scholarly journals Evaluation of pathogenesis and biofilm formation ability of Yersinia pestis after 40-day exposure to simulated microgravity

2021 ◽  
Author(s):  
Ye Li ◽  
Yulu Chen ◽  
Lei Wang ◽  
Yixuan Li ◽  
Ruifu Yang ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Simulated Microgravity ◽  
Normal Gravity ◽  
Microgravity Condition ◽  
Microgravity Environment ◽  
Crystal Violet Staining ◽  
Rna Seq ◽  
Manned Space ◽  
Manned Space Missions

Abstract Background: With the increase of manned space missions and the rise of space microbiology, the research of microbes grown under microgravity environment attracts more attentions. The research scope in space microbiology has been extended beyond pathogens directly related to spaceflight Y. pestis, the causative agent of plague, is also of interest to researchers. Results: After Y. pestis strain 201 cultivated for 40 consecutive passages in either simulated microgravity and normal gravity (NG) conditions, the cultures were used to observe the main phenotypic features of Y. pestis. By using crystal violet staining assays, increased biofilm amount was detected in Y. pestis grown under SMG condition. Besides that, the damage degrees of Hela cell caused by SMG-grown Y. pestis were found diminished in relative to those NG condition. Consistent with this observation, death course was delayed in mice infected with SMG-grown Y. pestis, suggesting that microgravity condition could contribute the attenuated virulence. RNA-seq-based transcriptomics analysis showed a total of 219 genes were differentially regulated, of which 92 upregulated and 127 downregulated. We found dozens of virulence-associated genes were downregulated, which partially explained the reduced virulence of Y. pestis under SMG condition. Our study demonstrated that long-term exposure to simulated microgravity influence the pathogenesis and biofilm formation ability of Y. pestis in a different way, which provides a novel avenue to study the mechanism of physiology and virulence in this pathogen.Conclusions: Microgravity enhanced the ability of biofilm formation of Y. pestis. The virulence and cytotoxicity of Y. pestis were reduced under the microgravity environment. The expressions of many virulence-associated genes of Y. pestis were differentially regulated in response to the stimulated microgravity.

scholarly journals Decreased biofilm formation in Proteus mirabilis after short-term exposure to a simulated microgravity environment

2021 ◽  
Author(s):  
Dapeng Wang ◽  
Po Bai ◽  
Bin Zhang ◽  
Xiaolei Su ◽  
Xuege Jiang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Proteus Mirabilis ◽  
Biofilm Formation ◽  
Simulated Microgravity ◽  
Microgravity Condition ◽  
Biological Characteristics ◽  
Space Environment ◽  
Microgravity Environment ◽  
Constructive Method ◽  
Short Term Exposure

Abstract Background Microbes threaten human health in space exploration. Studies have shown that Proteus mirabilis has been found in human space habitats. In addition, the biological characteristics of P. mirabilis in space have been studied unconditionally. The simulated microgravity environment provides a platform for understanding the changes in the biological characteristics of P. mirabilis. Objective This study intends to explore the effect of simulated microgravity on P. mirabilis, the formation of P. mirabilis biofilm, and its related mechanism. Methods The strange deformable rods were cultured continuously for 14 days under microgravity simulated in high-aspect rotating vessels (HARVs). The morphology, growth rate, metabolism, and biofilm formation of the strain were measured, and the phenotypic changes of P. mirabilis were evaluated. Transcriptome sequencing was used to detect differentially expressed genes under simulated microgravity and compared with phenotype. Results The growth rate, metabolic ability, and biofilm forming ability of P. mirabilis were lower than those of normal gravity culture under the condition of simulated microgravity. Further analysis showed that the decrease of growth rate, metabolic ability, and biofilm forming ability may be caused by the downregulation of related genes (pstS, sodB, and fumC). Conclusion The simulated microgravity condition enables us to explore the potential relationship between bacterial phenotype and molecular biology, thus opening up a suitable and constructive method for medical fields that have not been explored before. It provides a certain strategy for the treatment of P. mirabilis infectious diseases in space environment by exploring the microgravity of P. mirabilis.

scholarly journals Decreased biofilm formation in Proteus mirabilis after short-term exposure to a simulated microgravity environment

2021 ◽  
Author(s):  
Dapeng Wang ◽  
Po Bai ◽  
Bin Zhang ◽  
Xiaolei Su ◽  
Xuege Jiang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Biofilm Formation ◽  
Simulated Microgravity ◽  
Normal Gravity ◽  
Space Station ◽  
Biological Characteristics ◽  
Microgravity Environment ◽  
Short Term ◽  
Future Space ◽  
Short Term Exposure

Background: Microbes threaten human health in space exploration. Studies have shown that P. mirabilis has been found in human space habitats. In addition, the biological characteristics of P. mirabilis in space have been studied unconditionally. The simulated microgravity environment provides a platform for understanding the changes in the biological characteristics of P. mirabilis. Objective: This study intends to explore the effect of simulated microgravity on P. mirabilis, the formation of P. mirabilis biofilm and its related mechanism. Methods: The strange deformable rods were cultured continuously for 14 days under the microgravity simulated by (HARVs) in a high- aspect ratio vessels. The morphology, growth rate, metabolism and biofilm formation of the strain were measured, and the phenotypic changes of P. mirabilis were evaluated. Transcriptome sequencing was used to detect differentially expressed genes under simulated microgravity and compared with phenotype. Results: The growth rate, metabolic ability and biofilm forming ability of P. mirabilis were lower than those of normal gravity culture under the condition of simulated microgravity. Further analysis showed that the decrease of growth rate, metabolic ability and biofilm forming ability may be caused by the down-regulation of related genes (pstS,sodB and fumC). Conclusion: It provides a certain reference for the prevention and treatment of P. mirabilis infection in the future space station by exploring the effect of simulated microgravity exposure on P. mirabilis.

scholarly journals Effects of Simulated Microgravity on the Physiology of Stenotrophomonas maltophilia and Multiomic Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaolei Su ◽  
Yinghua Guo ◽  
Tingzheng Fang ◽  
Xuege Jiang ◽  
Dapeng Wang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Differentially Expressed Genes ◽  
Biofilm Formation ◽  
Stenotrophomonas Maltophilia ◽  
Simulated Microgravity ◽  
Normal Gravity ◽  
Differentially Expressed ◽  
Space Environment ◽  
Biological Adhesion ◽  
Proteomic Analyses

Many studies have shown that the space environment plays a pivotal role in changing the characteristics of conditional pathogens, especially their pathogenicity and virulence. However, Stenotrophomonas maltophilia, a type of conditional pathogen that has shown to a gradual increase in clinical morbidity in recent years, has rarely been reported for its impact in space. In this study, S. maltophilia was exposed to a simulated microgravity (SMG) environment in high-aspect ratio rotating-wall vessel bioreactors for 14days, while the control group was exposed to the same bioreactors in a normal gravity (NG) environment. Then, combined phenotypic, genomic, transcriptomic, and proteomic analyses were conducted to compare the influence of the SMG and NG on S. maltophilia. The results showed that S. maltophilia in simulated microgravity displayed an increased growth rate, enhanced biofilm formation ability, increased swimming motility, and metabolic alterations compared with those of S. maltophilia in normal gravity and the original strain of S. maltophilia. Clusters of Orthologous Groups (COG) annotation analysis indicated that the increased growth rate might be related to the upregulation of differentially expressed genes (DEGs) involved in energy metabolism and conversion, secondary metabolite biosynthesis, transport and catabolism, intracellular trafficking, secretion, and vesicular transport. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that the increased motility might be associated the upregulation of differentially expressed proteins (DEPs) involved in locomotion, localization, biological adhesion, and binding, in accordance with the upregulated DEGs in cell motility according to COG classification, including pilP, pilM, flgE, flgG, and ronN. Additionally, the increased biofilm formation ability might be associated with the upregulation of DEPs involved in biofilm formation, the bacterial secretion system, biological adhesion, and cell adhesion, which were shown to be regulated by the differentially expressed genes (chpB, chpC, rpoN, pilA, pilG, pilH, and pilJ) through the integration of transcriptomic and proteomic analyses. These results suggested that simulated microgravity might increase the level of corresponding functional proteins by upregulating related genes to alter physiological characteristics and modulate growth rate, motility, biofilm formation, and metabolism. In conclusion, this study is the first general analysis of the phenotypic, genomic, transcriptomic, and proteomic changes in S. maltophilia under simulated microgravity and provides some suggestions for future studies of space microbiology.

scholarly journals LABORATORY BIODEGRADATION OF POTENTIAL CELLULOSE WASTES GENERATED DURING LONG-TERM MANNED SPACE MISSIONS

2019 ◽  
pp. 71-78 ◽  
Author(s):  
Hristo Najdenski ◽  
Viacheslav Ilyin ◽  
Plamen Angelov ◽  
Venelin Hubenov ◽  
Denis Korshunov ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Anaerobic Bacteria ◽  
Space Missions ◽  
Microbial Consortia ◽  
Microbial Biodegradation ◽  
Thermophilic Conditions ◽  
Dividing Cells ◽  
Manned Space ◽  
Manned Space Missions

Anaerobic microbial biodegradation of cellulose containing wastes generated during the long-term manned space missions is a key technological approach for resolving the problem of wastes accumulated onboard of the spacecraft. Herewith are presented data on the possibilities of structurally stable multispecies microbial consortia originating from methanogenic bioreactors to decompose different cellulose substrates – filter paper, medical gauze and vegetable mix as potential cellulose wastes during space missions. The rates of biodegradation processes carried out at mesophilic and thermophilic conditions are not only measured and compared but are providing new opportunities for development of technology for microbial biodegradation of cellulose-rich organic wastes. Moreover, the studies have shown that paper and gauze hydrolysis with the help of cellulolytic bacterial communities can be an effective component of utilization of cosmonaut hygiene items. Biodegradation of plant wastes by community of anaerobic bacteria is promising and applicable tool also under terrestrial conditions. Light microscopy of bacterial communities reveals the presence of Gram-positive spore forming bacilli (short and long forms, bipolar and dividing cells) and typical clostridia forms.

scholarly journals EFFECT OF CHANNEL DEPTH ON YIELD OF SWEET POTATOES GROWN HYDROPONICALLY

HortScience ◽  
1990 ◽  
Vol 25 (8) ◽  
pp. 856b-856
Author(s):  
C. Morris ◽  
D. Mortley ◽  
P. Loretan ◽  
C. Bonsi ◽  
W. Hill
Keyword(s):  
Sweet Potato ◽  
Life Support ◽  
Storage Root ◽  
Life Support System ◽  
Storage Roots ◽  
Channel Depth ◽  
Sweet Potatoes ◽  
Manned Space ◽  
Manned Space Missions

The potential of the sweet potato as a food source for future long-term manned space missions is being evaluated for the National Aeronautics and Space Administration's (NASA) Controlled Ecological Life Support System (CELSS) Program. Several experiments have shown that the sweet potato can be grown hydroponically. However, an evaluation of the NASA fan-shaped Biomass Production Chamber (BPC) channel was initiated to determine if channel depths influenced the yield of hydroponically grownsweet potatoes. Three channel depths were studied, 5 cm (2 in) standard NASA BPC channel, 10 cm (4 in) channel and 15 cm (6 in) channel. The experiment consisted of one replication. The results show that channel depth does effect the yield of storage roots. The 15 cm depth channel provided the most consistent yield with all channels having significantly different fresh storage root yields in the replicate.

scholarly journals Increased biofilm formation ability in Klebsiella pneumoniae after short‐term exposure to a simulated microgravity environment

2016 ◽  
Vol 5 (5) ◽  
pp. 793-801 ◽  
Author(s):  
Haili Wang ◽  
Yanfeng Yan ◽  
Dan Rong ◽  
Jing Wang ◽  
Hongduo Wang ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Biofilm Formation ◽  
Simulated Microgravity ◽  
Microgravity Environment ◽  
Short Term ◽  
Short Term Exposure

scholarly journals Effects of simulated microgravity on rice (MR219) growth and yield

2018 ◽  
Vol 14 (2) ◽  
pp. 278-283 ◽  
Author(s):  
Nur Athirah Zulkifli ◽  
Teoh Chin Chuang ◽  
Ong Keat Khim ◽  
Ummul Fahri Abdul Rauf ◽  
Norliza Abu Bakar ◽  
...  
Keyword(s):  
Simulated Microgravity ◽  
Rotation Speed ◽  
Microgravity Condition ◽  
Blast Disease ◽  
Growth And Yield ◽  
Microgravity Environment ◽  
Rice Seed ◽  
Yield Parameters ◽  
Rice Tungro Disease ◽  
Rice Seeds

Rice (Oryza sativa L.) is a staple food in many Asian countries with an ever increasing demand. However, the production of high quality rice seeds is insufficient to meet this demand. Research on plant growth in space related to the exposure of a microgravity environment are rare, costly and time-limited. Similar experiments can be conducted on the ground to simulate the microgravity condition using a 2-D clinostat which compensates for the unilateral influence of gravity. This study was conducted to establish a simple and cost effective technique to enhance the quality of the Malaysian rice seed variety MR 219 by using a 2-D clinostat and to determine the effects of simulated microgravity on the growth and yield of the rice seeds. The experiments were performed at different rotation speeds (2 rpm and 10 rpm) for 10 days at room temperature. The rice growth and yield parameters were measured every 2 weeks and at harvest time (day 110), respectively.  The data were analysed using the MINITAB statistical software package. The mean value estimates of the parameters obtained under different conditions were compared using analysis of variance (ANOVA) with the Tukey test for multiple comparisons using a 0.05 significance level. Significant differences in the number of tiller, stem width , chlorophyll content , weight of grains and panicles and total grain weight per plant were identified at rotation speed 10 rpm  when compared to rotation speed 2 rpm and control. The highest means were mainly obtained under 10 rpm clinorotated rice seeds. In general, plants grown from 10 rpm clinorotated seeds are also more resistant to rice diseases (rice blast disease, rice tungro disease and hopper burn). These results suggest that simulated microgravity using a 2-D clinostat affected several rice (MR219) growth and yield parameters significantly. 

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