Ispitivanje aktivnosti elastaze u odabranih vrsta aspergila iz sekcije Nigri

master's thesis

• Title (english): Elastase activity in selected Aspergillus species from the Nigri section
• Author: Mia Jurinjak
• Mentor: Daniela Jakšić (mentor)
• Committee member: Daniela Jakšić (predsjednik povjerenstva)
• Committee member: Maja Šegvić Klarić (član povjerenstva)
• Committee member: Gordana Maravić Vlahoviček (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of microbiology); Zagreb
• Defense date and country: 2022-03-03, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Plijesni roda Aspergillus sekcije Nigri široko su rasprostranjene u okolišu te su neizmjerno značajne čovjeku zbog široke primjene u biotehnologiji i industriji. Također, ove plijesni predstavljaju rizik za zdravlje. Ukoliko plijesni proizvode enzim elastazu koja razgrađuje elastin u plućnom tkivu, povećava se invazivnost plijesni. Cilj ovog rada bio je ispitati uvjete rasta odabranih aspergila iz sekcije Nigri uključujući Aspergillus luchuensis, Aspergillus niger, Aspergillus piperis, Aspergillus tubingensis i Aspergillus welwitschiae nakon inkubacije 5, 7 i 14 dana na 37 °C na hranjivoj podlozi BHI koja sadrži ekstrakte mozga i srca te simulira fiziološke uvjete. Na podlogama CDA modificiranim s obzirom na udio anorganskog/organskog dušika ispitan je utjecaj dušika na rast plijesni (5, 7 i 14 dana na 37 °C). Elastazna aktivnost ispitana je na hranjivoj podlozi CDA bez nitrata uz dodatak supstrata elastin – kongo crveno (ECR), a procijenjena mjerenjem promjera razgradnje elastina provedeno 5., 7. i/ili 14. dan inkubacije na 37°C. Prikladnost modificirane CDA podloge sa ECR ispitana je pomoću standarda enzima elastaze nakon inkubacije 48 h na 37 °C.Sve ispitane vrste pokazale su dobar, propulzivni rast na podlozi BHI razmjerno period inkubacije na 37 °C. Na podlozi CDA sa i bez nitrata pokazano je da je dušik neophodni nutrijent osobito važan za razvoj micelija plijesni.Elastazna aktivnost dokazana je za izolate svih vrsta. Najveća aktivnost izmjerena je za vrstu Aspergillus niger te se ona kretala u rasponu od 1,556 do 1,680. Nešto niža elastazna aktivnost dokazana je kod vrsta A. tubingensis i A. welwitschiae, a po prvi puta je elastazna aktivnost pokazana kod vrsta A. luchuensis i A. piperis. Rezultati ovoga rada upućuju da i druge vrste crnih aspergila osim A. niger, A. tubingensis i A. welwitschiae mogu imati klinički značaj za čovjeka, posebno obzirom na utvrđenu elastaznu aktivnost ispitanih sojeva.

Abstract (english)

The Aspergillus section Nigri are widespread in the environment and due to their application in biotechnology and industry they are immensely important to humans. Furthermore, these molds have the potential to cause health problems. If the molds produce the enzyme elastase which breaks down elastin in lung tissue, the invasiveness of the mold increases.The aim of this paper was to examine the growth of selected Aspergilli from the section Nigri including Aspergillus luchuensis, Aspergillus niger, Aspergillus piperis, Aspergillus tubingensis and Aspergillus welwitschiae following five, seven and fourteen days of incubation at 37 °C on BHI agar containing brain and heart extracts and thus simulating physiological conditions. The impact of nitrogen on the fungal growth was investigated following five, seven and fourteen days of incubation at 37 °C on CDA agar modified with respect to the proportion of inorganic/organic nitrogen. Elastase activity was tested on the nitrate-free CDA with the addition of elastin - congo red (ECR) substrate. The measurement of the diameter of elastin degradation was carried out on the 5th, 7th and/or 14th day of incubation at 37°C. The suitability of the ECR-modified CDA was tested with elastase standard following 48 hrs incubation at 37 °C.All the tested isolates of the black Aspergilli showed good, propulsive growth on BHI medium. Growth characteristics on CDA, with or without nitrate, showed that nitrogen is essential nutrient for the growth of Aspergilli, especially for the mycelium development.The elastase activity was demonstrated for all the tested isolates. The highest elastase activity was measured for A. niger isolate (EI 1.556-1.680). Slightly lower levels of elastase activity were mesured for A. tubingensis and A. welwitschiae, while elastase activity was demonstrated for A. luchuensis and A. piperis for the first time. The results of this paper suggest that other species of the black Aspergilli besides A. niger, A. tubingensis, and A. welwitschiae may be clinically significant for humans, especially considering the observed elastase activity.

• Keywords: Aspergillus sekcija Nigri; elastaza; dušik
• Keywords (english): Aspergillus section Nigri; elastase; nitrogen
• Language: croatian
• URN:NBN: urn:nbn:hr:163:893379
• Study programme: Title: Pharmacy; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra farmacije (magistar/magistra farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-03-14 14:46:16