Krivulja rasta bakterije Gluconobacter oxydans u prisutnosti patulina

undergraduate thesis

• Title (english): Growth curve of bacterium Gluconobacter oxydans in the presence of patulin
• Author: Ena Miškulin
• Mentor: Ksenija Markov (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for General Microbiology and Food Microbiology); Zagreb
• Defense date and country: 2012-07-11, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Bakterije iz roda Gluconobacter, posebno Gluconobacter oxydans, koje se prirodno nalaze na površini voća i povrća, predstavljaju jedinstvenu skupinu bakterija koje se naširoko koriste kao prirodni biološki antagonisti prema plijesnima uzročnicima kvarenja i propadanja voća i povrća. Gluconobacter oxydans je gram-negativna bakterija koja pripada porodici Acetobacteriaceae i nema patogeni učinak na ljude i životinje. Jedna od osnovnih metoda upoznavanja svojstava pojedinih mikroorganizama jest praćenje mikrobnog rasta, koji se većinom prikazuje kao krivulja rasta. Neizravnom (posrednom) metodom određivanja broja živih stanica praćen je rast bakterije Gluconobacter oxydans tijekom 72 sata pri odabranim uvjetima uzgoja, u prirodnoj podlozi sok od jabuke i sintetskoj YPM podlozi, uz prisutnost patulina pri 28ºC. Iz dobivenih podataka izrađena je krivulja rasta bakterije. G. oxydans pokazuje izuzetnu prilagodbu na ekstremne uvjete, kao što je rast u prisutnosti patulina, toksičkog antibiotika širokog spektra, koji uzrokuje produženu lag-fazu rasta bakterije i izostanak stacionarne faze rasta. Rezultati praćenja rasta pokazuju povoljnije uvjete za preživljavanje istraživanog mikroorganizma tijekom rasta bakterije u sintetskoj YPM podlozi zbog prisutnog manitola, osnovnog izvora ugljika.

Abstract (english)

Bacteria of Gluconobacter genus, especially Gluconobacter oxydans, which naturally occur on surfaces of fruits and vegetables, represent a unique group of bacteria that are broadly used as natural biological antagonists to fungi that cause spoilage and decay of fruits and vegetables. Gluconobacter oxydans is a gram-negative bacterium that belongs to the family of Acetobacteriaceae and is non-pathogenic towards man and animals. One of the elementary methods of determining the properties of a specific microorganism is monitoring its microbial growth, which is mostly presented as a growth curve. Growth of bacterium Gluconobacter oxydans was monitored by an indirect method of determinig the number of viable cells, during 72 hours at selected growth conditions, in natural substrate, apple juice, and in synthetic YPM substrate, in the presence of patulin at 28ºC. The obtained data were used to make the growth curve of Gluconobacter oxydans. The bacterium shows exceptional adjustment to extreme condiotions, like the presence of patulin, a toxic, broad-spectrum antibiotic, that causes the elongation of lag-phase of bacterial growth and absence of stationary phase of growth. The results of monitoring the bacterial growth of Gluconobacter oxydans show that the observed microorganism has better conditions for growth in synthetic substrate because of mannitol, primary carbon source.

• Keywords: krivulja rasta; Gluconobacter oxydans; patulin
• Keywords (english): growth curve; Gluconobacter oxydans; patulin
• Language: croatian
• URN:NBN: urn:nbn:hr:159:673692
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-16 08:08:38