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摘 要：黄曲霉是引起食物霉变的主要真菌之一，在自然界中广泛存在，粮食在储藏过程中易受其污染。而产毒黄曲霉的次级代谢产物黄曲霉毒素是已知最强致癌物之一。良好地酸性化学防腐剂山梨酸钾能有效抑制黄曲霉的生长。本实验通过固体培养的方法，旨在从菌落在培养基上的形态特征，菌丝体在显微镜下的生理生化特征等方面对该真菌进行观察研究。将从发霉花生果荚上分离出的产毒黄曲霉的孢子接种到含有不同浓度山梨酸钾的固体培养基平板上，分别对其孢子萌发率、菌落颜色、菌落直径、包子颜色、孢子多少和分生孢子头形状大小进行检测。并对实验数据结果进行分析表明，低浓度的山梨酸钾对产毒黄曲霉的萌发和生长有促进作用，而高浓度的山梨酸钾则有抑制作用，随着浓度的升高抑制效果增加，当山梨酸钾浓度达到0.2 g/L时，抑制效果已经很明显。
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关键词：产毒黄曲霉；山梨酸钾；影响9419
Effects of Potassium Sorbate on the Growth of Aspergillus Flavus in Peanut Pods
Abstract: Aspergillus flavus is one of the main fungus causes of food mildew, widespread in nature, its vulnerability to contamination of food during storage. Aflatoxin, metabolites of Aspergillus flavus, is one of most deadly known carcinogens. Potassium sorbate, as a good acidic chemical preservatives, can effectively inhibit the growth of Aspergillus flavus. In order to study Aspergillus flavus, this experiments use of solid culture to observe colonies morphological on medium and physiological and biochemical characteristics of mycelium under the microscope aspect. Isolated the toxigenic Aspergillus flavus out from the moldy peanut pods, then Activated spores were cultured in solid culture medium containing various concentrations of potassium sorbate, Then, detecte the A. flavus spore germination, colony size, colony color and on, followed by a statistical analysis. The results of the experimental data for statistical analysis showed that low concentrations of potassium sorbate can promote germination and growth of toxigenic Aspergillus flavus, however, high concentrations of potassium sorbate which inhibit germination and growth. Inhibition of potassium sorbate increases as its concentration rises, Substantial inhibition was achieved with 0.2 g/L of potassium sorbate.
Key Words: Aspergillus flavus; Potassium sorbate; Influence
目 录
摘 要 1
引 言 2
1 实验材料 3
1.1 时间与地点 3
1.2 主要实验材料、试剂和用品 3
1.3 主要实验仪器 3
2 实验方法 3
2.1 培养基的配制 3
2.2 倒平板 4
2.3 产毒黄曲霉毒性的检测 5
2.4 产毒黄曲霉孢子悬液的制备 5
2.5 平板培养法测试山梨酸钾对产毒黄曲霉的影响 5
3 结果与分析 6
3.1 不同浓度山梨酸钾对产毒黄曲霉孢子萌发情况的影响 6
3.2 山梨酸钾对产毒黄曲霉菌落颜色和大小的影响 7
3.3 山梨酸钾对产毒黄曲霉分生孢子头、孢子及分生孢子梗的影响 8
4 讨论 9
5 结论 11
参考文献 12
致 谢 13
山梨酸钾对花生果荚上产毒黄曲霉生长的影响 引言
由微生物引起的食品霉变、腐败对人类的生产和生活带来很大的影响，造成了巨大损失。据不完全统计，世界上约有20 %的食品因霉变、腐败而浪费掉，同时还危及了人们的健康[1]。产毒黄曲霉因能分泌致癌物质黄曲霉毒素，同时污染最为普遍，成为粮食贮藏和农业贸易中最受关注的真菌种类[2]。黄曲霉毒素(Aflatoxin，AF)是所有真菌毒素中对环境污染最严重，对人畜危害最大且毒性最强的真菌次级代谢产物。黄曲霉毒素既有很强的急性毒性，导致肝脏坏死出血，使免疫系统受损，引起蛋白质营养不良症并导致儿童发育受阻也有明显的慢性毒性引起肝癌，并具有致癌、致畸、致突变作用，对人、家畜和家禽的健康威胁极大，因而受到世界范围的广泛关注[3]。食品防腐是保障食品安全的重要手段。