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1.
How does the project using BioBricks™ affect the safety of the researcher?
2.
How does the project using BioBricks™ affect public safety?
3.
Which effects has the project on environmental safety?
4.
Is
a local biosafety group,
committee, or review board involved in the risk assessment of the project?
5.
Is the project using BioBricks™ following special/official, national or international biosafety guidelines/rules?
6.
Do any new BioBrick™ parts or devices made in the context of the project raise any safety issues?
An obvious advantage of the iGEM risk assessment approach is its open access feature and the reliance on
standardised, exactly defined and characterised genetic elements which facilitates risk evaluation
substantially.
A certain drawback of the iGEM concept is its inclination on laboratory biosafety. BioBrick™ devices and viable
constructs intended for deliberate release into the environment will have to be assessed thoroughly according
to Directive 2001/18/ EC (EC 2001).
The engagement of the scientific community in implementing biosafety measures is essential (NRC 2009).
Without this commitment governments will run into difficulties to prevent accidents that could have possible
adverse effects on public health (De Lorenzo 2010). Actually, the optimal time point to prevent potential harm
is interfering during the developmental stage of a project.
The BioBrick™ concept is supporting this approach substantially and the involved scientific community is
raising awareness in this respect in a commendable way.
5.6
Potential impacts of synthetic biology in relation to biosafety
Biosafety in the context of synthetic biology is an issue of major concern. Accidental or deliberate release of
organisms resulting from synthetic biology techniques (= SB organisms) may have significant adverse effects
on human or animal health or the environment. In the following chapter possible unintended effects caused
by the intentional or unintentional release of SB organisms on the ecosystem, the accidental transfer of novel
genes and hereditary material and the emergence of unpredictable properties of SB organisms are discussed.
Measures for mitigation of these undesirable effects,
i.e. the application appropriate layers of containment,
are presented in the following chapter.
5.6.1
Impact on the ecosystem
Intentional and unintentional releases
Intentional and unintentional releases of SB organisms (outside from contained use in research laboratories
and production facilities) may result in adverse effects on biodiversity. Due to a change in biological fitness SB
organisms may either become more invasive, show an increased persistence or an improved survival pattern
and, thus, may reduce the viability of native inhabitants of the exposed habitat (Redford et al. 2013; Wright et
al. 2013). In this sense SB organisms would represent a new class of environmental pollutants.(International
Civil Society Working Group on Synthetic Biology (ICSWGSB) 2011) Even if their lifespan was intended to be
limited substantial short term interruptions in biodiversity may occur (compare with intermitting algal blooms)
(Snow and Smith 2012).
SB organisms intended for contained use
SB organisms originally intended only for contained use may accidentally be released into the environment by
spillage or bioreactor leakage. Usually these kinds of organisms are thought to suffer from reduced fitness and
are believed to bear a selective disadvantage compared to wild type populations (Garfinkel and Friedman
2010; De Lorenzo 2010; Bassler 2010). However, microbes are characterised by a high potential for rapid
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evolutionary change and innocuous or weak SB organisms may acquire fitness rapidly by beneficial mutations
(Snow and Smith 2012). It should be clear that SB organisms – once released into the environment – cannot be
retrieved anymore (Dana et al. 2012).
The first step in mitigation potential risks by SB organisms is to impose physical barriers which should help to
prevent accidental release into the environment (Schmidt and de Lorenzo 2012). As physical containment
might not suffice, biological containment is proposed as a solution to its drawbacks (Wright et al. 2013;
Marliere 2009). For biological containment the following lines of research are proposed and pursued:
a) induced lethality: “kill switches”, “suicide genes”
This approach is prone to mutations reverting the targeted phenotype by deactivation of the lethal gene
(Schmidt and de Lorenzo 2012). Due to the high rate of evolution of microorganisms this strategy is expected
to be unreliable (Wright et al. 2013).
b) prevention of
horizontal gene transfer
The application of phage-resistant strains or of plasmids lacking proper transfer sequences is proposed
(Skerker et al. 2009). However, the prevention of uptake of free DNA by natural transformation of competent
microorganisms will be challenging (Wright et al. 2013).
c) trophic containment:
Auxotrophic SB microorganisms relying on nutrients
only present in in vitro settings may be designed (Marliere
2009). Accidental release into the environment would lead to cell death due to starvation. This approach
suffers from several drawbacks as the necessary nutrients might well be present in the environment or the
auxotrophic mutant may use metabolites from neighbouring organisms or horizontal gene transfer might
compensate for the auxotrophic mutations (Moe-Behrens et al. 2013; Wright et al. 2013).
d) Semantic containment: Xenobiology
The application of altered nucleotides and/or alternate backbones other than phospho-ribose and deoxyribose
which would lead to incompatibilities with naturally occurring polymerases, and a confinement of the SB
organism from the living environment appears to be promising (Schmidt 2010b; Marliere 2009). However,
unnatural nucleotides and alternative backbones in nucleic acids may be toxic to conventional cells (Moe-
Behrens et al. 2013).
SB organisms intended for environmental release
Contrary to the experience obtained with genetically modified microorganisms to date, which had been
deliberately released and usually did not perform sufficiently well in their respective habitats, SB organisms
intended for environmental release are especially designed to survive harsh environmental conditions
(Anderson et al. 2012). They may inherently express traits which provide a selective advantage in the
respective habitat reducing inherently the survival capabilities of indigenous inhabitants of the exposed
ecosystem. In this context it is important to clarify that risk assessors and regulators to date have only
insufficient experience in considering potential risks of intentional SB releases and that they have no
experience in considering potential risks arising from the evolution of SB microorganisms
and their interactions
with the native populations in their new habitat (Pauwels et al. 2013; Rodemeyer 2009).