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Koutrotsios G, Larou E, Mountzouris KC, Zervakis GI. Detoxification of Olive Mill Wastewater and Bioconversion of Olive Crop Residues into High-Value-Added Biomass by the Choice Edible Mushroom Hericium erinaceus. Appl Biochem Biotechnol 2016; 180:195-209. [PMID: 27138726 DOI: 10.1007/s12010-016-2093-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 04/20/2016] [Indexed: 10/21/2022]
Abstract
Environmentally acceptable disposal of olive cultivation residues (e.g., olive prunings; olive pruning residues (OLPR)) and olive mill wastes is of paramount importance since they are generated in huge quantities within a short time. Moreover, olive mill wastewater (OMW) or sludge-like effluents ("alperujo"; two-phase olive mill waste (TPOMW)) are highly biotoxic. Hericium erinaceus is a white-rot fungus which produces choice edible mushrooms on substrates rich in lignocellulosics, and its suitability for the treatment of olive by-products was examined for the first time. Fungal growth resulted in a notable reduction of OMW's pollution parameters (i.e., 65 % decolorization, 47 % total phenolic reduction, and 52 % phytotoxicity decrease) and correlated with laccase and manganese peroxidase activities. Solid-state fermentation of various mixtures of OLPR, TPOMW, and beech sawdust (control) by H. erinaceus qualified OLPR in subsequent cultivation experiments, where it exhibited high mushroom yields and biological efficiency (31 %). Analyses of proximate composition and bioactive compound content revealed that mushrooms deriving from OLPR substrates showed significantly higher crude fat, total glucan, β-glucan, total phenolics, and ferric-reducing antioxidant potential values than the control. H. erinaceus demonstrated the potential to detoxify OMW and bioconvert OLPR into high-quality biomass, and hence, this fungus could be successfully exploited for the treatment of such by-products.
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Affiliation(s)
- Georgios Koutrotsios
- Laboratory of General and Agricultural Microbiology, Agricultural University of Athens, Iera Odos 75, 11855, Athens, Greece
| | - Evangelia Larou
- Laboratory of General and Agricultural Microbiology, Agricultural University of Athens, Iera Odos 75, 11855, Athens, Greece
| | - Konstantinos C Mountzouris
- Department of Nutritional Physiology and Feeding, Agricultural University of Athens, Iera Odos 75, 11855, Athens, Greece
| | - Georgios I Zervakis
- Laboratory of General and Agricultural Microbiology, Agricultural University of Athens, Iera Odos 75, 11855, Athens, Greece.
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Ntougias S, Baldrian P, Ehaliotis C, Nerud F, Merhautová V, Zervakis GI. Olive mill wastewater biodegradation potential of white-rot fungi--Mode of action of fungal culture extracts and effects of ligninolytic enzymes. BIORESOURCE TECHNOLOGY 2015; 189:121-130. [PMID: 25879179 DOI: 10.1016/j.biortech.2015.03.149] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 03/30/2015] [Accepted: 03/31/2015] [Indexed: 06/04/2023]
Abstract
Forty-nine white-rot strains belonging to 38 species of Basidiomycota were evaluated for olive-mill wastewater (OMW) degradation. Almost all fungi caused high total phenolics (>60%) and color (⩽ 70%) reduction, while COD and phytotoxicity decreased to a lesser extent. Culture extracts from selected Agrocybe cylindracea, Inonotus andersonii, Pleurotus ostreatus and Trametes versicolor strains showed non-altered physicochemical and enzymatic activity profiles when applied to raw OMW in the presence or absence of commercial catalase, indicating no interaction of the latter with fungal enzymes and no competition for H2O2. Hydrogen peroxide's addition resulted in drastic OMW's decolorization, with no effect on phenolic content, suggesting that oxidation affects colored components, but not necessarily phenolics. When fungal extracts were heat-treated, no phenolics decrease was observed demonstrating thus their enzymatic rather than physicochemical oxidation. Laccases added to OMW were reversibly inhibited by the effluent's high phenolic load, while peroxidases were stable and active during the entire process.
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Affiliation(s)
- Spyridon Ntougias
- Democritus University of Thrace, Department of Environmental Engineering, Laboratory of Wastewater Management and Treatment Technologies, Vas. Sofias 12, 67100 Xanthi, Greece
| | - Petr Baldrian
- Institute of Microbiology of the ASCR, Videnska 1083, 14220 Prague, Czech Republic
| | - Constantinos Ehaliotis
- Agricultural University of Athens, Laboratory of Soils and Agricultural Chemistry, Iera Odos 75, 11855 Athens, Greece
| | - Frantisek Nerud
- Institute of Microbiology of the ASCR, Videnska 1083, 14220 Prague, Czech Republic
| | - Věra Merhautová
- Institute of Microbiology of the ASCR, Videnska 1083, 14220 Prague, Czech Republic
| | - Georgios I Zervakis
- Agricultural University of Athens, Laboratory of General and Agricultural Microbiology, Iera Odos 75, 11855 Athens, Greece.
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Bokare AD, Choi W. Review of iron-free Fenton-like systems for activating H2O2 in advanced oxidation processes. JOURNAL OF HAZARDOUS MATERIALS 2014; 275:121-35. [PMID: 24857896 DOI: 10.1016/j.jhazmat.2014.04.054] [Citation(s) in RCA: 979] [Impact Index Per Article: 97.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 04/18/2014] [Accepted: 04/23/2014] [Indexed: 05/21/2023]
Abstract
Iron-catalyzed hydrogen peroxide decomposition for in situ generation of hydroxyl radicals (HO(•)) has been extensively developed as advanced oxidation processes (AOPs) for environmental applications. A variety of catalytic iron species constituting metal salts (in Fe(2+) or Fe(3+) form), metal oxides (e.g., Fe2O3, Fe3O4), and zero-valent metal (Fe(0)) have been exploited for chemical (classical Fenton), photochemical (photo-Fenton) and electrochemical (electro-Fenton) degradation pathways. However, the requirement of strict acidic conditions to prevent iron precipitation still remains the bottleneck for iron-based AOPs. In this article, we present a thorough review of alternative non-iron Fenton catalysts and their reactivity towards hydrogen peroxide activation. Elements with multiple redox states (like chromium, cerium, copper, cobalt, manganese and ruthenium) all directly decompose H2O2 into HO(•) through conventional Fenton-like pathways. The in situ formation of H2O2 and decomposition into HO(•) can be also achieved using electron transfer mechanism in zero-valent aluminum/O2 system. Although these Fenton systems (except aluminum) work efficiently even at neutral pH, the H2O2 activation mechanism is very specific to the nature of the catalyst and critically depends on its composition. This review describes in detail the complex mechanisms and emphasizes on practical limitations influencing their environmental applications.
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Affiliation(s)
- Alok D Bokare
- School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea
| | - Wonyong Choi
- School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea.
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Comparative examination of the olive mill wastewater biodegradation process by various wood-rot macrofungi. BIOMED RESEARCH INTERNATIONAL 2014; 2014:482937. [PMID: 24987685 PMCID: PMC4060750 DOI: 10.1155/2014/482937] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 04/30/2014] [Accepted: 05/01/2014] [Indexed: 11/23/2022]
Abstract
Olive mill wastewater (OMW) constitutes a major cause of environmental pollution in olive-oil producing regions. Sixty wood-rot macrofungi assigned in 43 species were evaluated for their efficacy to colonize solidified OMW media at initially established optimal growth temperatures. Subsequently eight strains of the following species were qualified: Abortiporus biennis, Ganoderma carnosum, Hapalopilus croceus, Hericium erinaceus, Irpex lacteus, Phanerochaete chrysosporium, Pleurotus djamor, and P. pulmonarius. Fungal growth in OMW (25%v/v in water) resulted in marked reduction of total phenolic content, which was significantly correlated with the effluent's decolorization. A. biennis was the best performing strain (it decreased phenolics by 92% and color by 64%) followed by P. djamor and I. lacteus. Increase of plant seeds germination was less pronounced evidencing that phenolics are only partly responsible for OMW's phytotoxicity. Laccase production was highly correlated with all three biodegradation parameters for H. croceus, Ph. chrysosporium, and Pleurotus spp., and so were manganese-independent and manganese dependent peroxidases for A. biennis and I. lacteus. Monitoring of enzymes with respect to biomass production indicated that Pleurotus spp., H. croceus, and Ph. chrysosporium shared common patterns for all three activities. Moreover, generation of enzymes at the early biodegradation stages enhanced the efficiency of OMW treatment.
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Daâssi D, Belbahri L, Vallat A, Woodward S, Nasri M, Mechichi T. Enhanced reduction of phenol content and toxicity in olive mill wastewaters by a newly isolated strain of Coriolopsis gallica. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:1746-1758. [PMID: 23979847 DOI: 10.1007/s11356-013-2019-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 07/16/2013] [Indexed: 06/02/2023]
Abstract
The search for novel microorganisms able to degrade olive mill wastewaters (OMW) and withstand the toxic effects of the initially high phenolic concentrations is of great scientific and industrial interest. In this work, the possibility of reducing the phenolic content of OMW using new isolates of fungal strains (Coriolopsis gallica, Bjerkandera adusta, Trametes versicolor, Trichoderma citrinoviride, Phanerochaete chrysosporium, Gloeophyllum trabeum, Trametes trogii, and Fusarium solani) was investigated. In vitro, all fungal isolates tested caused an outstanding decolorization of OMW. However, C. gallica gave the highest decolorization and dephenolization rates at 30 % v/v OMW dilution in water. Fungal growth in OMW medium was affected by several parameters including phenolic compound concentration, nitrogen source, and inoculum size. The optimal OMW medium for the removal of phenolics and color was with the OMW concentration (in percent)/[(NH4)2SO4]/inoculum ratio of 30:6:3. Under these conditions, 90 and 85 % of the initial phenolic compounds and color were removed, respectively. High-pressure liquid chromatography analysis of extracts from treated and untreated OMW showed a clear and substantial reduction in phenolic compound concentrations. Phytotoxicity, assessed using radish (Raphanus sativus) seeds, indicated an increase in germination index of 23-92 % when a 30 % OMW concentration was treated with C. gallica in different dilutions (1/2, 1/4, and 1/8).
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Affiliation(s)
- Dalel Daâssi
- Laboratory of Enzyme Engineering and Microbiology, Ecole Nationale d'Ingénieurs de Sfax, University of Sfax, Route de Soukra km 4.5, BP 1173, 3038, Sfax, Tunisia
| | - Lassaad Belbahri
- Laboratory of Soil Biology, University of Neuchatel, Rue Emile Argand 11, 2009, Neuchatel, Switzerland
| | - Armelle Vallat
- Institute of Chemistry, University of Neuchatel, Avenue de Bellevaux 51, 2000, Neuchatel, Switzerland
| | - Steve Woodward
- Department of Plant and Soil Science, Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen, AB24 3UU, Scotland, UK
| | - Moncef Nasri
- Laboratory of Enzyme Engineering and Microbiology, Ecole Nationale d'Ingénieurs de Sfax, University of Sfax, Route de Soukra km 4.5, BP 1173, 3038, Sfax, Tunisia
| | - Tahar Mechichi
- Laboratory of Enzyme Engineering and Microbiology, Ecole Nationale d'Ingénieurs de Sfax, University of Sfax, Route de Soukra km 4.5, BP 1173, 3038, Sfax, Tunisia.
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Ntougias S, Bourtzis K, Tsiamis G. The microbiology of olive mill wastes. BIOMED RESEARCH INTERNATIONAL 2013; 2013:784591. [PMID: 24199199 PMCID: PMC3809369 DOI: 10.1155/2013/784591] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 07/18/2013] [Accepted: 07/22/2013] [Indexed: 01/18/2023]
Abstract
Olive mill wastes (OMWs) are high-strength organic effluents, which upon disposal can degrade soil and water quality, negatively affecting aquatic and terrestrial ecosystems. The main purpose of this review paper is to provide an up-to-date knowledge concerning the microbial communities identified over the past 20 years in olive mill wastes using both culture-dependent and independent approaches. A database survey of 16S rRNA gene sequences (585 records in total) obtained from olive mill waste environments revealed the dominance of members of Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, and Actinobacteria. Independent studies confirmed that OMW microbial communities' structure is cultivar dependent. On the other hand, the detection of fecal bacteria and other potential human pathogens in OMWs is of major concern and deserves further examination. Despite the fact that the degradation and detoxification of the olive mill wastes have been mostly investigated through the application of known bacterial and fungal species originated from other environmental sources, the biotechnological potential of indigenous microbiota should be further exploited in respect to olive mill waste bioremediation and inactivation of plant and human pathogens. The implementation of omic and metagenomic approaches will further elucidate disposal issues of olive mill wastes.
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Affiliation(s)
- Spyridon Ntougias
- Department of Environmental Engineering, Democritus University of Thrace, Vas. Sofias 12, 67100 Xanthi, Greece
| | - Kostas Bourtzis
- Department of Environmental and Natural Resources Management, University of Patras, 2 Seferi Street, 30100 Agrinio, Greece
| | - George Tsiamis
- Department of Environmental and Natural Resources Management, University of Patras, 2 Seferi Street, 30100 Agrinio, Greece
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