Isolation and Characterization of <i>Lactobacillus paracasei</i> 85 and <i>Lactobacillus buchneri</i> 93 to Absorb and Biotransform Zearalenone

Abstract

As one of the most prevalent estrogenic mycotoxins in cereals and animal feed, zearalenone (ZEN) can cause serious reproductive disorders. ZEN control in food and feed commodities has been an imperative area of research. In this study, 87 lactic acid bacteria (LAB) were isolated from pickles and their ZEN (5 mg/L) removal abilities ranged from 0% to 68.4%. Then, five strains with potent ZEN removal ability (>50%) were identified: Lactobacillus plantarum 22, L. plantarum 37, L. plantarum 47, L. paracasei 85, and L. buchneri 93. Under optimization conditions (48 h, pH 4.0, 37 °C, and 5 mg/L), the highest ZEN removal abilities of L. paracasei 85 and L. buchneri 93 reached 77.7% and 72.8%, respectively. Moreover, the two lactic acid bacteria decreased the toxicity of ZEN, because the levels of β-zearalenol (β-ZOL) transformed from ZEN were more than two-fold higher than α-zearalenol (α-ZOL). Additionally, cell free supernatant and pellet biotransformation of ZEN to α-ZOL and β-ZOL in LAB were detected for the first time. Furthermore, chemical and enzymatical treatments combined with Fourier-transform infrared spectroscopy analysis indicated that exopolysaccharides, proteins, and lipids on the cell wall could bond to ZEN through hydrophobic interactions. Scanning electron microscopy indicated that cell structure damage occurred during the ZEN clearance to L. buchneri 93, but it did not with L. paracasei 85. In addition, various organic acids, alcohols, and esters of the two LAB participated in ZEN removal. Hence, L. paracasei 85 and L. buchneri 93 can be considered as potential detoxification agents for ZEN removal for food and feedstuff.

Keywords

• lactic acid bacteria
• ZEN
• absorption
• biotransformation