Deacidification of grass silage press juice by continuous production of acetoin from its lactate via an immobilized enzymatic reaction cascade

Hohagen, H.H.HohagenSchwarz, D.D.SchwarzSchenk, G.G.SchenkGuddat, L.W.L.W.GuddatSchieder, D.D.SchiederCarsten, J.J.CarstenSieber, V.V.Sieber2022-03-052022-03-052017https://publica.fraunhofer.de/handle/publica/25058310.1016/j.biortech.2017.08.2032-s2.0-85029685818An immobilized enzymatic reaction cascade was designed and optimized for the deacidification of grass silage press juice (SPJ), thus facilitating the production of bio-based chemicals. The cascade involves a three-step process using four enzymes immobilized in a Ca-alginate gel and uses lactic acid to form acetoin, a value-added product. The reaction is performed with a continuous, pH-dependent substrate feed under oxygenation. With titrated lactic acid yields of up to 91% and reaction times of ca. 6 h was achieved. Using SPJ as titrant yields of 49% were obtained within 6 h. In this deacidification process, with acetoin one value-added bio-based chemical is produced while simultaneously the remaining press juice can be used in applications that require a higher pH. Such, this system can be applied in a multi-product biorefinery concept to take full advantage of nutrient-rich SPJ, which is a widely available and easily storable renewable resource.en333Deacidification of grass silage press juice by continuous production of acetoin from its lactate via an immobilized enzymatic reaction cascadejournal article