Filtration process of the spiramycin fermentation broth

This paper presents the effects Of acidity and additive pretreatment on the filtering rate and Spirarnycin (SPM) concentration in the filter liquor of SPM fermentation broth. The experimental results show that the SPM peak value in filter liquor iS obtained at pH5.5 with either 0.1% methanal or 0.1% BAPE. It is also indircatedt that there exists a dissolution equilibrium of proteins from the experiment results. The soluble proteins are denatured due to the too high/low acidity and then precipitate. Usually, the amount of soluble proteins reaches its lowest leve1 in pH range of 6.0–6.5. The protein precipitation will, together with other suspended solids, particles, contribute to the final SPM concentration in the filter liquor. This paper assumes that the contribution is the result of the adsorption equilibrium of SPM on the surfaces of suspened solids. For satisfactory explanation, the revised Landgmuir adsorption theory was employed and a model was developed.