the use of biological processes or materials to change organic substances into a new form, such as the conversion of waste into methane by fermentation
bioconversion in American English
(ˌbaɪoʊkənˈvɜrʒən; ˌbaɪoʊkənˈvɜrʃən)
noun
the process of generating a fuel from biological waste matter by the action of microorganisms