A new zearalenone biodegradation strategy using non-pathogenic Rhodococcus pyridinivorans K408 strain.
Zearalenone (hereafter referred to as ZEA) is a nonsteroidal estrogenic mycotoxin produced by several Fusarium spp. on cereal grains. ZEA is one of the most hazardous natural endocrine disrupting chemicals (EDC) which induces hyper estrogenic responses in mammals. This can result in reproductive disorders in farm animals as well as in humans. Consequently, detoxification strategies for contaminated crops are crucial for food safety. In this study we have developed a bacterial based detoxification system using a non-pathogen Rhodococcus pyridinivorans K408 strain. Following 5 days treatment of ZEA with R. pyridinivorans K408 strain HPLC analyses showed an 87.21% ZEA-degradation efficiency of the bacterial enzyme systems. In another approach, the strain biotransformation ability has also been confirmed by a bioluminescent version of the yeast estrogen screening system (BLYES), which detected an 81.75% of biodegradability of ZEA, in a good agreement with the chemical analyses. Furthermore, the capacity of R. pyridinivorans to eliminate the estrogenic effects of ZEA was tested by using an immature uterotrophic assay. Prepubertal female rats were treated with vehicle (olive oil), 17β-estradiol, ZEA (0.1-1-5-10 mg/kg body weight) and LB broth containing 500 mg/l ZEA that has already been incubated with or without Rhodococcus pyridinivorans K408 strain. Uterine weights were measured and the mRNA level changes relating to apelin, aquaporin 5, complement component 2, and calbindin-3 genes were measured by qRT-PCR. These genes represent the major pathways that are affected by estromimetic compounds. Zearalenone feeding significantly increased the uterus weight in a dose dependent manner and at the same time upregulated complement component 2 and calbindin-3 expression as well as decreased apelin and aquaporin 5 mRNA levels comparable to that seen in 17β-estradiol exposed rats. In contrast, LB broth in which ZEA was incubated with Rhodococcus pyridinivorans K408 prior to the feeding did not display any estrogenic effect neither on uterine weight nor on the expression of estrogen-regulated genes. Consequently, the identification of Rhodococcus pyridinivorans K408 strain in ZEA biodegradation proved to be a very efficient biological tool that is able to eliminate the complete estrogenic effects of ZEA. It is also remarkable that this biotransformation pathway of ZEA did not result in any residual estrogenic effects.
Laboratory of Molecular Neuroendocrinology, Institute of Experimental Medicine, Budapest, Hungary.
Rókus
R
Kriszt
Csilla
C
Krifaton
Sándor
S
Szoboszlay
Mátyás
M
Cserháti
Balázs
B
Kriszt
József
J
Kukolya
Arpád
A
Czéh
Szilvia
S
Fehér-Tóth
Lívia
L
Török
Zsuzsanna
Z
Szőke
Krisztina J
KJ
Kovács
Teréz
T
Barna
Szilamér
S
Ferenczi
D000328:Adult; D000818:Animals; D000073861:Apelin; D051402:Aquaporin 5 / Q000235:genetics / Q000378:metabolism; D001673:Biodegradation, Environmental; D064026:Calbindins; D003175:Complement C2 / Q000235:genetics / Q000378:metabolism; D004785:Environmental Pollutants / Q000378:metabolism* / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology; D004968:Estrogens, Non-Steroidal / Q000378:metabolism* / Q000494:pharmacology; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D012240:Rhodococcus / Q000737:chemistry / Q000378:metabolism*; D064030:S100 Calcium Binding Protein G / Q000235:genetics / Q000378:metabolism; D014599:Uterus / Q000187:drug effects* / Q000502:physiology; D015025:Zearalenone / Q000378:metabolism* / Q000494:pharmacology
D000073861:Apelin; C498579:Apln protein, rat; C496040:Aqp5 protein, rat; D051402:Aquaporin 5; D064026:Calbindins; D003175:Complement C2; D004785:Environmental Pollutants; D004968:Estrogens, Non-Steroidal; D036341:Intercellular Signaling Peptides and Proteins; D064030:S100 Calcium Binding Protein G; C576506:S100G protein, human; C576508:S100g protein, rat; D004958:Estradiol; D015025:Zearalenone