浅谈食品安全中药物残留的影响

食品安全是当今全世界共同关注的重大问题,也是各国政府、相关国际组织、学术机构研究的热点。而药物残留是食品安全问题中的重中之重,本文通过细致分析当前我国药物残留的主要问题,透视出我国食品安全管理的若干问题,并探索出几点食品安全的应对措施。     

绿色无公害优质马铃薯栽培技术

绿色无公害优质马铃薯栽培技术是在传统马铃薯栽培技术的基础上,通过多施有机肥,少施化肥,选用抗病性强、品质优的品种,使用物理手段杀虫灭菌的一项栽培技术。     

利用激光光测弹性法对复合材料内部残留应力分离解析

本文利用干涉性非常好的激光斜入射光测弹性法,对玻璃纤维增强环氧树脂复合材料成形时,所生成的复合材料纤维界面近傍的残留主应力进行观测和解析,并分别获得主应力δ_1和δ_2。其精度在数N/mm～2的范围时,可达±0.014N/mm～2的良好程度。另外,就形状比较简单的试样,对本方法测试的结果与数值解析法的结果进行了比较。两方法的结果比较一致,证明本论文提出的方法是有效的。     

结构不对称杀虫剂丙硫磷在松针上的消解动态

以倍硫磷为对照，研究了分别用聚乙烯醇和水作稀释剂时丙硫磷在松针上的消解动态，结果表明：丙硫磷和倍硫磷一样，同属于消解速率较慢的有机磷杀虫剂；用０．５％聚乙烯醇作稀释剂的丙硫磷在使用初期有较强的耐雨水冲刷能力，能延长药剂持效期，减少环境污染。     

40%灭铃特乳油分析方法的研究

灭铃特乳油中各有效成分的全分析方法，用气相色谱及液相色谱技术对灭铃特乳油中的高效氯氰菊酯、辛梳磷和甲基对硫磷进行了测定，再用气相色谱法测定氯氰菊酯的总酯含量；然后，用正相液相色谱法分离异构体，求出高效体含量；甲基对硫磷和辛硫磷的测定采用反相高效液相色谱法同时进行测定，结果令人满意。     

微生物降解四种农药的毒性效应

为了解除草剂氯磺隆.甲磺隆、丁草胺和杀虫剂单甲脒经微生物降解后毒性有无变化,对环境是否造成危害,在分别以上述农药为碳源、氮源和能源的液体培养基中接种土样,振荡培养,以灭菌土样作对照,定时取样,经微孔滤膜抽滤后,以隆线蚤毒性试验和Ames试验、微核试验测其急性毒性和遗传毒性.结果表明,四种受试农药经微生物降解后,对水蚤的急性毒性均有所降低;氯磺隆、甲磺隆和单甲脒在微生物降解后,与降解前一样,均无致突变性;丁草胺在微生物作用过程中会产生诱变剂,但可继续被微生物降解而使其致突变性消失.对降解前后微生物混合种群的分离、鉴定表明,降解菌主要是假单胞菌.     

Cloning and analysis of the antagonistic related genes of <Emphasis Type="Italic">Enterobacter cloacae</Emphasis> B8

To understand the antagonistic mechanism of the broad spectrum antagonistic Enterobacter cloacae B8,Tn5 transposon-mediated mutagenesis is performed using suicide plasmid pZJ25. Two mutant strains that lost antagonistic character are isolated. Tagging with kanr gene on Tn5,an antagonistic related DNA fragment, the F fragment, right of the Tn5 insertion site is cloned in a plasmid named pTLF,from one of the mutant strains B8F. The 733 bp F fragment is then sequenced after subcloning. Genomic DNA of the original B8 strain is isolated, digested with Pst I and ligated to Pst I cassette. DNA fragments left and right of the F fragment are amplified from the Pst I cassette library using cassette primer and specific primers designed according to known sequence. 1106 bp sequence left of the F fragment and 664bp sequence right of the F fragment are finally obtained. Bioinformatics analysis shows that the contig assembled from the sequences of the cloned antagonistic related DNA fragments of B8 encodes three ORFs and is homogeneous to admM,admN and admO genes of Pantoea agglomerans andrimid biosynthetic gene cluster (AY192157). The ORF, named anrF gene which encodes a polyketide synthase, knocked out by Tn5 insertion, is a homology of admM and the insertion site of Tn5 is at 214 bp upstream of the stop codon. It is concluded that the anrF gene is a gene related to the antagonistic activity of E. cloacae B8, and speculated that the antagonistic substance produced by B8 is an andrimid.