developed. The new bioproducts allows reducing on the grain surface Fusarium, Alternaria, Cochliobolus sativus infection, the diseases of root and the lesion of seeds by Fusarium genera and Cochliobolus sativus fungi. The attention was paid to bacteriophages of sourdough as well, because their infection can cause serious problems in fermentation processes as the viral particles can reduce, or even stop, the activity of fermentative bacteria.
