Problematika spor in biofilmov v biotehnologiji

Hribar, Tjaša (author), Danevčič, Tjaša (mentor)

Biofilmi so visoko organizirana skupnost bakterij, ki se razlikujejo v fenotipu in jih zato delimo v subpopulacije. Vsaka subpopulacija ima dodeljene vloge, ob zorenju biofilma pa nastajajo tudi spore. Spore so visoko odporne na kemijske in fizikalne dejavnike, kar jim omogoči njihova struktura. Pri starejšem biofilmu se te razpršijo in s tem kolonizirajo druga področja. Nastanejo novi biofilmi, ki so nezaželeni v raznih industrijah ter se komercialno uporabljajo kot biološki kontrolni agensi za zaščito rastlin in za čiščenje odpadnih voda. V okviru diplomske naloge smo spremljali vpliv gojenja bakterijskih celic v biofilmih na sporulacijo. Primerjali smo delež sporulacije za bakterijska seva PS-216 wt in PS-216 ΔcomQ. Poleg tega smo merili intenziteto fluorescence in optično gostoto sevov PS-216 wt in PS-216 ΔcomQ in njunih različic, ki vsebujeta poročevalsko fuzijo promotorja gena spoIIQ sklopljenega z genom za rumeni fluorescentni protein (yfp). Neoznačena seva, ki nista fluorescirala, sta služila kot kontroli. S tem smo spremljali rast in izražanje sporulacijskih genov v biofilmu. Pri označenem divjem sevu je bila opažena višja optična gostota in nižji nivo sporulacije celic, kar je bilo razvidno iz nižje intenzitete fluorescence. Pri sevu z okvarjeno signalizacijo (mutanti comQ) smo opazili manjšo optična gostoto in višjo intenziteto fluorescence.

• Language: Slovenian
• Keywords: biotehnologija, spore, biofilm, Bacillus subtilis
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [T. Hribar]
• Year: 2017
• PID: 20.500.12556/RUL-94540
• UDC: 602.3:579.852.11:579.26(043.2)
• COBISS.SI-ID: 8807289
• Publication date in RUL: 02.09.2017

Secondary language

• Language: English
• Title: Problematics of spores and biofilms in biotechnology

Abstract

Biofilms are highly structured group of bacteria that are different in phenotpye which divides them in several subpopulations. Each subpopulation has an important role and as biofilm matures spores are formed. Because of their structure they are very resistant to chemical and physical factors. In old biofilms spores and other vegetative cells disperse in the environment and colonise other areas. Biofilms are undesired in various industries but also commercially used as biological control agents for plant protection and wastewater treatment. Within the thesis we studied the influence of the growth of bacterial cells in biofilms on sporulation. The fractions of spores in biofilms were compared between bacterial strains PS-216 wt and PS-216 ΔcomQ. Besides this the intensity of fluorescence and optical density of strains PS-216 wt, PS-216 ΔcomQ and their marked strains was measured. In marked strains the fusion of the promoter of the gene spoIIQ and gen for yellow fluorescent protein (yfp) was used. Unmarked strains without fluorescent fusion were used as a control. They were used to monitor growth and expression of the sporulation genes. In comparison to marked mutant strain marked PS-216 wt strain had higher optical density and lower level of expression of the sporulation genes which has been observed in the lower fluorescence intensity.

• Keywords: biotechnology, spores, biofilm, Bacillus subtilis