Investigation of Newly Isolated Methylobacterium sp. as Potential Biofertilizer

Abstract

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 adaptability of soybean high yield varieties and farmer preferences in dry land area

“…The application of biofertilizer containing Methylobacterium sp did not affect number of nitrogen fixing bacteria in the soil. This finding was not in line with the statement Grossi et al [14], however, it was similar to the research result of Rahim et al [15] which is found that Methylobacterium sp was found poorly grew on two nitrogen-free media. Figure 2 presents the logarithms of the number of nitrogen-fixing bacteria, varied between 1.78 x 10 6 and 6.75 x 10 7 CFU/g soil.…”

“…The effect of this treatment may be related to the addition of biological fertilizers containing Methylobacterium sp. Methylobacterium sp is known as a bacterium that able to grow in a N 2 free medium, produce indole acetic acid and solubilizes mineral phosphate [14][15][16]. Therefor the addition of biofertilizer was able to improve the growth and yield of soybeans.…”

“…in rice was able to increase the growth of the lateral roots of rice, thereby increasing the growth and yield of rice. Rahim et al [15] suggested that Methylobacterium sp bacteria are able to increase dissolved phosphate which is very much needed by plant growth. In this study the fertilization packages were always supplemented with organic fertilizers because all studies indicated the need to use organic fertilizers [17][18][19].…”

Bioremediation and Accelerated Phytoremediation of a Soil Impacted by a Hydrocarbons Mixture

“…In Table 4, the germination percentage of P. vulgaris enhanced with M. symbioticum and X. autotrophicus fed with 50% mineral solution in soil polluted by 26,990 ppm of WMO remaining from biostimulation, with 83.33% germination, statistically different numerical value compared to 56.67% of P. vulgaris sown in the same soil not polluted by WMO, fed with 100% mineral solution or relative control (RC); and with 50% germination of P. vulgaris in the same soil impacted by 38,204 ppm of WMO used as a negative control (NC). The germination of the seeds of P. vulgaris enhanced with M. symbioticum and X. autotrophicus, supports the transformation of the metabolites, of the germination of the seeds, into phytohormones that induced a rapid and better of germination [14,11,15]. When both M. symbioticum and X. autotrophicus, were able to use, as a source of carbon and hydrocarbons energy of WMO, thereby reducing the phytotoxicity of WMO [2,10,16], that inhibit the germination of seeds, as showed in fig.…”