Fig. 2

The effect of salt supplementation and substrate milling on extracellular protein production by T. reesei on soybean hulls. T. reesei (VTT-BR-C0019) was cultivated in shake flasks on soybean hull mineral medium under various conditions. a Extracellular protein production on 12% milled soybean hulls with full mineral medium, with the removal of trace elements, MgSO₄ and CaCl₂, with the removal of the aforementioned salts and KH₂PO₄ and in the absence of all added salts including (NH₄)₂SO₄. Only the lack of (NH₄)₂SO₄ had a clear negative impact on extracellular protein production. b Extracellular protein production on 12% in-natura soybean hulls or with the same amount of soybean hulls milled to pass a 2, 0.84 or 0.59 mm sieve