Određivanje optimalne temperature za rast i proizvodnju etanola s pomoću kvasca Kluyveromyces marxianus NBRC 1777

master's thesis

• Title (english): Determination of optimal temperature for growth and ethanol production by yeast Kluyveromyces marxianus NBRC 1777
• Author: Ana Samardžić
• Mentor: Antonija Trontel (mentor)
• Committee member: Mario Novak (predsjednik 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: 2020-12-18, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Razvoj bioprocesa proizvodnje etanola trebao bi biti usmjeren prema pronalaženju termotolerantnog kvasca koji može koristiti različite ugljikohidrate kao izvore ugljika, posebice one prisutne u lignoceluloznim sirovinama, proizvoditi etanol uz visoke prinose i produktivnost pri temperaturama koje su optimalne za aktivnost enzima potrebnih za hidrolizu lignoceluloznih sirovina (≈ 50 °C). Kvasac Kluyveromyces marxianus je termotolerantni kvasac koji može rasti i pri temperaturi od 45 °C do 52 °C, a etanol može proizvoditi pri temperaturama od 38 °C do 45 °C ovisno o odabranom soju ovog kvasca. U ovom radu su zbog pronalaženja optimalne temperature za rast i proizvodnju etanola s pomoću kvasca Kluyveromyces marxianus NBRC 1777 provedeni uzgoji u YPD (Yeast extract pepton dextrose) podlozi pri temperaturama od 20 °C, 30 °C, 40 °C i 50 °C. Između testiranih temperatura, najveća specifična brzina rasta (μ = 0,42 hˉ¹) te brzine proizvodnje etanola (rEtOH = 0,35 hˉ¹) i glicerola (rglicerol = 0,19 hˉ¹), kao i produktivnost procesa proizvodnje etanola (PrEtOH =0,96 g Lˉ¹ hˉ¹) određene su pri temperaturi od 30 °C. Pri temperaturi od 50 °C ovaj soj kvasca raste vrlo sporo i proizvodi minimalne količine etanola uz vrlo nisku produktivnost procesa proizvodnje etanola (PrEtOH = 0,15 g Lˉ¹ hˉ¹).

Abstract (english)

The development of ethanol production bioprocess should be aimed at finding thermotolerant yeast that can use various carbohydrates as carbon sources, especially those present in lignocellulosic feedstocks, produce ethanol with high yields and productivity at temperatures optimal for the activity of enzymes required for hydrolysis of lignocells (≈ 50 °C). Yeast Kluyveromyces marxianus is a thermotolerant yeast that can grow at temperatures from 45 °C to 52 °C and ethanol can be produced at temperatures from 38 °C to 45 °C depending on the selected strain of this yeast. In this work, in order to find the optimal temperature for the growth and production of ethanol with the help of yeast Kluyveromyces marxianus NBRC 1777, cultivations were performed in YPD (Yeast extract pepton dextrose) medium at temperatures of 20 °C, 30 °C, 40 °C and 50 °C. Between the tested temperatures, the highest specific growth rate (μ = 0.42 hˉ¹) and the production rate of ethanol (rEtOH = 0.35 hˉ¹) and glycerol (rglycerol = 0.19 hˉ¹), as well as the productivity of the production process ethanol (PrEtOH = 0.96 g Lˉ¹ hˉ¹) were determined at 30 °C. At a temperature of 50 °C this yeast strain grows very slowly and produces minimal amounts of ethanol with very low productivity of the ethanol production process (PrEtOH = 0.15 g Lˉ¹ hˉ¹).

• Keywords: utjecaj temperature; bioetanol; glukoza; Kluyveromyces marxianus
• Keywords (english): influence of temperature; bioethanol; glucose; Kluyveromyces marxianus
• Language: croatian
• URN:NBN: urn:nbn:hr:159:135984
• 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: 2021-01-11 09:37:18