Biosinteza bakterijske celuloze pomoću združene kulture osmofilnih kvasaca i bakterija octene kiseline

master's thesis

• Title (english): Biosynthesis of bacterial cellulose assisted by symbiosis of osmophilic yeast and acetic acid bacteria
• Author: Filip Herceg
• Mentor: Sunčica Beluhan (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: 2017-07-14, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Bakterijska celuloza (BC), koju proizvodi združena kultura kvasaca i bakterija, je nova alternativa polimerima fosilnog podrijetla. U ovom radu, BC proizvedena pomoću kombuche je analizirana i karakterizirana nakon 14 dana fermentacije. Praćena je proizvodnja organskih kiselina (octena i glukonska), etanola i BC u čaju od ribiza zaslađenim saharozom (60 do 120 g/L) te Hestrin-Schramm (HS) podlozi s glukozom, maltozom, fruktozom (1-5 % tež/vol) ili glicerolom (1-5 % vol/vol) kao izvorom ugljika. Najveći prinos je postignut korištenjem saharoze i glukoze, 300 g/L odnosno 151 g/L. Debljina i prinos BC se povećala tijekom fermentacije te s porastom površine i dubinom hranjivog medija. Uzorci su analizirani FT-IR spetroskopijom te je utvrđeno da svi uzorci pokazuju veći postotak kristaliničnosti. Uočena je antimikrobna aktivnost u odnosu na Salmonella typhimurium, Escherichia coli i Pseudomonas sp., a Vibrio cholerae nije bio inhibiran djelovanjem združene kulture kombucha.

Abstract (english)

Bacterial cellulose (BC), which is produced by a symbiotic culture of yeast and bacteria, is a new alternative to conventional polymers based on petroleum. In this study, BC produced from kombucha was analysed and characterized by employing FT-IR and SEM after 14 days of fermentation. The production of organic acids (acetic and gluconic), ethanol and BC in currant tea sweetened with sucrose (60 to 120 g/L) and Hestrin-Schramm (HS) based media containing glucose, maltose, fructose (1-5 % w/v) or glycerol (1-5 % v/v) as carbon sources was studied. The highest BC yield was obtained using sucrose and glucose, 300 g/l and 151 g/L, respectively. The thickness and yield of BC increased with fermentation time and correspondingly with the increase of surface area and depth of media. Analyzing samples by FT-IR spectroscopy, it was detected that all samples had a higher percentage of crystallinity. Antimicrobial activity was observed tested against Salmonella typhimurium, Escherichia coli and Pseudomonas sp., but Vibrio cholerae was not inhibited by kombucha.

• Keywords: bakterijska celuloza; organske kiseline; kristaliničnost; antimikrobna aktivnost
• Keywords (english): bacterial cellulose; organic acids; crystallinity; antimicrobial activity
• Language: croatian
• URN:NBN: urn:nbn:hr:159:446791
• 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: 2017-11-16 09:55:36