| To explore an efficient,safty and environmentally friendly method of deoxynivalenol(DON)biodegradation and to reduce the poisonous effects of deoxynivalenol in feedstuff on animal.The aim of the experiment 1 was to conduct to analyze and evaluate the contamination situation of DON in feed and feedstuff in Beijing area.The aim of the experiment 2 and 3 were to screen for bacterial caplable of degrading efficiently DON and study the characteristics and explore the degradation mechanisms of DON degraded by ANSB714 strain.The aim of the experiment 4,5,6 were the safety and efficacy assessment of Devosia sp.ANSB714 and to study on application effects of Devosia sp.ANSB714 on mice and growing-finishing pigs exposed to DON.Experiment 1:The aim of this research was conducted to analyze and evaluate the contamination situation of DON in feed and feedstuff in Beijing area.A total of 131 feed samples from 15 pig farms in Beijing were sampled to detect and quantify the content of DON.An efficient HPLC/UV method was developed,including immunoaffinity step for DON extraction from feeds and feedstuff followed by liquid chromatography(LC)for quantification.These results indicated that the average content of DON in corn and DDGS were the highest,and DON contamination was widely found in both feed and feedstuff.Experiment 2:The aim of this research was to screen for bacterial caplable of degrading DON.The results showed that DON was degraded efficiently by ANSB714 strain.ANSB714 was identified as Devosia sp.strain.Experiment 3:This experiment studied the characteristics of DON degraded by ANSB714 strain.Research the effect of different reaction conditions for Devosia sp.ANSB714 on DON degradation,including the composition of the medium,initial pH,temperature,incubation time,in order to further improve the efficiency of its degradation;Research the active ingredient of Devosia sp.ANSB714 in DON degradation and the characteristics of the active ingredient.The degradation product was analysed with liquid chromatography-mass spectrometry,exploring the degradation mechanisms of Devosia sp.ANSB714 on DON degradation.The result showed that DON degradation was also high in media containing corn steep liquid.ANSB714 maintained high transformation ability over a broad range of pH values from 6.2 to 9.1 and temperatures from 4 to 37 ?.The active ingredient of Devosia sp.ANSB714 in DON degradation was bacterial cells,composed by a class of glycoprotein materials.The 3-keto-deoxynivalenol was identified as a product of DON transformation by bacterial strain ANSB714 isolated.Experiment 4:The aim of this research was the toxicology and safety assessment of Devosia sp.ANSB714.Acute toxicity test(rat and mouse)and two mutagenicity tests(Sperm shape abnormality test in mice and Mouse bone marrow micronucleus test)were proved that ANSB714 was low toxin and safe.The Devosia sp.ANSB714 had few antibacterial activity and a high survival rate and tolerance in simulated gastric fluid and intestinal fluid.Experiment 5:The aim of this research was to investigate study on effects of Devosia sp.ANSB714 on mice exposed to deoxynivalenol.In the experiment,80 male mice were randomized with 4 treatments:non-toxin control,non-toxin control + ANSB714,toxin control and toxin control +ANSB714.During 28 days of exposure to the mice in all treatments,the values in toxin control were significantly lower than those in the other groups with regard to average daily gain and average daily feed intake,while there was no significant difference among other groups.DON negatively affected the ALP and ALT levels and increased the values of BUN and CRE.Compared with the other groups,the levels of IgA,IL-2,IL-6 and TNF-a in toxin control were significantly higher.Serum chemistry and immunity function in toxin control diet containing ANSB714 returned to the normal state exhibited by the non-toxin control.The residues of DON in kidneys in the toxin diets supplemented with ANSB714 were significantly decreased compared with that in the toxin control group.The results showed that DON in diets caused tissue lesions of liver,kidney and small intestine in toxin control compared with the non-toxin control,and the addition of ANSB714 to toxin control could ameliorate these symptoms.The results suggested that adding Devosia sp.ANSB714 to toxin diets could eliminate the negative effects of DON on mice.Experiment 6:The aim of this research was to investigate study on effects of Devosia sp.ANSB714 on growing-finishing pigs exposed to deoxynivalenol.In the experiment,25 growing-finishing pigs were randomized with 5 treatments:non-toxin control,non-toxin control +ANSB714,toxin control,toxin control + ANSB714 and toxin control + mycotoxin biological degradation agent(MB DA).During 18 days of exposure to the growing-finishing pigs in all treatments,the values in toxin control were significantly lower than those in the other groups with regard to average daily gain(P<0.05),while there was no significant difference among other groups.The results showed that DON in diets significantly increased the liver,spleen and kidney organs weight of growing-finishing pigs in toxin control compared with the non-toxin control(P<0.05),and the addition of ANSB714 to toxin control could ameliorate these symptoms.DON in diets significantly decreased the ALB levels and significantly increased the activity of ALT and ALP and the values of BUN and CRE(P<0.05).The levels of IgA,IL-2,IL-6 and TNF-a in toxin control were significantly higher(P<0.05).DON in diets could significantly decreased the activities of GSH-PX in serum and liver(P<0.05).The addition of ANSB714 to toxin control could ameliorate these negative effects of DON on serum chemistry,immunoglobulin and serum cytokines and the oxidative status of serum and liver.The residues of DON in in the serum,liver and kidneys in the toxin diets supplemented with ANSB714 were significantly decreased compared with that in the toxin control group.The results showed that DON in diets caused tissue lesions of liver,kidney and small intestine in toxin control compared with the non-toxin control,and the addition of ANSB714 to toxin control could ameliorate these symptoms.Moreover,the results indicated that the protective effect of MBDA on DON in diet of· growing-finishing pigs was slight.The results suggested that adding Devosia sp.ANSB714 to toxin diets could more effectively eliminate the negative effects of DON on growing-finishing pigs than the toxin diets supplemented with MBDA.In summary,DON contamination was widely found in both feed and feedstuff in Beijing area.Devosia sp.ANSB714 strain was isolated for bacterial caplable of degrading efficiently DON.The 3-keto-deoxynivalenol was identified as a product of DON transformation by Devosia sp.ANSB714.The toxicology and safety assessment was proved that Devosia sp.ANSB714 was low toxin and safe.Adding Devosia sp.ANSB714 to toxin diets could eliminate the negative effects of DON on mice and growing-finishing pigs. |
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