J. Klein et al., NUCLEIC-ACID AND PROTEIN ELIMINATION DURING THE SUGAR MANUFACTURING PROCESS OF CONVENTIONAL AND TRANSGENIC SUGAR-BEETS, Journal of biotechnology, 60(3), 1998, pp. 145-153
The fate of cellular DNA during the standard purification steps of the
sugar manufacturing process from conventional and transgenic sugar be
ets was determined. Indigenous nucleases of sugar beet cells were foun
d to be active during the first extraction step (raw juice production)
which was carried out at 70 degrees C. This and the consecutive steps
of the manufacturing process were validated in terms of DNA degradati
on by competitive PCR of added external DNA. Each step of the process
proved to be very efficient in the removal of nucleic acids. Taken tog
ether, the purification steps have the potential to reduce the amount
of DNA by a factor of > 10(14), exceeding by far the total amount of D
NA present in sugar beets. Furthermore, the gene products of the trans
genes neomycin phosphotransferase and BNYVV (rhizomania virus) coat pr
otein CP21 were shown to be removed during the purification steps, so
that they could not be detected in the resulting white sugar. Thus, su
gar obtained from conventional and transgenic beets is indistinguishab
le or substantially equivalent with respect to purity. (C) 1998 Elsevi
er Science B.V. All rights reserved.