Optimization using response surface methodology of phospholipase C production from Bacillus cereus suitable for soybean oil degumming

Abstract

This work deals with the optimization of an extracellular phospholipase C production by Bacillus cereus (PLC_Bc) using Response Surface Methodology (RMS) and Box-Behnken design. In fact, after optimization, a maximum phospholipase activity (51 U/ml) was obtained after 6 h of cultivation on tryptone (10 g/L), yeast extract (10 g/L), NaCl (8.125 g/L), pH 7.5 with initial OD (0.15). The PLC_Bc activity, esteemed by the model (51 U) was very approximate to activity gutted experimentally (50 U). The PLC_Bc can be considered as thermoactive phospholipase since it showed a maximal activity of 50 U/mL at 60 °C using egg yolk or egg phosphatidylcholine (PC) as substrate. In addition, the enzyme was active at pH 7 and is stable after incubation at 55 °C for 30 min. The application of B. cereus phospholipase C in soybean oil degumming was investigated. Our results showed that when using enzymatic degumming, the residual phosphorus decrease more than with water degumming, indeed, it passes from 718 ppm in soybean crude oil to 100 ppm and 52 ppm by degumming using water and enzymatic process, respectively. The diacylgycerol (DAG) yield showed an increase of 1.2% with enzymatic degumming compared to soybean crude oil. This makes our enzyme a potential candidate for food industrial applications such as enzymatic degumming of vegetable oils.

Keywords:

• Bacillus cereus phospholipase C
• biochemical characterization
• enzymatic soybean oil degumming
• response surface methodology

Acknowledgment

We are grateful to Dr A. Verwey (Agrolab Roterdam, Netherlands) for DAG analysis.

Author contributions

Ines Abdelkader: Data curation, Formal analysis, Investigation, Methodology, Writing-Original Draft. Sameh Ben Mabrouk and Bilel Hadrich: Inversigation, Methodology, Writing – Review & Editing. Ahmed Fendri: Supervision, Writing – Review & Editing. Adel Sayari: Conceptualization, Writing – Review & Editing, Supervision, Project administration.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data generated during this study are included in the submitted manuscript.

Additional information

Funding

This work is a part of a doctoral thesis by Ines Abdelkader whose research was financially supported by ministry of higher education and scientific research (Tunisia) through a grant to Laboratory of Biochemistry and Enzymatic Engineering of Lipases-Engineering National School of Sfax (ENIS).