Enhanced production of di-(2-ethylhexyl) phthalate (DEHP) by Bacillus subtilis AD35 using response surface methodology (RSM)

Biotechnology & Biotechnological Equipment

Khaled Mohamed Ghanem¹  Amr Adel Abd El-Aal²  Sahar Wefky Mostafa Hassan²  Walid Ahmed Lotfy³ 

[1] Alexandria University;National Institute of Oceanography and Fisheries;Pharos University in Alexandria;

关键词: bacillus;    optimization;    antimicrobials;    fermentation;    response surface methodology;   

DOI  :  10.1080/13102818.2019.1640076

来源: DOAJ

【 摘 要 】

Our previous study demonstrated that a new Bacillus subtilis AD35 was the first Bacillus sp. so far possessing the capability to produce the antibacterial compound di-(2-ethylhexyl) phthalate (DEHP) [Lotfy WA, Mostafa SW, Adel AA, et al. Production of DEHP by Bacillus subtilis AD35: isolation, purification, characterization and biological activities. Microb Pathog. 2018;124:89–100]. In this study, we investigate the process parameters influencing DEHP production by B. subtilis AD35. The best culture medium, carbon and nitrogen source that significantly affected DEHP synthesis were beef-yeast-peptone medium, starch and L-asparagine, respectively. A fractional factorial design (FFD) was applied to screen the fermentation conditions affecting DEHP formation. Agitation rate, inoculum size and sodium chloride concentration were found to be the major factors affecting the synthesis of DEHP. Sequentially, response surface methodology (RSM) was implemented and a polynomial model was developed to predict maximum DEHP activities against Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA), Salmonella typhimurium, Staphylococcus aureus, Staphylococcus epidermidis, Listeria monocytogenes, Pseudomonas aeruginosa and Aeromonas hydrophila. At optimized conditions, agitation rate, 220 rpm; inoculum size, 0.075% (v/v) and sodium chloride concentration, 0.75% (w/v), DEHP activity markedly increased to 24.7 AU, which represents an approximately 707% increase when compared to the pre-optimized conditions. The work reported here represents the first optimization of the process parameters influencing DEHP synthesis by B. subtilis AD35.

【 授权许可】

Unknown