Haihong Chen ¹ Ting Cao ¹ Zhengduo Wang ¹ Yaohong Wang ¹ Dongyuan Lv ¹ Lixin Zhang ¹ Weishan Wang ^2* Gao-Yi Tan ^1*

• ¹ East China University of Science and Technology, Shanghai, Shanghai, China
• ² Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, China

Porphyrins are a class of cyclic aromatic compounds with significant applications in materials, food, and pharmaceuticals. Recently, bioproduction of porphyrins using microbial cell factories (Rhodobacter sphaeroids) have emerged as a green alternative. However, to date, there is no universal and uniform method for the efficient pretreatment of porphyrins from complicated microbial fermentation broth, which has impeded subsequent accurate quantification. In this study, taking R. sphaeroides as the sample, we established a convenient pretreatment method to achieve efficient extraction of extracellular and intracellular porphyrins from fermentation broth. Initially, acidic acetone has been screened out from various referenced reagents for porphyrins extraction through systematic comparison and evaluation. After optimizing the pH and the addition volume of acidic acetone, the accuracy of the developed method was validated by QC (quality control) samples, yielding recovery ratio exceeding 96%. Furthermore, a convenient pretreatment method for intracellular porphyrins was developed, the acidic acetone could pretreat intracellular porphyrins within 10 seconds. This study proposes an effective pretreatment approach for porphyrins from fermentation broth of R. sphaeroides. This standardized pretreatment method is critical for the precise quantification of porphyrin content in the engineering of high-yielding porphyrin strains. Consequently, this method would facilitates the efficient bioproduction of porphyrins,, thereby enabling their extensive applications across materials, food, and pharmaceutical industries.