The present invention provides methods for producing sialyloligosaccharides
in situ in dairy sources and cheese processing waste streams, prior to,
during, or after processing of the dairy source during the cheese
manufacturing process. The methods of the present invention use the
catalytic activity of .alpha.(2-3) trans-sialidases to exploit the high
concentrations of lactose and .alpha.(2-3) sialosides which naturally
occur in dairy sources and cheese processing waste streams to drive the
enzymatic synthesis of .alpha.(2-3) sialyllactose. .alpha.(2-3)
sialyloligosaccharides produced according to these methods are
additionally encompassed by the present invention. The invention also
provides for recovery of the sialyloligosaccharides produced by these
methods. The invention further provides a method for producing
.alpha.(2-3) sialyllactose. The invention additionally provides a method
of enriching for .alpha.(2-3) sialyllactose in milk using transgenic
mammals that express an .alpha.(2-3) trans-sialidase transgene. The
invention also provides for recovery of the sialyllactose contained in the
milk produced by this transgenic mammal either before or after processing
of the milk. Transgenic mammals containing an .alpha.(2-3) trans-sialidase
encoding sequence operably linked to a regulatory sequence of a gene
expressed in mammary tissue are also provided by the invention.
