Plant Growth-promoting and Bio-control Activity of Micrococcus luteus Strain AKAD 3-5 Isolated from the Soybean (Glycine max (L.) Merr.) Rhizosphere

Abstract

Background: Applications of bioinoculants for improving crop productivity may be an eco-friendly alternative to chemical fertilizers. Rhizosphere or soil-inhabiting beneficial microbes can enhance plant growth and productivity through direct and indirect mechanisms, i.e., phosphate solubilization, nutrient acquisition, phytohormone production, etc. Objective: This study is based on the hypothesis that diseases resistant plants can act as a source of potential microbes that can have good plant growth-promoting traits and bio-control potential. Methods: In this study, we have isolated the rhizobacterial strains (AKAD 2-1, AKAD 2-10, AKAD 3-5, AKAD 3-9) from the rhizosphere of a disease-resistant variety of soybean (JS-20-34) (Glycine max (L.) Merr.). These bacterial strains were further screened for various plant growth-promoting traits (phosphate solubilization, indole acetic acid (IAA), ammonia, biofilm, HCN, Exopolysaccharide (EPS), and enzyme production activity (catalase, cellulase, and chitinase)). Results: Among four, only bacterial strain AKAD 3-5 has shown plant-growth-promoting and biocontrol (98%) activity against Fusarium oxysporum. Morphological, biochemical, and molecular characterization (16S rRNA) revealed that this rhizobacterial isolate AKAD 3-5 closely resembles Micrococcus luteus (Gene bank accession: MH304279). Conclusion: Here, we conclude that this strain can be utilized to promote soybean growth under varied soil stress conditions.

IAA and ACC deaminase producing-bacteria isolated from the rhizosphere of pineapple plants grown under different abiotic and biotic stresses

“…Furthermore, B. diminuta MYS6 promotes root elongation, shoot growth, improves leaf chlorophyll, and increases dry and fresh weight of sunflower plant, under Cu stress [ 82 ]. In addition, Micrococcus yunnanensis RS222 is reported to increase root elongation and plant dry weight of canola seedlings under salinity stress conditions [ 83 ], whereas M. luteus AKAD 3-5 promotes soybean growth and has biocontrol activity against Fusarium oxysporum [ 84 ].…”

Environmental stressor assessment of hydrocarbonoclastic bacteria biofilms from a marine oil spill

“…The degree of biofilm formation exhibited by controls of M. luteus strain 2A1 is congruent with that documented by Malic et al [87] for a M. luteus species assessed using a microtiter plate in tryptone soy broth (TSB) and brain heart infusion broth (BHI) media at 37 °C for 24 h, with optical density (OD) values ranging from 0.15 to 0.20 at 595 nm. As well as for Micrococcus from rhizosphere soil, which was grown in a microtiter plate with nutrient broth for 4 days at 37 °C, resulting in a biofilm with an OD of 2.05 [93] . However, the results of microtiter tests using the halophiles Halomonas and Kushneria , supplemented with 60 g/L NaCl, at 37 °C for 24 h revealed 2.5 and 0.5 OD, respectively [94] ; these recorded behaviours are similar to those observed in 2A1 and 2Sc.…”

Improved species level bacterial characterization from rhizosphere soil of wilt infected Punica granatum

“…On the other hand, an abundance of Micrococcus luteus has been reported in the ISI sample. Micrococcus luteus is a gram-positive bacterium that has been reported to exhibit antifungal activity 42 , 43 and its growth promoting properties, biocontrol properties 44 , biotic and abiotic stress tolerance 43 . Another study has reported the growth promoting properties of Micrococcus luteus against F.oxysporum in chickpea 45 .…”

“…Micrococcus luteus is a gram-positive bacterium that has been reported to exhibit antifungal activity 42 , 43 and its growth promoting properties, biocontrol properties 44 , biotic and abiotic stress tolerance 43 . Another study has reported the growth promoting properties of Micrococcus luteus against F.oxysporum in chickpea 45 . However, there are reports of Micrococcus luteus causing plant diseases.…”