How can I get rid of Background from a String?

Question

For explanatory purposes I have marked parts of a string with different backgrounds.

But this string is part of some Mathematica expression, which processed. My program worked fine before I added the explanatory highlighting. It does not work any longer after my highlighting.

Now I look for some procedure, which removes all Background outline from a Mathematica string in order to be able to use my example without removing any highlighting it might contain. A Shift-Ctl-Space would be unsportsmanlike, of course, because the explanation is, after all, helpful for understanding.

Example:

"String mit einem \!\(\*StyleBox[\"markierten\",Background->RGBColor[1, 1, 0.85]]\) Wort."

shall become (regardless of the color of the Background)

"String mit einem markierten Wort."

Answer 1

str1 = "String mit einem \!\(\*StyleBox[\"markierten\",Background->RGBColor[1, 1, 0.85]]\) Wort.";

str2 = ExportString[str1, "Text"]

(* returns "String mit einem markierten Wort." *)