Utjecaj izvora i koncentracije dušika na rast i proizvode metabolizma kvasca Kluyveromyces marxianus NBRC 1777

master's thesis

• Title (english): Influence of nitrogen source and concentration on growth and products of metabolism of yeast Kluyveromyces marxianus NBRC 1777
• Author: Marko Buovac
• Mentor: Vlatka Petravić Tominac (mentor)
• Mentor: Nenad Marđetko (pomoć pri izradi, neposredni voditelj)
• Committee member: Mario Novak (predsjednik povjerenstva)
• Committee member: Andreja Leboš-Pavunc (član povjerenstva)
• Committee member: Jasna Mrvčić (član povjerenstva)
• 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: 2024-03-25, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Istražen je utjecaj izvora i koncentracije dušika na kvasac K. marxianus NBRC 1777. Uzgojem na triptonu kao jedinom izvoru dušika, najveći prinos biomase (1,99 g L⁻¹) i koeficijent konverzije supstrata (glukoze) u biomasu (0,20 g g⁻¹) postignuti su uzgojem na podlozi sastava 22,73 g L⁻¹ glukoze i 7,5 g L⁻¹ triptona, dok je najveći prinos etanola (2,36 g L⁻¹) ostvaren uzgojem na podlozi s 22,73 g L⁻¹ glukoze i 6 g L⁻¹ triptona. Zamjenom dijela triptona amonijevim solima uglavnom su se smanjili prinos biomase i proizvoda metabolizma. Međutim, uzgojem na podlozi s 45,46 g L⁻¹ glukoze, 5 g L⁻¹ triptona i 2,5 g L⁻¹ amonijevog hidrogenfosfata i amonijevog sulfata ostvaren je prinos biomase 2,59 g L⁻¹ . Kukuruzna močevina pokazala se kao najbolji izvor dušika za korišteni mikroorganizam pri istraženim uvjetima, jer je jedino njezinom primjenom radni mikroorganizam skoro potpuno potrošio glukozu, a postignuti su i najveći prinosi etanola. Najviše etanola (17,45 g L⁻¹) proizvedeno je u podlozi s 45,46 g L⁻¹ glukoze i 20 g L⁻¹ kukuruzne močevine.

Abstract (english)

The influence of the source and concentration of nitrogen on the yeast K. marxianus NBRC 1777 was investigated. With tryptone as a sole nitrogen source, the highest biomass yield (1.99 g L⁻¹) and the highest conversion coefficient of substrate (glucose) to biomass (0.20 g g⁻¹) were achieved by growing on a substrate containing 22.73 g L⁻¹ of glucose and 7.5 g L⁻¹ of tryptone, while the highest ethanol yield (2.36 g L-1) was achieved by cultivation on medium containing 22.73 g L⁻¹ of glucose and 6 g L⁻¹ of tryptone. By replacing part of tryptone with ammonium salts, the yields of biomass and metabolic products mainly decreased. However, growth in medium containing 45.46 g L⁻¹ glucose, 5 g L⁻¹ tryptone and 2.5 g L⁻¹ ammonium hydrogen phosphate and ammonium sulphate resulted in a biomass yield of 2.59 g L-1. Corn steep liquor (CSL) proved to be the best nitrogen source for the tested strain under the investigated conditions, since the working microorganism consumed glucose almost completely and the highest ethanol yields were achieved with CSL as the only nitrogen source. The highest ethanol concentration (17.45 g L⁻¹) was produced in medium containing 45.46 g L⁻¹ of glucose and 20 g L⁻¹ of CSL.

• Keywords: Kluyveromyces marxianus; kukuruzna močevina; amonijeve soli; tripton
• Keywords (english): Kluyveromyces marxianus; corn steep liquor; ammonium salts; tryptone
• Language: croatian
• URN:NBN: urn:nbn:hr:159:063064
• Study programme: Title: Bioprocess Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva (magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-07-25 11:40:20