Characterization of curdlan produced by Agrobacterium sp. IFO 13140 cells immobilized in a loofa sponge matrix, and application of this biopolymer in the development of functional yogurt.

BACKGROUND

Agrobacterium sp. IFO 13140 cells were immobilized on a loofa sponge and used to produce curdlan over five successive cycles. The interaction between microbial cells and the loofa sponge as well as the produced curdlan were characterized by Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectrometry. The purity of the curdlan was also evaluated. The storage stability of the immobilized cells was assessed and the produced curdlan was used in a functional yogurt formulation.

RESULTS

The average curdlan production by immobilized cells was 17.84 g L(-1) . The presence of the microorganism in the sponge was confirmed and did not cause alterations in the matrix, and the chemical structure of the curdlan was the same as that of commercial curdlan. The purity of both was similar. The immobilized cells remained active after 300 days of storage at -18 °C. The use of the produced curdlan in a functional yogurt resulted in a product with lower syneresis.

CONCLUSION

A large number of cells physically adhered to the surface of loofa sponge fibers, and its use as an immobilization matrix to produce curdlan was effective. The use of the produced curdlan in yogurt allowed the development of a more stable product. © 2015 Society of Chemical Industry.