养殖污水中蛋白核小球藻的分离鉴定及其污水处理效果

利用BG-11培养基从养殖污水中分离和筛选到小球藻,采用相差显微镜对其外部形态进行观察、傅里叶红外光谱分析球藻组成、X-ray方法分析其晶体组成、凯氏定氮以及有机溶剂萃取方法分别测定其蛋白质以及脂质含量、丙酮萃取法测定其叶绿素a以及国标法测定其处理污水效果。结果表明:根据相差显微镜对球藻外部观察,初步判断该小球藻为蛋白核小球藻;红外光谱测定结果表明,在波数1 080和1 240 cm~(-1)处均有明显的吸收峰,证明了该研究分离的小球藻含有大量蛋白质以及糖类和脂类成分;X-衍射分析结果显示在32°和20°两处均有明显的吸收峰,证明了本研究分离的小球藻含有蛋白质和脂类成分;定量成分测定表明该蛋白核小球藻蛋白质量分数为45.6%,脂质质量分数为8.1%;污水处理结果为化学需氧量去除率为70.9%;总氮、总磷去除率分别为23%和34.7%。该研究对蛋白核小球藻蛋白含量、脂肪含量的测定以及提取进行了分析,证明了蛋白核小球藻对养殖场污水的处理具有很好的效果,为生物新资源的开发以及水环境治理提供了一定的参考。

Isolation, identification of Chlorella pyrenoides from aquaculture wastewater and its purification of wastewater

Abstract: Algae has been studied for many years about its characteristics of rapid breed, easily obtained, high adsorption capacity and low nutrition demands and so on. The emission of aquaculture wastewater will caused severe damage on environment. Therefore, how to remove the compound of nitrogen and phosphorus from aquaculture wastewater becomes a serious problem around the world. Based above, many researchers have been focusing on this field and a lot of achievements have been found. Many environmental factors could influence on the growth of algae, including temperature, illumination and nutrition. For heterotrophism, carbon, nitrogen and phosphorus are the three most important factors influencing on the growth of Chlorella pyrenoides. Microalgae consist of several varieties, including Cyanophyta, Chlorophyta, Chrysophyta and Rhodophyta. Chlorella pyrenoides is belonged to Chlorophyta. Until now, studies of Chlorella pyrenoides have mainly focused on the processing, especially in the field of producing biodiesel, but few studies focused on the wastewater treatment by Chlorella pyrenoides. This study carried out the following experiments: the enrichment, isolation, purification and nutritional ingredient analysis for Chlorella pyrenoides. Then, the effect of treating with wastewater by Chlorella pyrenoides was carried out, including the removal of total nitrogen, total phosphorus and reducing COD. Chlorella pyrenoides was isolated from aquaculture wastewater with BG-11medium. The morphology and components of Chlorella pyrenoides were observed by phase contrast microscope and Fourier transform infrared spectrometer (FT-IR), respectively. The crystal structure of Chlorella pyrenoides was determined with X-ray. Protein and fat contents were measured by Kjeldahl determination and organic solvent extract method, respectively. The effect of treating with wastewater by Chlorella pyrenoides was tested with national standard methods. Chlorophyll a was extracted and analyzed with acetone extract method. The morphology observation with phase contrast microscope showed that Chlorella was belonged to Chlorella pyrenoides. FT-IR analysis showed that two peaks appeared at the wave numbers of 1 080 and 1 240 cm-1, which proved high contents of protein, carbohydrate and fat contained in Chlorella pyrenoides. X-ray diffraction spectrogram showed two main peaks appeared at about 32° and 20°, which proved both protein and fat were contained in Chlorella pyrenoides. Quantitative analysis indicated that contents of protein and fat were 45.6% and 8.1%, respectively. Correlational study indicated that the negative correlation of the increase of Chlorophyll a in Chlorella pyrenoides with the decrease of total nitrogen (T-N) and total phosphorus (T-P) remained in the wastewater. The removals of COD, total nitrogen (T-N) and total phosphorus (T-P) by Chlorella pyrenoides were 70.9%, 23% and 34.7%, respectively. Based on above results, the capability of treating with wastewater by Chlorella pyrenoides was proved in this study. Therefore, this study could provide a reference for the exploitation of a new bioresource and the water environment treatment.