Blachowicz Adriana, Mhatre Snehit, Singh Nitin Kumar, Wood Jason M, Parker Ceth W, Ly Cynthia, Butler Daniel, Mason Christopher E, Venkateswaran Kasthuri
Biotechnology and Planetary Protection Group, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States.
Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, United States.
Front Microbiol. 2022 Apr 26;13:777133. doi: 10.3389/fmicb.2022.777133. eCollection 2022.
Ensuring biological cleanliness while assembling and launching spacecraft is critical for robotic exploration of the solar system. To date, when preventing forward contamination of other celestial bodies, NASA Planetary Protection policies have focused on endospore-forming bacteria while fungi were neglected. In this study, for the first time the mycobiome of two spacecraft assembly facilities at Jet Propulsion Laboratory (JPL) and Kennedy Space Center (KSC) was assessed using both cultivation and sequencing techniques. To facilitate enumeration of viable fungal populations and downstream molecular analyses, collected samples were first treated with chloramphenicol for 24 h and then with propidium monoazide (PMA). Among cultivable fungi, 28 distinct species were observed, 16 at JPL and 16 at KSC facilities, while 13 isolates were potentially novel species. Only four isolated species , , , and were present in both cleanroom facilities, which suggests that mycobiomes differ significantly between distant locations. To better visualize the biogeography of all isolated strains the network analysis was undertaken and confirmed higher abundance of and . When amplicon sequencing was performed, JPL-SAF and KSC-PHSF showed differing mycobiomes. Metagenomic fungal reads were dominated by Ascomycota (91%) and Basidiomycota (7.15%). Similar to amplicon sequencing, the number of fungal reads changed following antibiotic treatment in both cleanrooms; however, the opposite trends were observed. Alas, treatment with the antibiotic did not allow for definitive ascribing changes observed in fungal populations between treated and untreated samples in both cleanrooms. Rather, these substantial differences in fungal abundance might be attributed to several factors, including the geographical location, climate and the in-house cleaning procedures used to maintain the cleanrooms. This study is a first step in characterizing cultivable and viable fungal populations in cleanrooms to assess fungal potential as biocontaminants during interplanetary explorations. The outcomes of this and future studies could be implemented in other cleanrooms that require to reduce microbial burden, like intensive care units, operating rooms, or cleanrooms in the semiconducting and pharmaceutical industries.
在组装和发射航天器时确保生物清洁对于太阳系的机器人探索至关重要。迄今为止，在防止对其他天体的正向污染方面，美国国家航空航天局（NASA）的行星保护政策一直侧重于产芽孢细菌，而真菌则被忽视。在本研究中，首次使用培养和测序技术对喷气推进实验室（JPL）和肯尼迪航天中心（KSC）的两个航天器组装设施的真菌群落进行了评估。为便于对存活真菌种群进行计数和下游分子分析，收集的样本首先用氯霉素处理24小时，然后用单叠氮化丙锭（PMA）处理。在可培养真菌中，观察到28个不同的物种，JPL设施中有16个，KSC设施中有16个，而13个分离株可能是新物种。两个洁净室设施中仅存在四种分离物种，即 、 、 和 ，这表明不同地点的真菌群落存在显著差异。为了更好地可视化所有分离菌株的生物地理学，进行了网络分析，并证实了 和 的丰度更高。进行扩增子测序时，JPL - SAF和KSC - PHSF显示出不同的真菌群落。宏基因组真菌读数以子囊菌门（91%）和担子菌门（7.15%）为主。与扩增子测序类似，两个洁净室中抗生素处理后真菌读数的数量都发生了变化；然而，观察到相反的趋势。遗憾的是，抗生素处理无法确定两个洁净室中处理和未处理样本之间真菌种群中观察到的变化。相反，真菌丰度的这些显著差异可能归因于几个因素，包括地理位置、气候以及用于维护洁净室的内部清洁程序。本研究是表征洁净室中可培养和存活真菌种群的第一步，以评估在星际探索期间真菌作为生物污染物的潜力。本研究及未来研究的结果可应用于其他需要减少微生物负担的洁净室，如重症监护病房、手术室或半导体和制药行业的洁净室。
