Title Biorazgradnja polistirena i poli(vinil-klorida) bakterijama izoliranih iz okoliša Title (english) Biodegradation of polystyrene and polyvinyl chloride by bacteria isolated from the environment Author Paula Patrčević Mentor Dajana Kučić Grgić (mentor)Committee member Dajana Kučić Grgić (predsjednik povjerenstva)Committee member Šime Ukić (član povjerenstva)Committee member Matija Cvetnić (član povjerenstva)Granter University of Zagreb Defense date and country 2021-09-27, Croatia Scientific / art field, TECHNICAL SCIENCES Abstract Plastika se široko koristi u gotovo svakom aspektu svakodnevnog života, a neka od svojstava koja tome pogoduju su niska cijena, trajnost, mala gustoća i dobra rastezljivost. Zanimljivo je kako je godišnja globalna proizvodnja plastike premašila 300 milijuna tona, zbog čega njezino nakupljanje u kopnenom i morskom okolišu postupno privlači sve veću pažnju znanstvenika. Znanstvenici su tokom 1970-ih prvi puta izvijestili o malim plastičnim česticama u oceanu – mikroplastici. Mikroplastika
... More predstavlja bilo koju sintetičku čvrstu česticu plastike ili polimernu matricu (netopivu u vodi), pravilnog ili nepravilnog oblika i veličine od 1 μm do 5 mm. U ovom radu proučavana je biorazgradnja dviju vrsta mikroplastike – polistirena (PS) i poli(vinil-klorida) (PVC) pomoću dviju bakterijskih kultura – gram-negativne bakterijske kulture Pseudomonas alcaligenes i gram-pozitivne bakterijske kulture Bacillus subtilis. Plan eksperimenta je napravljen prema Taguchi dizajnu što znači da su definirani određeni čimbenici koji su ispitivani pri svojoj minimalnoj i maksimalnoj vrijednosti – pH vrijednost, temperatura, broj okretaja, veličina mikroplastike, koncentracija mikroplastike, optička gustoća i dodatak glukoze. U svrhu utvrđivanja značajnih čimbenika tijekom biorazgradnje mikroplastike PS-a i PVC-a bakterijskim kulturama Pseudomonas alcaligenes i Bacillus subtilis u ovom istraživanju provedeno je nekoliko analiza. Osim logaritamske vrijednosti ukupnog broja živih bakterijskih stanica, log CFU, pratila se i optička gustoća, koncentracija ukupnog ugljika, ukupnog organskog ugljika i ukupnog anorganskog ugljika, koncentracije kationa i aniona, toksičnost filtrata pomoću bakterijske kulture Vibrio fischeri, FTIR-ATR spektroskopska analiza mikroplastike, produkti biorazgradnje te prisutstvo aditiva tekućinskom kromatografijom visoke djelotvornosti (HPLC). Naposljetku su određeni značajni čimbenici za provedene procese biorazgradnje za obje bakterije i obje vrste MP-a, uz ANOVA statističku analizu eksperimentalnih podataka. Značajnijim čimbenicima u pokusu s bakterijskom kulturom Pseudomonas alcaligenes pokazali su se broj okretaja, veličina čestica MP-a, dok su značajniji čimbenici u pokusu s bakterijskom kulturom Bacillus subtilis bili pH-vrijednost, broj okretaja, veličina čestica mikroplastike, optička gustoća i koncentracija dodane glukoze. Less Abstract (english) Plastics are widely used in all aspects of daily life due to their properties such as low price, durability, light weight and good malleability. The global annual production of plastics exceeds 300 million tons, so the accumulation of plastics in the terrestrial and marine environment has attracted the attention of scientists. As early as the 1970s, scientists reported small plastic particles in the ocean - microplastics. Microplastic is defined as any synthetic solid plastic particle
... More or polymeric matrix (water insoluble) with regular or irregular shape and size from 1μm to 5 mm. In this study, the biodegradation process of two types of microplastics - polystyrene (PS) and polyvinyl chloride (PVC) - was observed using two different bacterial cultures - gram-negative Pseudomonas alcaligenes and gram-positive Bacillus subtilis. This experiment was conducted according to Taguchi design, therefore all the observed factors had their minimum and maximum value - pH, temperature, rpm, microplastic particle size, microplastic concentration, optical density and added glucose. In order to determine significant factors during the biodegradation of microplastics - PS and PVC with bacterial cultures of Pseudomonas alcaligenes and Bacillus subtilis, several analyzes were performed in this study. In addition to the logarithmic value of the total number of live bacterial cells, log CFU, optical density, total carbon, total organic carbon and total inorganic carbon concentration, cation and anion concentrations, filtrate toxicity with bacterial culture Vibrio fischeri, FTIR-ATR spectroscopic microplastic analysis, amonitoring of biodegradation products and the presence of additives using liquid high performance chromatography (HPLC). Finally, significant factors for the conducted biodegradation processes for both bacteria and both types of MP were determined, with ANOVA statistical analysis of the experimental data. Significant factors in the experiment with bacterial culture of Pseudomonas alcaligenes were the number of revolutions of the mixer per minute, particle size of MP, while more significant factors in the experiment with bacterial culture of Bacillus subtilis were pH value, number of revolutions of microplastic, particle size , optical density and concentration of added glucose. Less Keywords
mikroplastika
biorazgradnja
polistiren
poli(vinil-klorid)
Pseudomonas alcaligenes
Bacillus subtilis
Keywords (english)
microplastics
biodegradation
polystyrene
polyvinyl chloride
Pseudomonas alcaligenes
Bacillus subtilis
Language croatian URN:NBN urn:nbn:hr:149:174561 Project Number: IP-2019-04-9661 Study programme Title: Applied Chemistry - Graduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry Type of resource Text File origin Born digital Access conditions Open access Terms of use Created on 2023-04-19 11:44:01
