Item Refractive Index Water 1.3288 Fermentation Broth Before Filtration (1) 1.3866 Fermentation Broth After Filtration (1) 1.3861 Fermentation Broth Before Filtration (2) 1.39 Fermentation Broth After Filtration (2) 1.3889

Table 4: Refractive indices of fermentation broth before and after filtration.