Methylobacterium sp. are pink-pigmented facultative methylotrophs (PPFMs) that can promote plant’s growth due to several physiological characteristics such as the ability to produce phytohormone namely indole acetic acid (IAA) and effective roles in phosphate solubilization and nitrogen fixation process. Members of this genus are ubiquitous in the environment and characterized by its ability to utilize single C compound such as methanol as its energy source. These characteristics made Methylobacterium sp. as potential candidates for biofertilizer. In this study, Methylobacterium sp. were isolated from the leaves of paddy and palm oil tree using Ammonia Mineral Salt (AMS) agar supplemented with methanol. Nine isolates were selected based on the appearance of pink colonies on AMS agar. Several analyses were conducted to evaluate plant growth-promoting activities of the selected isolates. The production of IAA was quantified spectrophotometrically using Salkowski’s reagent, and solubilization of inorganic phosphate was determined using vanadate molybdate assay. The results showed that, all the isolates are capable to produce IAA and solubilize inorganic phosphate. As for nitrogen fixation, the lack/poor growth of the isolates on two nitrogen-free media, namely Burks’s and Jensen media manifested the absence or weak nitrogen fixing activity. Findings from these qualitative and quantitative analyses are vital and it will serve as preliminary data for the future exploration of Methylobacterium sp. as biofertilizer.
The genus Methylobacterium is known for its pink-pigmented facultative methylotrophs (PPFMs). They are able to utilize methanol emitted from plants and in return produce plant growth promoting substances. The genus Methylobacterium can be found in diverse habitats and they are known particularly for their close association with plants. The aims of this study are to isolate and characterize endophythic Methylobacterium sp. from palm oil leaves. Isolation of Methylobacterium sp was conducted using Ammonia Mineral Salts (AMS) agar supplemented with methanol. Three isolates were selected namely ENPM1, ENPM2 and ENPM3. Production of IAA by the selected isolates was evaluated under different concentration of L-tryptophan as an inducer. It was observed that the amount of(IAA) produced increased when higher concentration of tryptophan was used and ENPM1 recorded the highest amount of IAA production (1.930 μg/mL) at the 1000 μg/mL concentration of L-tryptophan. The ability to solubilized inorganic phosphate was investigated using Solubilisation Index (SI) assay on phosphate solubilisation media (PSM). The largest clear zone formation on PSM agar was shown by ENPM3 with the SI 1.5. As for nitrogen fixation, the growth of the selected isolates on two nitrogen free media namely Burk’s and Jensen media indicates potential nitrogen fixing activity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.