Liquid biofertilizers have gained the prominence over chemical fertilizers and have become crucial agents to enhance the crop productivity in sustainable agricultural approaches. In view of the demand and scarcity of liquid biofertilizer supply an attempt was made to formulate a liquid nutrient media with bioprocess variables in scalable laboratory batch fermentation bioprocess mode. In the current study, a statistical modeling with Response Surface Methodology (RSM) was simulated and scrutinized the process variables. The best optimum conditions were sorted out and fitted to formulate a liquid medium composition. Finally, liquid biofertilizer nutrient media with bioprocess variables were optimized. The current liquid biofertilizer has guaranteed the enhanced cell mass and efficient metabolic strength of Rhizobium WG strains for their mass production at scalable laboratory batch bioprocess mode. The results of the current investigation revealed that about 33.330 g/L of cell mass with Rhizobium strain WG MH290562 was achieved by a minimum liquid medium formulation comprising of yeast extract at 3.2 g, 55.6 rpm, 35.7 °C, K2HPO4 (0.5 g), MgSO4 (0.1 g), and pH 7.0. Based on the scrutinized data, it is satisfied with the optimized liquid biofertilizer formulation in scalable laboratory batch fermentation bioprocess mode. Hence, we strongly recommend this liquid nutrient media as sustainable biofertilizer formulation for Rhizobium WG Strain. At the same time, ecological survivability and sustained longevity studies and field trials are under progress.