1
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Sahu N, Mahanty B, Haldar D. Challenges and opportunities in bioprocessing of gellan gum: A review. Int J Biol Macromol 2024; 276:133912. [PMID: 39025193 DOI: 10.1016/j.ijbiomac.2024.133912] [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: 03/27/2024] [Revised: 06/26/2024] [Accepted: 07/14/2024] [Indexed: 07/20/2024]
Abstract
Gellan gum (GG) - the microbial exopolysaccharide is increasingly being adopted into drug development, tissue engineering, and food and pharmaceutical products. In spite of the commercial importance and expanding application horizon of GG, little attention has been directed toward the exploration of novel microbial cultures, development of advanced screening protocols, strain engineering, and robust upstream or downstream processes. This comprehensive review not only attempts to summarize the existing knowledge pool on GG bioprocess but also critically assesses their inherent challenges. The process optimization design augmented with advanced machine learning modeling tools, widely adopted in other microbial bioprocesses, should be extended to GG. The unification of mechanistic insight into data-driven modeling would help to formulate optimal feeding and process control strategies.
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Affiliation(s)
- Nageswar Sahu
- Division of Biotechnology, School of Agricultural Sciences, Karunya Institute of Technology and Sciences, Coimbatore 641114, Tamil Nadu, India.
| | - Biswanath Mahanty
- Division of Biotechnology, School of Agricultural Sciences, Karunya Institute of Technology and Sciences, Coimbatore 641114, Tamil Nadu, India.
| | - Dibyajyoti Haldar
- Division of Biotechnology, School of Agricultural Sciences, Karunya Institute of Technology and Sciences, Coimbatore 641114, Tamil Nadu, India.
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2
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Fundneider-Kale S, Kerres J, Engelhart M. Impact of benzalkonium chloride on anaerobic granules and its long-term effects on reactor performance. JOURNAL OF HAZARDOUS MATERIALS 2024; 476:135183. [PMID: 39024763 DOI: 10.1016/j.jhazmat.2024.135183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 07/06/2024] [Accepted: 07/10/2024] [Indexed: 07/20/2024]
Abstract
This study assessed the inhibitory and performance-degrading effects induced by the cationic surfactant benzalkonium chloride (BAC) on anaerobic granules during the long-term operation of a laboratory-scale expanded granular sludge bed (EGSB) reactor. To address the critical scientific problem of how BAC affects the efficiency of EGSB reactors, this research uniquely evaluated the long-term stress response to BAC by systematically comparing continuous and discontinuous inhibitor exposure scenarios. The novel comparison demonstrated that inhibitor concentration is of minor relevance compared to the biomass-specific cumulative inhibitor load in the reactor. After exceeding a critical biomass-specific cumulative inhibitor load of 6.1-6.5 mg BAC/g VS, continuous and discontinuous exposure to BAC caused comparable significant deterioration in reactor performance, including accumulation of volatile fatty acids (VFA), decreased removal efficiency, reduced methane production, as well as the wash-out, flotation, and disintegration of anaerobic granules. BAC exposures had a more detrimental effect on methanogenesis than on acidogenesis. Moreover, long-term stress by BAC led to an inhibition of protein production, resulting in a decreased protein-to-polysaccharide ratio of extracellular polymeric substances (EPS) that promoted destabilizing effects on the granules. Finally, hydrogenotrophic methanogenesis was triggered. Reactor performance could not be restored due to the severe loss of granular sludge.
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Affiliation(s)
- S Fundneider-Kale
- Technical University of Darmstadt, Institute IWAR, Chair of Wastewater Technology, Franziska-Braun-Straße 7, D-64287 Darmstadt, Germany.
| | - J Kerres
- Technical University of Darmstadt, Institute IWAR, Chair of Wastewater Technology, Franziska-Braun-Straße 7, D-64287 Darmstadt, Germany
| | - M Engelhart
- Technical University of Darmstadt, Institute IWAR, Chair of Wastewater Technology, Franziska-Braun-Straße 7, D-64287 Darmstadt, Germany
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3
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Buenaño-Vargas C, Gagliano MC, Paulo LM, Bartle A, Graham A, van Veelen HPJ, O'Flaherty V. Acclimation of microbial communities to low and moderate salinities in anaerobic digestion. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167470. [PMID: 37778560 DOI: 10.1016/j.scitotenv.2023.167470] [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: 07/14/2023] [Revised: 09/27/2023] [Accepted: 09/28/2023] [Indexed: 10/03/2023]
Abstract
In recent years anaerobic digestion (AD) has been investigated as suitable biotechnology to treat wastewater at elevated salinities. However, when starting up AD reactors with inocula that are not adapted to salinity, low concentrations of sodium (Na+) in the influent can already cause disintegration of microbial aggregates and wash-out. This study investigated biomass acclimation to 5 g Na+/L of two different non-adapted inocula in two lab-scale hybrid expanded granular sludge bed (EGSB)-anaerobic filter (AF) reactors fed with synthetic wastewater. After an initial biomass disintegration, new aggregates were formed relatively fast (i.e., after 95 days of operation), indicating microbial community adaptation. The newly formed microbial aggregates accumulated Na+ at the expense of calcium (Ca2+), but this did not hamper biomass retention or process performance. The hybrid reactor configuration, including a pumice stone filter in the upper section, and the low up-flow velocities applied, were key features for retaining the biomass within the system. This reactor configuration can be easily applied and represents a low-cost alternative for acclimating biomass to saline effluents, even in existing digesters. When the acclimated biomass was transferred from EGSB to an up-flow anaerobic sludge blanket (UASB) reactor configuration also fed with saline synthetic wastewater, more dense aggregates in the form of granules were obtained. The performances of the UASB inoculated with the acclimated biomass were comparable to another reactor seeded with saline-adapted granular sludge from a full-scale plant. Regardless of the inoculum origin, a defined core microbiome of Bacteria (Thermovirga, Bacteroidetes vadinHA17, Blvii28 wastewater-sludge group, Mesotoga, and Synergistaceae) and Archaea (Methanosaeta and Methanobacterium) was detected, highlighting the importance of these microbial groups in developing halotolerance and maintaining AD process stability.
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Affiliation(s)
- Claribel Buenaño-Vargas
- Microbial Ecology Laboratory, School of Biological and Chemical Sciences and Ryan Institute, University of Galway, University Road, Ireland
| | - M Cristina Gagliano
- Wetsus - European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911MA Leeuwarden, the Netherlands
| | - Lara M Paulo
- Microbial Ecology Laboratory, School of Biological and Chemical Sciences and Ryan Institute, University of Galway, University Road, Ireland
| | - Andrew Bartle
- Microbial Ecology Laboratory, School of Biological and Chemical Sciences and Ryan Institute, University of Galway, University Road, Ireland
| | - Alison Graham
- Microbial Ecology Laboratory, School of Biological and Chemical Sciences and Ryan Institute, University of Galway, University Road, Ireland
| | - H Pieter J van Veelen
- Wetsus - European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911MA Leeuwarden, the Netherlands
| | - Vincent O'Flaherty
- Microbial Ecology Laboratory, School of Biological and Chemical Sciences and Ryan Institute, University of Galway, University Road, Ireland.
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4
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Mills S, Trego AC, Prevedello M, De Vrieze J, O’Flaherty V, Lens PN, Collins G. Unifying concepts in methanogenic, aerobic, and anammox sludge granulation. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2024; 17:100310. [PMID: 37705860 PMCID: PMC10495608 DOI: 10.1016/j.ese.2023.100310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 06/17/2023] [Accepted: 08/05/2023] [Indexed: 09/15/2023]
Abstract
The retention of dense and well-functioning microbial biomass is crucial for effective pollutant removal in several biological wastewater treatment technologies. High solids retention is often achieved through aggregation of microbial communities into dense, spherical aggregates known as granules, which were initially discovered in the 1980s. These granules have since been widely applied in upflow anaerobic digesters for waste-to-energy conversions. Furthermore, granular biomass has been applied in aerobic wastewater treatment and anaerobic ammonium oxidation (anammox) technologies. The mechanisms underpinning the formation of methanogenic, aerobic, and anammox granules are the subject of ongoing research. Although each granule type has been extensively studied in isolation, there has been a lack of comparative studies among these granulation processes. It is likely that there are some unifying concepts that are shared by all three sludge types. Identifying these unifying concepts could allow a unified theory of granulation to be formed. Here, we review the granulation mechanisms of methanogenic, aerobic, and anammox granular sludge, highlighting several common concepts, such as the role of extracellular polymeric substances, cations, and operational parameters like upflow velocity and shear force. We have then identified some unique features of each granule type, such as different internal structures, microbial compositions, and quorum sensing systems. Finally, we propose that future research should prioritize aspects of microbial ecology, such as community assembly or interspecies interactions in individual granules during their formation and growth.
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Affiliation(s)
- Simon Mills
- Microbial Communities Laboratory, School of Biological and Chemical Sciences, National University of Ireland Galway, University Road, Galway, H91 TK33, Ireland
| | - Anna Christine Trego
- Microbial Ecology Laboratory School of Biological and Chemical Sciences, University of Galway, University Road, Galway, H91 TK33, Ireland
| | - Marco Prevedello
- Microbial Communities Laboratory, School of Biological and Chemical Sciences, National University of Ireland Galway, University Road, Galway, H91 TK33, Ireland
| | - Jo De Vrieze
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000, Gent, Belgium
| | - Vincent O’Flaherty
- Microbial Ecology Laboratory School of Biological and Chemical Sciences, University of Galway, University Road, Galway, H91 TK33, Ireland
| | - Piet N.L. Lens
- University of Galway, University Road, Galway, H91 TK33, Ireland
| | - Gavin Collins
- Microbial Communities Laboratory, School of Biological and Chemical Sciences, National University of Ireland Galway, University Road, Galway, H91 TK33, Ireland
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5
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Zhang B, Shen J, Mao X, Zhang B, Shen Y, Shi W. A novel membrane bioreactor inoculated with algal-bacterial granular sludge for sewage reuse and membrane fouling mitigation: Performance and mechanism. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 334:122194. [PMID: 37453682 DOI: 10.1016/j.envpol.2023.122194] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 07/04/2023] [Accepted: 07/12/2023] [Indexed: 07/18/2023]
Abstract
In this study, a novel membrane bioreactor (MBR) inoculated with algal-bacterial granular sludge (ABGMBR) was established to improve pollutant removal and alleviate membrane fouling. The ABGMBR system showed higher pollutant removal rate and longer operation time (152 day) compared to the control MBR (AGMBR). Moreover, the contents of the pollutants such as granular sludges, extracellular polymeric substances (EPS), and soluble microbial products on the membrane were remarkably reduced, leading to the formation of a porous and loose cake layer on the membrane and a slow increase in transmembrane pressure. Standard blocking was the main mechanism of membrane fouling; however, the membrane pore blockage was significantly reduced in ABGMBR. The extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory suggested that the aggregation and adhesion of foulants on the membrane were greatly inhibited in ABGMBR. Furthermore, correlation analysis showed significant differences in membrane fouling characteristics between AGMBR and ABGMBR. The ABGMBR system effectively retarded sludge disintegration and increased the repulsion between the sludge and membrane owing to the favorable mixed liquor characteristics. This study showcases the superior operational efficiency and anti-fouling performance of ABGMBR, offering a novel perspective on sewage reuse and membrane fouling mitigation.
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Affiliation(s)
- Bing Zhang
- National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing, 400067, China; Chongqing Yujiang Intelligent Technology Co., Ltd., Chongqing, 409003, China; Chongqing South-to-Thais Environmental Protection Technology Research Institute Co., Ltd., Chongqing, 400060, China.
| | - Jing Shen
- National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing, 400067, China
| | - Xin Mao
- National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing, 400067, China
| | - Bing Zhang
- School of Environmental and Ecology, Chongqing University, Chongqing, 400044, China.
| | - Yu Shen
- National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing, 400067, China; Chongqing Yujiang Intelligent Technology Co., Ltd., Chongqing, 409003, China; Chongqing South-to-Thais Environmental Protection Technology Research Institute Co., Ltd., Chongqing, 400060, China
| | - Wenxin Shi
- School of Environmental and Ecology, Chongqing University, Chongqing, 400044, China
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Sethi S, Gupta R, Bharshankh A, Sahu R, Biswas R. Celebrating 50 years of microbial granulation technologies: From canonical wastewater management to bio-product recovery. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 872:162213. [PMID: 36796691 DOI: 10.1016/j.scitotenv.2023.162213] [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: 11/16/2022] [Revised: 01/27/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
Microbial granulation technologies (MGT) in wastewater management are widely practised for more than fifty years. MGT can be considered a fine example of human innovativeness-driven nature wherein the manmade forces applied during operational controls in the biological process of wastewater treatment drive the microbial communities to modify their biofilms into granules. Mankind, over the past half a century, has been refining the knowledge of triggering biofilm into granules with some definite success. This review captures the journey of MGT from inception to maturation providing meaningful insights into the process development of MGT-based wastewater management. The full-scale application of MGT-based wastewater management is discussed with an understanding of functional microbial interactions within the granule. The molecular mechanism of granulation through the secretion of extracellular polymeric substances (EPS) and signal molecules is also highlighted in detail. The recent research interest in the recovery of useful bioproducts from the granular EPS is also emphasized.
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Affiliation(s)
- Shradhanjali Sethi
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Human Resource Development Centre (CSIR-HRDC), Ghaziabad, Uttar Pradesh 201002, India; Wastewater Technology Division, CSIR-National Environmental Engineering Research Institute, Nagpur, Maharashtra 440020, India
| | - Rohan Gupta
- Wastewater Technology Division, CSIR-National Environmental Engineering Research Institute, Nagpur, Maharashtra 440020, India
| | - Ankita Bharshankh
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Human Resource Development Centre (CSIR-HRDC), Ghaziabad, Uttar Pradesh 201002, India; Wastewater Technology Division, CSIR-National Environmental Engineering Research Institute, Nagpur, Maharashtra 440020, India
| | - Rojalin Sahu
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Human Resource Development Centre (CSIR-HRDC), Ghaziabad, Uttar Pradesh 201002, India; Wastewater Technology Division, CSIR-National Environmental Engineering Research Institute, Nagpur, Maharashtra 440020, India
| | - Rima Biswas
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Human Resource Development Centre (CSIR-HRDC), Ghaziabad, Uttar Pradesh 201002, India; Wastewater Technology Division, CSIR-National Environmental Engineering Research Institute, Nagpur, Maharashtra 440020, India.
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7
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Zhou R, Li H, Liu C, Liu Y, Lee JF, Lin YJ, Yan Z, Xu Z, Yi X, Feng C. Magnetic anaerobic granular sludge for sequestration and immobilization of Pb. WATER RESEARCH 2023; 239:120022. [PMID: 37172375 DOI: 10.1016/j.watres.2023.120022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 04/03/2023] [Accepted: 04/29/2023] [Indexed: 05/14/2023]
Abstract
The development of magnetic adsorbents with high capacity to capture heavy metals has been the subject of intense research, but the process usually involves costive synthesis steps. Here, we propose a green approach to obtaining a magnetic biohybrid through in situ grown anaerobic granular sludge (AGS) with the help of magnetite, constituting a promising adsorbent for sequestration and immobilization of Pb in aqueous solutions and soils. The resultant magnetite-embedded AGS (M-AGS) was not only capable of promoting methane production but also conducive to Pb adsorption because of the large surface area and abundant function groups. The uptake of Pb on M-AGS followed the pseudo-second order, having a maximum adsorption capacity of 197.8 mg gDS-1 at pH 5.0, larger than 159.7, 170.3, and 178.1 mg gDS-1 in relation to AGS, F-AGS (ferrihydrite-mediated), and H-AGS (hematite-mediated), respectively. Mechanistic investigations showed that Pb binding to M-AGS proceeds via surface complexation, mineral precipitation, and lattice replacement, which promotes heavy metal capture and stabilization. This was evident from the increased proportion of structural Pb sequestrated from the aqueous solution and the enhanced percentage of the residual fraction of Pb extracted from the contaminated soils.
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Affiliation(s)
- Rui Zhou
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Han Li
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Chengshuai Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, PR China
| | - Yizhang Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, PR China
| | - Jyh-Fu Lee
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan, ROC
| | - Yu-Jung Lin
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan, ROC
| | - Zhang Yan
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Zhangyi Xu
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Xiaoyun Yi
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Chunhua Feng
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
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Lv S, Zheng F, Wang Z, Dai L, Liu H, Hrynshpan D, Savitskaya T, Chen J. Effects of bamboo-charcoal modified by bimetallic Fe/Pd nanoparticles on n-hexane biodegradation by bacteria Pseudomonas mendocina NX-1. CHEMOSPHERE 2023; 318:137897. [PMID: 36657580 DOI: 10.1016/j.chemosphere.2023.137897] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/24/2022] [Accepted: 01/15/2023] [Indexed: 06/17/2023]
Abstract
The high hydrophobicity of n-hexane is the main reason why it is difficult to be removed biologically. In this study, the effects of bamboo-charcoal modified by bimetallic Fe/Pd (BBC) on n-hexane biodegradation by Pseudomonas mendocina NX-1 (PM) was investigated. The n-hexane removal efficiency was increased in the presence of BC. The highest n-hexane removal efficiency at 90.0% was achieved at 0.05 g L-1 BCE and 3 g L-1 NH4+ under pH 7.7 and 35 °C. Additionally, protein content (45.9 μg mL-1) and negative cell surface zeta potential (-26.4 mV) were increased during biodegradation process, with PM-BBC being 43.1 μg mL-1 and 19.1 mV. Bacterial growth was improved and maximum cell surface hydrophobicity was obtained after 20 h, which was 59.4% higher than the control with PM-BBC (37.7%) or PM (16.1%), showing biodegradation products of 1-butanol and acetic acid. The results indicate that BBC improved n-hexane biodegradation efficiency by promoting bacterial growth, reducing cell zeta potential, exposing hydrophobic proteins, and increasing cell surface hydrophobicity of bacterial strain NX-1. This investigation suggests that BBC-enhanced biodegradation can be promising to treat n-hexane-containing gas.
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Affiliation(s)
- Sini Lv
- College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Fengzhen Zheng
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou, 310015, China
| | - Zeyu Wang
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou, 310015, China
| | - Luyao Dai
- College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Huan Liu
- College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Dzmitry Hrynshpan
- Research Institute of Physical and Chemical Problems, Belarusian State University, Minsk, 220030, Belarus
| | - Tatsiana Savitskaya
- Research Institute of Physical and Chemical Problems, Belarusian State University, Minsk, 220030, Belarus
| | - Jun Chen
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou, 310015, China.
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Cydzik-Kwiatkowska A, Bernat K, Zielińska M, Gusiatin MZ, Wojnowska-Baryła I, Kulikowska D. Valorization of full-scale waste aerobic granular sludge for biogas production and the characteristics of the digestate. CHEMOSPHERE 2022; 303:135167. [PMID: 35653865 DOI: 10.1016/j.chemosphere.2022.135167] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/06/2022] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
Despite the dynamic development of aerobic granular sludge (AGS) technology in wastewater treatment, there is limited data on how the different properties of AGS and activated sludge (AS) translate into differences in waste sludge management. Waste sludge generated in both AGS and AS technology is the biggest waste stream generated in wastewater treatment plants (WWTPs). This study aimed to assess biogas production from waste AGS from a full-scale system. Additionally, the properties of the digestate were investigated in terms of its management in line with the assumptions of a circular economy. Both aspects are important because the characteristics of AGS differ from those of AS. Its dense, extracellular-polymer-rich granule structure makes the susceptibility of AGS to anaerobic stabilization lower than that of AS. Given the advantages of AGS for sustainable wastewater treatment and its increasing popularity, waste AGS management will pose a serious challenge for WWTP operators. Therefore, AGS from a full-scale municipal WWTP was valorized for biogas production by increasing the accessibility of the organics in the sludge by homogenization or ultrasound pretreatment. Ultrasound pretreatment released about an order of magnitude more organics from the biomass than homogenization and significantly improved the production of methane-rich biogas (455 L/kg VS, about 66% of CH4). The digestion time of pretreated AGS was reduced by 25% in comparison with that of untreated AGS making anaerobic digestion of AGS a feasible solution for sludge management. The AGS digestate was rich in Ca (77.0 g/kg TS), Mg (10.9 g/kg TS), N (35.1 g/kg TS) and P (32.4 g/kg TS), whereas its heavy metal levels and biochemical methane potential were low. AGS digestate is not only environmentally safe, but it can serve as a rich source of organics and elements essential for soil fertility and stability.
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Affiliation(s)
- Agnieszka Cydzik-Kwiatkowska
- University of Warmia and Mazury in Olsztyn, Faculty of Geoengineering, Department of Environmental Biotechnology, Sloneczna 45G, 10-709, Olsztyn, Poland
| | - Katarzyna Bernat
- University of Warmia and Mazury in Olsztyn, Faculty of Geoengineering, Department of Environmental Biotechnology, Sloneczna 45G, 10-709, Olsztyn, Poland.
| | - Magdalena Zielińska
- University of Warmia and Mazury in Olsztyn, Faculty of Geoengineering, Department of Environmental Biotechnology, Sloneczna 45G, 10-709, Olsztyn, Poland
| | - Mariusz Zygmunt Gusiatin
- University of Warmia and Mazury in Olsztyn, Faculty of Geoengineering, Department of Environmental Biotechnology, Sloneczna 45G, 10-709, Olsztyn, Poland
| | - Irena Wojnowska-Baryła
- University of Warmia and Mazury in Olsztyn, Faculty of Geoengineering, Department of Environmental Biotechnology, Sloneczna 45G, 10-709, Olsztyn, Poland
| | - Dorota Kulikowska
- University of Warmia and Mazury in Olsztyn, Faculty of Geoengineering, Department of Environmental Biotechnology, Sloneczna 45G, 10-709, Olsztyn, Poland
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10
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Gagliano MC, Sampara P, Plugge CM, Temmink H, Sudmalis D, Ziels RM. Functional Insights of Salinity Stress-Related Pathways in Metagenome-Resolved Methanothrix Genomes. Appl Environ Microbiol 2022; 88:e0244921. [PMID: 35477253 PMCID: PMC9128505 DOI: 10.1128/aem.02449-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 04/11/2022] [Indexed: 12/15/2022] Open
Abstract
Recently, methanogenic archaea belonging to the genus Methanothrix were reported to have a fundamental role in maintaining stable ecosystem functioning in anaerobic bioreactors under different configurations/conditions. In this study, we reconstructed three Methanothrix metagenome-assembled genomes (MAGs) from granular sludge collected from saline upflow anaerobic sludge blanket (UASB) reactors, where Methanothrix harundinacea was previously implicated with the formation of compact and stable granules under elevated salinity levels (up to 20 g/L Na+). Genome annotation and pathway analysis of the Methanothrix MAGs revealed a genetic repertoire supporting their growth under high salinity. Specifically, the most dominant Methanothrix (MAG_279), classified as a subspecies of Methanothrix_A harundinacea_D, had the potential to augment its salinity resistance through the production of different glycoconjugates via the N-glycosylation process, and via the production of compatible solutes as Nε-acetyl-β-lysine and ectoine. The stabilization and reinforcement of the cell membrane via the production of isoprenoids was identified as an additional stress-related pathway in this microorganism. The improved understanding of the salinity stress-related mechanisms of M. harundinacea highlights its ecological niche in extreme conditions, opening new perspectives for high-efficiency methanisation of organic waste at high salinities, as well as the possible persistence of this methanogen in highly-saline natural anaerobic environments. IMPORTANCE Using genome-centric metagenomics, we discovered a new Methanothrix harundinacea subspecies that appears to be a halotolerant acetoclastic methanogen with the flexibility for adaptation in the anaerobic digestion process both at low (5 g/L Na+) and high salinity conditions (20 g/L Na+). Annotation of the recovered M. harundinacea genome revealed salinity stress-related functions, including the modification of EPS glycoconjugates and the production of compatible solutes. This is the first study reporting these genomic features within a Methanothrix sp., a milestone further supporting previous studies that identified M. harundinacea as a key-driver in anaerobic granulation under high salinity stress.
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Affiliation(s)
- Maria Cristina Gagliano
- Wetsus – European Centre of Excellence for Sustainable Water Technology, Leeuwarden, the Netherlands
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, the Netherlands
| | - Pranav Sampara
- Civil Engineering, University of British Columbia, Vancouver, British Columbia, Canada
| | - Caroline M. Plugge
- Wetsus – European Centre of Excellence for Sustainable Water Technology, Leeuwarden, the Netherlands
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, the Netherlands
| | - Hardy Temmink
- Wetsus – European Centre of Excellence for Sustainable Water Technology, Leeuwarden, the Netherlands
- Department of Environmental Technology, Wageningen University and Research, Wageningen, the Netherlands
| | - Dainis Sudmalis
- Department of Environmental Technology, Wageningen University and Research, Wageningen, the Netherlands
| | - Ryan M. Ziels
- Civil Engineering, University of British Columbia, Vancouver, British Columbia, Canada
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Sibt-e-Hassan S, Hussain D, Mustafa G, Uddin Siddiqui G, Asiri YI, Uddin J, Ghulam Musharraf S. In-situ manipulation of gel layer fouling into gel layer membrane formation on porous supports for water treatment. ARAB J CHEM 2022. [DOI: 10.1016/j.arabjc.2021.103526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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12
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Paria K, Pyne S, Chakraborty SK. Optimization of heavy metal (lead) remedial activities of fungi Aspergillus penicillioides (F12) through extra cellular polymeric substances. CHEMOSPHERE 2022; 286:131874. [PMID: 34426280 DOI: 10.1016/j.chemosphere.2021.131874] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 08/08/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
Wastewater imposes a great threat to any ecosystem across the world, especially the aquatic one because of the different anthropogenic activities of human beings. The present study emphasizes the optimization of ecological parameters [pH, time (h) and temperature (°C)] employing Box-Behnken design (BBD) to achieve better bio-adsorption of a selected heavy metal [lead (Pb II)] from the wastewater through an extracellular polymeric substance (EPS) of a benthic fungus, Aspergillus penicillioides (F12) (MN210327). The relevant statistical analysis (ANOVA) has enabled to record of the optimized bio-adsorption (73.14 %) of lead (Pb II) by fungal EPS at pH (8.85) and temperature (32 °C) for a duration of 5.74 h. Besides that, at the concentration of 0.5 mg/L of EPS, the flocculating rate was noted to be highest (88.4 %) in kaolin clay and the 50 % emulsifying activity. This investigation has also opened up new vistas on the possibility of the development of an alternative method of eco-sustainable bioremediation of heavy metals by fungal EPS on an industrial scale.
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Affiliation(s)
- Kishalay Paria
- Department of Zoology, Vidyasagar University, Medinipur, 721102, West Bengal, India.
| | - Smritikana Pyne
- Department of Food Technology and Biochemical Engineering, Jadavpur University, Kolkata, 700032, West Bengal, India
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13
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Shi X, Li J, Wang X, Zhang X, Tang L. Effect of the gradual increase of Na 2SO 4 on performance and microbial diversity of aerobic granular sludge. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 292:112696. [PMID: 33984643 DOI: 10.1016/j.jenvman.2021.112696] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 04/16/2021] [Accepted: 04/20/2021] [Indexed: 06/12/2023]
Abstract
Aerobic granular sludge (AGS) is a promising technology in treating saline wastewater. The effects of sodium sulfate on contaminant removal performance and sludge characteristics of AGS were studied. The results showed that under the stress of sodium sulfate, AGS kept good removal performance of ammonia nitrogen (NH+ 4-N), chemical oxygen demand (COD), and total nitrogen (TN), with removal efficiency reaching 98.7%, 91.5% and 62.7%, respectively. When sodium sulfate reached 14700 mg/L, nitrite oxidizing bacteria (NOB) were inhibited and nitrite accumulation occurred, but it had little impact on total phosphorus (TP) removal. Under the stress of sodium sulfate, compactness and settling performance of AGS was enhanced. The microbial community greatly varied and the microbial diversity of aerobic granular sludge has decreased under the stress of sodium sulfate. The study reveals that AGS has great potential in application on treating saline wastewater.
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Affiliation(s)
- Xianbin Shi
- Department of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen, Shenzhen, 518055, China
| | - Ji Li
- Department of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen, Shenzhen, 518055, China
| | - Xiaochun Wang
- Department of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen, Shenzhen, 518055, China
| | - Xiaolei Zhang
- Department of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen, Shenzhen, 518055, China.
| | - Liaofan Tang
- Department of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen, Shenzhen, 518055, China
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14
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Hu X, Fu H, Bao M, Zhang X, Liu W, Sun X, Pan Y. Temperature mediates metabolism switching of Bacillus sp. ZT-1: Analysis of the properties and structure of exopolysaccharides. Microbiol Res 2021; 251:126839. [PMID: 34390957 DOI: 10.1016/j.micres.2021.126839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/21/2021] [Accepted: 08/02/2021] [Indexed: 10/20/2022]
Abstract
Microorganism was very sensitive to external temperature change, which also affected its normal metabolism and secretion. Low temperature exopolysaccharides (LT-EPS) and normal temperature exopolysaccharides (NT-EPS) secreted by Bacillus sp. ZT-1 mediated by temperature were studied in this paper. The total carbohydrate in the LT-EPS and NT-EPS were found to be 82.54 ± 2.56 % and 94.23 ± 1.59 % (w/w). The High Performance Liquid Chromatography (HPLC) revealed the mannose and galacturonic acid accounted for 45.52 and 23.49 % in LT-EPS, respectively. In like manner, mannose and galacturonic acid contained 43.99 and 25.24 % in NT-EPS. One-dimensional nuclear magnetic resonance (NMR) revealed the connection mode of sugar chains. NT-EPS exhibited higher viscosity, better emulsification properties and the larger molecular weight than LT-EPS. Scanning electron microscopy (SEM) showed that LT-EPS was sheet-like with sugar chain branches while NT-EPS was showed as network structure. Furthermore, the 2812 differentially expressed genes (DEGs) were analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment and located 739 biological pathways. Finally, transcriptome analysis revealed differences in gene expression of the pentose phosphate pathway of carbohydrate metabolism might be the main reason for this difference.
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Affiliation(s)
- Xin Hu
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; College of Chemistry & Chemical Engineering, Ocean University of China, Qingdao, 266100, China
| | - Hongrui Fu
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; College of Chemistry & Chemical Engineering, Ocean University of China, Qingdao, 266100, China
| | - Mutai Bao
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; College of Chemistry & Chemical Engineering, Ocean University of China, Qingdao, 266100, China.
| | - Xiuli Zhang
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, China
| | - Wei Liu
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; College of Chemistry & Chemical Engineering, Ocean University of China, Qingdao, 266100, China
| | - Xiaojun Sun
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; College of Chemistry & Chemical Engineering, Ocean University of China, Qingdao, 266100, China
| | - Yaping Pan
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; College of Chemistry & Chemical Engineering, Ocean University of China, Qingdao, 266100, China
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15
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Marine Gel Interactions with Hydrophilic and Hydrophobic Pollutants. Gels 2021; 7:gels7030083. [PMID: 34287300 PMCID: PMC8293255 DOI: 10.3390/gels7030083] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/16/2021] [Accepted: 06/27/2021] [Indexed: 02/07/2023] Open
Abstract
Microgels play critical roles in a variety of processes in the ocean, including element cycling, particle interactions, microbial ecology, food web dynamics, air-sea exchange, and pollutant distribution and transport. Exopolymeric substances (EPS) from various marine microbes are one of the major sources for marine microgels. Due to their amphiphilic nature, many types of pollutants, especially hydrophobic ones, have been found to preferentially associate with marine microgels. The interactions between pollutants and microgels can significantly impact the transport, sedimentation, distribution, and the ultimate fate of these pollutants in the ocean. This review on marine gels focuses on the discussion of the interactions between gel-forming EPS and pollutants, such as oil and other hydrophobic pollutants, nanoparticles, and metal ions.
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16
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Wang Z, Gao P, Ji Y, Zhang H, Wu X, Ma J, Li S. Effects of salinity on the simultaneous anammox and denitrification process: performance, sludge morphology and shifts in microbial communities. ROYAL SOCIETY OPEN SCIENCE 2021; 8:202099. [PMID: 34040787 PMCID: PMC8113906 DOI: 10.1098/rsos.202099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 04/14/2021] [Indexed: 05/07/2023]
Abstract
In this study, the long-term effects of different salinities on the performance, sludge morphology and shifts in microbial communities were studied in a simultaneous anammox and denitrification (SAD) process at a C/N ratio of 0.5. Stable nitrogen removal efficiencies of 86.96 and 84.58% and nitrogen removal rates of 0.95 and 0.93 kg (m3 d)-1 could be achieved under low (25 mmol l-1) and moderate (50 mmol l-1) salinity, respectively. However, the performance collapsed when the system was exposed to high salinity (100 mmol l-1). The content of extracellular polymeric substances increased as salinity increased, which resulted in larger sizes of granular sludge under low and moderate salinities. Nevertheless, high salinity shock disintegrated granular sludge, thereby decreasing the average granule size. The Illumina-Miseq sequencing results revealed that Candidatus Jettenia was the sole salinity-tolerant AnAOB genus during the entire operation, whereas the main denitrification bacterial genera shifted from Denitrisoma under low salinity to Denitrisoma, Thauera and Ignavibacterium under high salinity. The results of this study provide a comprehensive and practical evaluation of the SAD process for organic nitrogen-rich saline wastewater treatment.
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Affiliation(s)
- Zhaozhao Wang
- College of Energy and Environmental Engineering, Hebei University of Engineering, Handan 056038, People's Republic of China
- Hebei Technology Innovation Center for Water Pollution Control and Water Ecological Remediation, Hebei University of Engineering, Handan 056038, People's Republic of China
| | - Peng Gao
- College of Energy and Environmental Engineering, Hebei University of Engineering, Handan 056038, People's Republic of China
- Hebei Technology Innovation Center for Water Pollution Control and Water Ecological Remediation, Hebei University of Engineering, Handan 056038, People's Republic of China
| | - Ying Ji
- College of Energy and Environmental Engineering, Hebei University of Engineering, Handan 056038, People's Republic of China
- Hebei Technology Innovation Center for Water Pollution Control and Water Ecological Remediation, Hebei University of Engineering, Handan 056038, People's Republic of China
| | - Huan Zhang
- College of Energy and Environmental Engineering, Hebei University of Engineering, Handan 056038, People's Republic of China
- Hebei Technology Innovation Center for Water Pollution Control and Water Ecological Remediation, Hebei University of Engineering, Handan 056038, People's Republic of China
| | - Xinjuan Wu
- College of Energy and Environmental Engineering, Hebei University of Engineering, Handan 056038, People's Republic of China
- Hebei Technology Innovation Center for Water Pollution Control and Water Ecological Remediation, Hebei University of Engineering, Handan 056038, People's Republic of China
| | - Jun Ma
- College of Energy and Environmental Engineering, Hebei University of Engineering, Handan 056038, People's Republic of China
- Hebei Technology Innovation Center for Water Pollution Control and Water Ecological Remediation, Hebei University of Engineering, Handan 056038, People's Republic of China
| | - Simin Li
- College of Energy and Environmental Engineering, Hebei University of Engineering, Handan 056038, People's Republic of China
- Hebei Technology Innovation Center for Water Pollution Control and Water Ecological Remediation, Hebei University of Engineering, Handan 056038, People's Republic of China
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Busnelli MP, Lazzarini Behrmann IC, Ferreira ML, Candal RJ, Ramirez SA, Vullo DL. Metal- Pseudomonas veronii 2E Interactions as Strategies for Innovative Process Developments in Environmental Biotechnology. Front Microbiol 2021; 12:622600. [PMID: 33746918 PMCID: PMC7965972 DOI: 10.3389/fmicb.2021.622600] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 02/08/2021] [Indexed: 11/25/2022] Open
Abstract
The increase of industrial discharges is the first cause of the contamination of water bodies. The bacterial survival strategies contribute to the equilibrium restoration of ecosystems being useful tools for the development of innovative environmental biotechnologies. The aim of this work was to study the Cu(II) and Cd(II) biosensing, removal and recovery, mediated by whole cells, exopolymeric substances (EPS) and biosurfactants of the indigenous and non-pathogenic Pseudomonas veronii 2E to be applied in the development of wastewater biotreatments. An electrochemical biosensor was developed using P. veronii 2E biosorption mechanism mediated by the cell surface associated to bound exopolymeric substances. A Carbon Paste Electrode modified with P. veronii 2E (CPEM) was built using mineral oil, pre-washed graphite power and 24 h-dried cells. For Cd(II) quantification the CPEM was immersed in Cd(II) (1-25 μM), detected by Square Wave Voltammetry. A similar procedure was used for 1-50 μM Cu(II). Regarding Cd(II), removal mediated by immobilized EPS was tested in a 50 ml bioreactor with 0.13 mM Cd(II), pH 7.5. A 54% metal retention by EPS was achieved after 7 h of continuous operation, while a 40% was removed by a control resin. In addition, surfactants produced by P. veronii 2E were studied for recovery of Cd(II) adsorbed on diatomite, obtaining a 36% desorption efficiency at pH 6.5. Cu(II) adsorption from a 1 mM solution was tested using P. veronii 2E purified soluble EPS in 50 mL- batch reactors (pH = 5.5, 32°C). An 80% of the initial Cu(II) was retained using 1.04 g immobilized EPS. Focusing on metal recovery, Cu nanoparticles (NPs) biosynthesis by P. veronii 2E was carried out in Cu(II)-PYG Broth at 25°C for 5 days. Extracellular CuNPs were characterized by UV-Vis spectral analysis while both extracellular and intracellular NPs were analyzed by SEM and TEM techniques. Responses of P. veronii 2E and its products as biosurfactants, bound and soluble EPS allowed Cu(II) and Cd(II) removal, recovery and biosensing resulting in a multiple and versatile tool for sustainable wastewater biotreatments.
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Affiliation(s)
- María Pia Busnelli
- Área Química, Instituto de Ciencias, Universidad Nacional de General Sarmiento, Los Polvorines, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | | | - Maria Laura Ferreira
- Área Química, Instituto de Ciencias, Universidad Nacional de General Sarmiento, Los Polvorines, Argentina
| | - Roberto J. Candal
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Instituto de Investigación e Ingeniería Ambiental (IIIA), Universidad Nacional de General San Martin, San Martín, Argentina
| | - Silvana A. Ramirez
- Área Química, Instituto de Ciencias, Universidad Nacional de General Sarmiento, Los Polvorines, Argentina
| | - Diana L. Vullo
- Área Química, Instituto de Ciencias, Universidad Nacional de General Sarmiento, Los Polvorines, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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18
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Feng C, Lotti T, Canziani R, Lin Y, Tagliabue C, Malpei F. Extracellular biopolymers recovered as raw biomaterials from waste granular sludge and potential applications: A critical review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 753:142051. [PMID: 33207449 DOI: 10.1016/j.scitotenv.2020.142051] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 06/11/2023]
Abstract
Granular sludge (GS) is a special self-aggregation biofilm. Extracellular polymeric substances (EPS) are mainly associated with the architectural structure, rheological behaviour and functional stability of fine granules, given that their significance to the physicochemical features of the biomass catalysing the biological purification process. This review targets the EPS excretion from GS and introduces newly identified EPS components, EPS distribution in different granules, how to effectively extract and recover EPS from granules, key parameters affecting EPS production, and the potential applications of EPS-based biomaterials. GS-based EPS components are highly diverse and a series of new contents are highlighted. Due to high diversity, emerging extraction standards are proposed and recovery process is capturing particular attention. The major components of EPS are found to be polysaccharides and proteins, which manifest a larger diversity of relative abundance, structures, physical and chemical characteristics, leading to the possibility to sustainably recover raw materials. EPS-based biomaterials not only act as alternatives to synthetic polymers in several applications but also figure in innovative industrial/environmental applications, including gel-forming materials for paper industry, biosorbents, cement curing materials, and flame retardant materials. In the upcoming years, it is foreseen that productions of EPS-based biomaterials from renewable origins would make a significant contribution to the advancement of the circular economy.
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Affiliation(s)
- Cuijie Feng
- Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy.
| | - Tommaso Lotti
- Department of Civil and Environmental Engineering, University of Florence, Via di Santa Marta 3, 50139 Florence, Italy
| | - Roberto Canziani
- Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Yuemei Lin
- Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, the Netherlands
| | - Camilla Tagliabue
- Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Francesca Malpei
- Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
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