Razvoj novoga bioprocesa proizvodnje mliječne kiseline

doctoral thesis

• Title (english): Development of novel bioprocess for lactic acid production
• Author: Antonija Trontel
• Mentor: Srđan Novak (mentor)
• Committee member: Jagoda Šušković (predsjednik povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; Zagreb
• Defense date and country: 2013-05-21, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology
• Universal decimal classification (UDC): 66 - Chemical technology. Chemical and related industries

Abstract

Razvijen je novi bioproces za proizvodnju D-/L-mliječne kiseline, koji pripada bioprocesima simultane saharifikacije polimernih supstrata iz polučvrste sirovine i fermentacije jednostavnih ugljikohidrata. Ovaj bioproces je proveden s pomoću amilolitičke bakterije mliječne kiseline Lactobacillus amylovorus DSM 20531T u podlogama s visokom početnom koncentracijom škroba ili kukuruzne krupice i to u dva laboratorijska bioreaktora različite konstrukcije. Ovi visoko učinkoviti bioprocesi (YMK/glcNH = 0,85-0,91 g g-1) prikladni su za uvećanje do industrijskog mjerila. Različiti točno definirani omjeri D- i L-mliječne kiseline mogu se proizvesti podešavanjem temperature bioprocesa i korištenjem odabranih (združenih) kultura bakterija mliječne kiseline. Na temelju rezultata opisanih u ovom radu predloženi su mehanizmi regulacije metabolizma kod L. amylovorus DSM 20531T i razvijen je i primijenjen nestrukturirani matematički model, kojim se opisuje novi bioproces za proizvodnju D-/L-mliječne kiseline i predviđaju vrijednosti veličina koje nisu eksperimentalno određene u ovim heterogenim sustavima.

Abstract (english)

New bioprocess for D-/L-lactic acid production was developed. This bioprocess pertains to simultaneous semi solid state saccharification and fermentation type of bioprocesses. Bioprocess was carried out by amylolytic lactic acid bacterium Lactobacillus amylovorus DSM 20531T in medium with high initial concentration of starch or corn grits in two types of lab-scale bioreactors. These highly efficient bioprocesses (YMK/glcNH = 0,85-0,91g g-1) are suitable for scale-up to industrial proportions. Different exactly defined ratios of D- and L-lactic acid can be produced by combining cultivation temperature and selected (mixed) cultures of lactic acid bacteria. Based on results described in this work, metabolic regulatory mechanisms of L. amylovorus DSM 20531T were proposed, and unstructured primary mathematical model was developed and applied. The model describes the new bioprocess for D-/L-lactic acid production and predicts values of parameters which have not been experimentally determined in those heterogeneous systems.

• Keywords: amilaza Lactobacillus amylovorus DSM 20531T; (amilolitičke) bakterije mliječne kiseline [(A)BMK]; bioreaktor s miješalom; horizontalni rotirajući cijevni bioreaktor (HRCB); nestrukturirani matematički model; novi bioproces proizvodnje D-/L-mliječne kiseline; regulacija metabolizma L. amylovorus DSM 20531T; simultana saharifikacija i fermentacija (SSF); simultana saharifikacija polimernih supstrata iz polučvrste sirovine i fermentacije jednostavnih ugljikohidrata (s5f).
• Keywords (english): amylase from Lactobacillus amylovorus DSM 20531T; (amylolytic) lactic acid bacteria [(A)LAB]; stirred-tank bioreactor; horizontal rotating tubular bioreactor (HRTB); unstructured mathematical model; new bioprocess for production of D-/L-lactic acid; regulation of L. amylovorus DSM 20531T metabolism; simultaneous saccharification and fermentation (SSF); simultaneous semi-solid state saccharification and fermentation (s5f).
• Language: croatian
• URN:NBN: urn:nbn:hr:159:687164
• Promotion: 2013-09-22
• Study programme: Title: Postgraduate PhD Study in Biotechnology and Bioprocess Engineering; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti (doktor/doktorica znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Repository: Repository of the Faculty of Food Technology and Biotechnology
• Created on: 2018-05-17 09:48:06