Isolation and identification of an extracellular enzyme from Aspergillus Niger with Deoxynivalenol biotransformation capability

Abstract

In this study, the purification and characterization of an extracellular enzyme form Aspergillus niger was performed. With an optimized protocol, it was conducted a 42.6-fold purification with a yield of 26.2%. The purified lipase had a monomeric molecular weight of 40.5kDa and an isoelectric point of 6.01, and its maximum enzyme activity could be achieved at 40°C and pH 7.5-9.0. The enzyme could be activated by Ca2+, Mg2+ and Fe2+, while its activity could be inhibited by Zn2+ and Cu2+. Additionally, organic compounds exerted an inhibitory effect on the enzyme activity in a descending order of methanol, ethanol, DMSO, EDTA, acetone. Meanwhile, the specificity analysis of the enzyme indicated a preference to tributyrin and vegetable oils as well as long-chain fatty acid methyl esters (C12-C18). Most importantly, this enzyme could successfully transform deoxynivalenol (DON). Using HPLC analysis，it was detected a biotransformation rate of more than 70%.The liquid chromatography-mass spectrometry (LC-MS) analysis showed that the molecular weight of the transformation product was 18.0 larger than that of DON, indicating that DON could be hydrolyzed by the enzyme. Overall, the proposed method here provides a new avenue for reducing the toxicity of DON, which appears to have a wide application outlook for DON biotransformation.

Enzymes for Detoxification of Various Mycotoxins: Origins and Mechanisms of Catalytic Action

“…Aflatoxin dialdehyde aldo-keto reductase AKR7A1 (Figure 2 [15,16], Table 1 [17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58]) was isolated from rat liver, and its structure in complex with NADP + was solved [59]. This enzyme is assumed to reduce both aldehyde groups of dialdehyde of hydroxy aflatoxin B 2a , forming from 8,9-dihydrodiol aflatoxin B 1 , resulted in dihydroxy derivative.…”

“…Lipase from fungi Aspergillus niger can degrade deoxynivalenol [54]. EDTA has only a limited inactivating effect (<10%), while Zn 2+ and Cu 2+ ions significantly inhibit enzyme (up to 60%).…”

Biodegradation of Deoxynivalenol by Nocardioides sp. ZHH-013: 3-keto-Deoxynivalenol and 3-epi-Deoxynivalenol as Intermediate Products

“…Massive screening techniques using diverse methods have been conducted to identify DON-degrading microbes, several of which have high DON conversion ability. Over the last three decades, DON-degrading strains have been identified among genera including Eubacterium (Fuchs et al, 2002), Eggerthella (Gao et al, 2018), Desulfitobacterium (He et al, 2020), Devosia (He et al, 2016;Wang et al, 2017Wang et al, , 2019, Sphingomonas (Ito et al, 2013;He et al, 2017), Nocardioides (Ikunaga et al, 2011), Marmoricola (Ito et al, 2012, Bacillus (Li et al, 2011), Pelagibacterium (Zhang et al, 2020), and Aspergillus (He et al, 2008;Jaqueline and Eliana, 2010;Jaqueline et al, 2011;Yang et al, 2017).…”

“…(2) DON to 3-ADON or 15-ADON; (3) DON to 3-keto DON; (4) DON to 16-DON; and (5) two-step transformation: DON to 3-keto-DON and 3-keto-DON to 3-epi-DON. Some other strains, such as Aspergillus niger As-D.1 (Yang et al, 2017), exhibit different mechanisms; however, the degradation products have not been clearly explained based on detailed data. Moreover, the ZHH-013 strain exhibited a new degradation mechanism that differed from the five mechanisms mentioned above.…”

Digestive propensity of Aflatoxin M1 (4‐Hydroxyaflatoxin B1), an indication from in vitro digestion model system

“…Previously published reports suggested that lipase involves in the degradation of mycotoxins such as Deoxynivalenol, Ochratoxin A (OTA), patulin, etc (Lyagin & Efremenko, 2019). In particular, lipase obtained from the fungi Aspergillus niger can degrade the mycotoxin deoxynivalenol (Yang et al, 2017). Similarly, Lipase A produced from Aspergillus niger by Amano Corporation showed OTA hydrolase activity and caused OTA degradation.…”