Hola Joseba...my mother has been teaching Spanish for almost forty years, unfortunately I've never learned Spanish myself. Sad :( :(
About the mushroom. yes, it's undoubtly a member of Tremellaceae. a Tremella sp. . According to recent advances in the knowledge of this Genus, all live as parasites on other fungi, especially Stereum, but on Pyrenomycetes too, like yours. (Diaporthe? Hypoxylon?) and are host-specific (species or genus).
Probably another member could add further informations, perhaps a species name.
Bien cordialement
Jacques

Hola Jacques
No te martirices por no haber aprendido Español,  yo he estudiado durante años el Ingles y tampoco he conseguido aprenderlo´

He estado estudiando el hongo sobre el que esta parasitando y aunque solo he podido encontrar esporas en las 4 muerstras que he preparado,  creo que lo que es  claro es que se trata de un Diatrype,  aunque no he podido localizar cual, porque las medidasa de las esporas que he tomado son demasiado grandes para los que yo conozco.

Pongo las fotos a ver si puedes ayudar a alguien a darme alguna pista

Saludos
Joseba

Buena tarde Joseba

For me, both pictures of the pyrenomycete are consistent with Diatrype stigma, rather than D. disciformis (forming "true" discs, and spores much smaller) althought the carpophores (ascomes) aren't confluent as yet. But for the Tremella, I'm unable to put a sp. name on it; perhaps somebody in the forum could help?

About Spanish, I refuse to use Google translator or anything like, just a dictionnary to translate words I do not understand. Spanish and Italian (and Portuguese) are alongside French latin-based languages, so I try to find out the root of each word (e. g. "martirice", I think has the same root than the french "martyr" with is stronger) and hence the meaning.

Bonne soirée

Cordialement

jacques

Parece que puede ser Sirobasidium brefeldianum

Saludos
Joseba

Hola Joseba,

I found the original description of Sirobasidium, from Brazil; I don't know if the fungus has since been described from elsewhere in the world: it has been recorded in UK, so... Your specimens grow obviously ON the Pyrenomycetes. The swollen hyphae ("bubbles") are consistent with Tremella, but not the spores (globose by Tremella)???

https://www.biodiversitylibrary.org/page/13076899#page/367/mode/1up

Sorry, no further idea...

Bonne soirée

Jacques