基于多波长透射光谱的水体典型细菌多特征参量同步解析方法研究

Studies on characteristics of the bacteria can provide analysis reference for monitoring water quality. Muti-wavelength transmission spectroscopy is a new, rapid and effective method for analysis multi-feature parameters of bacteria by making full use of scattering, absorption information of bacteria in the 200-900nm band in comparison with single wavelength/band spectrum methods, which is generally used in bacterial characteristics research and only can obtain few characteristic of bacteria. However, this method is still faced various difficult problems, such as a characteristics interpretation model’s built based on complexity of cell structure and approximation of optical properties parameters. In view of above mentioned problems, this project will propose solutions and carry out research on synchronization analysis method of multi-feature parameters of typical pathogens in water based on multi-wavelength transmission spectroscopy. .The research work will start with analysis of spectral characteristics of complex structure of bacteria and built characteristics interpretation model based on Mie theory; According to the sub-band spectral characteristics of bacteria, scattering and absorption spectroscopy will be effectively separated by deconvolution analysis method of overlapping spectra which was accumulated in our group; Model molecules are used to characterize the absorption behaviors of chromophoric groups; The real refractive index of cell scattering structure is calculated by Cauchy approximation. As a result, the key input parameters to invert characteristics of bacteria are obtained by above methods. The effectiveness and universality of characteristics interpretation model for inversing multi-feature parameters of different bacteria were proved by validating and optimizing the sensitivity of the model.The coming out project will provide basic data and method support for further research on monitoring and early warning of typical pathogenic bacteria in water.

开展细菌特征研究可为水质安全监控提供分析参考依据。与目前普遍采用的仅获取部分细菌特征的单波长光谱法相比，多波长透射光谱法可充分利用细菌200-900nm全波段消光光谱信息，实现散射、吸收多特征快速、同步解析，是一种细菌特征解析新方法。但目前该方法尚面临细菌复杂结构相关的特征解析模型建立和光学特性参量获取难题。本项目针对上述问题提出解决方案并开展研究。.项目将从分析典型细菌复杂结构光谱特性入手，依据Mie散射理论，建立特征解析模型；利用细菌分波段光谱特征和实验室成熟的重叠光谱去卷积解析方法，有效分离散射、吸收特征光谱；引入模型分子表征生色团大分子吸收特性，采用柯西公式计算散射结构折射率实部参量，解决特征解析关键输入参量获取难题，从而实现细菌多特征参量解析；验证并优化解析模型灵敏度，证明该模型反演不同细菌多特征参量的有效性与普适性。为进而开展水体典型致病菌监控与预警研究提供基础数据和方法依据。

针对利用多波长透射光谱法开展水体细菌微生物检测所面临的细菌复杂结构特征解析模型建立和光学特性参量获取难题，搭建检测速度快、灵敏度高水体细菌微生物多波长透射光谱快速测量实验系统；依据Mie散射理论以及直径等效近似方法，构建细菌微生物透射光谱特征解释模型，实现细菌细胞组成的模型化准确表达；依据柯西公式和光谱拟合方法研究细菌细胞不同散射微结构光学特性参量的近似方法，采用模型分子表征紫外生色团大分子吸收特性，利用K-K变换计算模型分子相对折射率，解析吸收光谱特征参量，解析得到大肠杆菌体积为1.6899m3，浓度为4.5×107cells/ml，单个细菌平均核酸含量为7.1335×10-14g/cell，蛋白质含量为1.1764×10-13g/cell，其结果与文献报道数据相一致；利用多波长透射光谱技术研究并获取致病菌全生长阶段不同生长时期特征阈值，获得细胞形态学和化学组分等信息，验证模型的有效性的同时，掌握细菌的不同生长阶段特征参数的变化特征，对水体典型致病菌污染检测与预警具有十分重要的现实意义。