Naslov
Colonization of diatoms and bacteria on artificial substrates in the marine environment

Autori
Mejdandžić, Maja ; Ljubešić, Zrinka ; Ivanković, Tomislav ; Pfannkuchen, Martin ; Godrijan, Jelena ; Hrenović, Jasna

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Izvornik
Abstract book of the 8th Central European Diatom Meeting / Ljubešić, Zrinka, Godrijan, Jelena & Marić Pfankuchenn, Daniela - Zagreb : Hrvatsko Botaničko Društvo, 2014, 40-40

ISBN
978-953-99774-7-2

Skup
8th Central European Diatom Meeting

Mjesto i datum
Zagreb, Hrvatska, 10.04.2014. - 13.04.2014

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
diatoms ; colonization ; biofouling ; bacteria ; Adriatic sea

Sažetak
Any natural or artificial substrate that is immersed in seawater is rapidly covered by unavoidable biofouling. Growth of such fouling also known as biofilm formation is complex and not yet thoroughly investigated. Roughly known stages of biofilm generation are: adsorption of organic and inorganic macromolecules ; migration of microbial cells to the surface ; attachment of bacteria onto surface ; production of extra-cellular polymers ; and development of a more complex 3D community with the presence of micro- and macroalgae, leading to attachment of larger macro-invertebrates. Succession of diatoms and bacteria was investigated during a one month period incubation on artificial substrate mounted above the seafloor at five meters depth. Samples were collected after 1h, 12h, 24h, 48h, 4 days, 7 days and 30 days of contact. For bacteriological analysis the biofilm was detached from plexiglass plates (polymer of methyl methacrylate) using an ultrasonic probe and samples were inoculated onto selective agar plates. Biofilm for algological analysis was scraped with adopted toothbrush and resuspended in subsamples for epiphluorescent, light and electronic microscopy, as well as for HPLC pigment analysis. During monitoring of biofilm development, abundance of all biofilm components increased and reached maximum values after one month incubation. In the bacterial community heterotrophic marine bacteria were dominant and reached 1.94x104 CFU cm-2. Faecal coliforms and faecal enterococci were not detected in the biofilm. Phototrophic component of the biofilm was dominated by diatoms and reached 6.10x105 cells cm-2, which was supported by pigment analysis with fucoxantin as dominant pigment in concentration up to 110 ng cm-2. Dominant diatoms were Cylindrotheca closterium and unidentified penate benthic diatoms. More detailed taxonomic analysis of those diatoms by electronic microscopy revealed up to 20 different taxa of diatoms. The study confirmed that the plexiglass surface in a marine environment is susceptible to biofouling within 30 days of contact.

Izvorni jezik
Engleski

Znanstvena područja
Geologija, Biologija

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