“…RSMs with different designs have been successfully used for optimization in numerous bioprocesses, such as butanol production (Lin et al, 2011, Ranjan et al, 2013b), growth of propionic acid bacteria (Liew et al, 2005), lactic acid production (Dey et al, 2012), α-amylase production (Sivakumar et al, 2012), ethanol production (Ratnam et al, 2003, Wang et al, 2008), acid dye decolonization (Olya et al, 2014), fluoride ion removal in drinking water (Fakhri, 2014), wastewater treatment (Gengec et al, 2012) and biohydrogen production (Mu et al, 2006, Pan et al, 2008).…”