RT Journal Article T1 Viable microorganisms on fibers collected within and beyond the planetary boundary layer A1 González Pleiter, Miguel A1 Edo, Carlos A1 Casero, María Cristina A1 Aguilera, Ángeles A1 González Toril, Elena A1 Wierzchos, Jacek A1 Leganés, Francisco A1 Fernández Piñas, Francisca A1 Rosal, Roberto AB Fibers are found in all environments. However, the impact of their presence on ecosystems and human health is not yet well understood, especially in the case of the atmosphere. In this work, we presented evidence that fibers traveling through the atmosphere act as vectors to spread microorganisms. Here, we investigated the presence of viable microorganisms on fibers collected within and beyond the planetary boundary layer during flights of C-212 aircraft over Central Spain. In total, seven fibers, six of which transported viable microorganisms, were isolated in two flights. The viability of the microorganisms was determined by confocal microscopy by means of the fluorescent probes SYBR-Green to detect microorganisms and CTC redox dye to assess their cellular respiration activity. The fibers that transported viable microorganisms were spectroscopically analyzed by micro-FTIR and identified as wool-silk and cellulose-cotton. Taken together, the results demonstrated that fibers host viable microorganisms when traveling through the lower free troposphere. PB ACS Publications SN 2328-8930 YR 2020 FD 2020 LK https://hdl.handle.net/20.500.14352/130472 UL https://hdl.handle.net/20.500.14352/130472 LA eng NO Miguel González-Pleiter, Carlos Edo, María Cristina Casero-Chamorro, Ángeles Aguilera, Elena González-Toril, Jacek Wierzchos, Francisco Leganés, Francisca Fernández-Piñas, and Roberto Rosal Environmental Science & Technology Letters 2020 7 (11), 819-825 DOI: 10.1021/acs.estlett.0c00667 NO The authors acknowledge the financial support provided by the Spanish Government (CTM2016-74927-C2-1-R/2-R, CGL2017-92086-EXP, PGC2018-094076-B-100, and RTI2018-094867-B-I00). C.E. thanks the Spanish Ministry of Science, Innovation and Universities for the award of a predoctoral grant (FPI). C-212 airborne access was generously provided by INTA, coordinated by the Aerial Platform for Research team and with the logistic and operational support of Group 47 of the Spanish Air Force. NO Ministerio de Economía y Competitividad (España) NO Ministerio de Ciencia e Innovación (España) DS Docta Complutense RD 26 feb 2026