Abstract
Plant growth-promoting (PGP) bacteria are important to the development of sustainable agricultural systems. PGP microbes that fix atmospheric nitrogen (diazotrophs) could minimize the application of industrially derived fertilizers and function as a biofertilizer. The bacterium Gluconacetobacter diazotrophicus is a nitrogen-fixing PGP microbe originally discovered in association with sugarcane plants, where it functions as an endophyte. It also forms endophyte associations with a range of other agriculturally relevant crop plants. G. diazotrophicus requires microaerobic conditions for diazotrophic growth. We generated a transposon library for G. diazotrophicus and cultured the library under various growth conditions and culture medium compositions to measure fitness defects associated with individual transposon inserts (transposon insertion sequencing [Tn-seq]). Using this library, we probed more than 3,200 genes and ascertained the importance of various genes for diazotrophic growth of this microaerobic endophyte. We also identified a set of essential genes. IMPORTANCE Our results demonstrate a succinct set of genes involved in diazotrophic growth for G. diazotrophicus, with a lower degree of redundancy than what is found in other model diazotrophs. The results will serve as a valuable resource for those interested in biological nitrogen fixation and will establish a baseline data set for plant free growth, which could complement future studies related to the endophyte relationship.
Original language | English (US) |
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Journal | Applied and environmental microbiology |
Volume | 88 |
Issue number | 23 |
DOIs | |
State | Published - Dec 2022 |
Bibliographical note
Funding Information:This work was supported by grants from the National Institute of Food and Agriculture (project no. MIN-12-070 and MIN-12-081) and award no. 2020-67019-31148 through the United States Department of Agriculture. C.M.K. was further supported through funding from the National Science Foundation (CBET-1437758) and a BBE Graduate Fellowship from the Department of Bioproducts and Biosystems Engineering.
Publisher Copyright:
Copyright © 2022 American Society for Microbiology. All Rights Reserved.
Keywords
- gene essentiality
- Gluconacetobacter diazotrophicus
- nitrogen fixation
- Tn-seq
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, Non-P.H.S.