Where does Actino- come from in the genus Actinomycetota?

Question

This comment under Bacteria trapped in crystal inclusions found 'alive' after 50,000 years - what were they eating all that time? links to Quintana, Badillo ann Maldonado (2013) Characterisation of the first actinobacterial group isolated from a Mexican extremophile environment. The term "Actinobacteria" seems to be synonymous with the phylum Actinomycetota.

According to van Bergeijk et al. (2020) Ecology and genomics of Actinobacteria: new concepts for natural product discovery

Actinobacteria constitute a highly diverse bacterial phylum with an unrivalled metabolic versatility. They produce most of the clinically used antibiotics and a plethora of other natural products with medical or agricultural applications. Modern ‘omics’-based technologies have revealed that the genomic potential of Actinobacteria greatly outmatches the known chemical space.

I have found Phylum Actinomycetota:

Etymology: Ac.ti.no.my.ce.to’ta. N.L. masc. n. Actinomyces, type genus of the phylum; L. neut. pl. n. suff. -ota, ending to denote a phylum; N.L. neut. pl. n. Actinomycetota, the Actinomyces phylum

But so far I have not found the origin of the "Actino-" part of the genus name.

Question: Where does Actino- come from in the genus Actinomycetota?

Is it perhaps related to actinide somehow?

Answer 1

This one is easily answered.

The Actino part of is derived from the first described genus in this group; Actinomyces and means "ray" as the formation of a colony has a light-ray-like appearance, as seen in this photo from Wikimedia:

^{Image attribution: US gov, Public domain, via Wikimedia Commons}

Incidentally the "myce" part means "fungus", as it was thought from the appearance of the colonies, which sometimes show mycelia-like formations, that they were fungi, until later proven to be bacteria.