Safety guidelines | Using enzymes
safety when handling enzymes
The enzymes suggested for work in this booklet are safe to use, provided they are handled appropriately.
While all the enzymes are food-grade products, items made with them should not be consumed. There
are two reasons for this. Firstly, the proportions of enzyme products used in the activities suggested here
are far greater than are normally used in the food industry. Secondly, the enzymes have not been handled
aseptically, so they (and the products made using them) may have been contaminated. Readers are advised
to refer to any local safety guidelines and to carry out their own risk assessment for any practical work.
Novozymes
Pectinex™
Fungal pectinase
ez
t fre
Store at 4 °C. Do no
contacts
General rule
As enzymes are water-soluble, water should always
be used for their removal if they are spilt.
Liquid enzyme products
Do not let liquid products dry up. If liquid
preparations are allowed to dry up, there is a risk
of dust formation. In susceptible people the
repeated inhalation of such dust may provoke
asthma or a reaction similar to hay fever. Any
spillage — on equipment, on the floor or bench —
should immediately be rinsed away with water.
Avoid formation of aerosols
If enzyme-containing aerosols are formed, there is
a risk of inhalation of the enzyme. In susceptible
people the repeated inhalation of such aerosols may
provoke asthma or hay fever. For this reason
enzyme preparations should never be sprayed.
Avoid direct skin and eye contact
If, by accident, you get liquid enzyme on your skin
or in your eyes, the remedy is plenty of tap water.
The same applies to clothing. In the event of a
spill on clothes, rinse with water then wash as
usual. This treatment will generally prove
sufficient, but if symptoms develop in the
respiratory passages, on the skin or in the eyes,
consult a doctor immediately.
Detailed safety information is supplied
with all enzymes from the NCBE, and is
also available from the NCBE’s Web site:
http://www.ncbe.reading.ac.uk/
NCBE/SAFETY
Consortium of
Local Education
Authorities for the
Provision of
Science Services at
Brunel University,
UXBRIDGE,
UB8 3PH.
01895 251496
www.cleapss.org.uk
Scottish Schools’
Equipment
Research Centre
St Mary’s Building,
23 Holyrood Road,
EDINBURGH,
EH8 8AE.
0131 558 8180
www.sserc.org.uk
Note: CLEAPSS and
SSERC can help their
members only.
using enzymes
The internationally-recognised (SI) unit of enzyme
activity is the Katal (abbreviated to kat). It is
defined as that enzyme activity which transforms
one mole of substrate per second under optimal
conditions.
vitally important to study the data sheet supplied
with each enzyme, and the graphs in this booklet.
These will give you a rough guide as to how the
enzyme might behave in the circumstances (pH,
temperature, substrate, etc) of your experiment.
In practice, few enzyme suppliers (or biochemists)
use the Katal, preferring instead units that reflect
the preferences of their typical customers. For
example, bakers are often familiar with amylase
activity expressed in ‘SKB units’, whereas brewers
traditionally refer to amylase activity (which they
call diastatic activity) in ‘Degrees Lintner’. To
obtain these various measures of enzyme activity,
different assay methods are used, and
unfortunately there is no means of comparing
different enzymes without conducting further tests.
It may also be useful to consider that:
Many industrial enzyme products are also
mixtures of different enzymes. Thus a ‘pectinase’
preparation might exhibit a range of pectolytic and
cellulolytic activities. Other preparations might
contain only a single type of enzyme. When
planning your own investigations, it is therefore
• Very often the temperature and pH at which a
particular enzyme works best are not those at
which it is most stable. In practice this means
that, for example, you may have to use an
enzyme at less than its optimum temperature
or pH (and therefore sacrifice speed) to ensure
that it remains stable over the period of the
investigation.
• If you really need a quicker reaction (e.g., to fit
within the time you have available for the work)
you may find that sufficient catalysis is achieved
at a high temperature before the enzyme is
inactivated. Should either of these approaches
prove unsatisfactory, the enzyme dosage can
be increased.
resources
Life chemistry and
molecular biology.
An introductory text
by E. J. Wood, C. A.
Smith and W. R.
Pickering (1996)
Portland Press.
ISBN: 1 85578 064 X.
This highly-illustrated
biochemistry textbook
has been written with
post-16 biology
students in mind.
www.ncbe.reading.ac.uk |11