The solid substrate was supplemented with (0.005, 0.01 and 0.015 g/5 g ds of Tween 80 or triton ·100). The results in
Fig. 8. revealed clearly that Triton ·100 and Tween 80 enhanced phytase productivity at all concentrations , maximum enzyme production was observed with Tween 80 at 0.001 concentration (170± 4.2 U/g ds). This result was compatible with Esakkiraj et al. 2010, they enhance the production of phytase by Pseudomonas AP-MSU 2 with the addition of Tween 60 to the fermentation medium. Mandviwala and Khire 2000, reported that among various surfactants added to SSF, Trition X-100 (0.5%) exhibited a 30% increase in A. niger phytase productivity. On the contrary, surfactants such as Tween-80 (0Æ5% and 1Æ0%) and Triton X-100 (1Æ0%) did not affect the phytase production (Lan et al., 2002a, b).