Production and rheological studies of microalgal biopolymer from lactose using a green alga strain

Abstract

It was discovered that a green alga strain had the capacity of producing up to 5 g/l high viscosity biopolymers from lactose under mixotrophic cultivation conditions. The molecular weight of the polymer was determined to be around 505,000 daltons. The polymers were shown to have similar rheological characteristics as xanthan gum, a commercial bacterial polysaccharides, which has found numerous applications in a large variety of different fields. The ability of this strain to utilize lactose for biopolymer production promises the potential of valuable biopolymer production from cheese whey, a waste liquor stream of the cheese industry that contains approximately 50 g/1 lactose. Using Plackett-Burnman experiment design and statistical analysis, it was determined that the major parameters affecting biopolymer production were the concentrations of sodium nitrate and lactose and temperature as well. Further studies on polymer characterizations, production optimization, and applications are under way.