BioSafety, Volume 3, Paper 5 (BY97005) 1997
Online Journal - URL: http://www.bdt.org.br/bioline/by
Measurement of bioprocess containment by high flow rate air sampling and
quantitative polymerase chain reaction
M. Noble, I. Lisi, J. M. Ward, A. D. Buss & M. K. Turner
Received April 15th 1997
Accepted April 28th 1997
Published May 14th 1997
Code Number: BY97005
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ABSTRACT
A competitive quantitative polymerase chain reaction (QPCR) method has been
used to measure the concentration of cells of a genetically modified E.
coli K-12 strain in aerosols released from bioprocess operations. The
QPCR assay was shown to be specific for the process strain, and can measure
the target organism concentration over a 6 decade range. Air sampling was
achieved using an Aerojet General Cyclone which has a high sampling rate
and is efficient in the capture of bacteria bearing aerosol particles. The
release of process cells into fermenter exit-gas throughout a fermentation
was monitored using the cyclone-QPCR methodology. It was found that over
the course of a 5.5 hour period, 3 x 10^7 process cells were released.
This number of cells is contained within less than 2 uL of the fermentation
broth at harvest. Sampling of the air in the vicinity of a 50 L
fermentation has shown that some cellular material is released during
operation of the fermenter sampling valve. The extent of the releases
recorded and the implications of the ability to measure bioprocess release
are discussed with respect to the safe handling of recombinant
microorganisms and the need to balance losses due to accidental and
incidental release.
Keywords: bioprocess, containment, aerosol, air sampling,
genetically modified micro-organism, E. coli K-12, polymerase chain
reaction, fermentation, risk assessment.
Copyright held by the authors.
Published by Bioline Publications.
