TY - JOUR
T1 - Transcriptome analysis of the ammonia-oxidizing bacterium Nitrosomonas mobilis Ms1 reveals division of labor between aggregates and free-living cells
AU - Isshiki, Rino
AU - Fujitani, Hirotsugu
AU - Tsuneda, Satoshi
N1 - Funding Information:
NGS library preparation and the sequencing of Nitrosomonas mobilis Ms1 were supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI (grant 16H06279 [PAGS] [to H.F.]). The other part of this research was supported by a Grant-in-Aid for Young Scientists (B) from the JSPS (grant 16K18609 to H.F.) We also would like to thank Editage (www.editage.com) for English language editing.
Funding Information:
NGS library preparation and the sequencing of Nitrosomonas mobilis Ms1 were supported by the Japan Society for the Promo-E tion of Science ?JSPS) KAKENHI ?grant 16H06279 [PAGS] [to H.F.]). The other part of this research was supported by a Grant-in-Aid for Young Scientists ?B) from the JSPS ?grant 16K18609 to H.F.) We also would like to thank Editage www .editage.com) for English language editing.
Publisher Copyright:
© 2020, Japanese Society of Microbial Ecology. All rights reserved.
PY - 2020
Y1 - 2020
N2 - Bacteria change their metabolic states to increase survival by forming aggregates. Ammonia-oxidizing bacteria also form aggregates in response to environmental stresses. Nitrosomonas mobilis, an ammonia-oxidizing bacterium with high stress tolerance, often forms aggregates mainly in wastewater treatment systems. Despite the high frequency of aggregate formation by N. mobilis, its relationship with survival currently remains unclear. In the present study, aggregates were formed in the late stage of culture with the accumulation of nitrite as a growth inhibitor. To clarify the significance of aggregate formation in N. mobilis Ms1, a transcriptome analysis was performed. Comparisons of the early and late stages of culture revealed that the expression of stress response genes (chaperones and proteases) increased in the early stage. Aggregate formation may lead to stress avoidance because stress response genes were not up-regulated in the late stage of culture during which aggregates formed. Furthermore, comparisons of free-living cells with aggregates in the early stage of culture showed differences in gene expression related to biosynthesis (ATP synthase and ribosomal proteins) and motility and adhesion (flagella, pilus, and chemotaxis). Biosynthesis genes for growth were up-regulated in free-living cells, while motility and adhesion genes for adaptation were up-regulated in aggregates. These results indicate that N. mobilis Ms1 cells adapt to an unfavorable environment and grow through the division of labor between aggregates and free-living cells.
AB - Bacteria change their metabolic states to increase survival by forming aggregates. Ammonia-oxidizing bacteria also form aggregates in response to environmental stresses. Nitrosomonas mobilis, an ammonia-oxidizing bacterium with high stress tolerance, often forms aggregates mainly in wastewater treatment systems. Despite the high frequency of aggregate formation by N. mobilis, its relationship with survival currently remains unclear. In the present study, aggregates were formed in the late stage of culture with the accumulation of nitrite as a growth inhibitor. To clarify the significance of aggregate formation in N. mobilis Ms1, a transcriptome analysis was performed. Comparisons of the early and late stages of culture revealed that the expression of stress response genes (chaperones and proteases) increased in the early stage. Aggregate formation may lead to stress avoidance because stress response genes were not up-regulated in the late stage of culture during which aggregates formed. Furthermore, comparisons of free-living cells with aggregates in the early stage of culture showed differences in gene expression related to biosynthesis (ATP synthase and ribosomal proteins) and motility and adhesion (flagella, pilus, and chemotaxis). Biosynthesis genes for growth were up-regulated in free-living cells, while motility and adhesion genes for adaptation were up-regulated in aggregates. These results indicate that N. mobilis Ms1 cells adapt to an unfavorable environment and grow through the division of labor between aggregates and free-living cells.
KW - Aggregate
KW - Division of labor
KW - Nitrification
KW - RNA sequence
KW - Transcriptome
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U2 - 10.1264/jsme2.ME19148
DO - 10.1264/jsme2.ME19148
M3 - Article
C2 - 32115437
AN - SCOPUS:85080839397
SN - 1342-6311
VL - 35
JO - Microbes and Environments
JF - Microbes and Environments
IS - 2
ER -