Abstract: A range of concentrations exists in which fermentation inhibitors derived from pretreatment of lignocellulosic feed stocks inhibit growth of lactic acid bacteria without affecting fermentive yeast. By optimizing levels of fermentation inhibitors to fall within this range, yeast fermentations of lignocellulosic biomass can be conducted under non-sterile conditions with ethanol yields comparable to those achieved under sterile conditions. Optimised inhibitor levels can be achieved by controlling the water/biomass ratio of a lignocellulosic biomass during and after pretreatment, for example by washing the fiber fraction of a previously pretreated lignocellulosic biomass with a pre-defined amount of fresh water or recycled process solutions. Crude extracts of liquid fraction or process solutions from pretreatment of lignocellulosic biomass can also provide an effective anti-bacterial treatment for first generation starch fermentations.

Abstract: The invention relates to methods of processing ensiled biomass for production of bioethanol or other fermentation products and, in particular, to methods that do not require expensive pretreatment (e.g. heat or chemical pretreatment).

Abstract: Provided are methods of liquefaction, saccharification and fermentation of pre-treated lignocellulosic biomass in production of bioethanol. Addition of PEG or surfactant is effective to enhance cellulase hydrolysis yields at high dry matter (>20%) at surprisingly low concentrations compared with comparable results in low dry matter hydrolysis. This effect is most pronounced at comparatively low cellulase loading <7 FPU (g DM)?1. At high dry matter content, cellulase enzyme consumption can be reduced, without loss of hydrolysis yield, by addition of small quantities of PEG or surfactant.

Abstract: The present invention relates to a process for liquefaction and saccharification of polysaccharide containing biomasses, having a relatively high dry matter content. The present invention combines enzymatic hydrolysis with a type of mixing relying on the principle of gravity ensuring that the biomasses are subjected to mechanical forces, primarily shear and tear forces. Furthermore, the present invention relates to the further utilization of such processed biomasses, e.g. for subsequent fermentation into bio-ethanol, bio-gas, specialty carbohydrates for food and fees as well as carbon feedstock for processing into plastics and chemicals.