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

Abstract

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.

Keywords:

• Dephytinization
• fish feed
• large-scale
• P. oxalicum
• phytase
• statistical optimization
• wheat bran

Acknowledgement

The author acknowledges the Department of Biotechnology, Delhi Technological University, Delhi and Department of Microbiology, Maharshi Dayanand University, Rohtak for supporting this research work.

Authors contributions

The original draft was prepared and edited by Ms. Priya and all the experiments were performed by her. Data were analyzed by Priya, Dr. Bijender Singh, Dr. Bhoopander Giri and Dr. Jai Gopal Sharma. The draft was critically revised and improved under the supervision of Dr. Bijender Singh, Dr. Bhoopander Giri and Dr. Jai Gopal Sharma. All authors read and approved the final manuscript.

Disclosure statement

The authors declare no conflicts of result.

Financial support

The author (Ms. Priya) gratefully acknowledges the financial assistance as Junior/Senior research fellowship from the University Grants Commission (UGC), New Delhi, India.

Data availability statement

Data will be made available on request.