# Lab-on-Chip Culturing System for Fungi--Towards Nanosatellite Missions
## 4 Conclusions  
In the paper, a microfluidic lab-on-chip platform ensuring long-term culturing of the selected microscopic fungi species (_F. culmorum_) in terrestrial and simulated microgravity conditions is shown. The all-glass lab-on-chip of the described design is proposed to fulfil the demands of the development of this biological object and allow for appropriate mycelium growth for at least 14 days. Complementary modelling of the LOC using the _Comsol Multiphysics_ software is also provided to confirm appropriate LOC performance in the context of medium flow and gas cavity functioning. The lab-on-chip platform has been equipped with components that assure the use of the culturing system for both terrestrial and microgravity experiments, e.g., as a payload solution for potential astrobiological missions with nanosatellites. Microscopic fungi were dried with the established procedure which permits microflow culture with the desired time-shift and thus potential biological experimentation in Low-Earth-Orbit, even with a 3-month delay. The positive results of our experimentation encompass both technical and biological outcomes. As microfluidics for mycology is still a mostly unexplored branch, and further, no microscopic fungi (except for yeasts) have ever been investigated in microgravity, we decided to provide this new knowledge on a significant and cosmopolitan fungi representative--_F. culmorum_. Our research has shown that the culturing platform developed herein is suitable for long-term microflow cultivation of this species. For instance, notable mycelium growth could be observed in laboratory conditions, being consistent with the macroscale reference Petri dish culture and literature reports [49]. Interesting results were also obtained during simulated microgravity studies with the use of a custom-made RUV, which indicate repeatable, enhanced mycelium growth in these conditions compared to the reference culture on-chip. Figure 10: Concept of the first Polish nanosatellite with the microfluidic payload: (**a**) lab-on-chip in the holder, (**b**) overall 2U structure. With a view to the aforementioned results, it can be assumed that our lab-on-chip platform can be used by mycologists in other laboratory studies (e.g., concerning environmental approaches and coculture investigation with plants or soil organisms), but also as a tool for astrobiological research, e.g., conducted in a CubeSat in LEO. This undoubtedly opens new horizons for LOCs utility in agriculture and horticulture fields, making the creation of controlled environments on-chip vital and of indispensable need, especially in the context of single spore insight. Microfluidic approach towards precise investigation of microscopic fungi and other soil dwellings can provide new knowledge on interactions of these species and their mutual interplay (symbiotic/parasitic relations). Mycorrhiza and its mechanisms play an important role in plant cultivation, thus further research in this field can bring new advancement, especially needed with a view to our potential colonization aspirations. Use of lab-on-chip techniques fits the demands of the aforementioned subjects. In addition, numerical modelling of the LOC structures with microflow management is a good practice that performed prior to experimentation can answer most of the scientific questions and describe microfluidic performance thoroughly. Computational work, as shown in this paper, ensures to evaluate the microflow consistency, remaining the LOC functionalities as assumed. In conclusion, our lab-on-chip platform was fabricated by means of reliable, resistant and biocompatible miniaturised tools, to ensure it would be able to be applied in simulated microgravity instruments, space infrastructure (e.g., International Space Station--ISS) and/or to withstand potential harsh space environments, for instance during space missions with nanosatellites.