Bioreactors, Cell cultivation, Fermentation, Fermenting, Protein production, Clone Characterisation, Microbial cultivation, Perfusion, Micro organism, Metabolic activity, Respiratory Quotient, RQ, Oxygen Uptake Rate, OUR, Oxygen Transfer Rate, OTR, CTO, CER, Bio-plant, Fed-batch, Cellferm, Proteomics, Metabolomics, Feeding Strategies, Screening, Protein expression, Reactors, CTR, Bioreactor, Strain selection, Off gas analyzer