Krivulje rasta bakterija Bacillus subtilis i Acinetobacter baumannii u ovisnosti o temperaturi

master's thesis

• Title (english): Temperature dependent growth curves of bacteria Bacillus subtilis and Acinetobacter baumannii
• Author: Branimira Ćelić
• Mentor: Jasna Hrenović (mentor)
• Committee member: Jasna Hrenović (predsjednik povjerenstva)
• Committee member: Renata Šoštarić (član povjerenstva)
• Committee member: Biljana Balen (član povjerenstva)
• Committee member: Petar Kružić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2022-09-23, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Bacillus subtilis je Gram-pozitivna bakterija štapićastog oblika koja stvara spore otporne na
visoku temperaturu. Nalazi se u tlu i nepatogena je. Bakterija Acinetobacter baumannii je Gramnegativni kokobacil koji se najčešće pojavljuje u bolničkom okruženju. Cilj ovog istraživanja bio
je utvrditi krivulje rasta, preživljavanje i eventualno umnažanje bakterija B. subtilis i A.
baumannii, kao i koncentraciju endospora B. subtilis u ovisnosti o različitim temperaturama
inkubacije (4, 22, 35, 44 i 50 °C) kroz 52 h u hranjivom mediju. Obje bakterije su preživjele sve
istraživane temperaturne vrijednosti. Uočen je izostanak umnažanja obje bakterije pri
temperaturi od 4 °C. Što je temperatura inkubacije bila bliža temperaturnom optimumu
bakterijskih vrsta, to je i umnažanje bilo značajnije. Udio endospora u kulturi B. subtilis se
izrazito povećao nakon 5 h inkubacije pri 50 °C kao način prilagodbe na nepovoljne uvjete
okoliša.

Abstract (english)

Bacillus subtilis is a Gram-positive, rod-shaped bacterium that forms spores resistant to high
temperatures. It is found in the soil and is non-pathogenic. The bacterium Acinetobacter
baumannii is a Gram-negative coccobacillus that occurs most often in the hospital environment.
The aim of this research was to determine the growth curves, survival, and eventual reproduction
of B. subtilis and A. baumannii, as well as the concentration of B. subtilis endospores depending
on different incubation temperatures (4, 22, 35, 44 and 50 °C) over 52 hours. Both bacteria
survived all investigated temperature ranges. The absence of multiplication of both bacteria at a
temperature of 4 °C was observed. The closer the incubation temperature was to the temperature
optimum of the bacterial species, the more significant the multiplication was. The proportion of
endospores in the culture of B. subtilis increased after 5 hours of incubation at 50 °C as a way of
adapting to unfavorable environmental conditions.

• Keywords: bakterije; endospore; preživljavanje; temperatura; umnažanje
• Keywords (english): bacteria; endospores; survival; temperature; reproduction
• Language: croatian
• URN:NBN: urn:nbn:hr:217:046598
• Study programme: Title: Experimental Biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra eksperimentalne biologije (magistar/magistra eksperimentalne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-10-17 08:02:46