Curdlan production: Effect of Carbon and Nitrogen sources, characterization, and applications in health

10.30207/AHLA.202312.0006

Natasha Aquinas；Ramananda Bhat M；Subbalaxmi Selvaraj

Biopolymer ； Exopolysaccharide ； Fermentation ； FTIR spectroscopy

The Proceeding of the 9th AHLA International Health Literacy Conference: Health Literacy and Social Resilience

2023（2023 / 12 / 01）

6 - 6

英文

Background: Curdlan is an exopolysaccharide that comprises of repeating glucose units joined together by β-1,3 bonds. It is found as a colourless, odourless, and tasteless powder after processing. It can form two types of gels namely, thermo-reversible and thermo-irreversible gel. It is non-toxic and biodegradable. Since it can mimic the mouth feel of fatty food products, it can be used in fat-replacement. Some studies have shown curdlan does not have a caloric value. Therefore, its use in food helps diabetics. However, curdlan is not very well known and hence, awareness on its applications is very limited. Objectives: To determine best carbon and nitrogen source for the isolated curdlan-producing organism and to characterize curdlan produced. Method: The original carbon source 'Sucrose' in the fermentation media was replaced by others such as glucose, fructose, maltose, lactose. Similarly, optimization of nitrogen source was done by replacing (NH_4)_2HPO_4 with urea, peptone, ammonium nitrate and ammonium sulfate. Physical parameters were kept constant along with other media constituents. pH was maintained at 7.0, temperature at 30°C and agitation speed 180rpm. Fourier-transform infrared spectroscopy (FTIR) analysis was done to investigate the presence of functional groups in curdlan which would also help in confirming its identity. Results: Curdlan yield (g/L) was checked when various carbon and nitrogen sources were utilized. Curdlan production was maximum (0.45g/L) when sucrose was used as the carbon source and urea was used as the nitrogen source. The FTIR spectra showed characteristic peaks for biopolymer curdlan such as at ~890 cm^(-1) and others. Conclusion: The effect of carbon and nitrogen sources on the yield of curdlan was evaluated. Sucrose was the best carbon source and Urea was the best nitrogen source for curdlan yield from this isolated organism. The FTIR spectra confirmed that the obtained biopolymer was indeed curdlan.