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Junzhuo Liu - One of the best experts on this subject based on the ideXlab platform.
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paddy Periphyton reduced cadmium accumulation in rice oryza sativa by removing and immobilizing cadmium from the water soil interface
Environmental Pollution, 2020Co-Authors: Yue Dong, Linzhang Yang, Yuanyuan Feng, Yanchao Bai, Xianjin Tang, Junzhuo LiuAbstract:Abstract Periphyton plays a significant role in heavy metal transfer in wetlands, but its contribution to cadmium (Cd) bioavailability in paddy fields remains largely unexplored. The main aim of this study was to investigate the effect of Periphyton on Cd behavior in paddy fields. Periphyton significantly decreased Cd concentrations in paddy waters. Non-invasive micro-test technology analyses indicated that Periphyton can absorb Cd from water with a maximum Cd2+ influx rate of 394 pmol cm−2 s−1 and Periphyton intrusion significantly increased soil Cd concentrations. However, soil Cd bioavailability declined significantly due to soil pH increase and soil redox potential (Eh) decrease induced by Periphyton. With Periphyton, more Cd was adsorbed and immobilized on organic matter, carbonates, and iron and manganese oxides in soil. Consequently, Cd content in rice decreased significantly. These findings give insights into Cd biogeochemistry in paddy fields with Periphyton, and may provide a novel strategy for reducing Cd accumulation in rice.
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Periphyton growth reduces cadmium but enhances arsenic accumulation in rice oryza sativa seedlings from contaminated soil
Plant and Soil, 2017Co-Authors: Gao Ling Shi, Junzhuo Liu, Xianjin Tang, Lai Qing Lou, Hong XiangAbstract:Periphyton is ubiquitous in paddy fields, but its role in arsenic (As) and cadmium (Cd) bioavailability to rice plants remains unknown. A paddy field was simulated under controlled conditions to investigate the influences of Periphyton on As and Cd accumulation in rice seedlings grown in soil contaminated with both As and Cd. The presence of Periphyton significantly enhanced the growth of rice seedlings in As and Cd contaminated soil. Periphyton had significant effects on soil pH and Eh, resulting in a substantial decrease in the Cd concentration, but in an increase in the total As and As (III) concentrations in soil solution. Corresponding with these changes, Cd concentrations in rice roots and shoots were significantly decreased in the presence of Periphyton, while As concentrations increased. This study demonstrates that Periphyton growth can significantly affect soil As, Cd bioavailability and soil As speciation by changing soil pH and Eh, which affect As and Cd accumulation in rice seedlings as a result. These results suggest that controlling native Periphyton growth may be an effective strategy to regulate As and Cd translocation to the edible organs of food crops.
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responses of Periphyton to fe2o3 nanoparticles a physiological and ecological basis for defending nanotoxicity
Environmental Science & Technology, 2017Co-Authors: Jun Tang, Philip G Kerr, Junzhuo Liu, Ningyuan Zhu, Yan Zhu, Paul K S LamAbstract:The toxic effects of nanoparticles on individual organisms have been widely investigated, while few studies have investigated the effects of nanoparticles on ubiquitous multicommunity microbial aggregates. Here, Periphyton as a model of microbial aggregates, was employed to investigate the responses of microbial aggregates exposed continuously to Fe2O3 nanoparticles (5.0 mg L–1) for 30 days. The exposure to Fe2O3 nanoparticles results in the chlorophyll (a, b, and c) contents of Periphyton increasing and the total antioxidant capacity decreasing. The composition of the Periphyton markedly changes in the presence of Fe2O3 nanoparticles and the species diversity significantly increases. The changes in the Periphyton composition and diversity were due to allelochemicals, such as 3-methylpentane, released by members of the Periphyton which inhibit their competitors. The functions of the Periphyton represented by metabolic capability and contaminant (organic matter, nitrogen, phosphorus and copper) removal wer...
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the effect of Periphyton on seed germination and seedling growth of rice oryza sativa in paddy area
Science of The Total Environment, 2017Co-Authors: Junzhuo Liu, Philip G Kerr, Hongbo ShaoAbstract:Periphyton is widely distributed in paddy fields and its interactions with paddy soil and rice growth have been reported rarely. In this study, model paddy ecosystems with different additional soil substrates were simulated under controlled conditions to investigate the effects of Periphyton on rice seed germination and seedling growth. Results show that the selected soil substrates had significant effects on the metabolic activities and growth of Periphyton in paddy fields. The addition of straw to soil enhances but the addition of biochar leads to attenuation of Periphyton growth. The presence of Periphyton in the paddy system, especially with straw in soil greatly increased the germination index of rice seed (by maximally 21%). However, the biochar treatment in the presence of Periphyton was detrimental for the seed vitality with a decrease of 30%. As a result, the Periphyton cover on paddy soil surface significantly inhibited the growth of rice seedling, including rice height, leaf width and biomass. To summarize, this study indicates that the presence of Periphyton during seed germination period was detrimental for rice growth, but could be used to control the weed growth. Thus, this study provided insight into understanding the Periphyton-plant relationships with different soil-substrates and also new approaches to controlling weeds in paddy fields by regulating the growth of Periphyton.
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Responses of Periphyton to Fe2O3 Nanoparticles: A Physiological and Ecological Basis for Defending Nanotoxicity
2017Co-Authors: Jun Tang, Junzhuo Liu, Ningyuan Zhu, Yan Zhu, Philip Kerr, Paul K S LamAbstract:The toxic effects of nanoparticles on individual organisms have been widely investigated, while few studies have investigated the effects of nanoparticles on ubiquitous multicommunity microbial aggregates. Here, Periphyton as a model of microbial aggregates, was employed to investigate the responses of microbial aggregates exposed continuously to Fe2O3 nanoparticles (5.0 mg L–1) for 30 days. The exposure to Fe2O3 nanoparticles results in the chlorophyll (a, b, and c) contents of Periphyton increasing and the total antioxidant capacity decreasing. The composition of the Periphyton markedly changes in the presence of Fe2O3 nanoparticles and the species diversity significantly increases. The changes in the Periphyton composition and diversity were due to allelochemicals, such as 3-methylpentane, released by members of the Periphyton which inhibit their competitors. The functions of the Periphyton represented by metabolic capability and contaminant (organic matter, nitrogen, phosphorus and copper) removal were able to acclimate to the Fe2O3 nanoparticles exposure via self-regulation of morphology, species composition and diversity. These findings highlight the importance of both physiological and ecological factors in evaluating the long-term responses of microbial aggregates exposed to nanoparticles
Erik Jeppesen - One of the best experts on this subject based on the ideXlab platform.
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comparison of Periphyton communities on natural and artificial macrophytes with contrasting morphological structures
Freshwater Biology, 2017Co-Authors: Beibei Hao, Yu Cao, Wei Xing, Erik JeppesenAbstract:It remains an open question whether or not artificial macrophytes are good alternatives to natural macrophytes in studies of Periphyton abundance and composition in lakes. Here, a mesocosm experiment was conducted in winter (when plant growth is low) to compare simultaneously the Periphyton community on three submerged macrophytes (Potamogeton lucens, Vallisneria sp. and Cabomba caroliniana) with contrasting leaf structural complexities (leaf fractal dimension = 1.12, 1.17 and 1.37, respectively) and on three types of artificial macrophytes with similar morphologies as the natural plants. We also compared intertreatment differences in phytoplankton sampled from mesocosms. Both for natural and artificial macrophytes, the Periphyton chlorophyll a (Chl-a) was positively associated with leaf fractal dimension. Although the morphological structure of natural and artificial plants and the physicochemical characteristics of the water were similar, the Periphyton community differed between natural and artificial macrophytes, with the difference being dependent on the leaf structural complexity of the macrophytes. For leaves with a simple structural complexity, the abundance and composition of Periphyton on natural and artificial plants were not statistically different. In addition, Periphyton Chl-a, density and biovolume were higher on the adaxial side than on the abaxial side of natural P. lucens leaves, but no differences were found between sides of the artificial leaves. For leaves with a medium structural complexity, the abundance of Periphyton was lower on the natural than artificial plants, and the proportion of diatoms to the total community differed. For leaves with a high structural complexity, Periphyton Chl-a of the artificial plants was notably higher than on the natural plants, while no significant differences were found for Periphyton density, biovolume, and the proportion of diatoms and green algae. Permutational multivariate analysis of Periphyton genus composition confirmed that Periphyton composition on the artificial plants (medium and high leaf structural complexities) was different overall from that on the natural plants. Phytoplankton Chl-a, density, biovolume, and diversity did not show any pronounced differences among treatments. Our results suggest that artificial macrophytes cannot fully substitute for natural plants even when they are morphologically similar. Artificial macrophytes should therefore be used with caution when investigating the Periphyton community on macrophytes.
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effects of nutrient loading temperature regime and grazing pressure on nutrient limitation of Periphyton in experimental ponds
Freshwater Biology, 2014Co-Authors: Carolina Trochine, Lone Liboriussen, Marcelo Guerrieri, Torben L Lauridsen, Erik JeppesenAbstract:SUMMARY 1. We studied nutrient limitation of periphytic algae (henceforth Periphyton) in 24 mesocosms simulating shallow lakes with two nutrient levels, enriched (with added nitrogen, N, and phosphorus, P) and unenriched (control), and three temperature scenarios, ambient, A2 from the Intergovernmental Panel on Climate Change (IPCC) and A2 + 50%. Periphyton growth (measured as chlorophyll a) was investigated four times in situ using nutrient-diffusing substrata. The effect of grazing was also manipulated using exclusion cages. 2. We found that Periphyton responded differently to nutrient addition bioassays (N and P) depending on the background nutrient concentration and warming scenario. Our results indicate that singlenutrient limitation prevailed for Periphyton in our experimental temperate shallow lakes. The responses were season sensitive. 3. Periphyton in the unenriched mesocosms were P-limited in early summer in the ambient and A2 scenarios, N-limited in late summer in these two climate scenarios, not nutrient-limited in autumn and P-limited in spring in all climate scenarios. Periphyton in the A2 + 50% scenario showed a positive response to N and P added together in early summer. 4. In contrast, Periphyton in the enriched mesocosms showed no clear nutrient limitation, except for short-term periods of P limitation in the warmer systems. Grazers did not affect the quantitative response of Periphyton to nutrient addition, and the concentrations of P and N as well as mean monthly temperature were the main environmental factors driving P or N limitation. 5. We conclude that warming in low-productivity lakes affects the seasonality of N limitation and changes the single-nutrient limitation of Periphyton into NP co-limitation. This last observation suggests that warming reduces the sensitivity of temperate shallow lakes to bottom-up perturbations.
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Structure, biomass, production and depth distribution of Periphyton on artificial substratum in shallow lakes with contrasting nutrient concentrations
Freshwater Biology, 2005Co-Authors: Lone Liboriussen, Erik JeppesenAbstract:Summary 1. To examine how the vertical distribution of periphytic biomass and primary production in the upper 0–1 m of the water column changes along an inter-lake eutrophication gradient, artificial substrata (plastic strips) were introduced into the littoral zones of 13 lakes covering a total phosphorus (TP) summer mean range from 11 to 536 μg L−1. Periphyton was measured in July (after 8 weeks) and September (after 15 weeks) at three water depths (0.1, 0.5 and 0.9 m). 2. Periphyton chlorophyll a concentration and dry weight generally increased with time and the communities became more heterotrophic. Mean periphytic biomass was unimodally related to TP, reaching a peak between 60 and 200 μg L−1. 3. The proportion of diatoms in the Periphyton decreased from July to September. A taxonomic shift occurred from dominance (by biovolume) of diatoms and cyanobacteria at low TP to dominance of chlorophytes at intermediate TP and of diatoms (Epithemia sp.) in the two most TP-rich lakes. 4. The grazer community in most lakes was dominated by chironomid larvae and the total biomass of grazers increased with Periphyton biomass. 5. Community respiration (R), maximum light-saturated photosynthetic rate (Pmax), primary production and the biomass of macrograzers associated with Periphyton were more closely related to Periphyton biomass than to TP. Biomass-specific rates of R, Pmax and production declined with increasing biomass. 6. Mean net Periphyton production (24 h) was positive in most lakes in July and negative in all lakes in September. Net production was not related to the TP gradient in July, but decreased in September with increasing TP. 7. The results indicate that nutrient concentrations alone are poor predictors of the standing biomass and production of Periphyton in shallow lakes. However, because Periphyton biomass reaches a peak in the range of phosphorus concentration in which alternative states occur in shallow lakes, recolonisation by submerged macrophytes after nutrient reduction may potentially be suppressed by Periphyton growth.
Linzhang Yang - One of the best experts on this subject based on the ideXlab platform.
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paddy Periphyton reduced cadmium accumulation in rice oryza sativa by removing and immobilizing cadmium from the water soil interface
Environmental Pollution, 2020Co-Authors: Yue Dong, Linzhang Yang, Yuanyuan Feng, Yanchao Bai, Xianjin Tang, Junzhuo LiuAbstract:Abstract Periphyton plays a significant role in heavy metal transfer in wetlands, but its contribution to cadmium (Cd) bioavailability in paddy fields remains largely unexplored. The main aim of this study was to investigate the effect of Periphyton on Cd behavior in paddy fields. Periphyton significantly decreased Cd concentrations in paddy waters. Non-invasive micro-test technology analyses indicated that Periphyton can absorb Cd from water with a maximum Cd2+ influx rate of 394 pmol cm−2 s−1 and Periphyton intrusion significantly increased soil Cd concentrations. However, soil Cd bioavailability declined significantly due to soil pH increase and soil redox potential (Eh) decrease induced by Periphyton. With Periphyton, more Cd was adsorbed and immobilized on organic matter, carbonates, and iron and manganese oxides in soil. Consequently, Cd content in rice decreased significantly. These findings give insights into Cd biogeochemistry in paddy fields with Periphyton, and may provide a novel strategy for reducing Cd accumulation in rice.
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phototrophic Periphyton techniques combine phosphorous removal and recovery for sustainable salt soil zone
Science of The Total Environment, 2016Co-Authors: Yanfang Feng, Linzhang Yang, Hongbo ShaoAbstract:The P (Pi as KH2PO4 and Po as ATP) removal processes by phototrophic Periphyton were investigated by determining the removal kinetics, metal content (Ca, Mg, Al, Fe, Cu, and Zn) of the solution and P fractions (Labile-P, Fe/Al-P, Ca-P, and Res-P) within the Periphyton. Results showed that the Periphyton was able to remove completely both Pi and Po after 48h when Periphyton content was greater than 0.2gL(-1) (dry weight). The difference between Pi and Po removal was the conversion of Po into Pi by the Periphyton, after that the removal mechanism was similar. The P removal mechanism was mainly due to the adsorption on the surfaces of the Periphyton, including two aspects: i) the adsorption of PO4(3-) onto metal salts such as calcium carbonate (~50%) and ii) complexation between PO4(3-) and metal cations such as Ca(2+) (~40%). However, this bio-adsorptional process was significantly influenced by the extracellular polymeric substance (EPS) of Periphyton, water hardness, initial P concentration, temperature and light intensity. This study not only deepens the understanding of P biogeochemical process in aquatic ecosystem, but provides a potential biomaterial for combining phosphorous removal and recovery from non-point source wastewaters, especially around salt-soil zone.
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responses of Periphyton morphology structure and function to extreme nutrient loading
Environmental Pollution, 2016Co-Authors: Yanfang Feng, Jinhua Wang, Hongbo Shao, Linzhang YangAbstract:Periphyton have been widely applied in aquaculture systems, however, little information is available on how Periphyton respond to such high nutrient levels in water. Thus, changes in the morphological characteristics, community structure, and metabolic function of Periphyton under high eutrophic waters were evaluated. The results indicated that the morphology of Periphyton was affected by increasing the nutrient concentration of water, which shifted the micromorphology of Periphyton from spheriform to filamentous. The Periphyton under higher water nutrient levels were able to utilize more carbon source types. Additionally, higher water nutrient levels increased the bacterial and protozoal proportions in Periphyton. This study fills the gap in knowledge about the responses of periphytic communities to extremely eutrophic waters. It provides valuable information on the full understanding of the Periphyton-nutrient relationship in aquaculture systems, which is beneficial for regulating the microbial species or communities in Periphyton by manipulating the nutrient levels in water.
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the adsorption process during inorganic phosphorus removal by cultured Periphyton
Environmental Science and Pollution Research, 2014Co-Authors: Linzhang Yang, Sadaf ShabbirAbstract:To explain the detailed process involved in phosphorus removal by Periphyton, the Periphyton dominated by photoautotrophic microorganisms was employed in this study to remove inorganic phosphorus (Pi) from wastewater, and the removal kinetics and isotherms were then evaluated for the Pi removal process. Results showed that the Periphyton was capable of effectively removing Pi that could completely remove the Pi in 24 h at an initial Pi concentration of 13 mg P L(-1). Furthermore, the Pi removal process by the Periphyton was dominated by adsorption at initial stage (~24 h), which involved physical mechanistic process. However, this Pi adsorption process was significantly influenced by environmental conditions. This work provides an insight into the understanding of phosphorus adsorption by Periphyton or similar microbial aggregates.
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the behavior of organic phosphorus under non point source wastewater in the presence of phototrophic Periphyton
PLOS ONE, 2014Co-Authors: Linzhang Yang, Shanqing ZhangAbstract:To understand the role of ubiquitous phototrophic Periphyton in aquatic ecosystem on the biogeochemical cycling of organic phosphorus, the conversion and removal kinetic characteristics of organic phosphorus (Porg) such as adenosine triphosphate (ATP) were investigated in the presence of the Periphyton cultured in artificial non-point source wastewater. The preliminary results showed that the Periphyton was very powerful in converting Porg evidenced by the fact that inorganic phosphorus (Pinorg) content in solution increased from about 0.7 to 14.3 mg P L−1 in 48 hours in the presence of 0.6 g L−1 Periphyton. This was because the Periphyton could produce abundant phosphatases that benefited the conversion of Porg to Pinrog. Moreover, this conversion process was described more suitable by the pseudo-first-order kinetic model. The Periphyton was also effective in removing Porg, which showed that the Porg can be completely removed even when the initial Porg concentration was as high as 13 mg P L−1 in 48 hours in the presence of 1.6 g L−1 Periphyton. Furthermore, it was found that biosorption dominated the Porg removal process and exhibited the characteristics of physical adsorption. However, this biosorption process by the Periphyton was significantly influenced by biomass (absorbent dosage) and temperature. This work provides insights into Porg biogeochemical circulation of aquatic ecosystem that contained the Periphyton or similar microbial aggregates.
Evelyn E Gaiser - One of the best experts on this subject based on the ideXlab platform.
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Diatom-based Models for Inferring Hydrology and Periphyton Abundance in a Subtropical Karstic Wetland: Implications for Ecosystem-Scale Bioassessment
Wetlands, 2013Co-Authors: Evelyn E Gaiser, Joel C. TrexlerAbstract:We developed diatom-based prediction models of hydrology and Periphyton abundance to inform assessment tools for a hydrologically managed wetland. Because hydrology is an important driver of ecosystem change, hydrologic alterations by restoration efforts could modify biological responses, such as Periphyton characteristics. In karstic wetlands, diatoms are particularly important components of mat-forming calcareous Periphyton assemblages that both respond and contribute to the structural organization and function of the Periphyton matrix. We examined the distribution of diatoms across the Florida Everglades landscape and found hydroperiod and Periphyton biovolume were strongly correlated with assemblage composition. We present species optima and tolerances for hydroperiod and Periphyton biovolume, for use in interpreting the directionality of change in these important variables. Predictions of these variables were mapped to visualize landscape-scale spatial patterns in a dominant driver of change in this ecosystem (hydroperiod) and an ecosystem-level response metric of hydrologic change (Periphyton biovolume). Specific diatom assemblages inhabiting Periphyton mats of differing abundance can be used to infer past conditions and inform management decisions based on how assemblages are changing. This study captures diatom responses to wide gradients of hydrology and Periphyton characteristics to inform ecosystem-scale bioassessment efforts in a large wetland.
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everglades Periphyton a biogeochemical perspective
Critical Reviews in Environmental Science and Technology, 2011Co-Authors: Scot E Hagerthey, Brent J Bellinger, Kristin Wheeler, Miroslav Gantar, Evelyn E GaiserAbstract:Periphyton is an important component of the Everglades biogeochemical cycle but remains poorly understood. From a biogeochemical perspective, Periphyton is a dense aggregation of diverse microorganisms (autotrophic and heterotrophic) and particles (mineral and detrital) imbedded within an extracellular matrix. The authors synthesize Everglades Periphyton biogeochemistry and diversity at the ecosystem and community scales. The primary regulator of biogeochemical processes (material flux, transformation, and storage) is photosynthesis, which controls oxidation-reduction potentials and heterotrophic metabolism. Eutrophication and hydrologic alterations have resulted in fundamental Periphyton biogeochemical differences. Elucidation of these processes is required to predict and interpret responses to ecosystem restoration.
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Comparative study of Periphyton community structure in long and short-hydroperiod Everglades marshes
Hydrobiologia, 2006Co-Authors: Andrew D. Gottlieb, Jennifer H. Richards, Evelyn E GaiserAbstract:The Florida Everglades is a mosaic of short and long-hydroperiod marshes that differ in the depth, duration, and timing of inundation. Algae are important primary producers in widespread Everglades’ Periphyton mats, but relationships of algal production and community structure to hydrologic variability are poorly understood. We quantified differences in algal biomass and community structure between Periphyton mats in 5 short and 6 long-hydroperiod marshes in Everglades National Park (ENP) in October 2000. We related differences to water depth and total phosphorus (TP) concentration in the water, Periphyton and soils. Long and short-hydroperiod marshes differed in water depth (73 cm vs. 13 cm), Periphyton TP concentrations (172 μ g g^−1 vs. 107 μ g g^−1, respectively) and soil TP (284 μ g g^−1 vs. 145 μ g g^−1). Periphyton was abundant in both marshes, with short-hydroperiod sites having greater biomass than long-hydroperiod sites (2936 vs. 575 grams ash-free dry mass m^−2). A total of 156 algal taxa were identified and separated into diatom (68 species from 21 genera) and “soft algae” (88 non-diatom species from 47 genera) categories for further analyses. Although diatom total abundance was greater in long-hydroperiod mats, diatom species richness was significantly greater in short- hydroperiod Periphyton mats (62 vs. 47 diatom taxa). Soft algal species richness was greater in long-hydroperiod sites (81 vs. 67 soft algae taxa). Relative abundances of individual taxa were significantly different among the two site types, with soft algal distributions being driven by water depth, and diatom distributions by water depth and TP concentration in the water and Periphyton. Periphyton communities differ between short and long-hydroperiod marshes, but because they share many taxa, alterations in hydroperiod could rapidly promote the alternate community.
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Periphyton responses to eutrophication in the florida everglades cross system patterns of structural and compositional change
Limnology and Oceanography, 2006Co-Authors: Evelyn E Gaiser, Jennifer H. Richards, Daniel L Childers, Ronald D Jones, Leonard J Scinto, Joel C. TrexlerAbstract:We examined Periphyton along transects in five Everglades marshes and related compositional and functional aspects to phosphorus (P) gradients caused by enriched inflows. Results were compared to those of a P-addition experiment in a pristine Everglades marsh. While the water total P (TP) concentration was not related to P load in the marshes or experiment, the concentration of TP in Periphyton was strongly correlated with the distance from the P source. Increased P concentration in Periphyton was associated with a loss of biomass, particularly of the calcifying mat-forming matrix, regardless of the growth form of the Periphyton (epiphytic, floating, or epilithic). Diatom species composition was also strongly related to P availability, but the TP optima of many species varied among marshes. Enriched Periphyton communities were found 14 km downstream of P inputs to one marsh that has been receiving enhanced P loads for decades, where other studies using different biotic indicators show negligible change in the same marsh. Although recovery trajectories are unknown, Periphyton indicators should serve as excellent metrics for the progression or amelioration of P-related effects in the Everglades.
Philip G Kerr - One of the best experts on this subject based on the ideXlab platform.
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responses of Periphyton to fe2o3 nanoparticles a physiological and ecological basis for defending nanotoxicity
Environmental Science & Technology, 2017Co-Authors: Jun Tang, Philip G Kerr, Junzhuo Liu, Ningyuan Zhu, Yan Zhu, Paul K S LamAbstract:The toxic effects of nanoparticles on individual organisms have been widely investigated, while few studies have investigated the effects of nanoparticles on ubiquitous multicommunity microbial aggregates. Here, Periphyton as a model of microbial aggregates, was employed to investigate the responses of microbial aggregates exposed continuously to Fe2O3 nanoparticles (5.0 mg L–1) for 30 days. The exposure to Fe2O3 nanoparticles results in the chlorophyll (a, b, and c) contents of Periphyton increasing and the total antioxidant capacity decreasing. The composition of the Periphyton markedly changes in the presence of Fe2O3 nanoparticles and the species diversity significantly increases. The changes in the Periphyton composition and diversity were due to allelochemicals, such as 3-methylpentane, released by members of the Periphyton which inhibit their competitors. The functions of the Periphyton represented by metabolic capability and contaminant (organic matter, nitrogen, phosphorus and copper) removal wer...
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the effect of Periphyton on seed germination and seedling growth of rice oryza sativa in paddy area
Science of The Total Environment, 2017Co-Authors: Junzhuo Liu, Philip G Kerr, Hongbo ShaoAbstract:Periphyton is widely distributed in paddy fields and its interactions with paddy soil and rice growth have been reported rarely. In this study, model paddy ecosystems with different additional soil substrates were simulated under controlled conditions to investigate the effects of Periphyton on rice seed germination and seedling growth. Results show that the selected soil substrates had significant effects on the metabolic activities and growth of Periphyton in paddy fields. The addition of straw to soil enhances but the addition of biochar leads to attenuation of Periphyton growth. The presence of Periphyton in the paddy system, especially with straw in soil greatly increased the germination index of rice seed (by maximally 21%). However, the biochar treatment in the presence of Periphyton was detrimental for the seed vitality with a decrease of 30%. As a result, the Periphyton cover on paddy soil surface significantly inhibited the growth of rice seedling, including rice height, leaf width and biomass. To summarize, this study indicates that the presence of Periphyton during seed germination period was detrimental for rice growth, but could be used to control the weed growth. Thus, this study provided insight into understanding the Periphyton-plant relationships with different soil-substrates and also new approaches to controlling weeds in paddy fields by regulating the growth of Periphyton.
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Evaluating role of immobilized Periphyton in bioremediation of azo dye amaranth
Bioresource Technology, 2017Co-Authors: Samina Shabbir, Naeem Ali, Philip G Kerr, Muhammad Faheem, Yonghong WuAbstract:The aim of this study was to evaluate the bioremediation capabilities of three kinds of Periphyton (i.e. epiphyton, metaphyton and epilithon) immobilized in bioreactors to decolorize and biodegrade the sulphonated azo dye, amaranth. Results showed that Periphyton dominated by phyla including Cyanobacteria, Proteobacteria and Bacteroidetes. Complete removal of dye was shown by all the biofilms Periphyton (epiphyton showed highest removal efficacy) over a range of initial concentrations (50–500 mg L −1 ) within 84 h at pH 7 and 30 °C. Biodegradation of amaranth was confirmed through FTIR and HPLC and the biodegradation pathways were detected by GC–MS/MS analysis. The azo bonds in the amaranth were successfully broken by Periphyton and amaranth was converted to non-toxic, aliphatic compounds including isobutene, acetyl acetate and ethyl acetate. The results showed the potential application of immobilized Periphyton at industrial scale for the removal of azo dyes from wastewater containing azo dye amaranth.
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Periphyton an important regulator in optimizing soil phosphorus bioavailability in paddy fields
Environmental Science and Pollution Research, 2016Co-Authors: Junzhuo Liu, Philip G KerrAbstract:Periphyton is ubiquitous in paddy field, but its importance in influencing the bioavailability of phosphorus (P) in paddy soil has been rarely recognized. A paddy field was simulated in a greenhouse to investigate how Periphyton influences P bioavailability in paddy soil. Results showed that Periphyton colonizing on paddy soil greatly reduced P content in paddy floodwater but increased P bioavailability of paddy soil. Specifically, all the contents of water-soluble P (WSP), readily desorbable P (RDP), algal-available P (AAP), and NaHCO3-extractable P (Olsen-P) in paddy soil increased to an extent compared to the control (without Periphyton) after fertilization. In particular, Olsen-P was the most increased P species, up to 216 mg kg−1 after fertilization, accounting for nearly 60 % of total phosphorus (TP) in soil. The paddy Periphyton captured P up to 1.4 mg g−1 with Ca-P as the dominant P fraction and can be a potential crop fertilizer. These findings indicated that the presence of Periphyton in paddy field benefited in improving P bioavailability for crops. This study provides valuable insights into the roles of Periphyton in P bioavailability and migration in a paddy ecosystem and technical support for P regulation.
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redox zones stratification and the microbial community characteristics in a Periphyton bioreactor
Bioresource Technology, 2016Co-Authors: Junzhuo Liu, Fengwu Wang, Wei Liu, Philip G KerrAbstract:Bioremediation techniques based on microorganisms have been widely applied to treat polluted surface water, but the efficiencies have been limited, especially in deep and static waters. Microbial aggregates, known as Periphyton, were introduced into a tank bioreactor to improve pollutants removal and a Periphyton bioreactor with an 84 cm column was built to investigate microbe-wastewater interactions. Periphyton greatly improved water quality and produced a distinct stratification in the water column into five redox zones with slight overlaps. From top to bottom these were: oxygen reduction, nitrate reduction, iron reduction, sulfate reduction and methanogenic zone. Periphyton communities had high species diversities (767-947 OTUs) with the facultative zone (middle layer) having higher species richness and functional diversity than the aerobic (top layer) and anaerobic zones (bottom layer). A good knowledge of interactions between Periphyton and water column stratification could benefit from integration of Periphyton to improve bioremediation of deep and static water.
