which actually represent
20% of the total production cost (Chiaramonti et al., 2012) and seed
culture of the microorganisms, are considered to increase the
overall energy input and cost of ethanol production. Unless otherwise
stated no physical or physicochemical and/or chemical pretreatment
was used to separate the biomass components and
eventually remove the lignin so that the extractable parts of the
CER is accessible for the fermentation step.