摘要：控制环境的pH值对于一个生态系统的健康至关重要，这一指标会影响到系统内生物体的代谢活力，生长与发育。虽然从荧光染色到纳米传感，能够轻易获得pH值的技术范围很广，但这些技术并不能够反映检测开始前的环境pH值，即无法回溯环境pH值的历史大小，而了解环境pH值的历史大小对于了解一个生态系统内所发生的变化至关重要。因此，我们的长期目标就是发展一种能够反映这一指标的技术。在本次实验中，我们提出通过测量一种常见真菌的力学特性来监测环境pH值随时间的变化。我们选取了黑曲霉作为实验对象，通过计算黑曲霉孢子和菌丝的有效压痕模量来评估环境pH对其的影响，此步骤为获得环境pH历史值的第一步。在文章中我们指出，这种解磷菌即黑曲霉的压痕模量与环境的酸碱度有相关性，压痕模量通过原子力显微镜和纳米压痕获得。我们观察到在酸性环境中随着孵化过程模量有显著地单调增长，而在中性环境中模量随着孵化的进行并无显著变化。本实验结果提供了一种思路，即通过使用我们的方法来检测和追踪环境pH值，更进一步的，将微生物的力学特性作为一种环境监测的生物标记方法。43580

毕业论文关键词：纳米压痕；杨氏模量；环境pH值；生物标记 

Longitudinal Study of the Effects of Environmental pH on the Mechanical Properties of Aspergillus niger

Abstract： The regulation of environmental pH is key to the health of an ecosystem, influencing the metabolic activity, growth, and development of organisms within it. Although pH values can be measured by a wide range of readily available technologies ranging from fluorescent dyes and nanosensors, these cannot reveal the history of environmental pH from before monitoring begins. This information is sometimes crucial for piecing together what has happened to an ecosystem, and our long-term goal is therefore to develop technologies capable of obtaining it. Here, we propose monitoring environmental pH over time by tracking mechanical properties of a common fungus. As a first step toward obtaining a time history of pH, we evaluate the effect of pH upon the effective indentation modulus of spores and hyphae of Aspergillus niger. We report that the indentation modulus of this phosphorus-solubilizing fungus, obtained through atomic force microscopy and nano-indentation, correlated with environmental acidity. We observed a significant, monotonic increase in moduli over the course of incubation in an acidic environment, but no change in moduli over time for incubation in a neutral environment. Results show promise for using our scheme to detect and track environmental pH over time, and more broadly for using a microorganism’s mechanical properties as a biomarker for environmental detection.

Key words: nano indentation; Young’s modulus; environment pH; biomarker

目  录

摘要1

关键词1

Abstract…1

Key words1

引言（或绪论）…1

1材料与方法…2

1.1材料准备 …2

1.2 AFM检测 …2

1.3有效模量估算 3

1.3数据分析    3

2 结果与分析…4

3 讨论 5

致谢…5

参考文献5

研究随时间变化环境pH对黑曲霉力学特性的影响

引言  环境pH值能在很多方面对细胞和组织构成影响，包括细胞代谢，生长，发育等[1-4]。在生态系统修复方面，环境条件的改变起到决定性的因素，其中就包括了环境pH 值在内的各种环境理化性质。因此，了解环境背景的pH值对于生态系统的修复有重要参考价值。但是环境背景的pH值往往难以获得。前人采用诸如核磁共振成像[5]、荧光染色[6,7]、以及基于粒子的纳米传感器[8,9]等方法能够测出当时的pH，但不能够回溯环境历史的pH。因此，寻找一种能够测量并追踪环境历史pH值的方法是十分必要的。