An endophytic facultative methylotrophic bacteria with pink pigment was isolated from Jatropha curcas leaves and in vitro tests were used to identify its growth-promoting properties. Using morphological and 16S rRNA sequencing features, the isolate was recognized as Methylobacterium radiotolerans strain H-0A1. The identified strain H-0A1 of M. radiotolerans produces IAA, fixes nitrogen, forms ammonia, and soluble phosphate, according to the results of an in vitro evaluation. Furthermore, the stimulation effect of M. radiotolerans strain H-0A1 on the growth of J. curcas was investigated in a pot experiment. Plant height, leaves parameters (number, area, and dry weights), as well as stems diameter and dry weight, length, and dry weight of roots, were all greatly enhanced by inoculation and/or foliar spraying treatments of J. curcas seedlings. These treatments also had an impact on the amount of chlorophyll and the uptake of nutrients. According to the current research, the bacterium M. radiotolerans strain H-0A1 has a lot of potential for use as a biofertilizer in sustainable agriculture.