Razgradnja polimernih ugljikohidrata s pomoću bakterija mliječne kiseline

undergraduate thesis

• Title (english): Degradation of polymeric carbohydrates by lactic acid bacteria
• Author: Filip Cingesar
• 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: 2011-07-13, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Neke vrste bakterija mliječne kiseline, osim fermentativne, posjeduju i hidrolitičku aktivnost. Hidrolitička aktivnost ovih bakterija podrazumijeva amilolitičku, celulolitičku i/ili proteolitičku aktivnost. Ovaj dio fiziologije bakterija mliječne kiseline nije dovoljno istražen, pa zbog toga nije ni primijenjen u biotehnološkoj industrijskoj proizvodnji. Hidrolitičko-fermentativna aktivnost stanica ovih bakterija istražuje se za primjenu u jednostupanjskim bioprocesima proizvodnje različitih proizvoda iz polimernih supstrata (npr. škroba, celuloze i proteina) ili odgovarajućih sirovina. S pomoću ovih industrijskih mikroorganizama može se u jednostupanjskom bioprocesu (SSF) proizvesti mliječna kiselina koja je, između ostalog, i ishodišni spoj za sintezu polilaktata (PLA) i njihovih ko-polimera. Osim toga, istražuje se primjena ovih bakterija u visoko-učinkovitim jednostupanjskim bioprocesima proizvodnje alternativnih izvora energije. U takvom bioprocesu: (1) alge provode fotosintezu i nastaje glukoza, koja se polimerizira u molekule škroba; (2) amilolitička bakterija mliječne kiseline provodi hidrolizu škroba do glukoze i fermentaciju glukoze do mliječne kiseline; (3) uz prisustvo svjetlosti i mliječne kiseline, koja je donor elektrona, fotosintetska bakterija proizvodi vodik.

Abstract (english)

Some species of lactic acid bacteria, besides fermentative activity, posses also hydrolytic activity. The hydrolytic activity of this group of bacteria comprises amylolytic, celulolytic and/or proteolytic activity. This part of physiology of lactic acid bacteria has not been investigated in details and, therefore, implemented in biotechnological industrial production. Hydrolytic-fermentative activity of the bacterial cells has been investigated in order to be applied in single-step bioprocesses. In the bioprocesses different products can be yielded from polymeric substrates (e.g. starch, cellulose, and proteins) or corresponding raw materials. Lactic acid can be produced in the single-step bioprocess (SSF) by the industrial microorganisms. Among other uses, lactic acid is feedstock for synthesis of polylactides (PLA) and they co-polymers. Furthermore, the lactic acid bacteria are considered to be applied in highly-efficient single-step bioprocesses for production of alternative energy sources. In such bioprocess: (1) photosynthesis to glucose and polymerisation of glucose to starch is carried out by algae; (2) starch hydrolysis to glucose and fermentation of glucose to lactic acid is catalyzed by amylolytic lactic acid bacterium; (3) hydrogen is produced in the presence of light using lactic acid as electron donor by photosynthetic bacterium.

• Keywords: polimerni supstrati; obnovljive sirovine; bakterije mliječne kiseline; hidrolitičko-fermentativna aktivnost; proizvodnja mliječne kiseline i vodika
• Keywords (english): polymeric substrates; renewable raw materials; lactic acid bacteria; hydrolytic- fermentative activity; production of lactic acid and hydrogen
• Language: croatian
• URN:NBN: urn:nbn:hr:159:389418
• 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: 2017-05-18 11:47:48