Roberto Altieri | Università degli Studi di Perugia (original) (raw)

Papers by Roberto Altieri

Research paper thumbnail of Thermoplastic Blends Based on Poly(Butylene Succinate-co-Adipate) and Different Collagen Hydrolysates from Tanning Industry: I—Processing and Thermo-mechanical Properties

Journal of Polymers and the Environment

In this study, blends of a biodegradable thermoplastic polyester, poly (butylene succinate-co-adi... more In this study, blends of a biodegradable thermoplastic polyester, poly (butylene succinate-co-adipate) (PBSA) with two different raw hydrolyzed collagens (HCs), derived from the tannery industry, were investigated in terms of processability, rheological, thermal and mechanical properties. HCs, obtained by alkaline (HCa) and enzymatic (HCe) hydrolysis of the solid wastes generated during the shaving of the tanned leather, were used in PBSA/HC blends, up to 20 wt% of HC, produced by melting extrusion and processed by injection molding. All the blends up to 20 wt% HCs resulted suitable for the injection molding obtaining flexible molded specimens with good tensile properties. The different secondary structure of the two HCs influenced the rheology, morphology and mechanical properties of the produced blends. In particular, HCa, due its higher content of oligopeptides and free amino-acids, showed a good compatibility with the polymeric matrix acting as a plasticizer with consequent redu...

Research paper thumbnail of Polycaprolactone-collagen hydrolysate thermoplastic blends: Processability and biodegradability/compostability

Polymer Degradation and Stability

Research paper thumbnail of Recent Studies on Preparation of Humified Compost Using Olive Mill Waste for Horticultural Purposes

Acta Horticulturae

ABSTRACT This paper is a brief review of recent studies on the feasibility of using olive mill so... more ABSTRACT This paper is a brief review of recent studies on the feasibility of using olive mill solid waste (OMW) as a major ingredient in the preparation of humified compost (HC), and the application of the HC to soil on the growth of horticultural crops such as Olea europaea (olive), Lycopersicon esculentum (tomato), Lactuca sativa (lettuce), Fragaria vesca (strawberry) and Agaricus bisporus (white button mushroom). OMW-based compost subjected to thermal composting process resulted in significant decrease in the level of polyphenols making it non-phytotoxic. Addition of the compost to olive orchard soil significantly increased total organic carbon and humic substances by 40 and 58% respectively. Similar results on elevated nutritional status and enhanced crop productivity were obtained in trials with other horticultural crops and the cultivated mushrooms. The outcomes of these studies have been the integration of soil health and environmental management practices to achieve sustainable crop production.

Research paper thumbnail of Measuring the Biodegradability of Plastic Polymers in Olive-Mill Waste Compost with an Experimental Apparatus

Advances in Materials Science and Engineering

The use of biodegradable polymers is spreading in agriculture to replace those materials derived ... more The use of biodegradable polymers is spreading in agriculture to replace those materials derived from petroleum, thus reducing the environmental concerns. However, to issue a significant assessment, biodegradation rate must be measured in case-specific standardized conditions. In accordance with ISO 14855-1, we designed and used an experimental apparatus to evaluate the biodegradation rate of three biopolymers based on renewable resources, two poly(ε-caprolactone) (PCL) composites, and a compatibilized polylactic acid and polybutyrate (PLA/PBAT) blend. Biodegradation tests were carried out under composting condition using mature olive-mill waste (OMW) compost as inoculum. Carbon dioxide emissions were automatically recorded by infrared gas detectors and also trapped in saturated Ba(OH)2 solution and evaluated via a standard titration method to check the results. Some of the samples reached more than 80% biodegradation in less than 20 days. Both the experimental apparatus and the OMW...

Research paper thumbnail of Characterization and Use of Olive Mill Waste Compost as Peat Surrogate in Substrate for Cultivation of Photinia Potted Plants: Assessment of Growth Performance and In Vitro Suppressiveness

Waste and Biomass Valorization

Research paper thumbnail of Use of olive mill waste mix as peat surrogate in substrate for strawberry soilless cultivation

International Biodeterioration Biodegradation, Oct 1, 2010

The aim of paper was to evaluate the suitability of olive mill waste mixture (OMWM) as growth med... more The aim of paper was to evaluate the suitability of olive mill waste mixture (OMWM) as growth media for strawberry soilless cultivation. OMWM was used at the rate of 0, 25, 50, 75% (v/v) as peat substitute. In order to assess nutrient supply to plants by OMWM, the experimental design included fertigated (standard) and unfertigated sets. Some of the chemical

Research paper thumbnail of Nuovi ammendanti di qualità per prodotti particolari

Research paper thumbnail of 1 FAO bull 05 paper

Research paper thumbnail of Evolution of Chemical, Physical and Biological Parameters in Olive Mill Waste Mixtures During Aerobic Storage Trials

ISAFoM-CNR developed a new procedure able to convert raw olive-mill effluents in a non-percolatin... more ISAFoM-CNR developed a new procedure able to convert raw olive-mill effluents in a non-percolating and non-smelling Olive Mill Waste Mixtures (OMWMs) promptly packaged in net bags. With the aim of monitoring the main chemical, physical and biological parameters during storage, two aerobic systems, arranged outdoor, were compared: "Stack pile" made up of a stratification of 20 kg net sacks, and "Big bag", where the mixture was filled into a gas permeable 1 m 3 bag. After three months, "Stack pile" did not change considerably parameters monitored. On the other hand, "Big bag" recorded a higher mineralization of carbon and nitrogen, strong reduction of the water soluble organic carbon associated to a sensible decrease of C/N, higher biological stability and humification. Both systems were able to produce valuable amendments for different agronomic purposes.

Research paper thumbnail of Co-utilization of by-products for creation of synthetic soil

Research paper thumbnail of Complexation capacity of dissolved organic matter from pig slurry: A gel filtration and dialysis study

Water Air and Soil Pollution, 1999

The purpose of this research was to evaluate the apparent molecular weight distribution of dissol... more The purpose of this research was to evaluate the apparent molecular weight distribution of dissolved organic matter (DOM) from pig slurry and the binding ability of its fractions toward copper (Cu 2+) ions. In addition, the binding ability (maximum complexing capacity-MCC) of the DOM was compared with that of humic (HA) and fulvic (FA) acids from a clay-loam soil. The study was performed using Cu 2+ ions since this metal is widely used as a supplement in pig diets and, consequently, is present in pig slurry. The techniques adopted were gel filtration chromatography (GFC) and dialysis. GFC showed that the DOM from pig slurry is mainly composed of a fraction with an apparent molecular weight higher than 5000 Da and the copper naturally present in the slurry is completely complexed by this fraction. The dialysis procedure enabled MCC to be determined. The MCC of pig slurry DOM and soil HA, which contained a similar concentration of carboxylic groups, were analogous, while MCC of soil FA, which contained double the concentration of carboxylic groups, was higher.

Research paper thumbnail of Control of Verticillium dahliae by adding olive mill waste to the rhizosphere of nursery grown plants

Proceedings of the 4th …, 2008

Plant-growth substrates containing stabilized residues from different biomass are being studied a... more Plant-growth substrates containing stabilized residues from different biomass are being studied as alternative plantgrowth substrates not only for their agronomic properties, but also for their suppressiveness against phytopathogens. In this study two ...

Research paper thumbnail of Evaluation of the fertilizing effect of olive mill waste compost in short-term crops

International Biodeterioration & Biodegradation, 2010

Recycling to soil Olive Mill Waste (OMW) has the potential to improve soil fertility, thus reduci... more Recycling to soil Olive Mill Waste (OMW) has the potential to improve soil fertility, thus reducing CO2 emission associated to global warming. However, the short period in which OMW are produced and the high load of recalcitrant compounds, make difficult direct land spreading of raw OMW. Consequently, sustainable biological treatments able to transform OMW into a safe amendment have been

Research paper thumbnail of Performance of olive mill solid waste as a constituent of the substrate in commercial cultivation of Agaricus bisporus

International Biodeterioration & Biodegradation, 2009

... Total counts of heterotrophic microorganisms and actinomycetes were made using Triptic Soy Ag... more ... Total counts of heterotrophic microorganisms and actinomycetes were made using Triptic Soy Agar (TSA) (Difco) and Actinomycete Isolation ... Waste wool, –, –, 2.4, 3.0. ... In general, low differences were observed in the composition of fruit bodies grown on ES and control substrates ...

Research paper thumbnail of Validation of thermal composting process using olive mill solid waste for industrial scale cultivation of Agaricus bisporus

International Biodeterioration & Biodegradation, 2011

The production of a substrate containing destoned olive mill solid waste for the cultivation of A... more The production of a substrate containing destoned olive mill solid waste for the cultivation of Agaricus bisporus (Lange) Imbach on an industrial scale was studied. A standard mushroom compost (C) mainly made from straw and poultry manure was compared with the experimental compost (EC) containing the same ingredients as (C) but with added olive mill solid waste (10.6% w/w). Microbial indicators such as counts of heterotrophic microbes and actinomycetes were higher in EC than in C. In addition, compost selectivity as indicated by higher mushroom yield and biological efficiency of EC was higher than that of C. Market quality of the mushrooms produced in both C and EC were comparable. These findings support our work that olive mill solid waste can be used safely in thermal composting process to produce a selective substrate for industrial-scale cultivation of A. bisporus. This study also demonstrates an environmentally sustainable system to manage solid waste from olive oil extraction processes thus overcoming environmental pollution brought about by irrational disposal of the waste on farm lands.

Research paper thumbnail of Tannic acid degradation by bacterial strains Serratia spp. and Pantoea sp. isolated from olive mill waste mixtures

International Biodeterioration & Biodegradation, 2010

... Biological treatment, such as composting, has been showed effective in dropping phenolics in ... more ... Biological treatment, such as composting, has been showed effective in dropping phenolics in the olive mill effluents (Baeta-Hall et al., 2005), therefore allowing safe agronomic uses (Altieri and Esposito, 2008). Recently, Altieri et al. ...

Research paper thumbnail of Klebsiella sp. strain C2A isolated from olive oil mill waste is able to tolerate and degrade tannic acid in very high concentrations

FEMS Microbiology Letters, 2013

Four bacterial strains capable of growing in the presence of tannic acid as sole carbon and energ... more Four bacterial strains capable of growing in the presence of tannic acid as sole carbon and energy source were isolated from olive mill waste mixtures. 16S rRNA gene sequencing assigned them to the genus Klebsiella. The most efficient strain, Klebsiella sp. strain C2A, was able to degrade 3.5 g L À1 tannic acid within 35 h with synthesizing gallic acid as main product. The capability of Klebsiella sp. strain C2A to produce tannase was evidenced at high concentrations of tannic acid up to 50 g L À1. The bacteria adapted to the toxicity of tannic acids by an increase in the membrane lipid fatty acids degree of saturation, especially in the presence of concentrations higher than 20 g L À1. The highly tolerant and adaptable bacterial strain characterized in this study could be used in bioremediation processes of wastes rich in polyphenols such as those derived from olive mills, winery or tanneries.

Research paper thumbnail of Serratia spp. and Pantoea sp. tannins-degrading bacterial strains isolated from enrichment cultures arranged with olive mill wastes by-products

tirsavplus.eu

  1. Dipartimento di Scienze Ambientali, Università di Siena, Via PA Mattioli, 4; 53100, Siena; 2) ... more 1) Dipartimento di Scienze Ambientali, Università di Siena, Via PA Mattioli, 4; 53100, Siena; 2) Istituto per i Sistemi Agricoli e Forestali del Mediterraneo, Consiglio Nazionale delle Ricerche (ISAFoM-CNR), Via della Madonna Alta, 128; 06128, Perugia; 3) Ente Parco ...

Research paper thumbnail of Two-phase olive mill waste composting: Community dynamics and functional role of the resident microbiota

Bioresource Technology, 2011

In this study, physico-chemical modifications and community dynamics and functional role of the r... more In this study, physico-chemical modifications and community dynamics and functional role of the resident microbiota during composting of humid husk from a two-phase extraction system (TPOMW) were investigated. High mineralization and humification of carbon, low loss of nitrogen and complete degradation of polyphenols led to the waste biotransformation into a high-quality compost. Viable cell counts and denaturing gradient gel electrophoresis (DGGE) profiling of the 16S rRNA genes showed that the thermophilic phase was characterized by the strongest variations of cell number, the highest biodiversity and the most variable community profiles. The isolation of tannin-degrading bacteria (e.g. Lysinibacillus fusiformis, Kocuria palustris, Tetrathiobacter kashmirensis and Rhodococcus rhodochrous) suggested a role of this enzymatic activity during the process. Taken together, the results indicated that the composting process, particularly the thermophilic phase, was characterized by a rapid succession of specialized bacterial populations with key roles in the organic matter biotransformation.

Research paper thumbnail of Olive orchard amended with two experimental olive mill wastes mixtures: Effects on soil organic carbon, plant growth and yield

Bioresource Technology, 2008

Amendments of olive orchard soil with two different preparations of olive mill solid waste (OMWMs... more Amendments of olive orchard soil with two different preparations of olive mill solid waste (OMWMs) at the rate of 9 ton ha À1 per year for five years in two different plots were compared with an industry standard soil amendment using urea. Both the OMWMs amendments showed significant increases in total organic carbon and humic substances in soil of approximately 40% and 58%, respectively, without negative effects on tree growth and yield. This work has shown that olive oil mill waste (OMW) can be recycled safely using the bioremediation system used in this study. We suggest that this system is particularly beneficial to organic farming and is an alternative solution to direct spreading of raw OMW on farm lands.

Research paper thumbnail of Thermoplastic Blends Based on Poly(Butylene Succinate-co-Adipate) and Different Collagen Hydrolysates from Tanning Industry: I—Processing and Thermo-mechanical Properties

Journal of Polymers and the Environment

In this study, blends of a biodegradable thermoplastic polyester, poly (butylene succinate-co-adi... more In this study, blends of a biodegradable thermoplastic polyester, poly (butylene succinate-co-adipate) (PBSA) with two different raw hydrolyzed collagens (HCs), derived from the tannery industry, were investigated in terms of processability, rheological, thermal and mechanical properties. HCs, obtained by alkaline (HCa) and enzymatic (HCe) hydrolysis of the solid wastes generated during the shaving of the tanned leather, were used in PBSA/HC blends, up to 20 wt% of HC, produced by melting extrusion and processed by injection molding. All the blends up to 20 wt% HCs resulted suitable for the injection molding obtaining flexible molded specimens with good tensile properties. The different secondary structure of the two HCs influenced the rheology, morphology and mechanical properties of the produced blends. In particular, HCa, due its higher content of oligopeptides and free amino-acids, showed a good compatibility with the polymeric matrix acting as a plasticizer with consequent redu...

Research paper thumbnail of Polycaprolactone-collagen hydrolysate thermoplastic blends: Processability and biodegradability/compostability

Polymer Degradation and Stability

Research paper thumbnail of Recent Studies on Preparation of Humified Compost Using Olive Mill Waste for Horticultural Purposes

Acta Horticulturae

ABSTRACT This paper is a brief review of recent studies on the feasibility of using olive mill so... more ABSTRACT This paper is a brief review of recent studies on the feasibility of using olive mill solid waste (OMW) as a major ingredient in the preparation of humified compost (HC), and the application of the HC to soil on the growth of horticultural crops such as Olea europaea (olive), Lycopersicon esculentum (tomato), Lactuca sativa (lettuce), Fragaria vesca (strawberry) and Agaricus bisporus (white button mushroom). OMW-based compost subjected to thermal composting process resulted in significant decrease in the level of polyphenols making it non-phytotoxic. Addition of the compost to olive orchard soil significantly increased total organic carbon and humic substances by 40 and 58% respectively. Similar results on elevated nutritional status and enhanced crop productivity were obtained in trials with other horticultural crops and the cultivated mushrooms. The outcomes of these studies have been the integration of soil health and environmental management practices to achieve sustainable crop production.

Research paper thumbnail of Measuring the Biodegradability of Plastic Polymers in Olive-Mill Waste Compost with an Experimental Apparatus

Advances in Materials Science and Engineering

The use of biodegradable polymers is spreading in agriculture to replace those materials derived ... more The use of biodegradable polymers is spreading in agriculture to replace those materials derived from petroleum, thus reducing the environmental concerns. However, to issue a significant assessment, biodegradation rate must be measured in case-specific standardized conditions. In accordance with ISO 14855-1, we designed and used an experimental apparatus to evaluate the biodegradation rate of three biopolymers based on renewable resources, two poly(ε-caprolactone) (PCL) composites, and a compatibilized polylactic acid and polybutyrate (PLA/PBAT) blend. Biodegradation tests were carried out under composting condition using mature olive-mill waste (OMW) compost as inoculum. Carbon dioxide emissions were automatically recorded by infrared gas detectors and also trapped in saturated Ba(OH)2 solution and evaluated via a standard titration method to check the results. Some of the samples reached more than 80% biodegradation in less than 20 days. Both the experimental apparatus and the OMW...

Research paper thumbnail of Characterization and Use of Olive Mill Waste Compost as Peat Surrogate in Substrate for Cultivation of Photinia Potted Plants: Assessment of Growth Performance and In Vitro Suppressiveness

Waste and Biomass Valorization

Research paper thumbnail of Use of olive mill waste mix as peat surrogate in substrate for strawberry soilless cultivation

International Biodeterioration Biodegradation, Oct 1, 2010

The aim of paper was to evaluate the suitability of olive mill waste mixture (OMWM) as growth med... more The aim of paper was to evaluate the suitability of olive mill waste mixture (OMWM) as growth media for strawberry soilless cultivation. OMWM was used at the rate of 0, 25, 50, 75% (v/v) as peat substitute. In order to assess nutrient supply to plants by OMWM, the experimental design included fertigated (standard) and unfertigated sets. Some of the chemical

Research paper thumbnail of Nuovi ammendanti di qualità per prodotti particolari

Research paper thumbnail of 1 FAO bull 05 paper

Research paper thumbnail of Evolution of Chemical, Physical and Biological Parameters in Olive Mill Waste Mixtures During Aerobic Storage Trials

ISAFoM-CNR developed a new procedure able to convert raw olive-mill effluents in a non-percolatin... more ISAFoM-CNR developed a new procedure able to convert raw olive-mill effluents in a non-percolating and non-smelling Olive Mill Waste Mixtures (OMWMs) promptly packaged in net bags. With the aim of monitoring the main chemical, physical and biological parameters during storage, two aerobic systems, arranged outdoor, were compared: "Stack pile" made up of a stratification of 20 kg net sacks, and "Big bag", where the mixture was filled into a gas permeable 1 m 3 bag. After three months, "Stack pile" did not change considerably parameters monitored. On the other hand, "Big bag" recorded a higher mineralization of carbon and nitrogen, strong reduction of the water soluble organic carbon associated to a sensible decrease of C/N, higher biological stability and humification. Both systems were able to produce valuable amendments for different agronomic purposes.

Research paper thumbnail of Co-utilization of by-products for creation of synthetic soil

Research paper thumbnail of Complexation capacity of dissolved organic matter from pig slurry: A gel filtration and dialysis study

Water Air and Soil Pollution, 1999

The purpose of this research was to evaluate the apparent molecular weight distribution of dissol... more The purpose of this research was to evaluate the apparent molecular weight distribution of dissolved organic matter (DOM) from pig slurry and the binding ability of its fractions toward copper (Cu 2+) ions. In addition, the binding ability (maximum complexing capacity-MCC) of the DOM was compared with that of humic (HA) and fulvic (FA) acids from a clay-loam soil. The study was performed using Cu 2+ ions since this metal is widely used as a supplement in pig diets and, consequently, is present in pig slurry. The techniques adopted were gel filtration chromatography (GFC) and dialysis. GFC showed that the DOM from pig slurry is mainly composed of a fraction with an apparent molecular weight higher than 5000 Da and the copper naturally present in the slurry is completely complexed by this fraction. The dialysis procedure enabled MCC to be determined. The MCC of pig slurry DOM and soil HA, which contained a similar concentration of carboxylic groups, were analogous, while MCC of soil FA, which contained double the concentration of carboxylic groups, was higher.

Research paper thumbnail of Control of Verticillium dahliae by adding olive mill waste to the rhizosphere of nursery grown plants

Proceedings of the 4th …, 2008

Plant-growth substrates containing stabilized residues from different biomass are being studied a... more Plant-growth substrates containing stabilized residues from different biomass are being studied as alternative plantgrowth substrates not only for their agronomic properties, but also for their suppressiveness against phytopathogens. In this study two ...

Research paper thumbnail of Evaluation of the fertilizing effect of olive mill waste compost in short-term crops

International Biodeterioration & Biodegradation, 2010

Recycling to soil Olive Mill Waste (OMW) has the potential to improve soil fertility, thus reduci... more Recycling to soil Olive Mill Waste (OMW) has the potential to improve soil fertility, thus reducing CO2 emission associated to global warming. However, the short period in which OMW are produced and the high load of recalcitrant compounds, make difficult direct land spreading of raw OMW. Consequently, sustainable biological treatments able to transform OMW into a safe amendment have been

Research paper thumbnail of Performance of olive mill solid waste as a constituent of the substrate in commercial cultivation of Agaricus bisporus

International Biodeterioration & Biodegradation, 2009

... Total counts of heterotrophic microorganisms and actinomycetes were made using Triptic Soy Ag... more ... Total counts of heterotrophic microorganisms and actinomycetes were made using Triptic Soy Agar (TSA) (Difco) and Actinomycete Isolation ... Waste wool, –, –, 2.4, 3.0. ... In general, low differences were observed in the composition of fruit bodies grown on ES and control substrates ...

Research paper thumbnail of Validation of thermal composting process using olive mill solid waste for industrial scale cultivation of Agaricus bisporus

International Biodeterioration & Biodegradation, 2011

The production of a substrate containing destoned olive mill solid waste for the cultivation of A... more The production of a substrate containing destoned olive mill solid waste for the cultivation of Agaricus bisporus (Lange) Imbach on an industrial scale was studied. A standard mushroom compost (C) mainly made from straw and poultry manure was compared with the experimental compost (EC) containing the same ingredients as (C) but with added olive mill solid waste (10.6% w/w). Microbial indicators such as counts of heterotrophic microbes and actinomycetes were higher in EC than in C. In addition, compost selectivity as indicated by higher mushroom yield and biological efficiency of EC was higher than that of C. Market quality of the mushrooms produced in both C and EC were comparable. These findings support our work that olive mill solid waste can be used safely in thermal composting process to produce a selective substrate for industrial-scale cultivation of A. bisporus. This study also demonstrates an environmentally sustainable system to manage solid waste from olive oil extraction processes thus overcoming environmental pollution brought about by irrational disposal of the waste on farm lands.

Research paper thumbnail of Tannic acid degradation by bacterial strains Serratia spp. and Pantoea sp. isolated from olive mill waste mixtures

International Biodeterioration & Biodegradation, 2010

... Biological treatment, such as composting, has been showed effective in dropping phenolics in ... more ... Biological treatment, such as composting, has been showed effective in dropping phenolics in the olive mill effluents (Baeta-Hall et al., 2005), therefore allowing safe agronomic uses (Altieri and Esposito, 2008). Recently, Altieri et al. ...

Research paper thumbnail of Klebsiella sp. strain C2A isolated from olive oil mill waste is able to tolerate and degrade tannic acid in very high concentrations

FEMS Microbiology Letters, 2013

Four bacterial strains capable of growing in the presence of tannic acid as sole carbon and energ... more Four bacterial strains capable of growing in the presence of tannic acid as sole carbon and energy source were isolated from olive mill waste mixtures. 16S rRNA gene sequencing assigned them to the genus Klebsiella. The most efficient strain, Klebsiella sp. strain C2A, was able to degrade 3.5 g L À1 tannic acid within 35 h with synthesizing gallic acid as main product. The capability of Klebsiella sp. strain C2A to produce tannase was evidenced at high concentrations of tannic acid up to 50 g L À1. The bacteria adapted to the toxicity of tannic acids by an increase in the membrane lipid fatty acids degree of saturation, especially in the presence of concentrations higher than 20 g L À1. The highly tolerant and adaptable bacterial strain characterized in this study could be used in bioremediation processes of wastes rich in polyphenols such as those derived from olive mills, winery or tanneries.

Research paper thumbnail of Serratia spp. and Pantoea sp. tannins-degrading bacterial strains isolated from enrichment cultures arranged with olive mill wastes by-products

tirsavplus.eu

  1. Dipartimento di Scienze Ambientali, Università di Siena, Via PA Mattioli, 4; 53100, Siena; 2) ... more 1) Dipartimento di Scienze Ambientali, Università di Siena, Via PA Mattioli, 4; 53100, Siena; 2) Istituto per i Sistemi Agricoli e Forestali del Mediterraneo, Consiglio Nazionale delle Ricerche (ISAFoM-CNR), Via della Madonna Alta, 128; 06128, Perugia; 3) Ente Parco ...

Research paper thumbnail of Two-phase olive mill waste composting: Community dynamics and functional role of the resident microbiota

Bioresource Technology, 2011

In this study, physico-chemical modifications and community dynamics and functional role of the r... more In this study, physico-chemical modifications and community dynamics and functional role of the resident microbiota during composting of humid husk from a two-phase extraction system (TPOMW) were investigated. High mineralization and humification of carbon, low loss of nitrogen and complete degradation of polyphenols led to the waste biotransformation into a high-quality compost. Viable cell counts and denaturing gradient gel electrophoresis (DGGE) profiling of the 16S rRNA genes showed that the thermophilic phase was characterized by the strongest variations of cell number, the highest biodiversity and the most variable community profiles. The isolation of tannin-degrading bacteria (e.g. Lysinibacillus fusiformis, Kocuria palustris, Tetrathiobacter kashmirensis and Rhodococcus rhodochrous) suggested a role of this enzymatic activity during the process. Taken together, the results indicated that the composting process, particularly the thermophilic phase, was characterized by a rapid succession of specialized bacterial populations with key roles in the organic matter biotransformation.

Research paper thumbnail of Olive orchard amended with two experimental olive mill wastes mixtures: Effects on soil organic carbon, plant growth and yield

Bioresource Technology, 2008

Amendments of olive orchard soil with two different preparations of olive mill solid waste (OMWMs... more Amendments of olive orchard soil with two different preparations of olive mill solid waste (OMWMs) at the rate of 9 ton ha À1 per year for five years in two different plots were compared with an industry standard soil amendment using urea. Both the OMWMs amendments showed significant increases in total organic carbon and humic substances in soil of approximately 40% and 58%, respectively, without negative effects on tree growth and yield. This work has shown that olive oil mill waste (OMW) can be recycled safely using the bioremediation system used in this study. We suggest that this system is particularly beneficial to organic farming and is an alternative solution to direct spreading of raw OMW on farm lands.