Biosinteza bakterijske nanoceluloze uzgojem kokulture vodenih kefirnih zrnaca i kombuche u kokosovoj vodi

master's thesis

• Title (english): Biosynthesis of bacterial nanocellulose assisted by coculture of water kefir grains and kombucha in fermented coconut water
• Author: Antonela Kovačina
• 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: 2018-07-19, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Kefir i kombucha su tradicionalni fermentirani napitci proizvedeni simbiotičkim djelovanjem kultura bakterija mliječne i octene kiseline te kvasaca. U ovom je radu proučavan uzgoj kokulture vodenih kefirnih zrnaca i kombuche u kokosovoj vodi tijekom 14 dana fermentacije na sobnoj temperaturi uz dodatak različitih koncentracija saharoze. Praćene su promjene pH vrijednosti, koncentracija etanola, octene, glukonske i mliječne kiseline, kao i prinos bakterijske nanoceluloze (BNC) u kokulturi. Svojstva, kristaliničnost i strukturna karakterizacija BNC proučavane su pomoću difrakcije rendgenskim zrakama (XRD), FT-IR spektroskopije i skenirajuće elektronske mikroskopije (SEM). Antimikrobna aktivnost BNC testirana je na bakterijama Staphylococcus aureus i Bacillus subtilis te na kvascima vrsta Candida albicans i Schizosaccharomyces pombe. Rezultati određivanja kapaciteta zadržavanja vode (WHC) i otpuštanja vode (WRR) dokazali su moguću primjenu BNC kao antimikrobnog pokrovnog materijala za rane. Bakterijska nanoceluloza (BNC) dobivena djelovanjem kokulture vodenih kefirnih zrnaca i kombuche, sa svojim jedinstvenim svojstvima mikrofibrilne strukture, može se smatrati mnogostranim biomaterijalom za različita područja primjene.

Abstract (english)

Kefir and kombucha are traditional fermented drinks produced by adding symbiotic cultures of lactic and acetic acids and yeasts to medium. This work studies cultivation of coculture of water kefir grains and kombucha in aerobic conditions over a period up to 14 days of fermentation in coconut water, at room temperature with different sucrose concentrations added. Changes in pH value, ethanol, acetic acid, gluconic acid, and lactic acid were observed, as well as yield of bacterial nanocellulose (BNC) in coculture. Properties, crystallinity and structural characterization of BNC produced from coculture were evaluated by employing X-ray diffractometry, FT-IR and SEM. The antimicrobial activity of BNC was tested against bacteria Staphylococcus aureus and Bacillus subtilis, as well as yeasts Candida albicans and Schizosaccharomyces pombe. The water holding capacity (WHC) and release rate (WRR) were calculated, and the results supported its anticipated use as antimicrobial wound dressing material. Bacterial nanocellulose (BNC) produced from coculture of water kefir grains and kombucha shown its unique microfibril characteristic properties, which make it a versatile biomaterial for application in various domains.

• Keywords: bakterijska nanoceluloza; organske kiseline; kristaliničnost; antimikrobna aktivnost
• Keywords (english): bacterial nanocellulose; organic acids; crystallinity; antimicrobial activity
• Language: croatian
• URN:NBN: urn:nbn:hr:159:276136
• 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: 2019-12-02 14:55:25