Table 1.

Some examples of currently commercially available 3- and 6-phytases and their characteristics

Type†	Protein origin	Expression	pH optima	Temperature optima (°C)	Trade name
3	A. niger*	A. niger	2; 5–5.5	65	Natuphos®
3	A. niger*	A. niger, non-recombinant	6.0	–	Allzyme® SSF
3	A. niger*	Trichoderma reesei	2.5	–	Finase® P/L
6	Escherichia coli*	Schizosaccharomyces pombe (ATCC 5233)	4.5	55	Phyzyme® XP
6	Escherichia coli*	Pichia pastoris	4.5	–	Quantum®
6	Escherichia coli	Trichoderma reesei	—	–	Quantum Blue®
6	Escherichia coli*	Pichia pastoris	3.4, 5.0	58	OptiPhos®
6	Peniophora lycii*	Aspergillus oryzae	4–4.5	50–55	Ronozyme®
6	Citrobacter braakii	Aspergillus oryzae	—	—	Ronozyme Hiphos®
6	Buttiauxella spp.	Trichoderma reesei	3.5–4.5#	60#	Axtra® PHY

^*Adapted from Lei et al.¹ with modifications;

^†3- or 6-phytase; —, no information available;

^#personal communication (C Evans).