Two-stage algal cultivation for the biotransformation of urban wastewater’s pollutants into multiple bioproducts in a circular bioeconomy paradigm
Two-stage algal cultivation for the biotransformation of urban wastewater’s pollutants into multiple bioproducts in a circular bioeconomy paradigm
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DOI：
10.1016/j.enconman.2022.116400
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发表时间：
2022-12
影响因子：
10.4
通讯作者：
Aqib Zafar Khan;S. Malik;M. Mehmood;A. Shahid;T. Shahzad;Xinqing Zhao;F. Bai;Chen-Guang Liu
中科院分区：
文献类型：
--
作者：
Aqib Zafar Khan;S. Malik;M. Mehmood;A. Shahid;T. Shahzad;Xinqing Zhao;F. Bai;Chen-Guang Liu
由于水资源的迅速枯竭，城市污水的资源化和循环利用已变得至关重要。利用一株新分离的蓝藻--珊瑚假振荡杆菌BERC01，采用两级培养系统对城市污水进行生物处理，并将其生物转化为多种生物产物。在第一阶段，蓝藻菌株BERC01在3-7天内通过生物吸附去除水体中100%的悬浮固体(9-27微克/L)，并将所产生的生物量用作土壤改良剂，使土壤的磷素有效性、微生物碳生物量和硝态氮分别提高2.65-5.86倍、2.27-3.65倍和3.20-6.57倍。在第二阶段，与对照相比，在循环水中重新培养BERC01使碳水化合物和蛋白质的产量分别提高了10倍和3倍。BERC01的培养还提高了UWW的pH值(9.47±0.2-10.93±0.16)，以减少细菌和/或真菌的污染。UWW中BERC01的两级培养使UWW的总氮、总磷、化学需氧量和生物需氧量分别降低了41.94%、95%、79%和89.64%，使经处理的水的水质处于世界卫生组织的农业用途安全范围内。第二阶段生物质的级联处理产生了食品级色素(藻蓝蛋白=148.95±1.81 mg/g，别藻蓝蛋白=151.92±0.51 mg/g)，以及470-490 mg/g的脂类，其中含有具有药用价值的化合物，如十一酸、十五酸和二十酸。最后，以10-50 mg/L的无色素脱油残渣为唯一营养来源，经真菌发酵完全转化为真菌蛋白和α-淀粉酶。结果表明，培养96h，黑曲霉和米曲霉的α-淀粉酶产量分别为98.44U/m L和118.56 U/m L，发酵产物的蛋白质含量分别提高了10.42倍和7.34倍。这一新方法有助于实现藻类生物精炼厂的经济和环境可持续性。
Resource recovery and recycling of urban wastewater have become essential due to rapidly depleting water resources. Here, a newly isolated cyanobacteriumPseudoscillatoria coraliiBERC01 was employed for the biotreatment of urban wastewater (UWW) via a two-stage cultivation system followed by biotransformation of the biomass into multiple bioproducts. During the stage-I, the cyanobacterial strain BERC01 removed 100 % suspended solids (9–27 g/L) from the UWW within 3–7 days via biosorption, and the resultant biomass was used as a soil amender which improved the phosphate availability, microbial carbon biomass, and nitrate-nitrogen of the soil by 2.65–5.86-fold, 2.27–3.65-fold, and 3.20–6.57-fold, respectively. During stage-II, re-culturing the BERC01 in the recycled water improved the productivities of carbohydrates and proteins by 10-fold and 3-fold, respectively, when compared to the control. Cultivation of BERC01 also improved the pH of UWW (9.47 ± 0.2 – 10.93 ± 0.16) to reduce the bacterial and/or fungal contamination. The two-stage cultivation of BERC01 in the UWW lowered the total nitrogen, total phosphorous, chemical oxygen demand, and biological oxygen demand of the UWW by 41.94 %, 95 %, 79 %, and 89.64 %, respectively, bringing the quality of treated water within the WHO’s safety limits of agricultural purposes. Cascading processing of the stage-II biomass yielded food-grade pigments (phycocyanin = 148.95 ± 1.81 mg/g, allophycocyanin = 51.92 ± 0.51 mg/g), and 470–490 mg/g of lipids which contained compounds of pharmaceutical interest such as undecanoic acid, pentadecanoic acid, and eicosanoic acid. Finally, the pigment-free and de-oiled residual biomass (PDRB) was completely valorized to mycoprotein and α-amylase through fungal fermentation using 10–50 g/L PDRB as a sole source of nutrition. Resultantly,Aspergillus nigerandAspergillus oryzaeproduced 98.44 U/mL and 118.56 U/mL of α-amylase in 96 h of incubation, respectively, whereas the protein content of the fermented biomass was improved by 10.42-fold and 7.34-fold, respectively. This novel approach could help in achieving the economic and environmental sustainability of the algal biorefineries.