嗜硫原始红藻Galdieria sulphuraria高产藻胆蛋白的混养条件优化

为提高混养条件下单细胞红藻-嗜硫原始红藻(G.sulphuraria)的藻胆蛋白生产,本研究以细胞密度、藻胆蛋白含量为评价指标,系统优化了培养温度、培养基碳氮比、初始细胞密度、光照强度等环境因素。结果表明,适当降低培养温度和碳氮比有利于促进藻胆蛋白的积累,提高光强和初始细胞密度也可促进细胞生长和藻胆蛋白合成。研究证实,G.sulphuraria混养培养体系的最适条件为:30℃、碳氮比6.0、初始细胞密度为1×10^8 cells/mL、光照强度为110μmol/(m^2·s)。在优化后的培养体系中培养8 d,最大细胞密度可达5.48×10^8cells/m L;同时最大生物量产量可达到11.65g/L,是优化前的1.46倍;藻胆蛋白含量占生物量干重的13.63%,对应产量为1588.36 mg/L,产量比优化前提高了187.91%。因此,混养培养条件系统优化是强化嗜硫原始红藻生物量和藻胆蛋白生产的有效手段。

Recovering rare earth elements via immobilized red algae from ammonium-rich wastewater

Biotreatment of acidic rare earth mining wastewater via acidophilic living organisms is a promising approach owing to their high tolerance to high concentrations of rare earth elements(REEs);however,simultaneous removal of both REEs and ammonium is generally hindered since most acidophilic organisms are positively charged.Accordingly,immobilization of acidophilic Galdieria sulphuraria(G.sulphuraria)by calcium alginate to improve its affinity to positively charged REEs has been used for simultaneous bioremoval of REEs and ammonium.The results indicate that 97.19%,96.19%,and 98.87%of La,Y,and Sm,respectively,are removed by G.sulphuraria beads(GS-BDs).The adsorption of REEs by calcium alginate beads(BDs)and GS-BDs is well fitted by both pseudo first-order(PFO)and pseudo second-order(PSO)kinetic models,implying that adsorption of REEs involves both physical adsorption caused by affinity of functional groups such as-COO-and -OH and chemical adsorption based on ion exchange of Ca^(2+) with REEs.Notably,GS-BDs exhibit high tolerance to La,Y,and Sm with maximum removal efficiencies of 97.9%,96.6%,and 99.1%,respectively.Furthermore,the ammonium removal efficiency of GS-BDs is higher than that of free G.sulphuraria cells at an initial ammonium concentration of 100 mg L^(-1),while the efficiency decreases when initial concentration of ammonium is higher than 150 mg L^(-1).Last,small size of GS-BDs favors ammonium removal because of their lower mass transfer resistance.This study achieves simultaneous removal of REEs and ammonium from acidic mining drainage,providing a potential strategy for biotreatment of REE tailing wastewater.

非灭菌光发酵嗜硫原始红藻高效去除工业废水中铵根的补糖模式优化

使用高氨氮工业废水配制混养培养基,在5 L光发酵罐中对嗜硫原始红藻(Galdieria sulphuraria)进行非灭菌条件下的分批和补料分批培养,通过比较间歇补糖和连续流加补糖模式,优化确定了生物量高产率、高NH_(4)^(+)去除速率的补糖模式。结果表明,2种模式均能促进生物量生产和NH_(4)^(+)的去除,其中C/N为2.5~5.0的连续流加补糖是最佳补糖模式。在此模式下,最高N H_(4)^(+)去除速率达到1529.25 mg·(L·d)^(-1),最终生物量质量浓度、蛋白质和藻蓝蛋白(PC)含量分别为92.30 g·L^(-1)、42.29%和1.76 mg·g^(-1),比12 h间歇补糖模式(最高1234.38 mg·(L·d)^(-1),生物量质量浓度为89.55 g·L^(-1),蛋白质和PC含量为别为38.32%和1.66 mg·g^(-1))分别提高了23.89%、3.07%、10.36%和6.02%,葡萄糖消耗量也显著降低。以上构建的基于优化补糖模式的非灭菌光发酵技术能有效促进嗜硫原始红藻生物量生产,可实现废水中NH_(4)^(+)的高效去除并联产蛋白质,从而达到废水高效脱氮、资源化利用和降本增效等多重目的。