Meanwhile, the brewing industry holds a strategic economic position with an annual world
beer production exceeding 1.34×109 hL in 2002. The brewing process uses large volumes of
water in a number of different batch-type operations in processing raw materials to the final
beer product. Water is a very substantial ingredient of beer, composing of 90–95 % of beer by
mass [10]. An efficient brewery uses between 4 and 7 L of water to produce 1 L of beer for the
brewing, rinsing, and cooling processes [11]. Thus, a large amount of brewery wastewater
(BW) is discharged to the drains as effluent. This water must be disposed of or safely treated
for reuse, which is often costly and problematic for most breweries. The BW contains
biological contaminants (0.7–2.1 kg of BOD/barrel) [10]. The main solid wastes are spent
grains, yeast, spent hops, and diatomaceous earth. BW is not toxic, does not usually contain
appreciable quantities of heavy metals, and is easily biodegradable [12]. BW can be a good
source of nutrition for microorganism and bioproduction of a platform chemical which is
important from both carbohydrate economy and biorefinery prospects.