Rast bakterije Leuconostoc mesenteroides LMG 7954 pri različitim uvjetima šaržnog uzgoja

undergraduate thesis

• Title (english): Growth of bacterium Leuconostoc mesenteroides LMG 7954 during batch cultivation under different conditions
• Author: Iva Blašković
• Mentor: Anita Slavica (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Biochemical Engineering, Industrial Microbiology and Malting and Brewing Technology); Zagreb
• Defense date and country: 2019-07-15, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Fiziološki potencijal bakterija mliječne kiseline nedovoljno je istražen i primijenjen u biotehnološkoj industrijskoj proizvodnji različitih proizvoda. Neka najnovija istraživanja ukazuju na robusnost ovih bakterija i njihovu potencijanu primjenu u proizvodnji vrlo vrijednih biokemikalija kao i drugih proizvoda, koji su inače izvanredno prihvaćeni na tržištu. U ovom radu istraživana je mogućnost soja Leuconostoc mesenteroides LMG 7954 da osim glukoze koristi i saharozu kao izvor ugljika i energije. Kreirani su mikroaerofilni i aerobni uvjeti šaržnog uzgoja ovog soja u laboratorijskom mjerilu i praćena je krivulja rasta ove heterofermentativne bakterije mliječne kiseline. Osim toga, preživljavanje L. mesenteroides LMG 7954 okarakterizirano je u reakcijskoj smjesi s visokim koncentracijama glicerola (c = 2,0 mol/L), još jednog potencijalnog izvora ugljika za ovaj soj, i saharoze (c = 0,8 mol/L). U ovoj reakcijskoj smjesi visokog osmotskog tlaka bakterijske stanice iz polovice eksponencijalne faze rasta tretirane su ultrazvukom. Na temelju eksperimentalnih rezultata procijenjeni su trajanje faza rasta i specifična brzina rasta soja L. mesenteroides LMG 7954 pri odabranim uvjetima šaržnog uzgoja, koji predstavljaju izvrsnu polaznu točku za daljnja istraživanja fiziologije ovog soja i njezinu primjenu u održivoj biotehnološkoj proizvodnji proizvoda i usluga visoke dodane vrijednosti.

Abstract (english)

Physiological potential of lactic acid bacteria has been insufficiently investigated and implemented in biotechnological industrial production of different products. Few latest investigations indicate robustness of those bacteria as well as their potential applications in manufacturing of value added biochemicals and other products that are remarkably accepted in a market. In this work a capacity of a strain Leuconostoc mesenteroides LMG 7954 to use sucrose, besides glucose, as a source of carbon and energy was explored. Microaerophilic and aerobic conditions of laboratory scale batch cultivations were created and a growth curve of those heterofermentative lactic acid bacterium was followed. Besides, survival of L. mesenteroides LMG 7954 in a reaction mixture containing high concentration of glycerol (c = 2,0 mol/L), another potential source of a carbon for the strain, and sucrose (c = 0,8 mol/L) was characterized. In this reaction mixture with high osmotic pressure bacterial culture with the cells from the middle of exponential growth phase were treated by ultrasound. Duration of growth phases and specific growth rate of the strain L. mesenteroides LMG 7954 were estimated based on the experimental results obtained under selected conditions of batch cultivations. Obtained values represents excellent starting point for further investigations of physiology of the strain and its implementation in sustainable biotechnological production of different products and high added value utilities.

• Keywords: bakterije mliječne kiseline; Leuconostoc mesenteroides LMG 7954; šaržni uzgoj; tretman ultrazvukom
• Keywords (english): lactic acid bacteria; Leuconostoc mesenteroides LMG 7954; batch cultivation; ultrasound treatment
• Language: croatian
• URN:NBN: urn:nbn:hr:159:659762
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2019-07-26 07:50:24