As a result of these kinds of fermentation, cellulose- and
hemicellulose-derived sugars from lignocellulosic biomass can be
utilized with higher efficiency and productivity; however mixed
sugar cultures have not been used on an industrial scale because of
their many limitations. In mixed sugar cultures, the strains used do
not always have similar optimum culture conditions for pH, temperature,
nutrients, oxygen demand, etc.; therefore, it is not easy to
define the optimum condition or to maintain stable conditions for
such cultures during fermentation, and corresponding studies are
scarce. The discovery of LAB that have the capability to homofermentatively
utilize a wide range of sugars, including C5 and C6
sugars, and can resist the inhibitory compounds generated during
the pretreatment process is still a major challenge in fermentation
technology for the production of lactic acid from lignocellulosic
biomass.