| 摘要: |
| 【目的】筛选对梓醇具有转化能力的真菌菌株，并对转化产物进行生物学活性测定及分离鉴定。【方法】用PDA固体培养基从地黄重茬土壤样品中分离纯化具梓醇转化能力的真菌菌株，对目标菌株进行形态学观察和分子生物学鉴定；以白菜、萝卜和芝麻种子为材料，蒸馏水为对照，测定在发酵液体积分数为25%，50%，75%和100%时，3种种子的发率和幼苗根长、苗高及鲜质量等指标的影响，分析梓醇的真菌转化产物对植物生长发育的影响；利用薄层层析法和GC MS法对转化产物进行分离、纯化及鉴定。【结果】从地黄重茬土壤样品中筛选出1株对梓醇转化能力强的菌株（33号菌株），经形态学和分子生物学鉴定，确定该菌为日本曲霉棘孢变种（Aspergillus japonicus Saito var.aculeatus）。该菌转化梓醇发酵液产物对白菜、萝卜种子发芽率影响不大，但发酵液体积分数为100%时芝麻种子发芽率由92%降至12%，抑制作用显著。与空白对照相比，随发酵液体积分数增加，3种作物幼苗的根长、苗高和鲜质量均受到不同程度的抑制作用；当发酵液体积分数为100%时，白菜种子的根长、苗高和鲜质量分别降低了82.8%，30.0%，22.7%，萝卜种子分别降低了31.2%，90.9%，54.5%，芝麻种子分别降低了75.6%，71.4%，64.7%。梓醇转化产物中发挥抑制作用的物质最终被确定为2-癸烯酸甲酯。【结论】从地黄重茬土壤中筛选获得1株具梓醇转化能力的菌株，其转化产物具有抑制植物幼苗生长的作用，发挥抑制作用的物质为2-癸烯酸甲酯。 |
| 关键词: 地黄 梓醇 真菌转化 生物活性 抑制作用 |
| DOI： |
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| 基金项目:科技部“十二五”农村领域科技计划项目(2013AA102101-2)；河南省重点科技攻关项目(142102110086)；河南省自然科学基金项目（2011A180014） |
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| Screening of catalpol transforming strain and separation and identification of the products |
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WANG Hongyang,WANG Mingdao,XING Yan,et al
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| Abstract: |
| 【Objective】This study screened fungi strains with catapol conversion ability, isolated and identified the conversion products,and determined their biological activities.【Method】Fungus strains with catalpol transforming ability were isolated and purified from Rehmannia re-cropping soil by PDA solid medium.Morphological observation and molecular biology identification were conducted to confirmed the catalpol converting ability.The effects on seed germination rate,seedling root length,seedling height and fresh weight of cabbage,radish and sesame seeds were determined when the volume fractions of fermentation broth were 25%,50%,75% and 100% using distilled water as blank control.At last,the products were separated and identified by thin layer chromatography and GC-MS.【Result】The strain 33 was selected from Rehmannia re-cropping soil and it was Aspergillus japonicus Saito var.aculeatus based on morphological observation and molecular biology identification.The volume fractions of catalpol converting products of the strain had little effect on germination rate of cabbage and radish seeds.The germination rate of sesame seeds reduced from 92% to 12% at the fermentation broth volume fraction of 100%,showing significant inhibitory effect.With the increase of volume fraction of the fermentation broth,root length,seedling height and fresh weight of the three seedlings showed different degrees of inhibitory effects.The root length,seedling height and fresh weight of cabbage were decreased by 82.8%,30.0% and 22.7%,those of radish were reduced by 31.2%,90.9% and 54.5%,and those of sesame were decreased by 75.6%,71.4% and 64.7%,respectively.The bioconversion product was identified as methyl 2-decenoate.【Conclusion】One strain with strong catalpol converting ability was screened from Rehmannia glutinosa re-cropping soil.The product methyl 2-decenoate inhibited seedling growth. |
| Key words: Rehmannia glutinosa catalpol fungal transformation biological activity inhibitory effect |
