The theory and application of space microbiology: China's experiences in space experiments and beyond

Abstract

SummaryMicroorganisms exhibit high adaptability to extreme environments of outer space via phenotypic and genetic changes. These changes may affect astronauts in the space environment as well as on Earth because mutant microbes will inevitably return with the spacecraft. However, the role and significance of these phenotypic changes and the underlying mechanisms are important unresolved questions in the field of space biology. By reviewing, especially the Chinese studies, we propose a space microbial molecular effect theory, that is, the space environment affects the nature of genes and the molecular structure of microorganisms to produce phenotypic changes. In this review, we discussed three basic theories for the research of space microbiology, including (1) space microbial pathogenicity and virulence mutations and the human mutualism theory; (2) space microbial drug-resistance mutations and metabolism associated with space pharmaceuticals theory; (3) space corrosion, microbial decontamination, and new materials technology theory.

Increased growth rate and amikacin resistance of Salmonella enteritidis after one‐month spaceflight on China’s Shenzhou‐11 spacecraft

“…Monitoring of the microorganisms on the space station is greatly important to evaluate risk factors for the health of astronauts and to assess material integrity of the spacecrafts (Liu, 2017). It has been reported that modeled reduced gravity and the space environment impacted microbial physiology, including growth rate, biofilm formation, antibiotic resistance, virulence, and metabolism (Byloos et al, 2017;Castro, Nelman-Gonzalez, Nickerson, & Ott, 2011;Fajardo-Cavazos, Narvel, & Nicholson, 2014;Horneck, Klaus, & Mancinelli, 2010;Orsini, Lewis, & Rice, 2017;Zea et al, 2018).…”

Responses of Intestinal Mucosal Barrier Functions of Rats to Simulated Weightlessness

“…The microgravity and related low fluid shear dynamics has also been proved to be able to regulate microbial gene expression, physiology and pathogenesis ( Horneck et al, 2010 ). Certain bacteria obtain increased pathogenic features after exposure to microgravity or spaceflight, including improved growth rate and virulence, enhanced resistance to several environmental stress, altered responses to antibiotics and increased biofilm formation ( Li et al, 2015 ; Liu, 2017 ; Shi et al, 2017 ). Those may heighten the risk for intestinal microbial infections mentioned above.…”

The influence of bioregenerative life‐support system dietary structure and lifestyle on the gut microbiota: a 105‐day ground‐based space simulation in Lunar Palace 1

“…The maintenance of human health has been focused on as a crucial issue for realizing manned deep-space exploration (Mora et al, 2016a;Kuda et al, 2017;White, 2017). The gut microbiota is essential to health; it plays a vital role in host physiology, metabolism, nutrition and immune system development (Dore and Blottiere, 2015;Greenhalgh et al, 2016;Lv et al, 2016); dysbiosis of the gut microbiota is associated with illness and infection (Liu, 2016;Schwendner et al, 2017). Hence, one of the major challenges in manned space exploration is protecting astronauts from microbiota dysbiosis.…”