Plant growth promoting potential and phylogenetic characteristics of a lichenized nitrogen fixing bacterium, Enterobacter cloacae.
Lichens are complex symbiotic association of mycobionts, photobionts, and bacteriobionts, including chemolithotropic bacteria. In the present study, 46 lichenized bacteria were isolated by conventional and enrichment culture methods on nitrogen-free bromothymol blue (NFb) medium. Only 11 of the 46 isolates fixed nitrogen on NFb and had reduced acetylene. All these 11 isolates had also produced siderophore and 10 of them the IAA. Further, ammonia production was recorded from nine of these nitrogen fixers (NF). On molecular characterization, 16 S rRNA sequencing recorded that, nine NF belonged to Proteobacteria, within Gammaproteobacteria, and were closely related to Enterobacter sp. with a maximum similarity to Enterobacter cloacae. Each one of our NF isolates was aligned closely to Enterobacter pulveris strain E443, Cronobacter sakazakii strain PNP8 and Providencia rettgeri strain ALK058. Notably, a few strains we examined found to possess plant growth promoting properties. This is the first report of Enterobacter sp. from lichens which may be inhabit lichen thalli extrinsically or intrinsically.
Department of Studies in Microbiology, Davangere University, Shivagangothri, Davangere, Karnataka, India.
Chidanandamurthy Thippeswamy
CT
Swamy
Department of Studies in Microbiology, Davangere University, Shivagangothri, Davangere, Karnataka, India.
Devaraja
D
Gayathri
ICAR-Taralabalu Krishi Vigyan Kendra, Kadalivana, Davangere, Karnataka, India.
Thimmalapura Neelakantaiah
TN
Devaraja
CSIR-National Institute of Oceanography, Dona Paula, Goa, India.
Mandar
M
Bandekar
CSIR-National Institute of Oceanography, Dona Paula, Goa, India.
Stecy Elvira
SE
D'Souza
CSIR-National Institute of Oceanography, Dona Paula, Goa, India.
Ram Murti
RM
Meena
CSIR-National Institute of Oceanography, Dona Paula, Goa, India.
Nagappa
N
Ramaiah
D000114:Acetylene / Q000378:metabolism; D000641:Ammonia / Q000378:metabolism; D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000235:genetics; D016972:Enterobacter cloacae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D020563:Gammaproteobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D008011:Lichens / Q000382:microbiology*; D009584:Nitrogen / Q000378:metabolism; D009586:Nitrogen Fixation; D010802:Phylogeny; D063245:Plant Development; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D058441:Rhizosphere; D017422:Sequence Analysis, DNA; D017262:Siderophores / Q000096:biosynthesis
D004269:DNA, Bacterial; D007210:Indoleacetic Acids; D012336:RNA, Ribosomal, 16S; D017262:Siderophores; D000641:Ammonia; D009584:Nitrogen; D000114:Acetylene
16S rRNA; ARA; Enterobacter sp.; Gammaproteobacteria; Lichenized bacteria