Phycobiliproteins—A Family of Algae-Derived Biliproteins: Productions,Characterization and Pharmaceutical Potentials

Phycobiliproteins (PBPs) are colored and water-soluble biliproteins found in cyanobacteria, rhodophytes, cryptomonads and cyanelles. They are divided into three main types: allophycocyanin, phycocyanin and phycoerythrin, according to their spectral properties. There are two methods for PBPs preparation. One is the extraction and purification of native PBPs from Cyanobacteria, Cryptophyta and Rhodophyta, and the other way is the production of recombinant PBPs by heterologous hosts. Apart from their function as light-harvesting antenna in photosynthesis, PBPs can be used as food colorants, nutraceuticals and fluorescent probes in immunofluorescence analysis. An increasing number of reports have revealed their pharmaceutical potentials such as antioxidant, anti-tumor, anti-inflammatory and antidiabetic effects. The advances in PBP biogenesis make it feasible to construct novel PBPs with various activities and produce recombinant PBPs by heterologous hosts at low cost. In this review, we present a critical overview on the productions, characterization and pharmaceutical potentials of PBPs, and discuss the key issues and future perspectives on the exploration of these valuable proteins.     

Multi-Step Enzymatic Production and Purification of 2-Keto-3-Deoxy-Galactonate from Red-Macroalgae-Derived Agarose

2-keto-3-deoxy sugar acids, which have potential as precursors in medicinal compound production, have gained attention in various fields. Among these acids, 2-keto-3-deoxy-l-galactonate (KDGal) has been biologically produced from D-galacturonate originating from plant-derived pectin. KDGal is also found in the catabolic pathway of 3,6-anhydro-l-galactose (AHG), the main component of red-algae-derived agarose. AHG is converted to 3,6-anhydrogalactonate by AHG dehydrogenase and subsequently isomerized to KDGal by 3,6-anhydrogalactonate cycloisomerase. Therefore, we used the above-described pathway to produce KDGal from agarose. Agarose was depolymerized to AHG and to agarotriose (AgaDP3) and agaropentaose (AgaDP5), both of which have significantly higher molecular weights than AHG. When only AHG was converted to KDGal, AgaDP3 and AgaDP5 remained unreacted. Finally, KDGal was effectively purified from the enzymatic products by size-exclusion chromatography based on the differences in molecular weights. These results show that KDGal can be enzymatically produced and purified from agarose for use as a precursor to high-value products.     

海藻硫酸多糖和中药复方对鸡胚接种H9N2亚型禽流感病毒的作用

为探讨海藻硫酸多糖（sulfated polysaccharide from algae,SPA）及中药复方提取液（compound extracts of Chinese medicine,CECM）对H9N2亚型禽流感病毒（avian influenza virus,AIV）的作用,将SPA及CECM以3种不同加药方式作用于接种了H9N2亚型AIV的10日龄SPF鸡胚中,无菌收集鸡胚尿囊液,测定血凝效价,检测2种药液对H9N2亚型AIV的预防、治疗及直接灭活作用。结果显示,SPA及CECM的最大安全浓度分别为50和200 mg/mL;3种不同加药方式下,不同浓度SPA及CECM均能极显著降低鸡胚尿囊液中H9N2亚型AIV的血凝效价（P<0.01）,以直接灭活作用组的血凝效价降低幅度最大,预防作用组和治疗作用组次之。预防作用组,CECM高剂量组（200 mg/mL）的抗病毒效果显著优于SPA各剂量组（12.5、25和50 mg/mL）及CECM低、中剂量组（50和100 mg/mL）（P<0.05）;治疗作用组,SPA高剂量组（50 mg/mL）及CECM中、高剂量组（100和200 mg/mL）抗病毒效果显著优于SPA低剂量组（12.5 mg/mL）（P<0.05）;直接灭活作用组,SPA及CECM的抗病毒效果均佳,CECM各剂量组的抗病毒效果与SPA各剂量组差异极显著（P<0.01）。结果表明,SPA和CECM对10日龄鸡胚几乎无毒副作用;SPA及CECM均能显著抑制H9N2亚型AIV在鸡胚尿囊液中的增殖,以直接灭活作用组的抗病毒效果最佳,其抗H9N2亚型AIV作用的强弱与药物浓度、用药和病毒的感染时间顺序密切相关。     

特定藻类对土壤有效磷影响的研究

采用混合正交实验L(6×2)2设计,研究了藻类对土壤有效磷含量的影响,通过对实验结果进行统计分析,发现藻类能有效提高土壤有效磷含量,且不同的藻种间存在一定的差异。这揭示直接利用特定藻类能有效提高土壤可利用磷含量,又能增加土壤有机质,达到减少速效磷肥的施用和改善土壤肥力,这对保护环境、维持农业生态系统的可持续发展有重要现实意义。     

Nitrogen fixation and balance studies of rice soil

Summary A nitrogen balance study conducted in ceramic pots under net house conditions for four seasons showed that flooded rice soil leaves a positive nitrogen balance (N increase) in soil after rice cropping in both fertilized and unfertilized soil. Recovery of nitrogen from rice soil was more than its input in unfertilized soil, but it was reverse in fertilized soil. Incorporation of Azolla or BGA twice as basal and 20 days after transplanting (DAT) alone or in combination showed higher nitrogen balance and N₂-fixation (N gain) in soil than in that where it was applied once either as basal or 20 DAT. Planted soil showed more N₂-fixation than that of fallow rice, and flooded soil fixed more nitrogen in comparison to non-flooded soil in light but less in dark. Soil exposed to light fixed more nitrogen than that of unexposed soil in both flooded and non-flooded conditions.     

电气浮工艺对富营养化湖泊型原水中蓝藻的去除

选用电气浮工艺对富营养化湖泊型原水进行试验。结果表明：在进水流量为6 L/h,水温30℃,控制极板间距0.6 cm,电流强度1.2 A,电极板4组的条件下,连续运行24 h,对水体中Chl-a的平均去除率可达到89.01%。试验期间,装置运行稳定,可对富营养化湖泊型原水中藻类的去除提供参考。     

鸡粪厌氧消化废液的生物处理研究

应用好氧接触氧化，颤藻附着生物床和水生植物联合处理新工艺，对厌氧处理后的难生化降解的，碳氮磷比严重失调的鸡粪发酵液进行小规模的生产处理，经处理后出水可达ＧＢ８９７８－８８污水综合排放标准。颤藻为敝开处理系统中的优势藻种，固定在填料上的藻类去污能力强，脱氮，脱磷以及色素等效果好。充分进行光合作用，大量产生溶解氧能清洁水体。颤藻个大，易收集，定时采收后可作为畜用高蛋白饲料。     

藻类对沼液中氮,磷去除作用的初步研究

分别采用悬浮藻和固定藻处理鸡粪厌氧发酵液，在不同的季节和温度条件下进行试验，结果表明，藻类对沼液中的ＮＨ＾＋４－Ｎ、ＴＰ等污染成分有较高的净化效率。处理后，悬浮藻对污染物的平均去除率为：ＮＨ＾＋４－Ｎ６２．４％，ＴＰ６２．７％；固定藻对污染物的平均去除率为：ＮＨ＾＋４－Ｎ８４．０％，ＴＰ７３．８％。试验结果稳定。     

显微彩色图像处理在藻类识别统计中的应用

水体中藻类与水质状况之间存在着密切的关系，可根据藻类综合指数、生物多样性指数等对被监测水体的水质状况做出评价。为此，通过对水体中藻类的显微彩色图像进行处理和分析，提出了藻类显微彩色图像识别统计的方法。通过研究图像的预处理、分割和识别等过程，识别出水体中的藻类并统计出藻类细胞的个数。实验结果表明，与人工识别统计方式相比，显微彩色图像识别符合率大于90％。