Microbial production of hyaluronic acid from agro-industrial by-products: molasses and corn steep liquor

Abstract

Agro-industrial by-products are being explored as alternative low-cost nutrients to produce hyaluronic acid (HA) by Streptococcus zooepidemicus. In this study, we formulated three culture media containing corn steep liquor (CSL) and sugarcane molasses (M), to produce microbial HA using batch bioreactor conditions (pH 6.7, 500 rpm and 1 vvm aeration). Final HA concentrations of 3.48 g L1 were produced in culture medium containing corn steep liquor (10% v/v) and glucose, being comparable (3.60 g L1) to the control medium containing tryptone and glucose. The use of molasses (10% v/v) as carbon source produced a marked inhibition of S. zooepidemicus growth and HA production due to a low sugar consumption. The HA produced in CSL culture media had a high molecular weight of 3.8 × 103 kDa, greater than HA produced in tryptone-containing medium (3.0 × 103 kDa). This is the first report achieving HA productions comparable to synthetic a medium in a batch bioreactor using CSL as the main nitrogen source. However, further optimization of culture conditions must be carried out towards using this agricultural by-product for the sustainable industrial production of HA.