Učinak nanočestica srebra na vodenu leću (Lemna minor L.)

master's thesis

• Title (english): The effect of silver nanoparticels on duckweed ( Lemna minor L.)
• Author: Eda Puntarić
• Mentor: Sandra Radić Brkanac (mentor)
• Committee member: Sandra Radić Brkanac (predsjednik povjerenstva)
• Committee member: Renata Matoničkin Kepčija (član povjerenstva)
• Committee member: Blanka Cvetko Tešović (član povjerenstva)
• Committee member: Danijel Orešić (član povjerenstva)
• Committee member: Mladen Juračić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2014-12-12, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Nanočesticama smatramo tvari čije su sve tri dimenzije manje od 100 nm. Zbog veće aktivne površine po masi, nanočestice su se pokazale biološki aktivnije od njihovih "većih dvojnika" (čestice mikrometarskih dimenzija) istog kemijskog sastava. Povećano korištenje nanočestica rezultira otpuštanjem istih u okoliš. U ovom je radu istražen učinak nanočestica srebra u rasponu koncentracija 0,1, 0,5, 1, 2 i 5 mg L-1 na vodenu leću (Lemna minor L.) koja je često korištena testna biljka. Primijenjen je statički oblik standardiziranog Lemna-testa (test inhibicije rasta) u trajanju od sedam dana koji se temelji na stopama rasta. Osim rasta, određen je sadržaj srebra u biljkama i podlogama, sadržaj klorofila a i b, karotenoida, te pojedini pokazatelji oksidacijskog stresa u vodenoj leći. Nanočestice srebra značajno su smanjile stopu rasta broja listića i mase svježe tvari te sadržaj mjerenih fotosintetskih pigmenata. S druge strane, taj je metal uzrokovao povećanje oksidacijskog oštećenja lipida te promjene u aktivnosti antioksidacijskih enzima (superoksid dismutaze, askorbat peroksidaze i katalaze). Dobiveni rezultati ukazuju na toksičnost nano čestica srebra za vodenu leću što je vjerojatno posljedica povećanog nakupljanja nanočestica u biljnom tkivu. Rezultati također pokazuju da je oksidacijski stres uključen u mehanizam toksičnosti nanočestica srebra.

Abstract (english)

Nanoparticles are substances with all three dimensions less than 100 nm. Due to the larger active surface area per mass, nanoparticles have proven to be biologically active than their "larger duplicates" (particles of micrometer dimensions) of the same chemical composition. Increased use of nanoparticles results in their release into the environment. This thesis examines the effect of silver nanoparticles in the concentration range of 0.1,0.5,1,2 and 5 mg L-1) on duckweed (Lemna minor L.), which is often used as a test plant. A static test design of the standardized Lemna toxicity test (a growth inhibition test) based on growth rates in the duration of seven days was applied. In addition to growth, Ag content of media and plant material, chlorophylls, carotenoids and certain indicators of oxidative stress in duckweed have been determined. Silver nanoparticles significantly reduced growth rate and content of photosynthetic pigments. On the other hand, metal nanoparticles caused oxidative damage to lipids as well as the modulation of antioxidant enzyme activities (superoxide dismutase, catalase and ascorbate peroxidase). The obtained results confirm the toxicity of silver nanoparticles to duckweed, which is probably due to increased accumulation of silver nanoparticles in plant tissue. Furthermore, the results indicate that oxidative stress is involved in the toxicity mechanism of silver.

• Keywords: nanočestice; srebro; vodena leća; toksičnost; oksidacijski stres
• Keywords (english): nanoparticles; silver; duckweed; toxicity; oxidative stress
• Language: croatian
• URN:NBN: urn:nbn:hr:217:051188
• 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: Access restricted to students and staff of home institution
• Created on: 2017-04-26 11:54:14