magistrsko delo
Ines Grebenc (Author), Borut Poljšak (Reviewer), Martina Oder (Mentor), Gregor Jereb (Co-mentor)

Abstract

Uvod: Fosfor je bistven kemijski element za vse žive organizme, saj sestavlja ključne molekule za delovanje in življenje vseh živih bitij. Velikokrat je fosfor zanemarjen element kot limitirajoče se hranilo za rast in razmnoževanje bakterij. V pitni vodi je eden izmed virov fosforja lahko dodajanje kemičnih mehčal za preprečevanje nastajanja kotlovca. Dodani fosfati lahko predstavljajo hranilo bakterijam, ki so prisotne v pitni vodi ter s tem povzročijo povečanje števila ne le zdravju neškodljivih bakterij, temveč se lahko poveča tudi število patogenih bakterij. E. coli je ena izmed najpogosteje preverjanih bakterij v pitni vodi, saj njena prisotnost nakazuje na fekalno onesnaženje vode. Namen: Namen magistrske naloge je raziskati povezavo med dodajanjem različnih vrst fosfatnih pripravkov z različnimi koncentracijami ter njihov vpliv na razmnoževanje testne bakterije E. coli. Metode dela: Bakterije E. coli so bile izpostavljene različnim koncentracijam fosfatov. Odziv bakterij je bil spremljan v času 0, 24, 48 in 72 ur. Štetje porastlih bakterijskih kultur je bilo izvedeno na navadnem agarju po preteklih 48 urah inkubacije pri temperaturi 36 °C. Vse analize so bile izvedene v dveh paralelkah s tremi ponovitvami. Rezultati: Rezultati raziskave kažejo na verjetno povezavo med dodanimi fosfatnimi pripravki in pospešenim razmnoževanjem bakterij E. coli vendar okviru magistrske naloge te povezave nismo statistično potrdili. Bakterije se najbolje odzovejo na višjo koncentracijo natrijevega fosfata(V). Tudi ob dodatku komercialnega pripravka za mehčanje vode se bakterije bolje razmnožujejo ob prisotnosti le tega. Razprava in zaključek: Na podlagi pridobljenih rezultatov lahko zaključimo, da ima dodajanje fosfatov verjetno vpliv na razmnoževanje bakterije E. coli. Poudariti moramo, da je raziskava potekala v kontroliranih laboratorijskih pogojih, kjer so izključeni dejavniki iz realnega okolja (pH, temperatura, prisotnost drugih bakterijskih vrst ipd.), ki bi lahko vplivali na razmnoževanje bakterij. Za nadaljnje razumevanje vpliva fosfatov na razmnoževanje bakterije E. coli je smiselno raziskavo ponoviti na večjem številu vzorcev in ne le pod laboratorijskimi pogoji, temveč tudi v simuliranem okolju vodovodnega sistema.

Keywords

magistrska dela;sanitarno inženirstvo;Escherichia coli;fosfati;fosfor;razmnoževanje bakterij;anorganska hranila;vodno okolje;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL ZF - University College of Health Studies
Publisher: [I. Grebenc]
UDC: 614
COBISS: 32854275 Link will open in a new window
Views: 522
Downloads: 131
Average score: 0 (0 votes)
Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary language: English
Secondary title: Impact of phosphate on reproduction of bacteria Escherichia coli
Secondary abstract: Introduction: Phosphorus is an essential chemical element for all living organisms because it is the key molecule for the functioning and life of all living things. Phosphorus is often a neglected element as a limiting nutrient for bacterial growth and reproduction. In drinking water, one of the sources of phosphorus might be an addition of plasticizers to prevent boiler formation of lime stone. This can be a nutrient to the bacteria which are present in drinking water, leading to an increase in the number of not only harmless bacteria but also an increase in the number of pathogenic bacteria, including Escherichia coli strains. It is one of the most commonly reported bacteria in drinking water since its presence indicates fecal contamination of water. Purpose: The aim of the master's thesis is to investigate the positive relationship between addition of different types of phosphate preparations at different concentrations and their effect on the reproduction of the E. coli test bacterium. Methods: E. coli bacterial culture were exposed to various concentrations of phosphorus and their reaction of was followed at 0, 24, 48 and 72 hours. Growth of bacterial culture was done on ordinary agar after 48 hours at temperature of 36 °C. All analyzes were performed in parallel duplicates and repeated three times. Results: The results of our research indicate a probable correlation between the addition of different concentrations of different phosphate preparations and regrowth of bacteria E. coli, but this correlation was not statistically proven in our study. Bacteria responded the best to the higher concentrations of sodium phosphate(V). With the addition of a commercial water softener bacteria also multiplied better in the presence of it. Discussion and conclusion: Based on the obtained results, we can conclude that the addition of phosphorus probably have significant affect on the reproduction of bacteria E. coli. It should be emphasized that the experiment was conducted in controlled laboratory circumstances, which excluded factors from the real environment (pH, temperature, presence of other bacterial species, surface materials, flow rate, etc.) that could have possibly affected reproduction of bacteria. For further undernstanding the influence of phosphates on the reproducition of E. coli the research can be repeated on a larger scale of samples and not only in laboratory conditions but also in simulated enviroment of water supply system.
Secondary keywords: master's theses;sanitary engineering;Escherichia coli;sanitary engineering phosphates;phosphorus;bacterial regrowth;inorganic nutrients;water environment;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Zdravstvena fak., Oddelek za sanitarno inženirstvo
Pages: 44 str.
ID: 12080797