Optimization of Fermentation Conditions for Phytase Production by Two Strains of Bacillus licheniformis (LF1 and LH1) Isolated from the Intestine of Rohu, Labeo rohita (Hamilton)

Valorisation of untreated cane molasses for enhanced phytase production by Bacillus subtilis K46b and its potential role in dephytinisation

BACKGROUND

The high cost of phytase production is the most limiting factor in its application in animal feeds. The present study aimed to develop a low-cost medium for production of a novel phytase in submerged fermentation using inexpensive agro-industrial by-products. The applicability of phytase in dephytinisation of commonly used food/feed ingredients, i.e. soybean meal and wheat bran, was also investigated.

RESULTS

Using a one-factor-at-a-time approach, soybean meal and cane molasses were identified as significant agro-industrial by-products and these factors were subsequently optimised using response surface methodology (RSM). A central composite design was employed to further enhance phytase yield. Under optimum conditions of soybean meal 22.3 g L-1 , cane molasses 100 g L-1 and 39 h fermentation, phytase production increased to 56.562 U mL-1 , indicating more than 28-fold enhancement. The enzyme efficiently dephytinised wheat bran and soybean meal after 24 h incubation at 56.5 °C and increased inorganic phosphate content by 240% and 155%, respectively.

CONCLUSION

Soybean meal and cane molasses were successfully used for enhancement of phytase production as economical carbon, nitrogen and phytic acid sources using RSM. The phytase showed a good capability to dephytinise wheat bran and soybean meal, demonstrating that the enzyme can be considered as a potential candidate for industrial food and feed applications. © 2016 Society of Chemical Industry.

Effective bioconversion of sophoricoside to genistein from Fructus sophorae using immobilized Aspergillus niger and Yeast

In this study, sophoricoside from Fructus sophorae was highly bioconversed to genistein by co-immobilized Aspergillus niger and Yeast. Bioconversion conditions for genistein were optimized with single-factor experiments. The optimal conditions were as follows: microbial concentration 1.5 × 10(7) cells/mL, wet weight of microorganisms beads 10.0 g/g material, pH 5, ratio of liquid to solid 25:1 (mL/g), temperature 32 °C and time 24 h. Under these conditions, a 34.45-fold increase in production of genistein was observed with a bioreactor. Moreover, the antioxidant activities of the extracts from the fermented and untreated F. sophorae were 0.287 ± 0.11, 0.384 ± 0.08 mg/mL (IC50) and 1.84 ± 0.13, 1.28 ± 0.25 mmol Fe(II)/g, according to the DPPH test and FRAP assay, respectively. The results indicated that the method described in the current work were valuable procedure for the production of genistein, which is of most importance for industrial scale applications as well as food industry.