Sugarcane juice is an effective feedstock for the production of gellan gum: process development and characterization

Gellan gum (GG) is a versatile biopolymer with multifaceted industrial applications. However, its high cost limits its preferential use. This work reports on the production of GG at shake flask and bioreactor level in previously optimized chemically defined medium (CDM) and a newly developed sugarcane juice-based medium (ScJM) by S. trueperi MTCC 25345. The ScJM was optimized by Plackett-Burman followed by FCCD design. The optimized ScJM produced higher GG titer (29 g/L) at 0.8 g/L/h batch productivity than CDM (23 g/L, 0.5 g/L/h) with higher conversion efficiency (63%) than CDM (33%). The kinetics of cell growth, substrate utilization, and GG production were best explained by logistic, exponential decay, and Luedeking-Piret model, respectively. Different purification strategies were investigated and maximum recovery yield of 22.99 +/- 1.6 g/L with 71% w/w purity was obtained. The GG produced was characterized by FTIR, DSC, XRD, SEM, GPC, and physico-chemical attributes and compared with commercial GG.