20.500.12556/RUL-186674 Penicillium expansum kot modelni mikroorganizem za oceno adsorpcije pesticidov na kmetijskih folijah magistrsko delo Penicillium expansum as a model microorganism for assessing pesticide adsorption on agricultural films master thesis Uvod: Folije iz umetnih mas in biorazgradljive folije predstavljajo pomemben zastirni material v sodobnem kmetijstvu. Naloga zastirk je zaščita pridelka pred neugodnimi vremenskimi vplivi, zmanjševanje rasti plevela, ohranjaje vlage v tleh ter zmanjševanje spiranja hranil. Kljub številnim prednostim pa njihova uporaba prispeva k onesnaževanju z mikroplastiko v kmetijskih okoljih. Razgradnja zastirnih biorazgradljivih folij in folij iz fosilnih polimerov (PE), ki so pogosto obremenjene s pesticidi, je povezana s sproščanjem adsorbiranih, potencialno škodljivih snovi v okolje. To lahko povzroči negativne učinke na mikrobiom tal in širši ekosistem. Njihovo razgradnjo povzroča v veliki večini izpostavljenost UV svetlobi in vodna hidroliza. Namen: Raziskava se osredotoča na učinek adsorbiranega fungicida azoksistrobina (AZO) na konvencionalnih in biorazgradljivih folijah na rast plesni Penicillium expansum, ki predstavlja modelni mikroorganizem, prisoten v talnem ekosistemu. Gliva tvori toksin patulin (PAT), ki v naši študiji služi za merjenje aktivnosti plesni na folijah ob prisotnosti AZO. Metode dela: Preučevali smo vpliv adsorbiranega fungicida AZO na rast plesni P. expansum na novih in staranih (konvencionalnih in biorazgradljivih) zastirnih folijah (PBAT/PLA, TPS, PE). Na sterilizirane koščke folije velikosti 3 × 3 cm, pridobljene z njive v Jabljah, smo nanesli AZO v treh koncentracijah (0,56 mg m-2; 1,11 mg m-²; 1,67 mg m-²). Folije smo položili na površino nehranljivega trdnega gojišča z anorganskimi solmi brez vira ogljika, nanje položili sterilne diske filter papirja, na katere smo vcepili suspenzijo konidijev plesni P. expansum. Po 21 dneh inkubacije pri 25 ℃ smo določili premer poraslih kolonij in z visokozmogljivo tekočinsko kromatografijo z diodnim detektorjem (HPLC-DAD) kemijsko določili koncentracijo mikotoksina PAT, kot tudi vse ostale raztopine, ki so vsebovale AZO. Pridobljene rezultate smo statistično obdelali in primerjali vpliv različnih vrst zastirnih folij ter koncentracij adsorbiranega fungicida na rast plesni in tvorbo PAT. Rezultati: Plesen P. expansum je uspešno rasla na vseh uporabljenih biorazgradljivih zastirnih folijah, TPS in PBAT/PLA, medtem ko je bila rast na PE folijah zelo slaba. Med staranimi in novimi folijami statistično značilnih razlik v premeru kolonij ni bilo. Prisotnost adsorbiranega fungicida AZO je vplivala na rast plesni, vendar je pri tem vplivala vrsta folije in koncentracija fungicida. Določanje PAT je prikazalo spremembe v aktivnosti plesni, ki niso nujno sovpadne z rastjo kolonij, kar poudari pomen spremljanja obeh parametrov. Ugotovili smo, da lahko vrsta zastirne folije pomembno vpliva na razvoj plesni in njeno presnovno aktivnost v kmetijskih tleh. Razprava in zaključek: AZO se je izkazal kot učinkovit fungicid pri zaviranju rasti plesni P. expansum in je lahko dobra modelna spojina za študij vektorskega vpliva adsorbiranih pesticidov na MP. Največji učinek je bil ugotovljen na PE folijah, kjer je bila rast popolnoma zavrta. Na biorazgradljivih zastirnih folijah je bila inhibicija manjša, kar nakazuje, da polimer vpliva na afiniteto vezave AZO in odziv plesni. Tvorba PAT ni bila neposredno povezana s dodano koncentracijo AZO, saj so nižje koncentracije AZO spodbujale njegovo sintezo, medtem ko so višje koncentracije sintezo zavirale. Zlasti biorazgradljive folije so zmanjšale tvorbo PAT tudi ob odsotnosti AZO, kar je verjetno povezano s spremembami površinskih lastnosti materialov med izpostavljenostjo okoljskim dejavnikom. Kombinacija fungicidov in lastnosti folij pomembno vpliva na rast te plesni ter njeno presnovno aktivnost v kmetijskih tleh. Introduction: Plastic and biodegradable films are important mulching materials in modern agriculture. Mulches protect crops from adverse weather conditions, reduce weed growth, retain soil moisture and reduce nutrient leaching. Despite their numerous advantages, their use contributes to microplastic pollution in agricultural environments. The degradation of biodegradable and fossil polymer (PE) mulch films, which are often loaded with pesticides, is associated with the release of adsorbed, potentially harmful substances into the environment. This can cause negative effects on the soil microbiome and the wider ecosystem. Their degradation is largely caused by exposure to UV light and aqueous hydrolysis. Purpose: The research focuses on the effect of the adsorbed fungicide azoxystrobin (AZO) on conventional and biodegradable films on the growth of the mould Penicillium expansum, which is a model microorganism present in the soil ecosystem. The fungus produces the toxin patulin (PAT), which in our study serves as a chemical measure of mould activity on films in the presence of AZO). Methods: We studied the effect of the adsorbed fungicide AZO on the growth of P. expansum mould on new and aged conventional and biodegradable mulch films (PBAT/PLA, TPS, PE). AZO was applied to sterilised pieces of film measuring 3 × 3 cm, obtained from a field in Jablje, in three concentrations (0.56 mg m-2; 1.11 mg m-²; 1.67 mg m-²). The films were placed on the surface of a non-nutritive solid medium with inorganic salts and without a carbon source, and sterile filter paper discs were placed on them, onto which a suspension of P. expansum mould conidia was inoculated. After 21 days of incubation at 25 ℃, the diameter of the colonies was measured and the concentration of the mycotoxin PAT was determined chemically by high-performance liquid chromatography with a diode array detector (HPLC-DAD), as were all other solutions containing AZO. The results obtained were processed statistically and the influence of different types of mulch films and concentrations of adsorbed fungicide on mould growth and PAT formation was compared. Results: The mould P. expansum grew successfully on all biodegradable mulch films used, TPS and PBAT/PLA, while growth on PE films was very poor. There were no statistically significant differences in colony diameter between aged and new films. The presence of adsorbed fungicide AZO affected mould growth, but this depended on the type of film and the concentration of the fungicide. PAT determination showed changes in mould activity that did not necessarily coincide with colony growth, which emphasises the importance of monitoring both parameters. We found that the type of mulch film can significantly affect the development of the mould and its metabolic activity in agricultural soils. Discussion and conclusion: AZO proved to be an effective fungicide in inhibiting the growth of the mould P. expansum and can be a good model compound for studying the vectorial impact of adsorbed pesticides on MPs. The greatest effect was observed on PE mulch film, where growth was completely inhibited. On biodegradable mulch film, inhibition was lower, suggesting that the polymer affects the binding affinity of AZO and the mould response. PAT formation was not directly related to colony diameter, as lower concentrations of AZO promoted its synthesis, while higher concentrations inhibited synthesis. In particular, biodegradable films reduced PAT formation even in the absence of AZO, which is probably related to changes in the surface properties of the materials during exposure to environmental factors. The combination of fungicides and mulch film properties significantly affects the growth of this mould and its metabolic activity in agricultural soils. magistrska dela sanitarno inženirstvo folija Penicillium expansum azoksistrobin patulin biorazgradljivost master's theses sanitary engineering plastic mulch film Penicillium expansum azoxystrobin patulin biodegradability true false false [M. Smrečnik] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2026-09-04 07:46:39 2026-09-04 07:46:47 2026-09-05 04:33:55 0000-00-00 00:00:00 2026 0 Ljubljana 0 Ljubljana XI, 40 str. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 614 163156 290049795 63417.pdf 63417.pdf 1 210A019696BEA0BB46BCC81EE6FF8A41 63007924f24bd0f391514371fdf3f076be6c49422fa3b01ea86dea3bbdeaf325 0402ab7e-a824-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=245992 Zdravstvena fakulteta 0 0 0