黄杆菌 ANSM068 产黄曲霉毒素降解酶的制备、纯化及特性。

Preparation, purification and characteristics of an aflatoxin degradation enzyme from Myxococcus fulvus ANSM068.

机构信息

National Laboratory of Animal Nutrition, College of Animal Science & Technology, China Agricultural University, Beijing, China.

出版信息

J Appl Microbiol. 2011 Jan;110(1):147-55. doi: 10.1111/j.1365-2672.2010.04867.x. Epub 2010 Oct 13.

DOI:10.1111/j.1365-2672.2010.04867.x

PMID:21040271

Abstract

AIMS

To prepare, purify and characterize an extracellular enzyme from Myxococcus fulvus ANSM068, designated as myxobacteria aflatoxin degradation enzyme (MADE), which possesses degradation activity against aflatoxin B(1) (AFB(1) ), G(1) (AFG(1) ) and M(1) (AFM(1) ) in solution.

METHODS AND RESULTS

The culture supernatant of strain M. fulvus demonstrated high degradation ability against AFB(1) (71·89%), AFG(1) (68·13%) and AFM(1) (63·82%) after 48 h of incubation. An enzyme was purified from the supernatant of M. fulvus using ethanol precipitation and chromatography on DEAE-Sepharose and Superdex 75. An overall 166-fold purification of the enzyme with a recovery of 57% and a final specific activity of 569·44 × 10(3) U mg(-1) was obtained using the present purification protocol. The apparent molecular mass of MADE was estimated to be 32 kDa by SDS-PAGE. AFG(1) and AFM(1) were significantly degraded, by 96·96 and 95·80%, respectively, when treated with pure MADE (100 U ml(-1) ) produced by strain ANSM068. MADE exhibited the largest amount of activity at 35°C and pH 6·0, with Mg(2+) ions greatly promoting and Zn(2+) strongly inhibiting MADE activity.

CONCLUSIONS

An aflatoxin DEGRADATION ENZYME FROM BACTERIAL ISOLATES CAN EFFECTIVELY REMOVE AFLATOXIN B(1) , G(1) AND M(1) IN SOLUTION.

SIGNIFICANCE AND IMPACT OF THE STUDY

The high activity and wide temperature and pH range of MADE for the degradation of aflatoxin have promising applications in control of mycotoxins during food and feed processing.

摘要

目的

从粘细菌粘球菌 ANSM068 中制备、纯化和鉴定一种胞外酶，命名为粘细菌黄曲霉毒素降解酶（MADE），其具有降解溶液中黄曲霉毒素 B(1)（AFB(1)）、G(1)（AFG(1)）和 M(1)（AFM(1)）的活性。

方法和结果

粘球菌 M. fulvus 的培养上清液在孵育 48 h 后对 AFB(1)（71.89%）、AFG(1)（68.13%）和 AFM(1)（63.82%）表现出高降解能力。用乙醇沉淀和 DEAE-Sepharose 和 Superdex 75 层析从 M. fulvus 的上清液中纯化酶。采用本纯化方案，酶的总纯化度为 166 倍，回收率为 57%，最终比活为 569.44×10(3) U mg(-1)。SDS-PAGE 估计 MADE 的表观分子量为 32 kDa。用由 ANSM068 菌株产生的纯 MADE（100 U ml(-1)）处理时，AFG(1)和 AFM(1)分别显著降解 96.96%和 95.80%。MADE 在 35°C 和 pH 6.0 下表现出最大的活性，Mg(2+)离子大大促进 MADE 活性，Zn(2+)强烈抑制 MADE 活性。