Biološki učinci mikroplastike onečišćene teškim metalima na barsku leću Spirodela polyrhiza

master's thesis

• Title (english): Biological effects of microplastics contaminated by heavy metals on greater duckweed Spirodela polyrhiza
• Author: Emilie Kokić
• Mentor: Sandra Radić Brkanac (mentor)
• Mentor: Marija Babić (komentor)
• Committee member: Sandra Radić Brkanac (predsjednik povjerenstva)
• Committee member: Perica Mustafić (član povjerenstva)
• Committee member: Kristina Pikelj (član povjerenstva)
• Committee member: Neven Bočić (član povjerenstva)
• Committee member: Blanka Cvetko Tešović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2024-07-11, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Zbog svoje ekonomske isplativosti i široke primjene, plastika je postala neizostavan materijal
u svakodnevnom ljudskom životu. Plastika se u okolišu djelovanjem različitih fizičkih i
kemijskih procesa razgrađuje na manje čestice plastike koje tada nazivamo mikroplastika (MP).
Degradirane čestice MP kasnije postaju veliki problem i prijetnja za ekosustav i organizme koji
dođu u doticaj s njom jer lakše stupaju u interakciju s organskim i anorganskim onečišćivačima
i adsorbiraju ih. MP najčešće na sebe adsorbira teške metale i postupno ih otpušta u okoliš. U
ovome radu istražen je utjecaj čiste MP (smjesa čestica polietilena, polistirena, polipropilena i
gume) i MP onečišćene smjesom teških metala (bakar, olovo i cink) na stopu rasta barske leće
(Spirodela polyrhiza L.) i na pojedine fiziološke i biokemijske pokazatelje oksidacijskog stresa
(sadržaj fotosintetskih pigmenata, karbonila i malondialdehida te aktivnost akntioksidacijskih
enzima). Rezultati su pokazali da dolazi do otpuštanja metala s površine MP u hranjivu podlogu
te do njihovog nakupljanja u barskoj leći, no samo je nakupljanje Cu pri najvećoj koncentraciji
MP onečišćene teškim metalima bilo statistički značajno u usporedbi s kontrolom i drugim
tretmanima. Sedmodnevno izlaganje barske leće česticama čiste MP i MP onečišćene metalima
nije statistički značajno utjecalo na stopu rasta. Primjećen je porast aktivnosti antioksidacijskih
enzima pri nižim koncentracijama čiste MP i višim koncentracijama MP s adsorbiranim
metalima. Lipidna peroksidacija bila je značajno povećana pri pojedinim koncentracijama MP
s adsorbiranim metalima, dok se sadržaj karbonila i topivih proteina nije statistički značajno
mijenjao. Zaključno, barska leća predstavlja pogodan model za fitoremedijaciju.

Abstract (english)

Due to its economic profitability and wide application, plastic has become an indispensable
material in everyday human life. Plastic is broken down in environment by various physical
and chemical processes into smaller plastic particles, which is then known as microplastics
(MP). Degraded MP particles later become a big problem and a threat to the ecosystem and
organisms that come into contact with it, because they more easily interact with organic and
inorganic pollutants and adsorb them. MP usually adsorbs heavy metals and gradually releases
them into the environment. In this work the influence of pristine MP (a mixture of polyethylene,
polystyrene, polypropylene and rubber particles) and MP contaminated with a mixture of heavy
metals (copper, lead and zinc) was studied on the growth rate of greater duckweed (Spirodela
polyrhiza L.) and on certain physiological and biochemical indicators of oxidative stress
(photosynthetic pigments, carbonyls and malondialdehyde and activity of antioxidant
enzymes). Release of metals from the MP surface into the nutrient medium was determined, as
well as metal accumulation in the greater duckweed, though only accumulation of Cu at the
highest concentration of MP contaminated with metals was statistically significant compared
to control and other treatments. The growth rate was not statistically significantly affected by
the seven-day exposure of duckweed to pristine MP and MP contaminated with metals. An
increase in the activity of antioxidant enzymes was observed at the lower concentrations of
pristine MP and at the higher concentrations of MP with adsorbed metals. Lipid peroxidaiton
increased in response to MP contaminated with metals, while the content of carbonyls and
soluble proteins did not change significantly. In conclusion, greater duckweed represents a
suitable model for phytoremediation.

• Keywords: barska leća; reaktivni oblici kisika; antioksidacijski enzimi; lipidna peroksidacija; karbonili
• Keywords (english): greater duckweed; reactive oxygen species; lipid peroxidation; antioxidant enzymes; carbonyl
• Language: croatian
• URN:NBN: urn:nbn:hr:217:791201
• Study programme: Title: Enviromental Sciences; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra struke znanosti o okolišu (magistar/magistra struke znanosti o okolišu)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-09-03 12:44:49