A New Zearalenone Biodegradation Strategy Using Non-Pathogenic Rhodococcus pyridinivorans K408 Strain

Abstract

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.

Effect of the combined compound probiotics with mycotoxin–degradation enzyme on detoxifying aflatoxin B₁ and zearalenone

“…For instance, there are some reports about Mycobacterium fluoranthenivorans, Rhodococcus erythropolis and other microbes related to their potentials of aflatoxin degradation (Teniola et al, 2005;Krifaton et al, 2011;Cserháti et al, 2013). Other studies indicate that ZEA can be degraded by Pseudomonas sp., Rhodococcus pyridinivorans and S. Cerevisiae (Altalhi, 2007;Kriszt et al, 2012;Gupta et al, 2012). Liu et al (1998) demonstrated that aflatoxin detoxifizyme obtained from Armillariella tabescens showed AFB 1 detoxification activities.…”

Biodegradation of aflatoxin-B1 and zearalenone by Streptomyces sp. collection

“…AFB1-degrading bacteria may be aromatic ringdegrading microbes (Cserh ati et al, 2013;Krifaton et al, 2011). ZON degradation was reported to be successful using several Rhizopus strains (Varga et al, 2005), the Pseudomonas putida ZEA-1 strain (Altalhi, 2007), the Rhodococcus pyridinivorans (K408) strain (Kriszt et al, 2012) and some Streptomyces and Rhodococcus strains .…”

Metabolic responses of Rhodococcus erythropolis PR4 grown on diesel oil and various hydrocarbons

“…Certain strains of rhodococci were shown to degrade mycotoxins: zearalenone (Kriszt et al 2012), or aflatoxin B 1 (Alberts et al 2006).…”