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Title: Mikrobiološka aktivnost v obdobju pojavljanja polisaharidno bogatih makroagregatov v Tržaškem zalivu : diplomsko delo Authors: ID Kalin, Meta (Author) ID Turk, Valentina (Mentor) More about this mentor... Files: UNI_Kalin_Meta_i2005.pdf (1,94 MB) MD5: 370BD165E5FBE97CB67FB73375FF8354   http://www.ung.si/~library/diplome/OKOLJE/4Kalin.pdf   Language: Slovenian Work type: Undergraduate thesis Typology: 2.11 - Undergraduate Thesis Organization: FZO - Faculty of Environmental Sciences Abstract: V spomladanskem obdobju leta 2004 smo raziskovali razporeditev združbe heterotrofnih bakterij v vzhodnem delu Tržaškega zaliva. Bakterijske celice smo šteli pod epifluorescentnm mikroskopom. Bakterijsko produkcijo smo merili z metodo asimilacije radioaktivno označene spojine 3H-timidin in 3H-leucin. Število bakterij na dveh postajah Tržaškega zaliva se je spreminjalo od 0,2z109 do 2,1z109 celic/L. Najbolj izrazit padec bakterijske biomase smo beležili v maju, visoko biomaso pa smo beležili v času pojava sluzastih makroagregatov. Vzorce sluzastih makroagregatov smo pregledovali s pomočjo različnih mikroskopskih tehnik (svetlobni, epifluorescentni in elektronski mikroskop). V obdobju pojava sluzi smo izolirali posamezne bakterijske kolonije in jim določili osnovne morfološke znake. Z metodo fluorescentne in situ hibridizacije (FISH) smo opravili preliminarne analize določanje bakterijskih filogenetskih skupin. Bakterijske kolonije smo uporabili v dveh poskusih obogatitve morske vode z anorganskimi in organskimi hranili. Organsko hranilo je predstavljala sluz z visokim deležem polisaharidov. Odziv bakterijske združbe na dodatek hranil je bil hiter in se kaže v povečanju števila bakterijskih celic in visoki bakterijski produkciji že v prvih 24 urah. Sluz je heterotrofnim bakterijam služila kot vir energije in ogljika. V ta namen smo sledili koncentracijam celokupnih ogljikovih hidratov in proteinov. Spremembe v koncentraciji celokupnih ogljikovih hidratov so najverjetneje posledica povečanja bakterijske encimatske aktivnosti in istočasnega ponovnega privzema sproščenih ogljikovih hidratov. Preliminarni rezultati kažejo na velik pomen bakterijske heterotrofne združbe v procesih pretvorbe organske snovi v morskem ekosistemu. Keywords: morje, mikrobiologija, kultura Place of publishing: Nova Gorica Place of performance: Nova Gorica Publisher: M. Kalin Year of publishing: 2005 Number of pages: 40 f. PID: 20.500.12556/RUNG-1764  COBISS.SI-ID: 1566799  UDC: 574 NUK URN: URN:SI:UNG:REP:DUFWKWVW Publication date in RUNG: 19.02.2015 Views: 5636 Downloads: 270 Metadata:    Cite this work Plain text BibTeX EndNote XML EndNote/Refer RIS ABNT ACM Ref AMA APA Chicago 17th Author-Date Harvard IEEE ISO 690 MLA Vancouver : Copy citation

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Distribution of heterotrophic bacteria was studied during spring period in 2004 at two different locations in the Gulf of Trieste (Adriatic Sea). Bacterial abundance was determined using the counting method on epifluorescence microscope. Bacterial production was measured with the method of incorporation of radio-labelled 3Hthymidine and 3H-leucine. Bacterial abundance at both locations varied between 0,2z109 and 2,1z109 cell/L. In May the bacterial biomass was low, but an increase in biomass quantity in the period of mucus macroaggregate appearance was observed. In further studies themucus macroaggregate samples were examined with different microscopic (optical, epifluorescence and electronic) and microbiological techniques. Bacterial colonies isolated on agar plates formed different morphological details. Preliminary analysis of bacterial phylogenetic diversity was performed with the fluorescence in situ hybridisation (FISH) method. The influence of addition of inorganic and organic nutrient on bacterial growth dynamics were studied on previously isolated bacteria in two laboratory experiments. The concentration of nutrient, total carbohydrates and protein were studied simultaneously with bacterial biomass and production. Mucus with high portion of polysaccharides served as an organic nutrient for bacteria. Asconsequence changes in carbohydrates concentration were observed probably duo to increased bacterial enzymatic activity, and in the same time bacterial consumption of released carbohydrates. Our preliminary results showed that therole of heterotrophic bacterial community is of great significance in the process of transformation of organic matter in marine ecosystem.

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