Hydrophobins are proteins produced only by fungi (Ascomycetes and Basidiomycetes) that are able to self-assemble into an amphipatic membrane at an interface thus changing the nature of surfaces. Although hydrophobins from different species have low sequence homology, they present approximate hydrophaty patterns, are rich in cysteine and can be distinguished in two classes, class I and class II. The general objective of this research was the production and characterization of hydrophobins with potential use in oral medicine. Three strains, fungal isolates L7 and C1.1 from the laboratory collection and Bjerkandera sp. BOS55 (L3) also from the laboratory collection were tested for hydrophobin production. Fungal ITS amplification and sequencing allowed the identification to species of L7 and C1.1 isolates, respectively, Mucor circinelloides and Hypocrea lixii (Trichoderma harzianum). Hydrophobins from all three strains were produced, extracted and further characterized. For biochemical characterization of all three isolates, the extracellular fluid of all isolates was tested for foam stability, oil spreading assay and surface tension. The assessment of conidial hydrophobicity was performed for conidial suspension and mycelium wettability was tested in surface hyphae. Extracellular fluid of isolate Hypocrea lixii (Trichoderma harzianum) showed better performance than the others, and also presented the most impermeable mycelia, as observed by surface wettability assay. Mucor circinelloides presented the most hydrophobic conidia. SEM observations seem to indicate that all three isolates possess class I surface hydrophobins. All hydrophobin mixtures obtained presented antimicrobial, as well as efficient inhibition of biofilm formation by Candida albicans. The characterization of concentrated hydrophobin mixtures by HPLC showed two peaks with hydrophobic characteristics, which will be characterized in future studies. So, within this work was possible to isolate hydrophobins with efficacy on the protection of biofilm formation and inhibition of microbial growth, demonstrating a potential for oral medicine applications.
Date of Award | 2014 |
---|
Original language | English |
---|
Awarding Institution | - Universidade Católica Portuguesa
|
---|
Supervisor | Maria Manuela Pintado (Supervisor) & Patrícia Moreira (Supervisor) |
---|
- Mestrado em Microbiologia Aplicada
Production and characterization of hydrophobins wirh potential for oral medicine applications
Fernandes, C. F. (Student). 2014
Student thesis: Master's Thesis