Constantina Kourmentza - Profile on Academia.edu (original) (raw)
Papers by Constantina Kourmentza
Deleted Journal, May 27, 2024
Biotechnology for Sustainable Materials, positioned at the forefront of environmentally conscious... more Biotechnology for Sustainable Materials, positioned at the forefront of environmentally conscious practices, is pivotal in realizing the objectives of Sustainable Development Goal 12 (Responsible Consumption and Production). Sustainable materials are essential components in the quest for environmentally responsible practices. These materials, derived from renewable sources or recycled content, aim to minimize adverse environmental impacts throughout their life cycle. They contribute to the circular economy by prioritizing reuse, recycling, and closed-loop systems. Sustainable materials are characterized by low carbon footprints, biodegradability, and the ability to be recycled without compromising integrity. Biotechnological innovations play a pivotal role in developing materials derived from renewable sources or repurposed waste, aligning with the principles of sustainability. Biotechnology facilitates the production of plantand microbe-based biopolymers, bioplastics, and other biomaterials with enhanced environmental credentials. This critical intersection of sustainable materials and biotechnology not only addresses immediate environmental concerns but also shapes a circular economy, promoting efficient resource use and waste reduction. BMC, part of Springer Nature, symbolizes a commitment to excellence in scientific publishing. As a renowned publisher, Springer Nature brings a wealth of experience
Biotechnology for biofuels and bioproducts, Mar 12, 2024
Background The main challenge for large-scale production of bacterial cellulose (BC) includes hig... more Background The main challenge for large-scale production of bacterial cellulose (BC) includes high production costs interlinked with raw materials, and low production rates. The valorization of renewable nutrient sources could improve the economic effectiveness of BC fermentation while their direct bioconversion into sustainable biopolymers addresses environmental pollution and/or resource depletion challenges. Herein a green bioprocess was developed to produce BC in high amounts with the rather unexplored bacterial strain Komagataeibacter rhaeticus, using waste streams such as wine distillery effluents (WDE) and biodiesel-derived glycerol. Also, BC was evaluated as a bio-adsorbent for phenolics, dyes and metals removal to enlarge its market diversification. Results BC production was significantly affected by the WDE mixing ratio (0-100%), glycerol concentration (20-45 g/L), type of glycerol and media-sterilization method. A maximum BC concentration of 9.0 g/L, with a productivity of 0.90 g/L/day and a water holding capacity of 60.1 g water/g dry BC, was achieved at 100% WDE and ≈30 g/L crude glycerol. BC samples showed typical cellulose vibration bands and average fiber diameters between 37.2 and 89.6 nm. The BC capacity to dephenolize WDE and adsorb phenolics during fermentation reached respectively, up to 50.7% and 26.96 mg gallic acid equivalents/g dry BC (in-situ process). The produced BC was also investigated for dye and metal removal. The highest removal of dye acid yellow 17 (54.3%) was recorded when 5% of BC was applied as the bio-adsorbent. Experiments performed in a multi-metal synthetic wastewater showed that BC could remove up to 96% of Zn and 97% of Cd. Conclusions This work demonstrated a low-carbon approach to produce low-cost, green and biodegradable BC-based bio-adsorbents, without any chemical modification. Their potential in wastewater-treatment-applications was highlighted, promoting closed-loop systems within the circular economy era. This study may serve as an orientation for future research towards competitive or targeted adsorption technologies for wastewater treatment or resources recovery.
Sustainability, Jun 26, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Journal of Chemical Technology & Biotechnology, Aug 31, 2019
Life cycle assessment (LCA) of end-of-life dairy products (EoL-DPs) valorization via anaerobic co... more Life cycle assessment (LCA) of end-of-life dairy products (EoL-DPs) valorization via anaerobic co-digestion with agro-industrial wastes for biogas production Article Accepted Version Kopsahelis, A., Kourmentza, C., Zafiri, C. and Kornaros, M. (2019) Life cycle assessment (LCA) of end-of-life dairy products (EoL-DPs) valorization via anaerobic co-digestion with agro-industrial wastes for biogas production. Journal of Chemical Technology and Biotechnology, 94 (11). pp. 3687-3697.
Competitive Advantage and Market Introduction of PHA Polymers and Potential Use of PHA Monomers
Membrane Filtration of Biosurfactants
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.
Integrated Biorefinery Approach for the Valorization of Olive Mill Waste Streams Towards Sustainable Biofuels and Bio-Based Products
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.
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 ...
Valorization of fruit processing by-product streams into integrated biorefinery concepts: extraction of value-added compounds and bioconversion to chemicals
Valorization of Agri-Food Wastes and By-Products, 2021
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...
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.
Microbial Conversion of Waste and Surplus Materials into High-Value Added Products: The Case of Biosurfactants
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.
International Journal of Biological Macromolecules, 2015
The present study aimed at investigating the ability of bacteria isolated from an enriched mixed ... more The present study aimed at investigating the ability of bacteria isolated from an enriched mixed culture to produce polyhydroxyalkanoates (PHAs) and examining the effect of nitrogen and dual nitrogen-oxygen limitation on PHAs production, by using both synthetic and olive mill wastewater (OMW). PHAs production was performed through batch experiments using both the enriched culture and the isolated strains (belonging to the genus of Pseudomonas) aiming to compare PHAs accumulation capacity, yields and rates. The use of enriched culture and synthetic wastewater under nitrogen limitation resulted in the highest PHA accumulation, i.e. 64.4% g PHAs/g of cell dry mass (CDM). However, when OMW was used, PHAs accumulation significantly decreased, i.e. 8.8% g PHAs/g CDM. The same trend was followed by the isolated strains, nevertheless, their ability to synthesize PHAs was lower. Although, dual nitrogenoxygen limitation generally slowed down PHAs biosynthesis, in certain strains PHAs production was positively affected.
Bioconversion of underutilized brewing by-products into bacterial cellulose by a newly isolated Komagataeibacter rhaeticus strain: A preliminary evaluation of the bioprocess environmental impact
Bioresource Technology
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
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...
Journal of Chemical Technology & Biotechnology, 2018
Gate-to-gate life cycle assessment (LCA) of biosurfactants and bioplasticizers production via bio... more Gate-to-gate life cycle assessment (LCA) of biosurfactants and bioplasticizers production via biotechnological exploitation of fats and waste oils
Ecotoxicology and Environmental Safety, 2019
The effects of B. thailandensis rhamnolipids on D. tertiolecta were investigated. § B. thailanden... more The effects of B. thailandensis rhamnolipids on D. tertiolecta were investigated. § B. thailandensis predominant RL congener is the di-rhamnolipid Rha-Rha-C 14-C 14 § Algal growth and photosynthetic parameters, using the JIP test, were tested. § B. thailandensis rhamnolipids do not affect algal growth rate. § RLs showed no significant effects on algae photosynthetic ability
Journal of Chemical Technology & Biotechnology, 2019
BACKGROUND: N,N'-diacetylchitobiose (GlcNAc 2) is known to be highly functional and offers a wide... more BACKGROUND: N,N'-diacetylchitobiose (GlcNAc 2) is known to be highly functional and offers a wide range of applications, especially as an antimicrobial agent. In this study, a thermal pre-treatment process using steam under pressure in an autoclave, has been employed to facilitate subsequent enzymatic hydrolysis of chitin with chitinase from Streptomyces griseus. RESULTS: Pre-treatment of chitin with 0.05 M sodium acetate buffer (pH=6.0) at 121 ºC for 60 min, followed by enzymatic hydrolysis involving 24 h incubation, was found to be the best condition for producing the GlcNAc 2. The GlcNAc 2 obtained was tested regarding its antimicrobial activity against Gram-negative and Gram-positive strains
Bioresource Technology, 2019
Occurrence of non-toxic bioemulsifiers during polyhydroxyalkanoate production by Pseudomonas stra... more Occurrence of non-toxic bioemulsifiers during polyhydroxyalkanoate production by Pseudomonas strains valorizing crude glycerol by-product,
Deleted Journal, May 27, 2024
Biotechnology for Sustainable Materials, positioned at the forefront of environmentally conscious... more Biotechnology for Sustainable Materials, positioned at the forefront of environmentally conscious practices, is pivotal in realizing the objectives of Sustainable Development Goal 12 (Responsible Consumption and Production). Sustainable materials are essential components in the quest for environmentally responsible practices. These materials, derived from renewable sources or recycled content, aim to minimize adverse environmental impacts throughout their life cycle. They contribute to the circular economy by prioritizing reuse, recycling, and closed-loop systems. Sustainable materials are characterized by low carbon footprints, biodegradability, and the ability to be recycled without compromising integrity. Biotechnological innovations play a pivotal role in developing materials derived from renewable sources or repurposed waste, aligning with the principles of sustainability. Biotechnology facilitates the production of plantand microbe-based biopolymers, bioplastics, and other biomaterials with enhanced environmental credentials. This critical intersection of sustainable materials and biotechnology not only addresses immediate environmental concerns but also shapes a circular economy, promoting efficient resource use and waste reduction. BMC, part of Springer Nature, symbolizes a commitment to excellence in scientific publishing. As a renowned publisher, Springer Nature brings a wealth of experience
Biotechnology for biofuels and bioproducts, Mar 12, 2024
Background The main challenge for large-scale production of bacterial cellulose (BC) includes hig... more Background The main challenge for large-scale production of bacterial cellulose (BC) includes high production costs interlinked with raw materials, and low production rates. The valorization of renewable nutrient sources could improve the economic effectiveness of BC fermentation while their direct bioconversion into sustainable biopolymers addresses environmental pollution and/or resource depletion challenges. Herein a green bioprocess was developed to produce BC in high amounts with the rather unexplored bacterial strain Komagataeibacter rhaeticus, using waste streams such as wine distillery effluents (WDE) and biodiesel-derived glycerol. Also, BC was evaluated as a bio-adsorbent for phenolics, dyes and metals removal to enlarge its market diversification. Results BC production was significantly affected by the WDE mixing ratio (0-100%), glycerol concentration (20-45 g/L), type of glycerol and media-sterilization method. A maximum BC concentration of 9.0 g/L, with a productivity of 0.90 g/L/day and a water holding capacity of 60.1 g water/g dry BC, was achieved at 100% WDE and ≈30 g/L crude glycerol. BC samples showed typical cellulose vibration bands and average fiber diameters between 37.2 and 89.6 nm. The BC capacity to dephenolize WDE and adsorb phenolics during fermentation reached respectively, up to 50.7% and 26.96 mg gallic acid equivalents/g dry BC (in-situ process). The produced BC was also investigated for dye and metal removal. The highest removal of dye acid yellow 17 (54.3%) was recorded when 5% of BC was applied as the bio-adsorbent. Experiments performed in a multi-metal synthetic wastewater showed that BC could remove up to 96% of Zn and 97% of Cd. Conclusions This work demonstrated a low-carbon approach to produce low-cost, green and biodegradable BC-based bio-adsorbents, without any chemical modification. Their potential in wastewater-treatment-applications was highlighted, promoting closed-loop systems within the circular economy era. This study may serve as an orientation for future research towards competitive or targeted adsorption technologies for wastewater treatment or resources recovery.
Sustainability, Jun 26, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Journal of Chemical Technology & Biotechnology, Aug 31, 2019
Life cycle assessment (LCA) of end-of-life dairy products (EoL-DPs) valorization via anaerobic co... more Life cycle assessment (LCA) of end-of-life dairy products (EoL-DPs) valorization via anaerobic co-digestion with agro-industrial wastes for biogas production Article Accepted Version Kopsahelis, A., Kourmentza, C., Zafiri, C. and Kornaros, M. (2019) Life cycle assessment (LCA) of end-of-life dairy products (EoL-DPs) valorization via anaerobic co-digestion with agro-industrial wastes for biogas production. Journal of Chemical Technology and Biotechnology, 94 (11). pp. 3687-3697.
Competitive Advantage and Market Introduction of PHA Polymers and Potential Use of PHA Monomers
Membrane Filtration of Biosurfactants
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.
Integrated Biorefinery Approach for the Valorization of Olive Mill Waste Streams Towards Sustainable Biofuels and Bio-Based Products
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.
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 ...
Valorization of fruit processing by-product streams into integrated biorefinery concepts: extraction of value-added compounds and bioconversion to chemicals
Valorization of Agri-Food Wastes and By-Products, 2021
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...
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.
Microbial Conversion of Waste and Surplus Materials into High-Value Added Products: The Case of Biosurfactants
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.
International Journal of Biological Macromolecules, 2015
The present study aimed at investigating the ability of bacteria isolated from an enriched mixed ... more The present study aimed at investigating the ability of bacteria isolated from an enriched mixed culture to produce polyhydroxyalkanoates (PHAs) and examining the effect of nitrogen and dual nitrogen-oxygen limitation on PHAs production, by using both synthetic and olive mill wastewater (OMW). PHAs production was performed through batch experiments using both the enriched culture and the isolated strains (belonging to the genus of Pseudomonas) aiming to compare PHAs accumulation capacity, yields and rates. The use of enriched culture and synthetic wastewater under nitrogen limitation resulted in the highest PHA accumulation, i.e. 64.4% g PHAs/g of cell dry mass (CDM). However, when OMW was used, PHAs accumulation significantly decreased, i.e. 8.8% g PHAs/g CDM. The same trend was followed by the isolated strains, nevertheless, their ability to synthesize PHAs was lower. Although, dual nitrogenoxygen limitation generally slowed down PHAs biosynthesis, in certain strains PHAs production was positively affected.
Bioconversion of underutilized brewing by-products into bacterial cellulose by a newly isolated Komagataeibacter rhaeticus strain: A preliminary evaluation of the bioprocess environmental impact
Bioresource Technology
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
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...
Journal of Chemical Technology & Biotechnology, 2018
Gate-to-gate life cycle assessment (LCA) of biosurfactants and bioplasticizers production via bio... more Gate-to-gate life cycle assessment (LCA) of biosurfactants and bioplasticizers production via biotechnological exploitation of fats and waste oils
Ecotoxicology and Environmental Safety, 2019
The effects of B. thailandensis rhamnolipids on D. tertiolecta were investigated. § B. thailanden... more The effects of B. thailandensis rhamnolipids on D. tertiolecta were investigated. § B. thailandensis predominant RL congener is the di-rhamnolipid Rha-Rha-C 14-C 14 § Algal growth and photosynthetic parameters, using the JIP test, were tested. § B. thailandensis rhamnolipids do not affect algal growth rate. § RLs showed no significant effects on algae photosynthetic ability
Journal of Chemical Technology & Biotechnology, 2019
BACKGROUND: N,N'-diacetylchitobiose (GlcNAc 2) is known to be highly functional and offers a wide... more BACKGROUND: N,N'-diacetylchitobiose (GlcNAc 2) is known to be highly functional and offers a wide range of applications, especially as an antimicrobial agent. In this study, a thermal pre-treatment process using steam under pressure in an autoclave, has been employed to facilitate subsequent enzymatic hydrolysis of chitin with chitinase from Streptomyces griseus. RESULTS: Pre-treatment of chitin with 0.05 M sodium acetate buffer (pH=6.0) at 121 ºC for 60 min, followed by enzymatic hydrolysis involving 24 h incubation, was found to be the best condition for producing the GlcNAc 2. The GlcNAc 2 obtained was tested regarding its antimicrobial activity against Gram-negative and Gram-positive strains
Bioresource Technology, 2019
Occurrence of non-toxic bioemulsifiers during polyhydroxyalkanoate production by Pseudomonas stra... more Occurrence of non-toxic bioemulsifiers during polyhydroxyalkanoate production by Pseudomonas strains valorizing crude glycerol by-product,