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Harvey THP. Colonial green algae in the Cambrian plankton. Proc Biol Sci 2023; 290:20231882. [PMID: 37876191 PMCID: PMC10598416 DOI: 10.1098/rspb.2023.1882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 09/28/2023] [Indexed: 10/26/2023] Open
Abstract
The fossil record indicates a major turnover in marine phytoplankton across the Ediacaran-Cambrian transition, coincident with the rise of animal-rich ecosystems. However, the diversity, affinities and ecologies of Cambrian phytoplankton are poorly understood, leaving unclear the role of animal interactions and the drivers of diversification. New exceptionally preserved acritarchs (problematic organic-walled microfossils) from the late early Cambrian (around 510 Ma) reveal colonial organization characterized by rings and plates of interconnected, geometrically arranged cells. The assemblage exhibits a wide but gradational variation in cell size, ornamentation and intercell connection, interpreted as representing one or more species with determinate (coenobial) colony formation via cell division, aggregation and growth by cell expansion. An equivalent strategy is known only among green algae, specifically chlorophycean chlorophytes. The fossils differ in detail from modern freshwater examples and apparently represent an earlier convergent radiation in marine settings. Known trade-offs between sinking risk and predator avoidance in colonial phytoplankton point to adaptations triggered by intensifying grazing pressure during a Cambrian metazoan invasion of the water column. The new fossils reveal that not all small acritarchs are unicellular resting cysts, and support an early Palaeozoic prominence of green algal phytoplankton as predicted by molecular biomarkers.
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Affiliation(s)
- Thomas H. P. Harvey
- Centre for Palaeobiology and Biosphere Evolution, School of Geography, Geology and the Environment, University of Leicester, University Road, Leicester LE1 7RH, UK
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Cho DH, Choi JW, Kang Z, Kim BH, Oh HM, Kim HS, Ramanan R. Microalgal diversity fosters stable biomass productivity in open ponds treating wastewater. Sci Rep 2017; 7:1979. [PMID: 28512332 PMCID: PMC5434013 DOI: 10.1038/s41598-017-02139-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 04/06/2017] [Indexed: 11/09/2022] Open
Abstract
It is established that biodiversity determines productivity of natural ecosystems globally. We have proved that abiotic factors influenced biomass productivity in engineered ecosystems i.e. high rate algal ponds (HRAPs), previously. This study demonstrates that biotic factors, particularly microalgal diversity, play an essential role in maintaining stable biomass productivity in HRAP treating municipal wastewater by mutualistic adaptation to environmental factors. The current study examined data from the second year of a two-year study on HRAP treating municipal wastewater. Microalgal diversity, wastewater characteristics, treatment efficiency and several environmental and meteorological factors were documented. Multivariate statistical analyses reveal that microalgae in uncontrolled HRAPs adapt to adverse environmental conditions by fostering diversity. Subsequently, five dominant microalgal strains by biovolume were isolated, enriched, and optimum conditions for high biomass productivity were ascertained. These laboratory experiments revealed that different microalgal strains dominate in different conditions and a consortium of these diverse taxa help in sustaining the algae community from environmental and predatory pressures. Diversity, niche or seasonal partitioning and mutualistic growth are pertinent in microalgal cultivation or wastewater treatment. Therefore, enrichment of selective species would deprive the collective adaptive ability of the consortium and encourage system vulnerability especially in wastewater treatment.
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Affiliation(s)
- Dae-Hyun Cho
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong-gu, Daejeon, 305-806, Republic of Korea
| | - Jung-Woon Choi
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong-gu, Daejeon, 305-806, Republic of Korea.,Green Chemistry and Environmental Biotechnology, University of Science and Technology (UST), Yuseong-gu, Daejeon, 305-350, Republic of Korea
| | - Zion Kang
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong-gu, Daejeon, 305-806, Republic of Korea.,Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701, Republic of Korea
| | - Byung-Hyuk Kim
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong-gu, Daejeon, 305-806, Republic of Korea
| | - Hee-Mock Oh
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong-gu, Daejeon, 305-806, Republic of Korea.,Green Chemistry and Environmental Biotechnology, University of Science and Technology (UST), Yuseong-gu, Daejeon, 305-350, Republic of Korea
| | - Hee-Sik Kim
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong-gu, Daejeon, 305-806, Republic of Korea. .,Green Chemistry and Environmental Biotechnology, University of Science and Technology (UST), Yuseong-gu, Daejeon, 305-350, Republic of Korea.
| | - Rishiram Ramanan
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Yuseong-gu, Daejeon, 305-806, Republic of Korea. .,Department of Environmental Science, School of Earth Science Systems, Central University of Kerala, Kasaragod District, Kerala, India.
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Mehrabadi A, Craggs R, Farid MM. Wastewater treatment high rate algal pond biomass for bio-crude oil production. BIORESOURCE TECHNOLOGY 2017; 224:255-264. [PMID: 27816350 DOI: 10.1016/j.biortech.2016.10.082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 10/25/2016] [Accepted: 10/26/2016] [Indexed: 06/06/2023]
Abstract
This study investigates the production potential of bio-crude from wastewater treatment high rate algal pond (WWT HRAP) biomass in terms of yield, elemental/chemical composition and higher heating value (HHV). Hydrothermal liquefaction (HTL) of the biomass slurry (2.2wt% solid content, 19.7kJ/g HHV) was conducted at a range of temperatures (150-300°C) for one hour. The bio-crude yield and HHV varied in range of 3.1-24.9wt% and 37.5-38.9kJ/g, respectively. The bio-crudes were comprised of 71-72.4wt% carbon, 0.9-4.8wt% nitrogen, 8.7-9.8wt% hydrogen and 12-15.7wt% oxygen. GC-MS analysis indicated that pyrroles, indoles, amides and fatty acids were the most abundant bio-crude compounds. HTL of WWT HRAP biomass resulted, also, in production of 10.5-26wt% water-soluble compounds (containing up to 293mg/L ammonia), 1.0-9.3wt% gas and 44.8-85.5wt% solid residue (12.2-18.1kJ/g). The aqueous phase has a great potential to be used as an ammonia source for further algal cultivation and the solid residue could be used as a process fuel source.
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Affiliation(s)
- Abbas Mehrabadi
- Chemical and Materials Engineering Department, University of Auckland, New Zealand.
| | - Rupert Craggs
- National Institute of Water and Atmospheric Research Ltd. (NIWA), PO Box 11-115, Hamilton 3200, New Zealand.
| | - Mohammed M Farid
- Chemical and Materials Engineering Department, University of Auckland, New Zealand.
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Park JBK, Craggs RJ, Shilton AN. Algal recycling enhances algal productivity and settleability in Pediastrum boryanum pure cultures. WATER RESEARCH 2015; 87:97-104. [PMID: 26397451 DOI: 10.1016/j.watres.2015.09.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 08/25/2015] [Accepted: 09/07/2015] [Indexed: 06/05/2023]
Abstract
Recycling a portion of gravity harvested algae (i.e. algae and associated bacteria biomass) has been shown to improve both algal biomass productivity and harvest efficiency by maintaining the dominance of a rapidly-settleable colonial alga, Pediastrum boryanum in both pilot-scale wastewater treatment High Rate Algal Ponds (HRAP) and outdoor mesocosms. While algal recycling did not change the relative proportions of algae and bacteria in the HRAP culture, the contribution of the wastewater bacteria to the improved algal biomass productivity and settleability with the recycling was not certain and still required investigation. P. boryanum was therefore isolated from the HRAP and grown in pure culture on synthetic wastewater growth media under laboratory conditions. The influence of recycling on the productivity and settleability of the pure P. boryanum culture was then determined without wastewater bacteria present. Six 1 L P. boryanum cultures were grown over 30 days in a laboratory growth chamber simulating New Zealand summer conditions either with (Pr) or without (Pc) recycling of 10% of gravity harvested algae. The cultures with recycling (Pr) had higher algal productivity than the controls (Pc) when the cultures were operated at both 4 and 3 d hydraulic retention times by 11% and 38% respectively. Furthermore, algal recycling also improved 1 h settleability from ∼60% to ∼85% by increasing the average P. boryanum colony size due to the extended mean cell residence time and promoted formation of large algal bio-flocs (>500 μm diameter). These results demonstrate that the presence of wastewater bacteria was not necessary to improve algal productivity and settleability with algal recycling.
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Affiliation(s)
- Jason B K Park
- National Institute of Water and Atmospheric Research Ltd (NIWA), P. O. Box 11-115, Hamilton, New Zealand.
| | - Rupert J Craggs
- National Institute of Water and Atmospheric Research Ltd (NIWA), P. O. Box 11-115, Hamilton, New Zealand.
| | - Andy N Shilton
- School of Engineering and Advanced Technology, Massey University, Private Bag 11 222, Palmerston North, New Zealand.
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