Biološko aktivni metaboliti ekstremofilnih glivnih vrst iz rodu Wallemia

izolacija, struktura in biološka aktivnost

Tanja Botić (Author), Željko Knez (Mentor), Kristina Sepčić (Co-mentor)

Abstract

Rod Wallemia obsega tri vrste, Wallemia sebi, Wallemia ichthyophaga in Wallemia muriae. W. sebi je kserotolerofilna, ubikvitarna, z živili povezana mikotoksigena gliva, ki je bila do leta 2005 tudi edina znana vrsta omenjenega rodu. V dostopni literaturi je le skopo opisana biološka aktivnost mikotoksinov, ki jih omenjena vrsta producira zatorej smo v doktorski nalogi podrobneje raziskali učinek izoliranih glivnih metabolitov iz vrst Wallemia na rdeče krvne celice, kakšno afiniteto izkazujejo do umetnih lipidnih veziklov ter tudi identificirali njihovo kemijsko strukturo. Ekstrakti, pridobljeni iz glivne biomase W. sebi s pomočjo kloroforma, superkritičnega CO2 in etanola, so izkazovali močno hemolitično aktivnost, ki je bila pri nižji vodni aktivnosti v rastnem gojišču glive večinoma izrazitejša. V testu litičnosti eritrocitov se je izkazalo, da je hemoliza odvisna od koncentracije etanolnega ekstrakta ter je močnejša v primeru bolj fluidnih membran. Analiza etanolnega ekstrakta in ekstrakta pridobljenega s superkritičnim CO2, opravljena s plinsko kromatografijo z masno spektrometričnim detektorjem je pokazala prisotnost mešanice sterolov in nenasičenih maščobnih kislin. Slednje smo potrdili kot povzročiteljice hemolize v biološkem testu. Litična aktivnost W. sebi kaže na potencialno vlogo izoliranih metabolitov pri tvorbi lezij ob subkutanih infekcijah, pri pljučih poljedelcev ter po zaužitju kontaminiranih živil, z glivo W. sebi. V doktorski nalogi se prvič omenja tudi produkcija hemolitično aktivnih metabolitov s strani drugih dveh vrst iz rodu Wallemia.

Keywords

glive;ekstremofili;Wallemia;metabolti;mikotoksini;biološka aktivnost;hemolitična aktivnost;lipidni vezikli;kemijska struktura;disertacije;

Data

Language:	Slovenian
Year of publishing:	2012
Source:	[Maribor
Typology:	2.08 - Doctoral Dissertation
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	T. Botić]
UDC:	615.918:582.284(043.3)
COBISS:	261873920
Views:	2923
Downloads:	256
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	BIOLOGICALLY ACTIVE METABOLITES FROM EXTREMOPHILIC FUNGAL STRAINS OF GENUS Wallemia: ISOLATION, STRUCTURE AND BIOLOGICAL ACTIVITY
Secondary abstract:	Within genus Wallemia three species has been recognized, Wallemia sebi, Wallemia ichthyophaga and Wallemia muriae. W. sebi is a xerotolerant, ubiquitous, food-borne, mycotoxigenic fungus and till 2005 it was the only known species of the genus Wallemia. Since very limited data about biological activity of mycotoxins produced by W. sebi exist, research work aimed to explore in more details effect of isolated fungal metabolites obtained from Wallemia species onto red blood cells, the affinity towards artificial lipid vesicles and finally to identify their chemical structure. A chlorophorm, supercritical CO2 and ethanol extract of W. sebi mycelium demonstrated a strong hemolytic activity, which was in most cases enhanced at lower water activity of the growth medium. The lytic activity of the ethanol extract showed a concentration-dependent hemolysis and preferential activity towards lipid membranes with greater fluidity. Characterization of the ethanol extract and extract obtained using supercritical CO2 by gas chromatography–mass spectrometry revealed a mixture of sterols and unsaturated fatty acids. Latter were confirmed to be responsible for the hemolytic activity in the biological assay. The W. sebi lytic activity on mammalian erythrocytes shows its potential involvement in the formation of lesions in subcutaneous infections, in farmer's lung disease, and in consumption of contaminated food and feed with W. sebi. For the first time the production of biologically active metabolites by two other strains within genus Wallemia has been revealed.
Secondary keywords:	genus Wallemia;Wallemia sebi;mycotoxins;hemolytically active metabolites;fatty acids;
URN:	URN:SI:UM:
Type (COBISS):	Dissertation
Thesis comment:	Univ. Maribor, Medicinska fak.
Pages:	XVI f., 127 str.
Keywords (UDC):	mathematics;natural sciences;naravoslovne vede;matematika;biological sciences in general;biologija;microbiology;mikrobiologija;
ID:	13049