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001-es BibID:	BIBFORM073406
Első szerző:	Szilágyi Melinda (biológus)
Cím:	Autolytic enzymes are responsible for increased melanization of carbon stressed Aspergillus nidulans cultures / Melinda Szilágyi, Fruzsina Anton, István Pócsi, Tamás Emri
Dátum:	2018
ISSN:	0233-111X
Megjegyzések:	Melanization of carbon stressed Aspergillus nidulans cultures were studied. Melanin production showed strong positive correlation with the activity of the secreted chitinase and ?-1,3-glucanase. Deletion of either chiB encoding an autolyticendochitinase or engA encoding an autolytic ?-1,3-endoglucanase, or both, almost completely prevented melanization of carbon stressed cultures. In contrast, addition of Trichoderma lyticase to cultures induced melanin production. Synthetic melanin couldefficiently inhibit the purified ChiB chitinase activity. It could also efficiently decrease the intensity of hyphal fragmentation and pellet disorganization in Trichoderma lyticase treated cultures. Glyphosate, an inhibitor of L-3,4 dihydroxyphenylalanine type melanin synthesis, could prevent melanization of carbon-starved cultures and enhanced pellet disorganization, while pyroquilon, a 1,8-dihydroxynaphthalene-type melanin synthesis inhibitor, enhanced melanization, and prevented pellet disorganization. We concluded that cell wall stress induced by autolytic cell wall hydrolases was responsible for melanization of carbon-starved cultures. The produced melanin can shield the living cells but may not inhibit the degradation and reutilization of cell wall materials of dead hyphae. Controlling the activity of autolytic hydrolase productioncan be an efficient approach to prevent unwanted melanization in the fermentation industry, while applying melanin synthesis inhibitors can decrease the resistance of pathogenic fungi against the chitinases produced by the host organism.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Journal of Basic Microbiology 58 : 5 (2018), p. 440-447. -
További szerzők:	Anton Fruzsina Pócsi István (1961-) (vegyész) Emri Tamás (1969-) (biológus)
Pályázati támogatás:	K112181 OTKA
Internet cím:	DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM031081
Első szerző:	Szilágyi Melinda (biológus)
Cím:	Extracellular proteinase formation in carbon starving Aspergillus nidulans cultures - physiological function and regulation / Melinda Szilágyi, Nak-Jung Kwon, Fruzsina Bakti, Márta M-Hamvas, Katalin Jámbrik, HeeSoo Park, István Pócsi, Jae-Hyuk Yu, Tamás Emri
Dátum:	2011
ISSN:	0233-111X
Megjegyzések:	Extracellular proteinase formation in carbon depleted cultures of the model filamentousfungus Aspergillus nidulans was studied to elucidate its regulation and possible physiologicalfunction. As demonstrated by gene deletion, culture optimization, microbial physiological andenzymological experiments, the PrtA and PepJ proteinases of A. nidulans did not appear to playa decisive role in the autolytic decomposition of fungal cells under the conditions we tested.However, carbon starvation induced formation of the proteinases observable in autolyticcultures. Similar to other degradative enzymes, production of proteinase was regulated byFluG-BrlA asexual developmental signaling and modulated by PacC-dependent pH-responsivesignaling. Under the same carbon starved culture conditions, alterations of CreA, MeaB orheterotrimeric G protein mediated signaling pathways caused less significant changes in theformation of extracellular proteinases. Taken together, these results indicate that while theaccumulation of PrtA and PepJ is tightly coupled to the initiation of autolysis, they are notessential for autolytic cell wall degradation in A. nidulans. Thus, as Aspergillus genomes contain alarge group of genes encoding proteinases with versatile physiological functions, selectivecontrol of proteinase production in fungal cells is needed for the improved industrial use offungi.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Journal Of Basic Microbiology. - 51 : 6 (2011), p. 625-634. -
További szerzők:	Kwon, Nak-Jung Bakti Fruzsina Mikóné Hamvas Márta (1963-) (biológus) Jámbrik Katalin Park, Hee-Soo Pócsi István (1961-) (vegyész) Yu Jae-Hyuk Emri Tamás (1969-) (biológus)
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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