Growth Promoting and Probiotic Potential of the Endophytic Bacterium Rhodococcus globerulus colonizing the Medicinal Plant Plectranthus amboinicus (Lour.) Spreng

Abstract

Objectives: It was intended to isolate endophytic bacteria from Plectranthus amboinicus leaves to elucidate the plant growth promotion potential.Methodology: Phytochemical constituents of Plectranthus amboinicus leaves were analyzed following standard procedures. Endophytic bacteria were isolated in nitrogen limited medium after surface sterilization process as described by Coombs & Franco (2003) and identified by biochemical, molecular analyses. Plant growth promotion and quorum quenching potential of the isolate was determined as described by Patel et al. (2011). Probiotic potential of the isolates was elucidated following a series of assays (Ahire et al. 2011).Results: Phytochemical investigation of the leaves revealed the presence of alkaloids, flavonoids and terpenoids. An endophytic bacterium with probiotic properties was isolated and identified as Rhodococcus globerulus. Plant growth promotion (PGP) traits such as phosphate solubilization, IAA production and ACC deaminase activity of R. globerulus was estimated to be 37.3 μg ml-1, 36.7 μg ml-1 and 35.00 ± 1.2 nmol α-ketobutyrate mg-1 h-1 respectively at 60 h of incubation. The isolate was found to produce trihydroxamate siderophores with hexadentate ligands. Presence of the bacterium within the leaf tissues was confirmed by SEM imaging. R. globerulus was found to produce quorum sensing inhibitor (QSI) molecules. Endophytic isolate was also found to possess probiotic potential. Conclusion:The results illustrate that the plant-associated microbiome serve as a repertoire of metabolic products that facilitate nutritional and defense pathway of the host plant. Probiotic properties of the endophyte confer an added advantage to the therapeutic potential of the plant P. amboinicus.

Genome-Based Characterization of Plant-Associated Rhodococcus qingshengii RL1 Reveals Stress Tolerance and Plant–Microbe Interaction Traits

“…Despite of that, the in vitro assay for this trait was positive for RL1 which suggests the presence of alternative organic acids involved in phosphate solubilization. Phosphate solubilization capacity was previously reported for Rhodococcus globerulus isolated from Plectranthus amboinicus (Murugappan et al, 2017).…”

“…Many plant associated Rhodococci also show plant beneficial traits in vitro (Trivedi et al, 2007;Abbamondi et al, 2016;Murugappan et al, 2017) and in planta (Belimov et al, 2001).…”

Review: Profil Fitokimia dan Multipotensi dari Coleus amboinicus (Lour.)

“…Rhodococcus globerulus, bakteri endofit yang diisolasi dari C. amboinicus (Lour.) dilaporkan memiliki aktivitas yang bisa memacu pertumbuhan tanaman seperti adanya produksi asam asetat indol, 1-aminocyclopropane-1-carboxylate deaminase (ACC deaminase), Hydrogen Cyanide (HCN), produksi ammonia dan pelarutan fosfat, serta produksi Siderofor yang menggambarkan penghambatan patogen (Murugappan et al, 2017).…”