Patulin Removal Mechanism of Rhodosporidiobolus ruineniae PJM3 isolated from peaches

Abstract

Patulin contamination in food is very common, serious harm to human health. Microbial removal of patulin has broad prospects. In this study, yeasts were collected, screened and identified to find those with high efficiency of removing patulin from peach, and indestifated the removal characteristics and removal mechanism of patulin were studied.Yeasts were isolated from the peach peels collected from Yeongcheon-si Gyeongsangbuk-do, and identified by 26S rDNA sequence of 6 yeasts, PJM1, PJM3 and PJM6 were identified as Rhodosporidiobolus ruineniae; PJM2 was Sporidiobolus pararoseus; PJM4 was Metschnikowia sp. JSKim-2014; PJM5 was Kurtzmaniella quercitrusa. After patulin was extracted with ethyl acetate, purified with NA2CO3 solution, dried over anhydrous NA2SO4, dried over N2, and dissolved in acetic acid solution (pH 4.0), it was analyzed by high performance liquid chromatography-ultraviolet detector. The recovery of this method was 89.18-89.99%, RSD was 1.32-3.37%, LOD and LOQ were 0.009 μg/mL and 0.030 μg/mL, respectively. The HPLC analysis method had good reliability and good precision. Rhodosporidiobolus ruineniae PJM3 had high removal rates of patulin. The removal rate of patulin by R. ruineniae PJM3 was nearly 100% at 72 h. The removal performance was best when the temperature was 35°C. With the increase of initial toxin concentration, the ability of yeast to remove patulin gradually decreased. The mode of action of R. ruineniae PJM3 to remove patulin was analyzed. After yeast cells are inactivated, patulin was not be removed; the active yeast treated with patulin was disrupted and found that its cell wall did not contain patulin, indicating that the removal of patulin by yeast was biodegradation. The extracellular fraction of R. ruineniae PJM3 culture did not degrade patulin, which indicated that the degradation of patulin may be the function of R. ruineniae PJM3 intracellular enzymes