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Yang S, Zuo J, Grossart HP, Dai G, Liu J, Song L, Gan N. Evaluating microcystinase A-based approach on microcystins degradation during harvested cyanobacterial blooms. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 348:123878. [PMID: 38548158 DOI: 10.1016/j.envpol.2024.123878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/21/2024] [Accepted: 03/25/2024] [Indexed: 04/07/2024]
Abstract
Addressing notorious and worldwide Microcystis blooms, mechanical algae harvesting is an effective emergency technology for bloom mitigation and removal of nutrient loads in waterbodies. However, the absence of effective methods for removal of cyanobacterial toxins, e.g., microcystins (MCs), poses a challenge to recycle the harvested Microcystis biomass. In this study, we therefore introduced a novel approach, the "captured biomass-MlrA enzymatic MC degradation", by enriching microcystinase A (MlrA) via fermentation and spraying it onto salvaged Microcystis slurry to degrade all MCs. After storing the harvested Microcystis slurry, a rapid release of extracellular MCs occurred within the initial 8 h, reaching a peak concentration of 5.33 μg/mL at 48 h during the composting process. Upon spraying the recombinant MlrA crude extract (about 3.36 U) onto the Microcystis slurry in a ratio of 0.1% (v/v), over 95% of total MCs were degraded within a 24-h period. Importantly, we evaluated the reliability and safety of using MlrA extracts to degrade MCs. Results showed that organic matter/nutrient contents, e.g. soluble proteins, polysaccharides, phycocyanin and carotenoids, were not significantly altered. Furthermore, the addition of MlrA extracts did not significantly change the bacterial community composition and diversity in the Microcystis slurry, indicating that the MlrA extracts did not increase the risk of pathogenic bacteria. Our study provides an effective and promising method for the pre-treatment of harvested Microcystis biomass, highlighting an ecologically sustainable framework for addressing Microcystis blooms.
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Affiliation(s)
- Siyu Yang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Jun Zuo
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Zhejiang Provincial Key Lab for Water Environment and Marine Biological Resources Protection, Institute for Eco-Environmental Research of Sanyang Wetland, Wenzhou University, Wenzhou, 325035, China.
| | - Hans-Peter Grossart
- Department of Plankton and Microbial Ecology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries IGB, Stechlin, Germany; Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Guofei Dai
- Jiangxi Academy of Water Science and Engineering, Nanchang, 330029, China
| | - Jin Liu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Lirong Song
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Nanqin Gan
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
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Jiang J, Zeng J, Wang J, Zuo J, Wei N, Song L, Shan K, Gan N. Changes in CO 2 concentration drive a succession of toxic and non-toxic strains of Microcystis blooms. WATER RESEARCH 2024; 250:121056. [PMID: 38171175 DOI: 10.1016/j.watres.2023.121056] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 11/30/2023] [Accepted: 12/21/2023] [Indexed: 01/05/2024]
Abstract
The dynamic changes between toxic and non-toxic strains of Microcystis blooms have always been a hot topic. Previous studies have found that low CO2 favors toxic strains, but how changing dissolved CO2 (CO2 [aq]) in water body influences the succession of toxic and non-toxic strains in Microcystis blooms remains uncertain. Here, we combined laboratory competition experiments, field observations, and a machine learning model to reveal the links between CO2 changes and the succession. Laboratory experiments showed that under low CO2 conditions (100-150 ppm), the toxic strains could make better use of CO2 (aq) and be dominant. The non-toxic strains demonstrated a growth advantage as CO2 concentration increased (400-1000 ppm). Field observations from June to November in Lake Taihu showed that the percentage of toxic strains increased as CO2 (aq) decreased. Machine learning highlighted links between the inorganic carbon concentration and the proportion of advantageous strains. Our findings provide new insights for cyanoHABs prediction and prevention.
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Affiliation(s)
- Jingyu Jiang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China,; University of Chinese Academy of Sciences, Beijing, China
| | - Jiaying Zeng
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China,; University of Chinese Academy of Sciences, Beijing, China
| | - Jingkai Wang
- University of Chinese Academy of Sciences, Beijing, China,; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Jun Zuo
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Zhejiang Provincial Key Lab for Water Environment and Marine Biological Resources Protection, Institute for Eco-Environmental Research of Sanyang Wetland, Wenzhou University, Wenzhou 325035, China
| | - Nian Wei
- Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China
| | - Lirong Song
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China,; University of Chinese Academy of Sciences, Beijing, China
| | - Kun Shan
- University of Chinese Academy of Sciences, Beijing, China,; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China,.
| | - Nanqin Gan
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China,; University of Chinese Academy of Sciences, Beijing, China,.
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Gao L, Wang F, Wu T, Zhou Q, Zhang D, Hou X, Zhang X, Ye J, Ma Y, Wang Z, Song L, Chen W. New insights into the production of fucoxanthin by mixotrophic cultivation of Ochromonas and Microcystis aeruginosa. BIORESOURCE TECHNOLOGY 2022; 363:127922. [PMID: 36087653 DOI: 10.1016/j.biortech.2022.127922] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/04/2022] [Accepted: 09/05/2022] [Indexed: 06/15/2023]
Abstract
Fucoxanthin (Fx) has attracted great interest due to its remarkable biological activities such as antioxidant and anti-obesity, and its increasing demands in biopharmaceutical and cosmetic fields. However, its commercial production is limited by low yield and high cost. In this study, we isolated and identified a species of golden algae (Ochromonas sp.) capable of engulfing Microcystis aeruginosa (M. aeruginosa) and accumulating Fx. After 72 h mixotrophic cultivation of Ochromonas sp. and M. aeruginosa, the algal culture changed from green to yellow-brown, and the content of Fx and the daily production rate were up to 11.58 mg g-1, and 1.315 mg L-1 d-1, respectively. The utilization rate of M. aeruginosa was 527.27 fg cell-1. This study will not only provide a new thought to produce Fx in an efficient, low-cost, and sustainable way but an innovative method for the control and treatment of harmful cyanobacterial blooms from eutrophic freshwaters as well.
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Affiliation(s)
- Lei Gao
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong Province 266109, China
| | - Fengjing Wang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong Province 266109, China
| | - Tianyue Wu
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong Province 266109, China
| | - Qi Zhou
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong Province 266109, China
| | - Duo Zhang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong Province 266109, China
| | - Xinbin Hou
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong Province 266109, China
| | - Xinpeng Zhang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong Province 266109, China
| | - Jingrun Ye
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong Province 266109, China
| | - Yan Ma
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong Province 266109, China
| | - Zhipeng Wang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong Province 266109, China
| | - Lirong Song
- Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan, Hubei 430072, China
| | - Wei Chen
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong Province 266109, China.
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