Methods for producing high molecular weight poly-gamma-glutamic acid
(PGA). The PGA is produced by fermentation, and purified by use of
tangential flow filtration, followed by diafiltration, as necessary, to
yield a product of the desired purity. Product obtained may be of very
high purity using all the prescribed purification steps. Product of this
purity is suitable for in vivo medical applications. Other applications,
such as food or agricultural, may utilize lower purity levels, and hence
do not require all the purification steps specified.
