Naslov
Procjena udjela alkalne fosfataze u biomasi pikoplanktona južnog Jadrana
(Assessment of the alkaline phosphatase share in biomass of picoplankton in South Adriatic)

Autori
Hrustić, Enis ; Bobanović-Ćolić, Svjetlana

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

Izvornik
Knjiga sažetaka/Book of Abstracts: 4. Hrvatski Botanički Simpozij s međunarodnim sudjelovanjem Split 2013./4th Croatian Botanical Symposium with International participation Split 2013. / Alegro, Antun ; Boršić, Igor - Split : Hrvatsko botaničko društvo, Sveučilište u Splitu, 2013, 37-38

ISBN
978-953-99774-6-5

Skup
4. Hrvatski Botanički Simpozij s međunarodnim sudjelovanjem Split 2013./4th Croatian Botanical Symposium with International participation Split 2013.

Mjesto i datum
Split, Hrvatska, 26.09.2013. - 29.09.2013

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
alkalna fosfataza; pikoplankton; cijanobakterije; fitoplankton; južni Jadran
(picoplankton; cianobacteria; alkaline phosphatase; phytoplankton; South Adriatic)

Sažetak
Orthophosphate concentration is usual limiting factor of the phytoplankton growth in South Adriatic, which indirectly impacts the growth of heterotrophic bacteria. Alkaline phosphatases AP are widely synthesized in plants and animals and play numerous roles in cell life. In phytoplankton the most important role of AP is degradation of phosphomonoesters and uptake of orthophosphate, while in heterotrophic bacteria AP is mostly constitutive enzyme being also active in uptake of organic moiety (carbon and nitrogen source) after dephosphorilation. Cyanobacteria dominate the biomass of picoplankton in South Adriatic. Alkaline phosphatase activities APA were detected as relative measure of enzyme abundance (at 37 °C) by spectrophotometer Perkin Elmer λ15 (absorbances of p-nitrophenol read at λ = 400 nm, cuvettes 1 cm) in 283 samples of picoplankton after concentrating enzymes from 200 mL of filtered sea in fraction 0.2 – 2 μm throughout photic zone and deeper at 6 locations (Small Lake, Big Lake and Gonoturska in Mljet aquatory, Ombla Estuary, coastal sea near Lokrum and open waters of South Adriatic Pit) in period October 2009. - January 2012. Biomass of picoplankton constituents were assessed after counting abundances and measuring dimensions of cells by epifluorescent microscope Zeiss – Jenalumar (magnification 1500) and using factors for conversion of volume and abundance into carbon content. Specific APA of picoplankton sAPAp were calculated as APA of picoplankton/biomass of picoplankton. Model enzyme "alkaline phosphatase from calf intestine" (Roche) with specified activity of 2 IU/μg at different buffer, higher pH, higher S0 of p-nitrophenyl phosphate and higher concentration of activator (0.5 mM Mg2+) was tested in the same reaction conditions as for picoplankton APA (Tris-HCl 0.1 M, S0 1.812 mM, pH 8.35 – 8.25). After correction and mass normalization of sAPAp according to activity of model enzyme, assessment of the average AP share in picoplankton biomass was given. It remained unknown to which degree model enzyme suited the specific activity of picoplankton AP (activity per mass of enzyme) and what was the similarity among AP of picoplankton constitutents (cyanobacteria, heterotrophic bacteria, pigmented and heterotrophic flagellates). Relative dimension of error introduced to the final result remained unevaluated, while average AP share in picoplankton biomass of South Adriatic was estimated at 1 µg AP/20000 µg C (0.05 ‰).

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Biologija

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