Fahrion Jana, Fink Carina, Zabel Paul, Schubert Daniel, Mysara Mohamed, Van Houdt Rob, Eikmanns Bernhard, Beblo-Vranesevic Kristina, Rettberg Petra
Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany.
Institute of Microbiology and Biotechnology, Faculty of Natural Sciences, University of Ulm, Ulm, Germany.
Front Microbiol. 2020 Mar 31;11:525. doi: 10.3389/fmicb.2020.00525. eCollection 2020.
The EDEN ISS greenhouse, integrated in two joined containers, is a confined mobile test facility in Antarctica for the development and optimization of new plant cultivation techniques for future space programs. The EDEN ISS greenhouse was used successfully from February to November 2018 for fresh food production for the overwintering crew at the Antarctic Neumayer III station. During the 9 months of operation, samples from the different plants, from the nutrition solution of the aeroponic planting system, and from diverse surfaces within the three different compartments of the container were taken [future exploration greenhouse (FEG), service section (SS), and cold porch (CP)]. Quantity as well as diversity of microorganisms was examined by cultivation. In case of the plant samples, microbial quantities were in a range from 10 to 10 colony forming units per gram plant material. Compared to plants purchased from a German grocery, the produce hosted orders of magnitude more microorganisms than the EDEN ISS plants. The EDEN ISS plant samples contained mainly fungi and a few bacteria. No classical food associated pathogenic microorganism, like and , could be found. Probably due to the used cultivation approach, Archaea were not found in the samples. The bioburden in the nutrition solutions increased constantly over time but never reached critical values like 10-10 cfu per 100 mL in irrigation water as it is stated, e.g., for commercial European plant productions. The surface samples revealed high differences in the microbial burden between the greenhouse part of the container and the SS and CP part. However, the numbers of organisms (bacteria and fungi) found in the planted greenhouse were still not critical. The microbial loaded surfaces showed strong temporal as well as spatial fluctuations. In samples of the nutrition solution and the surface, the amount of bacteria exceeded the amount of fungi by many times. For identification, 16S rRNA gene sequencing was performed for the isolated prokaryotic organisms. Phylogenetic analyses revealed that the most abundant bacterial phyla were Firmicutes and Actinobacteria. These phyla include plant- and human-associated bacterial species. In general, it could be shown that it is possible to produce edible fresh food in a remote environment and this food is safe for consumption from a microbiological point of view.
伊甸园国际空间站温室集成在两个相连的容器中，是南极洲一个封闭的移动测试设施，用于为未来太空计划开发和优化新的植物栽培技术。2018年2月至11月，伊甸园国际空间站温室成功用于为南极新迈耶三号站的越冬人员生产新鲜食物。在9个月的运行期间，从不同植物、气培种植系统的营养液以及容器三个不同舱室（未来探索温室（FEG）、服务舱（SS）和冷廊（CP））内的不同表面采集了样本。通过培养检查微生物的数量和多样性。就植物样本而言，微生物数量范围为每克植物材料10至10个菌落形成单位。与从德国杂货店购买的植物相比，伊甸园国际空间站种植的农产品所含微生物数量比其多几个数量级。伊甸园国际空间站的植物样本主要含有真菌和少量细菌。未发现经典的与食物相关的致病微生物，如 和 。可能由于所采用的栽培方法，样本中未发现古细菌。营养液中的生物负荷随时间不断增加，但从未达到如欧洲商业植物生产中规定的灌溉水中每100毫升10 - 10 cfu这样的临界值。表面样本显示容器温室部分与服务舱和冷廊部分的微生物负荷存在很大差异。然而，在种植温室中发现的生物（细菌和真菌）数量仍不关键。微生物负载的表面显示出强烈的时间和空间波动。在营养液和表面样本中，细菌数量比真菌数量多很多倍。为进行鉴定，对分离出的原核生物进行了16S rRNA基因测序。系统发育分析表明，最丰富的细菌门是厚壁菌门和放线菌门。这些门包括与植物和人类相关的细菌种类。总体而言，可以证明在偏远环境中生产可食用的新鲜食物是可能的，并且从微生物学角度来看这种食物食用是安全的。
