Team:DTU-Denmark/Safety

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Knowing your organism, its pros and cons and the precautions that must be taken to avoid hazards, is an important part of iGEM. Since we used a non-standard organism in our project, more considerations had to be made in regards to laboratory safety.

Our project has a foundation in filamentous fungi, more specifically Aspergillus niger, sp. ATCC 1015 ("Aspergillus niger van Tieghem ATCC ® 1015™", 2020). Aspergilli are common and important producers of many biotechnological products, such as citric acid and various enzymes, as described in our project description. A toolbox for genetic engineering of Aspergilli using CRISPR-Cas9 has already been developed (Nødvig et al., 2018), opening a perfect opportunity for working with and getting insight into an important industrial organism – and for putting fuel on the fire of the revolution from petrochemical production towards sustainable biomanufacturing.

A. niger is a spore-forming fungus and is not directly on the white list. The spores are produced asexually and are airborne. Therefore, we performed a check-in to assess how we would handle it in the laboratory.

Even though some Aspergilli are known to cause aspergillosis, the species we have been working with is non-pathogenic. We could therefore work in a biosafety level 1 lab approved for GMO organism. All our transformations and other experiments with the fungus were performed in a sterile laf-bench with airflow to filter out and retain the spores. Furthermore, all workplaces were cleaned with 70% ethanol before and after every use to wipe away spores and other cross-contaminating substances and organisms (e.g. E. coli or other fungal species used in the building).

We also grew our strains in 1L stirred tank bioreactors. These are under pressure and have 2M acid and base bottles connected so as to regulate pH during the fermentation process. Extra care was taken to ensure our personal safety when working with these machines. Only those that had received instruction from qualified personnel were therefore responsible for running the fermentations. They wore gloves, security glasses and lab coats at all times when the tanks were running.