Constantina Kourmentza | The University of Nottingham (original) (raw)
Papers by Constantina Kourmentza
Sustainability, Jun 26, 2023
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Journal of Chemical Technology & Biotechnology, Aug 31, 2019
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Elsevier eBooks, 2019
Abstract Biosurfactants are surfactants produced by microorganisms. Their high surface activity a... more Abstract Biosurfactants are surfactants produced by microorganisms. Their high surface activity and a range of biological activities including antimicrobial activity as well as their biodegradability make them very attractive molecules for a range of applications. However, their higher cost of production in contrast to their synthetic counterparts is hindering their wider commercialization. Downstream processing can account for more than 60% of overall process cost. This chapter is an overview of the application of membrane filtration processes for the recovery and purification of a range of biosurfactants, in particular lipopeptides. The main challenges and future developments in this area are highlighted.
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Microbial Applications Vol.1, 2017
Olive oil extraction and refining process generate large amounts of by-products that represent a ... more Olive oil extraction and refining process generate large amounts of by-products that represent a huge environmental concern, especially for countries located within the Mediterranean region, because of their phytotoxicity against soil and aquatic environments. Their valorization is considered challenging due to their high organic content, complexity, and the presence of phenolic compounds that inhibit their biodegradation. In order to minimize their environmental impact, many research groups within the last decades have been focusing on exploring and suggesting strategies regarding their physicochemical and microbiological treatment. According to various reports, the potential of olive mill wastewater to be converted to sustainable resources of biofuels and bio-based products has been demonstrated. In the present chapter, the most significant advances concerning a variety of promising valorization scenarios have been reviewed.
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Frontiers in Microbiology, 2021
Lipopeptide biosurfactants produced by Bacillus sp. were assessed regarding their antimicrobial a... more Lipopeptide biosurfactants produced by Bacillus sp. were assessed regarding their antimicrobial activity against foodborne pathogenic and food spoilage microorganisms. Both Gram-positive and Gram-negative bacteria were found not to be susceptible to these lipopeptides. However, mycosubtilin and mycosubtilin/surfactin mixtures were very active against the filamentous fungi Paecilomyces variotti and Byssochlamys fulva, with minimum inhibitory concentrations (MICs) of 1–16 mg/L. They were also active against Candida krusei, MIC = 16–64 mg/L. Moreover it was found that the antifungal activity of these lipopeptides was not affected by differences in isoform composition and/or purity. Furthermore their cytotoxicity tested on two different cell lines mimicking ingestion and detoxification was comparable to those of approved food preservatives such as nisin. Overall, for the first time here mycosubtilin and mycosubtilin/surfactin mixtures were found to have high antifungal activity against ...
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Valorization of Agri-Food Wastes and By-Products, 2021
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Journal of Chemical Technology & Biotechnology, 2019
BACKGROUNDThe aim of the present study was to assess the environmental impacts of end‐of‐life dai... more BACKGROUNDThe aim of the present study was to assess the environmental impacts of end‐of‐life dairy products (EoL‐DPs) management via their co‐treatment with agro‐industrial wastes (AgW) in a centralized biogas facility located in Cyprus using a gate‐to‐gate life cycle assessment (LCA) approach. Two different scenarios were examined under the framework of this project. In the first one, co‐treatment of EoL‐DPs with various AgW in a 20:80 (w/w) ratio was evaluated in a one‐stage mesophilic anaerobic digestion (AD) process. In the second scenario, the same amount of EoL‐DPs were acidified before methanogenesis with AgW in order to improve biogas production.RESULTSPrior acidification of EoL‐DPs showed a better environmental performance compared with the results obtained upon direct co‐digestion in a mesophilic digester, having a total impact of 52.44 Pt against 57.13 Pt respectively. Biogas production upon acidification, and therefore energy yield, was higher, reaching up to 22.88 m3 C...
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Bioengineering (Basel, Switzerland), Jan 11, 2017
Sustainable biofuels, biomaterials, and fine chemicals production is a critical matter that resea... more Sustainable biofuels, biomaterials, and fine chemicals production is a critical matter that research teams around the globe are focusing on nowadays. Polyhydroxyalkanoates represent one of the biomaterials of the future due to their physicochemical properties, biodegradability, and biocompatibility. Designing efficient and economic bioprocesses, combined with the respective social and environmental benefits, has brought together scientists from different backgrounds highlighting the multidisciplinary character of such a venture. In the current review, challenges and opportunities regarding polyhydroxyalkanoate production are presented and discussed, covering key steps of their overall production process by applying pure and mixed culture biotechnology, from raw bioprocess development to downstream processing.
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Microbial Applications Vol.1, 2017
During the last decades, researchers have been focusing on the development of economically viable... more During the last decades, researchers have been focusing on the development of economically viable bioprocesses, in order to produce fine and platform chemicals and polymers that will eventually replace the ones deriving from the petrochemical industries. Waste and surplus materials are inexpensive raw materials that do not directly compete with food, while their utilization maximizes the efficiency of the overall production process. Microbial conversion of such materials, deriving from various industrial processes, into biosurfactants is considered beneficial from a societal, environmental, and economic point of view since it contributes toward environmental protection, sustainability, and reduction of costs. Biosurfactants produced by bacteria may eventually replace synthetic surfactants due to their biodegradability and environmental compatibility. Interestingly, the diversity of their chemical structures and their complexity provides them unique features. Therefore, they are characterized by remarkable physicochemical properties so their potential industrial applications are quite diverse as they can be used as emulsifiers, de-emulsifiers, wetting, spreading, and foaming agents, functional food ingredients, and detergents in various industrial sectors such as petroleum and petrochemicals, organic chemicals, food and beverages, cosmetics and pharmaceuticals, mining and metallurgy, agrochemicals and fertilizers, and environmental control and management.
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International Journal of Biological Macromolecules, 2015
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Bioresource Technology
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Abstract: The utilization of fermentation media derived from waste and by-product streams from bi... more Abstract: The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen) 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L) and commercial sucrose (4.9 g/L) were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L) were obtained when flour-rich hydrolysates produced from confectionery industry
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International journal of molecular sciences, 2015
The utilization of fermentation media derived from waste and by-product streams from biodiesel an... more The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen) 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L) and commercial sucrose (4.9 g/L) were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L) were obtained when flour-rich hydrolysates produced from confectionery industry waste streams were used. The properties of bacterial celluloses developed when different fermentation media were used showed water holding capacities of 102-138 g·water/g·dry bacterial cellulose, v...
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Journal of Chemical Technology & Biotechnology, 2018
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Ecotoxicology and Environmental Safety, 2019
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Journal of Chemical Technology & Biotechnology, 2019
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Bioresource Technology, 2019
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Bioresource Technology, 2018
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Bioresource Technology, 2016
Mixed microbial cultures that undergo successful enrichment, following eco-biotechnological appro... more Mixed microbial cultures that undergo successful enrichment, following eco-biotechnological approaches, to form a community dominant in polyhydroxyalkanoates (PHA) forming bacteria, represent an attractive economic alternative towards the production of those biopolymers. In the present study, an enriched mixed culture was investigated for the production of PHA at different initial pH values under non-controlled conditions in order to minimize process control and operational costs. Short-chain fatty acids were provided as PHA precursors and they were tested as sole carbon sources and as mixtures under nitrogen deficiency. By the obtained kinetic and stoichiometric parameters it was shown that at an initial pH value of 6.90 PHA production was favored. Butyrate was characterized as the preferred carbon source, whereas simultaneous feeding led to increased rates and yields when butyrate and acetate were present.
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Sustainability, Jun 26, 2023
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Journal of Chemical Technology & Biotechnology, Aug 31, 2019
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Elsevier eBooks, 2019
Abstract Biosurfactants are surfactants produced by microorganisms. Their high surface activity a... more Abstract Biosurfactants are surfactants produced by microorganisms. Their high surface activity and a range of biological activities including antimicrobial activity as well as their biodegradability make them very attractive molecules for a range of applications. However, their higher cost of production in contrast to their synthetic counterparts is hindering their wider commercialization. Downstream processing can account for more than 60% of overall process cost. This chapter is an overview of the application of membrane filtration processes for the recovery and purification of a range of biosurfactants, in particular lipopeptides. The main challenges and future developments in this area are highlighted.
Bookmarks Related papers MentionsView impact
Microbial Applications Vol.1, 2017
Olive oil extraction and refining process generate large amounts of by-products that represent a ... more Olive oil extraction and refining process generate large amounts of by-products that represent a huge environmental concern, especially for countries located within the Mediterranean region, because of their phytotoxicity against soil and aquatic environments. Their valorization is considered challenging due to their high organic content, complexity, and the presence of phenolic compounds that inhibit their biodegradation. In order to minimize their environmental impact, many research groups within the last decades have been focusing on exploring and suggesting strategies regarding their physicochemical and microbiological treatment. According to various reports, the potential of olive mill wastewater to be converted to sustainable resources of biofuels and bio-based products has been demonstrated. In the present chapter, the most significant advances concerning a variety of promising valorization scenarios have been reviewed.
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Frontiers in Microbiology, 2021
Lipopeptide biosurfactants produced by Bacillus sp. were assessed regarding their antimicrobial a... more Lipopeptide biosurfactants produced by Bacillus sp. were assessed regarding their antimicrobial activity against foodborne pathogenic and food spoilage microorganisms. Both Gram-positive and Gram-negative bacteria were found not to be susceptible to these lipopeptides. However, mycosubtilin and mycosubtilin/surfactin mixtures were very active against the filamentous fungi Paecilomyces variotti and Byssochlamys fulva, with minimum inhibitory concentrations (MICs) of 1–16 mg/L. They were also active against Candida krusei, MIC = 16–64 mg/L. Moreover it was found that the antifungal activity of these lipopeptides was not affected by differences in isoform composition and/or purity. Furthermore their cytotoxicity tested on two different cell lines mimicking ingestion and detoxification was comparable to those of approved food preservatives such as nisin. Overall, for the first time here mycosubtilin and mycosubtilin/surfactin mixtures were found to have high antifungal activity against ...
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Valorization of Agri-Food Wastes and By-Products, 2021
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Journal of Chemical Technology & Biotechnology, 2019
BACKGROUNDThe aim of the present study was to assess the environmental impacts of end‐of‐life dai... more BACKGROUNDThe aim of the present study was to assess the environmental impacts of end‐of‐life dairy products (EoL‐DPs) management via their co‐treatment with agro‐industrial wastes (AgW) in a centralized biogas facility located in Cyprus using a gate‐to‐gate life cycle assessment (LCA) approach. Two different scenarios were examined under the framework of this project. In the first one, co‐treatment of EoL‐DPs with various AgW in a 20:80 (w/w) ratio was evaluated in a one‐stage mesophilic anaerobic digestion (AD) process. In the second scenario, the same amount of EoL‐DPs were acidified before methanogenesis with AgW in order to improve biogas production.RESULTSPrior acidification of EoL‐DPs showed a better environmental performance compared with the results obtained upon direct co‐digestion in a mesophilic digester, having a total impact of 52.44 Pt against 57.13 Pt respectively. Biogas production upon acidification, and therefore energy yield, was higher, reaching up to 22.88 m3 C...
Bookmarks Related papers MentionsView impact
Bioengineering (Basel, Switzerland), Jan 11, 2017
Sustainable biofuels, biomaterials, and fine chemicals production is a critical matter that resea... more Sustainable biofuels, biomaterials, and fine chemicals production is a critical matter that research teams around the globe are focusing on nowadays. Polyhydroxyalkanoates represent one of the biomaterials of the future due to their physicochemical properties, biodegradability, and biocompatibility. Designing efficient and economic bioprocesses, combined with the respective social and environmental benefits, has brought together scientists from different backgrounds highlighting the multidisciplinary character of such a venture. In the current review, challenges and opportunities regarding polyhydroxyalkanoate production are presented and discussed, covering key steps of their overall production process by applying pure and mixed culture biotechnology, from raw bioprocess development to downstream processing.
Bookmarks Related papers MentionsView impact
Microbial Applications Vol.1, 2017
During the last decades, researchers have been focusing on the development of economically viable... more During the last decades, researchers have been focusing on the development of economically viable bioprocesses, in order to produce fine and platform chemicals and polymers that will eventually replace the ones deriving from the petrochemical industries. Waste and surplus materials are inexpensive raw materials that do not directly compete with food, while their utilization maximizes the efficiency of the overall production process. Microbial conversion of such materials, deriving from various industrial processes, into biosurfactants is considered beneficial from a societal, environmental, and economic point of view since it contributes toward environmental protection, sustainability, and reduction of costs. Biosurfactants produced by bacteria may eventually replace synthetic surfactants due to their biodegradability and environmental compatibility. Interestingly, the diversity of their chemical structures and their complexity provides them unique features. Therefore, they are characterized by remarkable physicochemical properties so their potential industrial applications are quite diverse as they can be used as emulsifiers, de-emulsifiers, wetting, spreading, and foaming agents, functional food ingredients, and detergents in various industrial sectors such as petroleum and petrochemicals, organic chemicals, food and beverages, cosmetics and pharmaceuticals, mining and metallurgy, agrochemicals and fertilizers, and environmental control and management.
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International Journal of Biological Macromolecules, 2015
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Bioresource Technology
Bookmarks Related papers MentionsView impact
Abstract: The utilization of fermentation media derived from waste and by-product streams from bi... more Abstract: The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen) 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L) and commercial sucrose (4.9 g/L) were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L) were obtained when flour-rich hydrolysates produced from confectionery industry
Bookmarks Related papers MentionsView impact
International journal of molecular sciences, 2015
The utilization of fermentation media derived from waste and by-product streams from biodiesel an... more The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen) 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L) and commercial sucrose (4.9 g/L) were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L) were obtained when flour-rich hydrolysates produced from confectionery industry waste streams were used. The properties of bacterial celluloses developed when different fermentation media were used showed water holding capacities of 102-138 g·water/g·dry bacterial cellulose, v...
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Journal of Chemical Technology & Biotechnology, 2018
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Ecotoxicology and Environmental Safety, 2019
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Journal of Chemical Technology & Biotechnology, 2019
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Bioresource Technology, 2019
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Bioresource Technology, 2018
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Bioresource Technology, 2016
Mixed microbial cultures that undergo successful enrichment, following eco-biotechnological appro... more Mixed microbial cultures that undergo successful enrichment, following eco-biotechnological approaches, to form a community dominant in polyhydroxyalkanoates (PHA) forming bacteria, represent an attractive economic alternative towards the production of those biopolymers. In the present study, an enriched mixed culture was investigated for the production of PHA at different initial pH values under non-controlled conditions in order to minimize process control and operational costs. Short-chain fatty acids were provided as PHA precursors and they were tested as sole carbon sources and as mixtures under nitrogen deficiency. By the obtained kinetic and stoichiometric parameters it was shown that at an initial pH value of 6.90 PHA production was favored. Butyrate was characterized as the preferred carbon source, whereas simultaneous feeding led to increased rates and yields when butyrate and acetate were present.
Bookmarks Related papers MentionsView impact