Microbial detoxification of eleven food and feed contaminating trichothecene mycotoxins.
Microbial detoxification of eleven food and feed contaminating trichothecene mycotoxins.
复制标题
DOI：
10.1186/s12896-017-0352-7
复制
发表时间：
2017-03-15
影响因子：
3.5
通讯作者：
Pauls KP
中科院分区：
文献类型：
--
作者：
Ahad R;Zhou T;Lepp D;Pauls KP
由产毒镰刀菌产生的多种霉菌毒素对农产品的污染是一个食品安全问题，严重影响全球粮食生产和销售。重要的是，由于它们的协同和/或相加作用，暴露在多种三氯乙烯中可能会增加动物的毒性。为了解决这一问题，本研究旨在获得一种新的生物学特性，能够在好氧和厌氧条件下以及广泛的温度范围内对各种污染的食品和饲料进行解毒。经过土壤微生物培养与200μg/mL脱氧雪腐镰刀菌烯(DON)的长时间孵育，获得了能够将11种三氯乙烯转化为毒性显著较低的脱环氧化合物的高度浓缩的微生物联合体(称为DX100)。DX100在好氧和厌氧条件下、较宽的温度范围和中性pH条件下表现出脱环氧化活性。该联合体含有70%的已知细菌和30%的未知细菌，以营养狭窄性单胞菌为主。新的细菌包括营养单胞菌和嗜碱杆菌-布鲁氏菌复合体可能分别参与了毛霉烯的好氧和厌氧脱环氧化反应。50μg/mLDX100在48h内对脱氧雪腐镰刀菌烯醇的脱环率为100%，在矿物盐发酵液中继代培养100次后仍保持脱环氧化能力。它能够脱环氧化高浓度的DON(500g/μ)，并将另外10种污染食品的三环烯转化为脱环氧形式和/或其他已知/未知的化合物。微生物脱环氧化速率随着发酵液中三环烯浓度的增加而增加，表明DX100保持了较强的三环烯解毒机制。此外，微生物脱环氧化反应的本质和叠氮化钠对该反应的抑制以及细菌细胞培养裂解物保持活性的发现表明，某些细胞质还原酶可能是脱环氧化活性的原因。本研究报道了获得有效和稳定的微生物联合体DX100的富集法，该微生物联合体能够脱环氧化几种污染毛霉烯真菌毒素的食品。DX100在广泛的条件下具有脱环氧化能力，是一种独特的酶来源，具有巨大的工业潜力，可减少食品/饲料中多个三氯乙烯的污染，并将其对消费者健康的协同/相加细胞毒性作用降至最低。
Contamination of agricultural commodities with multiple trichothecene mycotoxins, produced by toxigenic Fusarium species, is a food safety issue, which greatly affects grain production and marketing worldwide. Importantly, exposure to multiple trichothecenes may increase toxicity in animals due to their synergistic and/or additive effects. To address the problem this study aimed to achieve a novel biological trait capable of detoxifying various food and feed contaminating trichothecenes under aerobic and anaerobic conditions and wide range of temperatures. A highly enriched microbial consortium (called DX100) capable of transforming eleven trichothecenes to significantly less toxic de-epoxy forms was achieved after prolonged incubation of soil microbial culture with 200 μg/mL deoxynivalenol (DON). DX100 demonstrated de-epoxidation activity under aerobic and anaerobic conditions, a greater range of temperatures and around neutral pH. The consortium contains 70% known and 30% unknown bacterial species, dominated by Stenotrophomonas species. Probably novel bacteria including strains of Stenotrophomonas and Alkaliphilus-Blautia species complex could be involved in aerobic and anaerobic de-epoxidation of trichothecenes, respectively. DX100 showed rapid and stable activity by de-epoxidizing 100% of 50 μg/mL deoxynivalenol at 48 h of incubation and retaining de-epoxidation ability after 100 subcultures in mineral salts broth (MSB). It was able to de-epoxidize high concentration of DON (500 μg/mL), and transformed ten more food contaminating trichothecenes into de-epoxy forms and/or other known/unknown compounds. Microbial de-epoxidation rate increased with increasing trichothecene concentrations in the broth media, suggesting that DX100 maintains a robust trichothecene detoxifying mechanism. Furthermore, the nature of microbial de-epoxidation reaction and inhibition of the reaction by sodium azide and the finding that bacterial cell culture lysate retained activity suggests that certain cytoplasmic reductases may be responsible for the de-epoxidation activity. This study reports the enrichment procedure for obtaining an effective and stable microbial consortium DX100 capable of de-epoxidizing several food contaminating trichothecene mycotoxins. DX100, which has de-epoxidation ability under wide range of conditions, represents a unique enzymatic source which has great industrial potential for reducing contamination of foods/feeds with multiple trichothecenes, and minimizing their synergistic/additive cytotoxic effects on consumer health.