电磁衰减微生物材料的制备和光谱特性研究

发布时间：2018-05-06 10:54

本文选题：电磁衰减 + 真菌孢子　；参考：《中国科学技术大学》2015年博士论文

【摘要】：电磁衰减技术,就是利用介质对电磁波产生衰减作用的一种技术。具有电磁衰减作用介质主要有膨胀石墨、铁粉、铜粉等无机材料,广泛应用于航天、医药、食品等各大领域。这些衰减材料类型固定、衰减对象单一、衰减波段窄、持续时间短、环境危害较大。随着经济和社会的发展,需要进一步开发新的电磁衰减材料,满足各种需求。为此,我们提出了一种全新的理念——将生物材料应用于电磁衰减领域。生物材料之所以具有电磁衰减作用,是由其成分和结构对电磁波具有吸收和散射作用引起的。自然界生物具有种类多样、成分丰富、结构复杂、制备方便、环境友好等特点,且具有有效的电磁衰减功能。本论文主要围绕材料的选择、制备、测试以及衰减性能提高几个方面研究电磁衰减微生物制备和光谱特性。首先,利用傅里叶红外光谱进行静态测试,研究了七种不同微生物材料的吸收光谱,对引起不同谱带吸收作用的成分进行了分析。其次,采用了镜面反射法测定七种微生物材料在红外波段的反射谱,利用Kramers-Kronig (K-K)关系,计算了4000-400cm-1(2.5-25μm)波段的复折射率。然后根据Mie散射理论,计算出了质量消光系数。这七种材料在红外波段处复折射率m的实部n满足n≥1,虚部满足k≥0,符合物质与光相互作用关系,说明这种测定方法的准确性。在3-5μm波段,虫生真菌Bb3088孢子和虫生真菌Ma2677孢子的质量消光系数分别达到0.8968m2/g和1.0589m2/g,在8-14μm波段,这两种真菌孢子的质量消光系数分别为0.7137m2/g和0.7203m2/g,说明这两种微生物材料衰减性能良好。所以,我们选择虫生真菌Bb3088孢子和虫生真菌Ma2677孢子,作为生物电磁衰减物。目前的发酵条件下,虫生真菌Bb3088孢子和虫生真菌Ma2677孢子的产量都比较低。为了满足需要,本研究对发酵过程中的培养基和培养条件进行了优化,以提高孢子的产量。在优化后的培养基和培养条件下,虫生真菌Bb3088和虫生真菌Ma2677的孢子产量达到11.2mg/g和24.5mg/g,比优化前分别提高了72.3%和52.2%。固体发酵产生孢子以后,孢子、菌丝以及培养基混合在一起,难以分离。为了得到高纯度的孢子,对孢子的收集方式进行了研究,采用双气旋法作为最优的孢子收集方法。并对影响孢子产量的三个因素进行响应面优化。这三个因素分别是：基质高度与装料桶高度比、收集时间、物料干燥时间。得到最优的基质高度与装料桶高度比(A)、收集时间(B)、物料干燥时间(C)分别为18%、4min和44h。在优化状态下,虫生真菌Bb3088最大的估计值为20.9mg/g,比优化前提高了221.5%。利用双气旋装置,采用最优的收集参数,对虫生真菌Ma2677孢子进行验证收集,得到最大的孢子产量为42.2mg/g,比优化前总共提高了162.1%。为了验证双气旋法收集孢子的纯净度,对虫生真菌Bb3088和虫生真菌Ma2677的孢子形态进行了宏观和微观的观察,发现所收集到的虫生真菌Bb3088和虫生真菌Ma2677孢子粉直观表现类似细腻的滑石粉状粉末,不含菌丝和杂质,非常的纯净。这说明双气旋法是一种分离性能较好的孢子方法。静态测试只考虑到微生物的成分对电磁衰减的影响,为了全面研究微生物材料对电磁波的吸收和散射作用,进行了动态烟幕箱测试。测试的波段主要有可见光波段、中红外和远红外波段,测试项目内容有烟幕透过率、质量消光系数、有效遮蔽时间。结果发现,虫生真菌Bb3088孢子在可见光波段和中红外波段,透过率≤15%,质量消光系数≥1g/m2,有效遮蔽时间≥60s,具有非常好的消光性能。虫生真菌Bb3088孢子可作为可见光和中红外两个波段的良好的电磁衰减物。虫生真菌Ma2677孢子,在中红外波段时,透过率≤15%,质量消光系数≥1g/m2,有效遮蔽时间≥60s,消光性能良好,可作为中红外波段的较好的电磁衰减物。经过静态测试和烟幕箱测试,最终确定虫生真菌Bb3088和虫生真菌Ma2677孢子具有非常好的电磁衰减性能,其优良的衰减特性是由成分和形态共同决定的。为了进一步提高这两种真菌孢子的衰减能力,通过液质联用方法,对静态测试和大型烟幕箱测试确定得出的具有较好电磁衰减作用的虫生真菌Bb3088和虫生真菌Ma2677孢子的成分进行了分析。对孢子中含量较高的两种酯类卵磷脂和麦角甾醇对电磁衰减效应进行研究。结果发现,虫生真菌Bb3088孢子中以1：1的比例加入麦角甾醇后和卵磷脂后,相应谱带的吸收峰分别增加了19%和11%。当在虫生真菌Ma2677孢子中以1：1的比例加入麦角甾醇和卵磷脂后,相应谱带的吸收峰增加了22%和14%。因此,可以通过诱变、分子改造、条件优化等方法,使微生物样品中特定组分含量增加,达到增强特定波段电磁衰减作用的目的。
[Abstract]:Electromagnetic attenuation technology is a technology that uses medium to attenuate electromagnetic waves. The medium with electromagnetic attenuation is mainly inorganic materials such as expanded graphite, iron powder and copper powder. It is widely used in many fields such as space, medicine, food and so on. These attenuation materials are fixed, the attenuation object is single, the attenuation band is narrow, and the duration is short. With the development of economy and society, new electromagnetic attenuating materials need to be further developed to meet various needs. For this reason, we put forward a new concept - the application of biomaterials in the field of electromagnetic attenuation. The reason why biomaterials have electromagnetic attenuation is that they are absorbed by their components and structures for electromagnetic waves. The natural organisms have the characteristics of variety, rich composition, complex structure, convenient preparation, friendly environment and so on, and have effective electromagnetic attenuation functions. This paper mainly focuses on the selection, preparation, testing and attenuation performance of materials to study the preparation and spectral characteristics of electromagnetic attenuation microbes.
First, the absorption spectra of seven different microbial materials were studied by Fourier transform infrared spectroscopy. The components that caused the absorption of different spectral bands were analyzed. Secondly, the reflectance spectra of seven kinds of microbiological materials in the infrared band were measured by the mirror reflection method, and the Kramers-Kronig (K-K) relationship was used to calculate 4000-400. The complex refractive index of the cm-1 (2.5-25 m) band is obtained. Then according to the Mie scattering theory, the mass extinction coefficient is calculated. The real part of the complex refractive index m of the seven materials at the infrared band satisfies n more than 1, the virtual part satisfies K more than 0, which conforms to the interaction between the matter and the light. The accuracy of this method is explained. In the 3-5 Mug band, the spore Bb3088 spores of the entomogenic fungi and the Bb3088 spore are in the 3-5 Mug band. The quality extinction coefficient of the Ma2677 spores of the entomophyll fungus reached 0.8968m2/g and 1.0589m2/g respectively. At the 8-14 U M band, the quality extinction coefficients of the two fungal spores were 0.7137m2/g and 0.7203m2/g respectively, indicating that the two kinds of microbial materials have good attenuation performance. Therefore, we choose the Bb3088 spores and the entomous fungi Ma2677 spores of the entomous fungi. Biological electromagnetic attenuate.
Under the current fermentation conditions, the yield of the Bb3088 spores and the Ma2677 spores of the entomogenic fungi were low. In order to meet the needs, the culture medium and culture conditions in the fermentation process were optimized in order to improve the spore yield. Under the optimized medium and the culture strip, the entomogenic fungi Bb3088 and the entomogenic fungus Ma2677 were used. The spore yield reached 11.2mg/g and 24.5mg/g, and the spores, mycelium and culture medium were mixed together after 72.3% and 52.2%. solid fermentation respectively. In order to get high purity spores, the method of collecting spores was studied. The method of double gas rotation was used as the best method for collecting spores. Three factors of rounded spore yield were optimized in response surface. These three factors were: matrix height and barrel height ratio, collection time and material drying time. The optimum matrix height and barrel height ratio (A), collection time (B), material drying time (C) were 18%, 4min and 44h. were optimal, and insect fungus Bb3088 most The large estimated value was 20.9mg/g, which was improved by 221.5%. using the double gas rotating device before optimization. The optimum collection parameters were used to collect the Ma2677 spores of the entomophytic fungi, and the maximum spore production was 42.2mg/g. The purity of the spores collected by the double gas rotation method was improved by 162.1%. to verify the purity of the spores, Bb3088 and the entomopathogenic fungi. The sporophyte morphology of the entomophytic fungus Ma2677 was observed macroscopic and microscopic. It was found that the collected entomophytic fungi, Bb3088 and the entomogenic fungus Ma2677 spores, were similar to the fine talcum powder powder, which did not contain mycelium and impurities, and was very pure. This shows that the double gas rotation method is a better method for separating the spores.
The static test only takes into account the influence of the components of microbes on the electromagnetic attenuation. In order to study the absorption and scattering of the electromagnetic wave, the dynamic smoke box test is carried out. The test bands are mainly visible, medium and far infrared, and the content of the test items has the smoke transmission rate, the quality extinction coefficient and the effectiveness. The results showed that the Bb3088 spores of the entomophytic fungi were in the visible and middle infrared bands, the transmittance of the sporophyte was less than 15%, the mass extinction coefficient was more than 1g/m2, the effective masking time was more than 60s, and the Bb3088 spores of the entomogenic fungi could be used as good electromagnetic attenuates for the two bands of visible light and mid infrared. The Ma2677 of entomogenic fungi was Ma2677 When the spores are in the middle infrared band, the transmittance is less than 15%, the mass extinction coefficient is more than 1g/m2, the effective masking time is more than 60s, and the extinction performance is good, which can be used as the better electromagnetic attenuant in the middle infrared band.
After the static test and the smoke screen test, the final determination of the endophytic fungi Bb3088 and the entomotic fungi Ma2677 spores have very good electromagnetic attenuation performance. Their excellent attenuation characteristics are determined by the composition and morphology. In order to further improve the decay ability of these two fungal spores, the static test and large scale are used to test and large by the method of liquid chromatography. The composition of the Bb3088 and the Ma2677 spores of the entomotic fungi with better electromagnetic attenuation were determined by the smoke box test. The electromagnetic attenuation effects of two kinds of ester lecithin and ergosterol in the spores were studied. The results showed that the Bb3088 spores of the parasite were added to the angle of 1:1 in the proportion of 1:1. After sterol and lecithin, the absorption peaks of the corresponding bands increased by 19% and 11%., respectively, when ergosterol and lecithin were added to the 1:1 in the Ma2677 spores of the entomophyll fungi. The absorption peaks of the corresponding bands increased by 22% and 14%., so that the specific components in the microorganism samples could be contained by mutagenesis, molecular modification, and condition optimization. The purpose of increasing the electromagnetic attenuation of a specific band is increased.

【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB321

【参考文献】