uct, so it is not possible to implement a sin-
gle set of standardized procedures to cover
all. However, within any given production
process, standardized procedures for process
monitoring and recording should be applied
to ensure consistent production of reliable,
high-quality products.
In countries where product registration is
enforced, a complete description of the
process used for production of the agent is
generally required (McClintock, 1999; Neal
and Newton, 1999). In-process monitoring and
quality control should be an integral part of
this description. Since culture conditions are
known to affect a number of aspects of
pathogen performance (Burges, 1998b),
including virulence (Lane et al., 1991b), storage
longevity (Trinci et al., 1990; Lane et al., 1991a;
Hong et al., 2002) and durability, careful moni-
toring and recording of the fermentation
process is critical to ensuring a product of con-
sistent efficacy.
Records of all the following parameters
should be kept for each production batch
and maintained on file so that the informa-
tion gathered can be back-checked according
to batch number as and when required.
TemperatureTemperature has a direct effect on yield;
hence fermentations are generally run at or
close to the optimum temperature for the
growth of the fungal isolate. Since large-scale
fermentations generate heat, most large-scale
fungal production systems have some degree
of inbuilt temperature monitoring and regu-
lation. Temperature should be monitored and
recorded over the whole fermentation period.
Moisture contentIn solid-substrate fermentations, moisture
content should be adjusted to give optimum
production (Jenkins et al., 1998) and checked
postinoculation to ensure that it does not
vary significantly from batch to batch.
pHEntomopathogenic fungi tend to be tolerant
of pH and will grow over a wide pH range
(Ibrahim et al., 1993), whereas fungal antago-
nists have a narrower pH tolerance (Jackson
et al., 1991). The degree to which pH is moni-
tored in process will depend largely on the
effect that variations in pH have on yield. pH
tends to be monitored closely in liquid fer-
mentations but, because of the difficulty in
controlling pH in solid-substrate fermenta-
tions, it is often disregarded. None the less,
records of pH can be a useful reference. In
fermentations started with non-sterile media,
low pH can be an advantage as it inhibits
unwanted bacterial growth (Bartlett and
Jaronski, 1988) and, where this is used as a
technique in reducing contamination, pH
should be carefully recorded and monitored.Contamination monitoring
All microbial fermentations carry the poten-
tial risk of contamination. In in vitrosystems,
the unintentional parallel culture of contami-
nants with the desired fungal product will
inevitably lead to a lower yield of product
from the fermentation, due to competition
for nutrients and, in some cases, the
inhibitory effect of secondary metabolites. If
the contaminating organisms are included in
the final product, this can lead to dilution of
the active ingredient in the packaged prod-
uct, particularly if contamination has not
been closely monitored and quantified. With
respect to safety, the presence of contami-
nants increases the risk of production of
potentially harmful organisms. Where pro-
duction is in vivo, however, the presence of
other microbes is inevitable; indeed, in the
production of arbuscular mycorrhizal fungi,
the presence of some associated microorgan-
isms is important for both fungus and plant.
In such a system, only microorganisms that
are potentially harmful or may be detrimen-
tal to the production process are considered
to be contaminants.
For all production systems, each stage of
the production process must be monitored
for the entrance of contaminants to enable
the early detection of problems and the iden-
tification of the source of contamination
should it occur. Careful monitoring at each
stage will help in reducing as far as possible
the lost production time required to eradi-250 N.E. Jenkins and D. Grzywacz