Primjena metagenomskih esteraza za okolišno prihvatljivu razgradnju polimliječne kiseline

master's thesis

• Title (english): Application of metagenomic esterases for environmentally friendly degradation of polylactic acid
• Author: Eva Josić
• Mentor: Aleksandra Maršavelski (mentor)
• Mentor: Marko Močibob (mentor)
• Committee member: Aleksandra Maršavelski (predsjednik povjerenstva)
• Committee member: Tajana Begović (član povjerenstva)
• Committee member: Ivana Kekez (član povjerenstva)
• Committee member: Marko Močibob (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2024-02-21, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Polimliječna kiselina (PLA) je biorazgradiv polimer čija su termička i mehanička obilježja slična masovno korištenoj plastici problematičnoj za zbrinjavanje. Biorazgradivosti i fizikalna svojstva čine PLA kandidatom za proizvodnju plastike koja se može razgraditi na okolišno prihvatljiv način. Enzimi koji razgrađuju PLA, za prihvatljivu okolišnu i industrijsku razgradnju, spadaju u skupinu α/β-hidrolaza. Trenutno je identificiran mali broj hidrolaza s aktivnošću prema PLA, a jednu od najvećih posjeduje nedavno otkriveni enzim MGS0156. U ovom diplomskom radu proizvedeni su MGS0156, njegov mutant i novi, do sada neokarakterizirani homolog, pronađen pretragom metagenomskih baza podataka. Hidrolitička aktivnost enzima prema PLA provjerena je u agaroznom gelu i slobodnoj suspenziji. Ovdje je prvi put pokazana aktivnost novog metagenomskog enzima prema PLA, koja se pokazala značajno većom od većine aktivnosti zabilježenih u literaturi. Računalnim metodama utvrđeno je da oba enzima imaju mobilni poklopac, identificirane su aminokiseline veznog mjesta s najvećim doprinosom vezanju supstrata i potencijalne mete za mutacije.

Abstract (english)

Polylactic acid (PLA) is a biodegradable polymer with thermal and mechanical properties like those of widely used plastics with problematic disposal. Its biodegradability and physical properties make PLA a candidate for environmentally friendly plastic production. PLA-degrading enzymes used for environmentally friendly and industrial degradation, belong to the α/β-hydrolase group. A small number of PLA-hydrolases is identified, with one of the greatest activities belonging to a recently discovered MGS0156. Here, MGS0156, its mutant and a new, previously uncharacterized homologue discovered in metagenomic databases were produced. The hydrolytic activity towards PLA was tested in an agarose gel and a suspension. The hydrolytic activity of the new metagenomic enzyme was demonstrated for the first time and was found to be significantly higher than most activities documented in the literature. Using computational methods, it was found that both enzymes contain a mobile lid, binding site amino acids with the largest contribution to substrate binding were identified as well as potential mutation targets

• Keywords: depolimeraza plastike; difuzijski test enzimske aktivnosti; kružna mutageneza; polimliječna kiselina; simulacija molekulske dinamike; slobodna energija vezanja; test enzimske aktivnosti u suspenziji
• Keywords (english): circular mutagenesis; diffusion assay for enzymatic activity; enzyme activity in suspension assay; free energy of binding; molecular dynamics simulation; plastic depolymerase; polylactic acid
• Language: croatian
• URN:NBN: urn:nbn:hr:217:597947
• Study programme: Title: Graduate university studies in chemistry; specializations in: Graduate university studies in chemistry; Course: Graduate university studies in chemistry; Study programme type: university; Study level: graduate; Academic / professional title: sveučilišni/a magistar/magistra kemije (sveučilišni/a magistar/magistra kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2025-02-21
• Created on: 2024-03-07 14:14:31