Characteristics of an Acidic Phytase from Aspergillus aculeatus APF1 for Dephytinization of Biofortified Wheat Genotypes

Optimization of phytase production by Penicillium oxalicum in solid-state fermentation for potential as a feed additive

The study aims to statistically optimize the phytase production by Penicillium oxalicum PBG30 in solid-state fermentation using wheat bran as substrate. Variables viz. pH, incubation days, MgSO4, and Tween-80 were the significant parameters identified through the Plackett-Burman design (PBD) that majorly influenced the phytase production. Further, central composite design (CCD) method of response surface methodology (RSM) defined the optimum values for these factors i.e., pH 7.0, 5 days of incubation, 0.75% of MgSO4, and 3.5% of Tween-80 that leads to maximum phytase production of 475.42 U/g DMR. Phytase production was also sustainable in flasks and trays of different sizes with phytase levels ranging from 394.95 to 475.42 U/g DMR. Enhancement in phytase production is 5.6-fold as compared to unoptimized conditions. The in-vitro dephytinization of feed showed an amelioration in the nutritive value by releasing inorganic phosphate and other nutrients in a time-dependent manner. The highest amount of inorganic phosphate (33.986 mg/g feed), reducing sugar (134.4 mg/g feed), and soluble protein (115.52 mg/g feed) was achieved at 37 °C with 200 U of phytase in 0.5 g feed for 48 h. This study reports the economical and large-scale production of phytase with applicability in enhancing feed nutrition.

Cyclic extraction of phosphate from soybean meal using immobilized Aspergillus oryzae SBS50 phytase

Phytase enzyme found in plants, animals, and microorganisms is mainly involved in catalyzing the systematic removal of a phosphate group from phytic acid. Enzyme immobilization is one of the cost-effective methods for the wide usage of enzymes in the industrial sector. This paper reports the covalent immobilization of phytase on glutaraldehyde-activated aluminum oxide beads. The immobilization yield, efficiency, and activation energy were found to be 47.8%, 71.5%, and 15.78 J/mol, respectively. The bound enzyme displayed a shift in pH optima from 5.5 to 4.5, which is more beneficial to increase digestibility in comparison with the free enzyme. Immobilized phytase retained 42.60% of its activity after 1.0 h incubation at 80 °C, whereas free enzyme retained only 4.20% of its activity. Thermodynami increase in half-lives, D-values, enthalpy and free energy change after covalent immobilization could be credited to the enhanced stability. Immobilized phytase could be reused for five consecutive cycles retaining 51% of its initial activity with sodium phytate. The immobilized phytase was also found effective to hydrolyze the soybean meal, thus increasing the digestibility of poultry feed. The hydrolyzing reaction of soybean meal was carried out for six consecutive cycles and immobilized phytase retained nearly 50% of activity till the fifth cycle. The amount of phosphorus released after treatment with immobilized phytase was far higher than that from free phytase. Immobilization on this support is significant, as this support can sustain high mechanical resistance at high pH and temperature. This considerable stability and reusability of the bound enzyme may be advantageous for its industrial application.

Production of fungal phytases in solid state fermentation and potential biotechnological applications

Phytases are important enzymes used for eliminating the anti-nutritional properties of phytic acid in food and feed ingredients. Phytic acid is major form of organic phosphorus stored during seed setting. Monogastric animals cannot utilize this phytate-phosphorus due to lack of necessary enzymes. Therefore, phytic acid excretion is responsible for mineral deficiency and phosphorus pollution. Phytases have been reported from diverse microorganisms, however, fungal phytases are preferred due to their unique properties. Aspergillus species are the predominant producers of phytases and have been explored widely as compared to other fungi. Solid-state fermentation has been studied as an economical process for the production of phytases to utilize various agro-industrial residues. Mixed substrate fermentation has also been reported for the production of phytases. Physical and chemical parameters including pH, temperature, and concentrations of media components have significantly affected the production of phytases in solid state fermentation. Fungi produced high levels of phytases in solid state fermentation utilizing economical substrates. Optimization of culture conditions using different approaches has significantly improved the production of phytases. Fungal phytases are histidine acid phosphatases exhibiting broad substrate specificity, are relatively thermostable and protease-resistant. These phytases have been found effective in dephytinization of food and feed samples with concomitant liberation of minerals, sugars and soluble proteins. Additionally, they have improved the growth of plants by increasing the availability of phosphorus and other minerals. Furthermore, phytases from fungi have played an important roles in bread making, semi-synthesis of peroxidase, biofuel production, production of myo-inositol phosphates and management of environmental pollution. This review article describes the production of fungal phytases in solid state fermentation and their biotechnological applications.

Dephytinization of wheat and rice bran by cross-linked enzyme aggregates of Mucor indicus phytase: a viable prospect for food and feed industries

BACKGROUND

Novel feeds for improved feed intake and for enhanced nutrient bioavailability have recently attracted attention. Insoluble dietary fibers, especially rice and wheat bran, have generated much interest due to their nutritional value. Incorporating insoluble dietary fiber into diets could be a viable way to maximize the feed conversion ratio.

RESULTS

Cross-linked phytase aggregates (CLPA) were synthesized by precipitating enzymes followed by cross-linking with 5 mmol L^-1 glutaraldehyde, yielding 88.24 (U g^-1 ) of enzyme load without the assistance of a proteic feeder. The epitome of the study is the dephosphorylation of wheat bran and rice bran by varying pH, enzyme concentration, and temperature. The highest inorganic phosphorus liberation by 150 U L-^-1 of free phytase was 23.72 (wheat bran) and 48.08 mg g^-1 (rice bran) after 12 h of incubation.  Furthermore, 150 U L^-1 of CLPA liberated 28.72 (wheat bran) and 52.08 mg g^-1 (rice bran) of inorganic phosphorus with an incubation time of 12 h.

CONCLUSION

Thermostable free phytase was insolubilized to dephosphorylate the agro-residue, namely, wheat bran and rice bran, to reduce the anti-nutritional factor (the phytate content) of these insoluble dietary fibers. © 2022 Society of Chemical Industry.

Phytase Mediated Beneficial Impact on Nutritional Quality of Biofortified Wheat Genotypes

Background:

Biofortification has been proposed as an intervention towards alleviation of micronutrient deficiency in the population of developing countries. However, the presence of anti- nutritional factor phytic acid in staple cereals chelates divalent cations and decreases their bioavailability for monogastric animals. Thus, the use of phytase enzyme for hydrolysing phytate-P and enhancing the amount of free divalent cations is of great importance.

Methods :

In this study, two phytases i.e. APF1 phytase from fungal source and commercial wheat phytase were supplemented with flours of biofortified wheat genotypes and their impact on food quality parameters was accessed. Since commercial wheat phytase is costly, it was used as known phytase to compare the application of APF1 phytase. The phytic acid content was reduced in the range of 70 to 84% with APF1 phytase and 79 to 89% with the wheat phytase as compared to untreated samples, respectively. In contrast to phytate, the dialyzability of important micronutrients Fe and Zn enhanced in the range of 21.9 to 48% and 39.5 to 96% with APF1 phytase and, 6.10 to 30% and 23.2 to 81% with wheat phytase, over untreated samples, respectively.

Results and Discussion:

A decrease in tannin content was observed in the range of 8 to 23% and 7 to 23% after treatment with APF1 and wheat phytase, respectively. The phytase treatment has resulted in increased soluble protein content and inorganic phosphate content to different level over untreated samples.

Conclusion:

The study revealed that APF1 phytase was comparatively more effective for enhanced nutritional quality of wheat flour through phytase supplementation for its food based applications.