Use of wheat straw and chicken feather hydrolysates as a complete medium for lactic acid production

Biotechnological production of lactic acid has experienced a boom that is hindered only by the lack of low-cost, abundant material that might be used as a substrate for lactic acid bacteria. Such material should contain not only carbon but also complex nitrogen sources, amino acids and vitamins necessary for the balanced growth of the bacteria. Here, for the first time, a combination of hydrolysates of wheat straw and chicken feathers was used as a complete waste cultivation medium for lactic acid production. It was shown to be a promising substrate for lactic acid production, reducing the medium price by 73% compared with MRS broth, providing more than 98% lactic acid yield and high productivity (2.28 +/- 0.68 g/l/h) in a fed-batch process using Lactobacillus reuterii LHR14.