In this work, L-glutamic acid polymorphs of beta and alpha crystal were grown by the slow evaporation method by using additives of ammonium sulphate. The selective additive ammonium sulphate was added at different concentrations to study the L-glutamic acid polymorphs. It creates that at a level of 0.04 g/100 ml, the additive contributed to the crystallization of L-glutamic acid in alpha-form, and this additive exhibited an inhibitory action on the transition of a crystal to beta crystals. The lower concentration of ammonium sulphate provides beta polymorph whereas the higher concentration of ammonium sulphate provides alpha polymorph crystal. Structural confirmation of the grown polymorph was executed by powder X-ray diffraction study. UV-Vis-NIR spectral analysis the optical transparency of grown crystals. The powder second harmonic conversion efficiency of grown crystal was determined by using Kurtz and Perry powder technique and the efficiency compared to standard inorganic material potassium dihydrogen phosphate. The dielectric properties of dielectric constant and dielectric loss of grown crystal have been measured as a function of frequency and temperature. The photoconductivity study contributed its positive photo conducting nature. In vitro antimicrobial activity of grown crystals was analyzed against gram positive and negative bacteria's carried out by disk diffusion process and created that the crystal proves superior inhibition against various bacteria's strains.