Uzgoj ljubičastih nesumpornih bakterija u bioreaktoru s miješalom bez izvora svjetlosti na različitim izvorima ugljika

master's thesis

• Title (english): Cultivation of purple non-sulfur bacteria in a stirred tank bioreactor under dark conditions with different carbon sources
• Author: Manda Madaras
• Mentor: Mario Novak (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: 2019-10-22, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Ljubičaste bakterije se kroz zadnjih nekoliko desetljeća prezentiraju kao modelni organizmi za istraživanje i shvaćanje fotosintetskih prokariota zahvaljujući njihovoj iznimnoj sposobnosti prilagodbe raznim uvjetima okoline. Također, ljubičaste nesumporne bakterije su naročito zanimljive s komercijalnog aspekta s obzirom na činjenicu da proizvode veliki niz proizvoda kao što su vodik, pigmenti, biokemikalije, biopolimeri i mnoge druge. U ovom radu se ispitivao aerobni kemoheterotrofni rast, potrošnja supstrata, te sinteza pigmenata bakterija Rhodobacter azotoformans JCM 9340 i Rhodovulum adriaticum DSM 2781 u bioreaktoru s miješalom bez prisutnosti svjetla uz različite izvore ugljika. Kao izvori ugljika su se koristile glukoza i ksiloza, te hidrolizat lignocelulozne biomase dobiven kiselinskom predobradom u visokotlačnom reaktoru. Uzgoj Rhodobacter azotoformans JCM 9340 je pokazao slabiji rast, te sintezu pigmenata tijekom uzgoja na glukozi i ksilozi, dok je Rhodovulum adriaticum DSM 2781 najveću produktivnost 0,154 g L-¹h-¹ procesa postigao tijekom uzgoja na predobrađenoj lignoceluloznoj biomasi. Također, tijekom tog procesa se postigao i najveći prinos biomase bakterije 3,7 g L-¹. Najviše vrijednosti koncentracije pigmenata, prikazane kao vrijednosti bakterioklorofila a, su postignute tijekom uzgoja Rhodovulum adriaticum DSM 2781 na glukozi i ksilozi 8,599 mg L-¹.

Abstract (english)

In the last couple of decades, purple non-sulfur bacteria have presented themselves as a model organism for researching and understanding of photosynthetic prokaryotes thanks to their excellent capability of adapting to different environmental conditions. These bacteria are also interesting in a commercial aspect due to their capability of producing a grand array of products such as biohydrogen, pigments, biochemicals, biopolymers etc. In this thesis, aerobic chemoheterotrophic growth, substrate consumption and pigment biosynthesis of bacteria Rhodovulum adriaticum DSM 2781 and Rhodobacter azotoformans JCM 9340 in a stirred tank bioreactor under dark conditions with different carbon sources, was studied. Glucose, xylose and lignocellulosic hydrolysates, obtained by acidic pretreatment in highpressure reactor, were used as carbon sources for cultivation. Results obtained by Rhodobacter azotoformans JCM 9340 showed poor growth and photosynthetic pigments synthesis on glucose and xylose, while results obtained by Rhodovulum adriaticum DSM 2781 showed great success. The highest bioprocess productivity of 0.154 g L-¹ h-¹ was observed during cultivation on pretreated lignocellulosic biomass. During that process, the highest yield of biomass of 3.7 g L-¹ was achieved, as well. The most successful medium for pigment biosynthesis, shown as bacteriochlorophyll a concentration, was glucose/xylose medium reaching 8.599 mg L-¹ of bacteriochlorophyll a.

• Keywords: ljubičaste nesumporne bakterije; Rhodovulum adriaticum; lignocelulozna biomasa; bakterioklorofil; bioreaktor s miješalom
• Keywords (english): purple non-sulfur bacteria; Rhodovulum adriaticum; lignocellulosic biomass; bacteriochlorophyll; stirred tank bioreactor
• Language: croatian
• URN:NBN: urn:nbn:hr:159:361338
• 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: 2019-12-11 13:52:07