Comprehensive evaluation of a cost-effective method of culturing Chlorella pyrenoidosa with unsterilized piggery wastewater for biofuel production

Abstract

Background The utilization of Chlorella for the dual goals of biofuel production and wastewater nutrient removal is highly attractive. Moreover, this technology combined with flue gas (rich in CO 2 ) cleaning is considered to be an effective way of improving biofuel production. However, the sterilization of wastewater is an energy-consuming step. This study aimed to comprehensively evaluate a cost-effective method of culturing Chlorella pyrenoidosa in unsterilized piggery wastewater for biofuel production by sparging air or simulated flue gas, including algal biomass production, lipid production, nutrient removal rate and the mutual effects between algae and other microbes. Results The average biomass productivity of C. pyrenoidosa reached 0.11 g L −1 day −1 /0.15 g L −1 day −1 and the average lipid productivity reached 19.3 mg L −1 day −1 /30.0 mg L −1 day −1 when sparging air or simulated flue gas, respectively. This method achieved fairish nutrient removal efficiency with respect to chemical oxygen demand (43.9%/55.1% when sparging air and simulated flue gas, respectively), ammonia (98.7%/100% when sparging air and simulated flue gas, respectively), total nitrogen (38.6%/51.9% when sparging air or simulated flue gas, respectively) and total phosphorus (42.8%/60.5% when sparging air or simulated flue gas, respectively). Culturing C. pyrenoidosa strongly influenced the microbial community in piggery wastewater. In particular, culturing C. pyrenoidosa enriched the abundance of the obligate parasite Vampirovibrionales, which can result in the death of Chlorella . Conclusion The study provided a comprehensive evaluation of culturing C. pyrenoidosa in unsterilized piggery wastewater for biofuel production. The results indicated that this cost-effective method is feasible but has considerable room for improving. More importantly, this study elucidated the mutual effects between algae and other microbes. In particular, a detrimental effect of the obligate parasite Vampirovibrionales on algal biomass and lipid production was found. Electronic supplementary material The online version of this article (10.1186/s13068-019-1407-x) contains supplementary material, which is available to authorized users.

A Low-Cost Fertilizer Medium Supplemented with Urea for the Lutein Production of Chlorella sp. and the Ability of the Lutein to Protect Cells against Blue Light Irradiation

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Effects of C/N ratio on the growth and protein accumulation of heterotrophic Chlorella in broken rice hydrolysate

“…Microalgae, as a potential source of non-animal protein, has the advantages of fast growth, short growth cycle, high protein content and no occupation of cultivated land [ 5 , 6 ]. In addition, this makes them a promising new source of protein to meet the nutritional needs of the world's population, as well as reducing pressure on the environment [ 7 , 8 ]. Chlorella vulgaris ( C. vulgaris ) is an edible single-cell microalgae strain that has been commercially produced for more than 50 years [ 9 ].…”

Simultaneous nutrition removal and high-efficiency biomass and lipid accumulation by microalgae using anaerobic digested effluent from cattle manure combined with municipal wastewater

“…and Chlorella vulgaris can accumulate lipids and carbohydrates for biofuels production [20, 21]. Thus, the objectives of wastewater treatment and biofuel feedstock production are aligned, at least in terms of maximizing biomass production [22]. Considering both wastewater treatment and lipid production, microalgae cultivated in different culture modes performed differently.…”