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Role of extracellular DNA in microbial biofilms
Gromov, Anton ; Chytilová, Aneta (referee) ; Obruča, Stanislav (advisor)
Abstract This bachelor’s thesis deals with defining the role of extracellular DNA in microbial biofilms. The thesis includes a part about the basic characteristics and functions of biofilms, as well as the characteristics and functions of extracellular DNA. The theoretic part additionally deals with the process of formation of biofilms, and the influence of different types of stresses on it. Also, the paper discusses the role of such stresses. The role of biofilm in bacteria and their reproduction methods are also discussed. An interesting section of the thesis outlines the impact of antibiotics on biofilms, or the ways to gain DNA or use DNase. The eDNA functions and their effects on bacterial defence will be discussed thoroughly. In the experimental part, the biofilm content was examined and compared with cells growing in a liquid and solid medium. Measurement of DNA content in media was carried out and the effects of salt and temperature stresses on biofilm were also measured. Stress conditions affected the production of PHB, which is used as a reserve form of energy and carbon. Total sugars were measured using an anthracite reagent to study the effects of stresses on the content of macromolecules. The presence of eDNA in biofilms and planktonic cells was firstly checked using gel electrophoresis and then accurate concentrations in planktonic and biofilm cells were determined using different spectrophotometric methods.
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Biofilm formation in Streptococcus pneumoniae
Jarošová, Václava ; Petráčková, Denisa (advisor) ; Matyska Lišková, Petra (referee)
Biofilm is a structured community of cells adhered to the surface or to each other and surrounded by extracellular matrix. Biofilm is fomed in several steps starting from single cells adhered to the surface up to microcolonies linked by channels. Because of a higher resistance to antibiotics the current hot topics in the biofilm research are formation of biofilms on medical materials and treatment of bacterial infections associated with biofilms. This work is focused on a biofilm forming bacteria Streptococcus pneumoniae. It is a potentially pathogenic bacterium which colonizes the upper respiratory tract and causes a number of diseases. Biofilms formed by S. pneumoniae exhibit increased resistance to antibiotics, therefore, alternative antimicrobial agents have been recently studied. For biofilm formation studies both open and closed systems are used. The flow cell and biofilm reactors represent commonly used open systems. Closed cultivation systems are for example a Calgary biofilm device and a micro titer plate-system developed by Christensen et al.
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Biofilm formation in Streptococcus pneumoniae
Jarošová, Václava ; Petráčková, Denisa (advisor) ; Matyska Lišková, Petra (referee)
Biofilm is a structured community of cells adhered to the surface or to each other and surrounded by extracellular matrix. Biofilm is fomed in several steps starting from single cells adhered to the surface up to microcolonies linked by channels. Because of a higher resistance to antibiotics the current hot topics in the biofilm research are formation of biofilms on medical materials and treatment of bacterial infections associated with biofilms. This work is focused on a biofilm forming bacteria Streptococcus pneumoniae. It is a potentially pathogenic bacterium which colonizes the upper respiratory tract and causes a number of diseases. Biofilms formed by S. pneumoniae exhibit increased resistance to antibiotics, therefore, alternative antimicrobial agents have been recently studied. For biofilm formation studies both open and closed systems are used. The flow cell and biofilm reactors represent commonly used open systems. Closed cultivation systems are for example a Calgary biofilm device and a micro titer plate-system developed by Christensen et al.
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Role of extracellular DNA in microbial biofilms
Gromov, Anton ; Chytilová, Aneta (referee) ; Obruča, Stanislav (advisor)
Abstract This bachelor’s thesis deals with defining the role of extracellular DNA in microbial biofilms. The thesis includes a part about the basic characteristics and functions of biofilms, as well as the characteristics and functions of extracellular DNA. The theoretic part additionally deals with the process of formation of biofilms, and the influence of different types of stresses on it. Also, the paper discusses the role of such stresses. The role of biofilm in bacteria and their reproduction methods are also discussed. An interesting section of the thesis outlines the impact of antibiotics on biofilms, or the ways to gain DNA or use DNase. The eDNA functions and their effects on bacterial defence will be discussed thoroughly. In the experimental part, the biofilm content was examined and compared with cells growing in a liquid and solid medium. Measurement of DNA content in media was carried out and the effects of salt and temperature stresses on biofilm were also measured. Stress conditions affected the production of PHB, which is used as a reserve form of energy and carbon. Total sugars were measured using an anthracite reagent to study the effects of stresses on the content of macromolecules. The presence of eDNA in biofilms and planktonic cells was firstly checked using gel electrophoresis and then accurate concentrations in planktonic and biofilm cells were determined using different spectrophotometric methods.
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