Nitrogen Fixation in Asaia sp. (Family Acetobacteraceae)

Abstract

The genus Asaia (family Acetobacteraceae) was first introduced with a single species-Asaia bogorensis and later six more species were described namely A. siamensis, A. krungthepensis, A. lannaensis, A. platycodi, A. prunellae, and A. astilbes. Acetobacteraceae family has been divided into ten genera but, only three of them include nitrogen fixing species: Gluconacetobacter, Acetobacter, and Swaminathania. This article originated from our study primarily aimed to isolate new endosymbiotic nitrogen fixer among Acetobacteraceae during which we have isolated, for the first time in India, four different strains of Asaia sp. from three different sources: Michalia champaca flower, Anopheles mosquito, and ant Tetraponera rufonigra. All the endosymbiotic strains isolated possess the ability to fix nitrogen. Evidence for both nitrogenase activity and the presence of nifH gene in isolated Asaia sp. is presented. Asaia bogorensis (MTCC 4041(T)) and A. siamensis (MTCC 4042(T)), two of the validated type strains available from the repository, were tested positive for the presence of functional nitrogenase. The nifH gene sequences from these type strains were also confirmed and compared with other nitrogen fixing members of the family Acetobacteraceae. Our result corroborate with the previous reports that Asaia sp. are indeed widely distributed in nature but this is the first time demonstration of their functional nitrogenase activity. This study shows Asaia sp. as fourth genera of nitrogen fixing bacteria in the family Acetobacteraceae.

Acetic acid bacteria encode two levansucrase types of different ecological relationship

“…B) or spoilers of beverages (Favia et al ., ; Kregiel et al ., ), can actually not be interpreted due to limited knowledge about their specific natural habitats and to the non‐conserved distribution of T2‐LS among species of this AAB genus. The fact that at least some Asaia strains are described as N 2 ‐fixing organisms (Samaddar et al ., ) could, however, point at a similar adaptation to the plant environment. Noticeably, in Zymomonas ( Z .)…”

By their own devices: invasive Argentine ants have shifted diet without clear aid from symbiotic microbes

“…While nitrogen fixation has been cited as a possible function for ant‐associated bacteria in this group (Samaddar et al . ), only one distantly related Rhodospirillales bacterial genome possessed the nifH gene encoding the dinitrogenase reductase enzyme used in this process (Fig. B).…”

Can social partnerships influence the microbiome? Insights from ant farmers and their trophobiont mutualists

“…Indeed, the observed OTUs are closely related to those previously published from the guts of other ants feeding on carbohydrate‐rich diets, including honeydew‐feeding Camponotus carpenter ants, Formica wood ants and Linepithema Argentine ants (Brown & Wernegreen, ; Hu et al., ; Russell et al., ) (Figure , Tables S2 and S3 in Appendix ). In addition, these bacteria are related to Asaia bacteria, recently found in Pseudomyrmex and Tetraponera ants, which both feed on another sugar‐rich diet of extra floral nectar (Kautz, Rubin, & Moreau, ; Samaddar et al., ). Their prevalence among these specific ants, in combination with shown experimental increase in bacterial density with sugar‐rich diets, suggests that Acetobacteraceae aid in the ants’ digestion of sugary honeydew, although more functional work is needed (Hu et al., ).…”

“…Their prevalence among these specific ants, in combination with shown experimental increase in bacterial density with sugar‐rich diets, suggests that Acetobacteraceae aid in the ants’ digestion of sugary honeydew, although more functional work is needed (Hu et al., ). In addition to sugar‐processing abilities, Asaia found in Tetraponera ants has been suggested to play a role in nitrogen fixation (Samaddar et al., ). This additional functionality could also be present in their relatives colonizing the Lasius ants in this study.…”