Comparable Nutrient Uptake across Diel Cycles by Three Distinct Phototrophic Communities

Abstract

The capacity of microalgae to advance the limit of technology of nutrient recovery and accumulate storage carbon make them promising candidates for wastewater treatment. However, the extent to which these capabilities are influenced by microbial community composition remains poorly understood. To address this knowledge gap, 3 mixed phototrophic communities sourced from distinct latitudes within the continental United States (28°N, Tampa, FL; 36°N , Durham, NC; and 40°N, Urbana, IL) were operated in sequencing batch reactors (8 day solids residence time, SRT) subjected to identical diel light cycles with media addition at the start of the nighttime period. Despite persistent differences in community structure as determined via 18S rRNA (V4 and V8−V9 hypervariable regions) and 16S rRNA (V1−V3) gene amplicon sequencing, reactors achieved similar and stable nutrient recovery after 2 months (8 SRTs) of operation. Intrinsic carbohydrate and lipid storage capacity and maximum specific carbon storage rates differed significantly across communities despite consistent levels of observed carbon storage across reactors. This work supports the assertion that distinct algal communities cultivated under a common selective environment can achieve consistent performance while maintaining independent community structures and intrinsic carbon storage capabilities, providing further motivation for the development of engineered phototrophic processes for wastewater management.

Algae Biofilm Reduces Microbe-Derived Dissolved Organic Nitrogen Discharges: Performance and Mechanisms

“…But no significant difference between AB 1 and AB 2 was observed, indicating that although the microbial communities in AB 1 and AB 2 differed (Figure ), their functional potentials concerning nitrogenous matter metabolisms were similar. This phenomenon supported AB microbiomes’ high functional redundancy in DON metabolisms, further underpinning the robustness of AB-based biotechnologies in nutrient recovery …”

“…This phenomenon supported AB microbiomes' high functional redundancy in DON metabolisms, further underpinning the robustness of AB-based biotechnologies in nutrient recovery. 22 A total of 134 and 137 KEGG Modules involved in nitrogenous matters metabolisms were enumerated in AB and AS, respectively (Figure 6b). Most of them were shared by AB and AS microbiomes, while only six and nine KEGG Modules were exclusively affiliated to AB and AS, respectively.…”

“…Nevertheless, knowledge about the mDON formation and utilization by algal–bacterial symbiosis is limited. In addition, although AB’s microbial structures have been investigated, , its metabolic traits, particularly those involving nitrogenous organic matter metabolisms, remain largely unexplored.…”

“…Organic substances are important carbon and nutrient sources for algae and phototrophic communities. 16−18 Recent studies experimentally demonstrated that the pure culture of Chlamydomonas reinhardtii 19 and the co-inoculum of Selenastrum capricornutum with bacteria 20 addition, although AB's microbial structures have been investigated, 21,22 its metabolic traits, particularly those involving nitrogenous organic matter metabolisms, remain largely unexplored. Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) has been widely used for the molecular characterization of dissolved organic matter.…”

Solids Residence Time Impacts Carbon Dynamics and Bioenergy Feedstock Potential in Phototrophic Wastewater Treatment Systems

“…In addition to air sparging, reactor sides were scraped daily using a stir bar to inhibit attached growth . Each reactor was fed continuously from the secondary effluent obtained weekly from the Urbana-Champaign Sanitary District (U-CSD) WRRF, which operated a high-rate activated sludge system, and stored in the dark at 4 °C before and during use.…”