Browsing by Author "Nicholaus, Regan"

Now showing 1 - 4 of 4
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    Enhanced Aquaculture Wastewater Treatment Using Water Spinach (Ipomoea Aquatica Forsskal) and Exogenous Compound Bacteria
    (Elsevier, 2024) Xu, Jiaojiao; Nicholaus, Regan; Wang, Yangcai; Yang, Wen; Zhu, Jinyong; Zheng, Zhongming
    Bioremediation technology has been widely recognized as a sustainable treatment method for purifying aqua culture wastewater. We established two types of ecological floating beds, one with water spinach (WS) only and another with water spinach combined with exogenous compound bacteria (WS-ECB) for the treatment of the Pacific white shrimp aquaculture wastewater of low-salinity. The exogenous compound bacteria used in this study was composed of Rhodopseudomonas palustris and Bacillus subtilis in a certain proportion. Microbial com munity dynamics were analyzed by using high-throughput sequencing of 16S rRNA and water quality was determined. Both two treatments were effective in the remediation of aquaculture wastewater. The removal efficiencies of CODMn, TN and TP in the WS group were 34.33 %, 66.54 % and 73.01 %, respectively, and the removal efficiency of NH4 + in the WS-ECB group was 93.79 %. Furthermore, the addition of water spinach and exogenous compound bacteria increased the abundance of some bacteria that are involved in regulating water quality and altered the succession of microbial communities. The microbial communities were shaped by both stochastic processes (including limited dispersal) and deterministic processes (including environmental condi tions and biotic interactions). Importantly, stochastic processes dominated the assembly of both water and rhizosphere microbial communities in different treatments, while deterministic processes contributed more to the rhizosphere microbial community in the WS-ECB than in the WS. Overall, our study emphasizes that plant and microbial remediation was a potential and effective approach to remove the nutrients of water, and clarifies the bacterial community dynamics and assembly mechanisms during aquaculture wastewater treatment processes.
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    Nitrogen and Phosphorus Related Functional Genes Enhance Nutrient Removal in The Integrated Aquaculture Wastewater Bioremediation System in The Presence of Photosynthetic Bacteria.
    (Springer, 2024-12-20) Ramzan, Muhammad Naeem; Shen, Ding; Wei, Yingzhen; Emmanuel, Arslan; Nicholaus, Regan; Yang, Wen; Zheng, Zhongming
    Integrated Aquaculture Wastewater Bioremediation Systems (IAWBSs) are crucial for treating nutrient-rich mariculture water. However, there is a lack of detailed information about the functional mechanisms between nitrogen (N) and phosphorus (P) functional genes and the bacterioplankton community in the presence of photosynthetic bacteria (PSB). This study evaluated the connections between N and P functional genes in IAWBSs under the influence of PSB. The results showed significant improvements in effluent quality, with removal efficiencies of 79, 74, 83, 90, and 71% for NO2 −−N,NO3 −−N, PO4 3−-P, NH4 +−N, and CODmn, respectively. Adding PSB enhanced and altered microbial diversity within the system, promoting the abundance of functional genes related to N and P cycling. Notably, genes associated in denitrification (nirK and nirS), ammonification (ureC) and amoB, involved in nitrification, were significantly increased after PSB was added. Furthermore, genes such as phnK, phoD, and phoX, which are involved in P transformation, also showed increased abundance levels. These genes were closely linked to the microbial community distribution, species diversity, and nutrient cycling. Microbial community changes can result in changes in functional gene abundance. This study provides important and novel insights for developing bioremediation strategies for polluted sites. This demonstrates the fundamental relationships between the IAWBSs’ functional units and the distribution of microbial communities under the influence of PSB.
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    Nitrogen and Phosphorus‑Related Functional Genes Enhance Nutrient Removal in the Integrated Aquaculture Wastewater Bioremediation System in the Presence of Photosynthetic Bacteria
    (Springer nature, 2025) Ramzan, Muhammad N.; Shen, Ding; Wei, Yingzhen; Emmanuel, Arslan; Nicholaus, Regan; Yang, Wen; Zheng, Zhongming
    Integrated Aquaculture Wastewater Bioremediation Systems (IAWBSs) are crucial for treating nutrient-rich mariculture water. However, there is a lack of detailed information about the functional mechanisms between nitrogen (N) and phosphorus (P) functional genes and the bacterioplankton community in the presence of photosynthetic bacteria (PSB). This study evaluated the connections between N and P functional genes in IAWBSs under the influence of PSB. The results showed significant improvements in effluent qual- ity, with removal efficiencies of 79, 74, 83, 90, and 71% for NO2− −N, NO3− −N, PO43−-P, NH 4+ −N, and COD Mn, respectively. Adding PSB enhanced and altered microbial diversity within the system, promoting the abundance of functional genes related to N and P cycling. Notably, genes associated in denitrification (nirK and nirS), ammonification (ureC) and amoB, involved in nitrification, were significantly increased after PSB was added. Fur- thermore, genes such as phnK, phoD, and phoX, which are involved in P transformation, also showed increased abundance levels. These genes were closely linked to the micro- bial community distribution, species diversity, and nutrient cycling. Microbial community changes can result in changes in functional gene abundance. This study provides important and novel insights for developing bioremediation strategies for polluted sites. This demon- strates the fundamental relationships between the IAWBSs’ functional units and the distri- bution of microbial communities under the influence of PSB.
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    The Impact of Mariculture Biofilters on the Distribution of Benthic Nutrient Fluxes, Organic Matters and Bacterial Community in a Mariculture Wastewater Treatment System
    (Elsevier, 2024) Nicholaus, Regan; Lukwambe. Betina; Zheng, Zhongming
    Constructed-wetlands, biofilms, and sedimentation are among biological filters used in mariculture wastewater treatments, however, their impacts on the distribution of benthic microbial community and inorganic-nutrient fluxes have not been fully explored. This study applied 16 S rRNA high-throughput sequencing technology to investigate the microbial community distribution and their impacts on nutrient fluxes in mariculture biofilters system. Results showed that bacterial community compositions were significantly different in the constructed wetland and biofilm treatments (p < 0.05) relative to sedimentation. The composition of the 16 S rRNA genes among the treatments were enriched with Proteobacteria (73%), Bacteroidetes (69%), Firmicutes (62%), and Fla vobacteria (61%) in Biofilm compared to Proteobacteria (53%), Bacteroidetes (39%), Firmicutes (32%), and Fla vobacteria (21%) in constructed wetlands. NMDS analysis showed that bacterial composition in constructed wetland and biofilms clustered separately compared to sedimentation treatment. Functional-Annotation-of Prokaryotic-Taxa analysis indicated that the proportions of sediment-microbial-functional groups (aerobic-che moheterotrophy, chemoheterotrophy, and nitrate-ammonification) were 47% in the constructed-wetland, 32% in biofilm and 13% in sedimentation system. Benthic-nutrient fluxes for phosphate, ammonium, nitrite, nitrate and sediment oxygen consumption differed markedly among the treatments (p < 0.05). Canonical correspondence analysis indicated constructed-wetland had the strongest association between biogeochemical contents and the bacterial community relative to other treatments. This study suggests that the mariculture wastewater biofilters promoted microbial community distributions, sediment bacterial functional-groups including chemohetero trophy, aerobic-chemoheterotroph, denitrification, and nitrification and interactions with nutrient fluxes which was more pronounced in the constructed-wetland system.