“…Continuous stirred tank reactors, bubble columns, packed columns, air-lift, trickle beds and hollow fiber reactors are some of the bioreactor configurations studied for alcohol production using syngas fermentation (Datar et al, 2004;Hickey et al, 2011;Kimmel et al, 1991;Kundiyana et al, 2010;Mohammadi et al, 2012;Shen et al, 2014a). Further, these reactors can be operated in different fermentation modes such as batch, fed-batch, continuous with and without cell recycle (Cotter et al, 2009;Grethlein et al, 1991;Lewis et al, 2007;Maddipati et al, 2011;Phillips et al, 1993).…”