1. Introduction
Lactic acid is one of the earliest fermentation products from
microbial metabolism. Lactic acid has a wide of applications,
and is used primarily in the food industry as acidulate and
preservative, and for production of emulsifying agents [1]. One
of its potentials is in its use as a precursor for biodegradable
poly lactic acid production [2,3].
Commonly, lactic acid is prepared by using refined sugars
and starch materials [4,5]. In recent years, for the sake of
decreasing environmental pollution and expense of lactic acid
production, various wastes like kitchen waste [6–8], waste
water sludge [9,10], food processing wastes [11], waste office
paper [12], crop residue including corn cobs, wheat stalk and
bran, have been used for lactic acid production [13–15].
However, utilization of soybean stalk for lactic acid production