硒对金针菇菌丝体生长的影响及其生物还原和迁移
文献类型：学位论文
| 作者 | 王吉鹏
|
| 学位类别 | 硕士 |
| 答辩日期 | 2013 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 张丹 |
| 关键词 | 亚硒酸钠 金针菇菌丝体 生物还原 吸收 |
| 学位专业 | 土壤学 |
| 中文摘要 | 为获取富硒金针菇栽培中合理亚硒酸钠（Na2SeO3）添加剂量和提高富硒金针菇菌丝体浸提物质的抗氧化能力，本研究探讨了不同浓度Na2SeO3在不同培养方式下对金针菇菌丝体生长的影响，并针对金针菇菌丝体在一定浓度Na2SeO3处理下出现的变红现象，研究了其对亚硒酸根的生物还原为元素态硒的过程，重点探讨了还原过程发生和Na2SeO3浓度的关系、发生时间和在菌丝体中位置。为检验还原现象在大型真菌中存在的普遍性，研究了12种在系统分类和生态习性上有明显差异的大型真菌之间菌丝生长对Na2SeO3的反应和菌丝体生物还原亚硒酸根的能力，并与金针菇作比较。亚硒酸根向金针菇菌丝体的迁移过程是其代谢的第一步，一定程度上控制着菌丝体对Na2SeO3的耐性以及生物还原过程，大型真菌中这一过程很少被研究。本研究从pH影响、P和S转运蛋白作用和代谢抑制剂影响三个方面入手研究金针菇菌丝体对低浓度亚硒酸根的吸收过程，拟初步揭示亚硒酸根向金针菇菌丝体中迁移的机理，从而调节Na2SeO3对菌丝体生长的影响和生物还原过程。 金针菇菌丝体对Na2SeO3相对敏感，10-2 mM Na2SeO3浓度（含）以下并没有菌丝中毒的现象产生，临界中毒浓度在10-2和3×10-2 mM之间，之后随着浓度的升高，金针菇菌丝体中毒越来越严重，直至3 mM时菌丝停止生长而进入休眠阶段。富硒金针菇栽培中Na2SeO3添加剂量应在3×10-2 mM以下进一步探究。 金针菇菌丝体表现出相对强的将亚硒酸根生物还原为元素态硒的能力，还原能力一方面受外围培养基中Na2SeO3浓度的控制，另一方面受菌丝体本身代谢制约，这一还原能力在大型真菌中可能普遍存在。 中性和偏酸性范围pH一定程度上影响了金针菇对亚硒酸根的吸收，可能是通过影响胞内外ΔpH或是膜电位起作用；P或S的饥饿处理可能严重影响菌丝体的代谢活性，导致亚硒酸根吸收能力的显著下降；代谢抑制剂2,4-DNP一定程度上抑制了亚硒酸根的吸收，说明亚硒酸根吸收至少部分上依赖代谢参与，但尚无法确定亚硒酸根跨膜运输本身是否需要能量参与。 |
| 英文摘要 | Responses of Flammulina velutipes mycelium to various concentrations of selenite under different cultivation conditions were studied. In the range of selenite concentrations used here, it was noted that mycelium of this macrofungi turned red in certain circumstances and the reason for this coloration was supposed to be biological reduction of selenite to elemental selenium. This phenomenon was further studied in terms of the relationship between reduction intensity and ambient selenite concerntrations and where and when the reduction occurred. To investigate if the ability of biological reduction of selenite to elemental selenium is common in macrofungi and for the comparison with F. velutipes, another 11 macrofungi of considerable phylogenic and ecological differences were tested for their responses to selenite exposure and their abilities of selenite reduction. Selenite uptake is the first step of its metabolism and, on some level, affects mycelial tolerance of selenite and reduction of selenite to elemental selenium. However, this process is poorly understood. In this study, the effects of pH, P and S starvation and metabolism inhibitor were investigated to gain some preliminary knowledge about selenite uptake process in F. velutipes mycelium. It turned out that F. velutipes was sensitive to selenite compared with other macrofungi. Selenite concerntrations of 10-2 mM or below did not affect mycelium growth at all and the concentration threshold for selenite poisoning was somewhere between 10-2 mM and 3×10-2 mM above which poisoning effects increased as concerntration increased. At 3 mM, mycelium stopped growing and moved to dormancy mode. Selenite concerntration in selenised F. velutipes cultivation should be lower than 3×10-2 mM to avoid poisoning. F. velutipes excelled in biological reduction ability of selenite to elemental selenium compared with other macrofungi. The reduction ability of selenite was controlled by ambient selenite concentrations and, at the same time, was metabolism dependent. Biological reduction of selenite to elemental selenium may be a common ability in macrofungi. pH in slight acid and neutral range affected selenite absorbtion possibly by means of changing transmenberace ΔpH or memberance potential. P and S starvation may caused substantial damage to metabolism and caused a marked drop in selenite uptake. 2, 4-DNP, which is a metabolism inhibitor, decreased selenite uptake indicating that selenite uptake is at least partly metabolism dependent. However, whether transmemberance transportation process itself is metabolism dependent or not requires further study. |
| 公开日期 | 2014-07-17 |
| 源URL | [http://ir.imde.ac.cn/handle/131551/7030]  |
| 专题 | 成都山地灾害与环境研究所_山地表生过程与生态调控重点实验室 |
| 推荐引用方式 GB/T 7714 | 王吉鹏. 硒对金针菇菌丝体生长的影响及其生物还原和迁移[D]. 北京. 中国科学院研究生院. 2013. |
入库方式： OAI收割
来源：成都山地灾害与环境研究所
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