The new trend in using photosynthetic microorganisms for the epuration of wastewater in recircula... more The new trend in using photosynthetic microorganisms for the epuration of wastewater in recirculating aquaculture systems (RAS) opens a new question concerning the economic significance of this newly synthesized biomass. In this paper, we present our original results concerning the production of photosynthetic biomass (both prokaryotes and eukaryotes) and associated non- photosynthetic microbiota during the purification process of artificial wastewater. The results present the wet and dry weight quantities of weekly synthesized photosynthetic biomass (with 3 harvesting processes per week). The obtained biomass is analysed with respect to the lipid content, total proteins, as well as carotenes. As our main task is to use this microbial biomass as valuable substrate for fish growth and not for the trivial usage as material for biogas production or fertilizer in agriculture, these results could make a big impact for a better utilization of natural resources, including in the rather new...
In the last decades there are reports concerning attempts to try to increase the amount and activ... more In the last decades there are reports concerning attempts to try to increase the amount and activity of a given physiological group of microorganisms from the activated sludge, in order to increase the overall yield of wastewater purification. In this paper we report our original results concerning the selective cultivation of microbial populations in growing media specific for ammonia oxidizing microorganisms (AOM), in order to increase the oxidation of ammonia from artificial wastewaters, model for those related to recirculating aquaculture systems. Different microbial populations were cultivated in batch systems at 20C, in aerobic conditions, in media with ammonium as sole electron source and carbon dioxide as sole carbon source. The results show that, after appropriate selective cultivation, there is a significant increase in the activity of AOB, in agreement with the increase in cell densities of AOB estimated by MPN technique. The improved populations thus obtained are good c...
T he biological treatment of different types of waste water involves the interaction of different... more T he biological treatment of different types of waste water involves the interaction of different types of microorganisms. In the last decade it has been a huge increase in: the use of photosynthetic microorganisms to treat domestic waste waters as well as; the use of activated sludge with improved specific activities (ammonia oxidation, denitrification etc.). In this paper are presented our results concerning the use of different selected populations of photosynthetic, ammonia oxidizing-and denitrifying microorganisms to clean synthetic waste waters. The untreated and biologically treated synthetic waste water were analyzed with respect to nitrate, nitrite, ammonia, orthophosphate, total nitrogen, total organic carbon, total inorganic carbon and total suspended solids. Microbiota was analyzed with respect to specific intracellular inclusions (polyphosphate, lipids droplets and polyhydroxybutyrate), extracellular transparent particles as well as the ratio between live cells and dead cells. The results obtained at laboratory level on synthetic waste water sustain the strong potential of using co-cultures of selected microorganisms for waste water treatment, being in general agreement with results already reported in the literature.
The use of microalgae in biotechnological processes, such as bioenergy production and wastewater ... more The use of microalgae in biotechnological processes, such as bioenergy production and wastewater treatment have been and continue to be of great interest. However, the commercialization of their potential is hindered due to various technical challenges, with biomass harvesting being the largest and most expensive energy consumer among them. Therefore, a major challenge is in finding an efficient harvesting method with high economic feasibility. In this study, a rapid-sedimentation freshwater green microalga was used for batch treatment of artificial wastewater. This strain, in addition to its ability to efficiently remove and use N, P as a source of nutrients, has the advantage of a fast-sedimentation innate feature that allows for a rapid biomass settling (less than 10 minutes) without the addition of any flocculant. This green microalgal strain grows in the form of macrocolonies that significantly favor harvesting by rapid natural gravitational sedimentation. Thus, as this microal...
In the last forty years there is an increased scientific interest in deeper understanding lipid m... more In the last forty years there is an increased scientific interest in deeper understanding lipid metabolism in photosynthetic microorganisms, aiming at using the most lipid-rich strains as source for biodiesel production. One of the many constraints is the selection of strains with high lipid content. This paper presents the isolation, purification and selection of three strains of photosynthetic microorganisms by using an already known method, iodine vapour method, (Work et al., 2010) which allows to rapidly and easily select those colonies which low starch content as potential high lipidcontaining isolates. These results show that in the three selected strains, the fluorescence emission after Nile red addition is increased with different values: 7.597; 10.832 and 11.428 for strains 9.3.1, 9.8.2 and 12.9.0, respectivley.
The aim of this paper is to review the published results on the interaction between prokaryotes, ... more The aim of this paper is to review the published results on the interaction between prokaryotes, both Archaea and Bacteria, with γ-irradiation at doses which do not inhibit cellular growth or cell multiplication. Special emphasis is on the ability of γ-radiation to stimulate cell metabolism, one applicative task being the synthesis of useful compounds both for the cells and for practical applications, such as biotechnological and medical uses.
“Agriculture for Life, Life for Agriculture” Conference Proceedings
In the last decade there is an increased interest in selecting photosynthetic microorganisms with... more In the last decade there is an increased interest in selecting photosynthetic microorganisms with higher lipid content useful for biotechnological applications. In this paper we present our original results concerning: i) the selection of naturally occurring photosynthetic microorganisms with higher lipid content; ii) the use of these isolates as biological material subject of randomly induced mutagenesis; iii) selection by iodine vapour method of clones with decreased polysaccharides content and expected higher lipid content) as well as iv) genetic analysis of most promising strains in order to check the if they are true mutants or not. The results thus obtained argue the importance of the selection of naturally occurring photosynthetic microorganisms with higher lipid content as well as the use of random mutagenesis as a valuable tool to improve the genetic diversity of photosynthetic microorganisms in order to increase their ability to synthesize lipids for further biodiesel prod...
The new trend in using photosynthetic microorganisms for the epuration of wastewater in recircula... more The new trend in using photosynthetic microorganisms for the epuration of wastewater in recirculating aquaculture systems (RAS) opens a new question concerning the economic significance of this newly synthesized biomass. In this paper, we present our original results concerning the production of photosynthetic biomass (both prokaryotes and eukaryotes) and associated non- photosynthetic microbiota during the purification process of artificial wastewater. The results present the wet and dry weight quantities of weekly synthesized photosynthetic biomass (with 3 harvesting processes per week). The obtained biomass is analysed with respect to the lipid content, total proteins, as well as carotenes. As our main task is to use this microbial biomass as valuable substrate for fish growth and not for the trivial usage as material for biogas production or fertilizer in agriculture, these results could make a big impact for a better utilization of natural resources, including in the rather new...
In the last decades there are reports concerning attempts to try to increase the amount and activ... more In the last decades there are reports concerning attempts to try to increase the amount and activity of a given physiological group of microorganisms from the activated sludge, in order to increase the overall yield of wastewater purification. In this paper we report our original results concerning the selective cultivation of microbial populations in growing media specific for ammonia oxidizing microorganisms (AOM), in order to increase the oxidation of ammonia from artificial wastewaters, model for those related to recirculating aquaculture systems. Different microbial populations were cultivated in batch systems at 20C, in aerobic conditions, in media with ammonium as sole electron source and carbon dioxide as sole carbon source. The results show that, after appropriate selective cultivation, there is a significant increase in the activity of AOB, in agreement with the increase in cell densities of AOB estimated by MPN technique. The improved populations thus obtained are good c...
T he biological treatment of different types of waste water involves the interaction of different... more T he biological treatment of different types of waste water involves the interaction of different types of microorganisms. In the last decade it has been a huge increase in: the use of photosynthetic microorganisms to treat domestic waste waters as well as; the use of activated sludge with improved specific activities (ammonia oxidation, denitrification etc.). In this paper are presented our results concerning the use of different selected populations of photosynthetic, ammonia oxidizing-and denitrifying microorganisms to clean synthetic waste waters. The untreated and biologically treated synthetic waste water were analyzed with respect to nitrate, nitrite, ammonia, orthophosphate, total nitrogen, total organic carbon, total inorganic carbon and total suspended solids. Microbiota was analyzed with respect to specific intracellular inclusions (polyphosphate, lipids droplets and polyhydroxybutyrate), extracellular transparent particles as well as the ratio between live cells and dead cells. The results obtained at laboratory level on synthetic waste water sustain the strong potential of using co-cultures of selected microorganisms for waste water treatment, being in general agreement with results already reported in the literature.
The use of microalgae in biotechnological processes, such as bioenergy production and wastewater ... more The use of microalgae in biotechnological processes, such as bioenergy production and wastewater treatment have been and continue to be of great interest. However, the commercialization of their potential is hindered due to various technical challenges, with biomass harvesting being the largest and most expensive energy consumer among them. Therefore, a major challenge is in finding an efficient harvesting method with high economic feasibility. In this study, a rapid-sedimentation freshwater green microalga was used for batch treatment of artificial wastewater. This strain, in addition to its ability to efficiently remove and use N, P as a source of nutrients, has the advantage of a fast-sedimentation innate feature that allows for a rapid biomass settling (less than 10 minutes) without the addition of any flocculant. This green microalgal strain grows in the form of macrocolonies that significantly favor harvesting by rapid natural gravitational sedimentation. Thus, as this microal...
In the last forty years there is an increased scientific interest in deeper understanding lipid m... more In the last forty years there is an increased scientific interest in deeper understanding lipid metabolism in photosynthetic microorganisms, aiming at using the most lipid-rich strains as source for biodiesel production. One of the many constraints is the selection of strains with high lipid content. This paper presents the isolation, purification and selection of three strains of photosynthetic microorganisms by using an already known method, iodine vapour method, (Work et al., 2010) which allows to rapidly and easily select those colonies which low starch content as potential high lipidcontaining isolates. These results show that in the three selected strains, the fluorescence emission after Nile red addition is increased with different values: 7.597; 10.832 and 11.428 for strains 9.3.1, 9.8.2 and 12.9.0, respectivley.
The aim of this paper is to review the published results on the interaction between prokaryotes, ... more The aim of this paper is to review the published results on the interaction between prokaryotes, both Archaea and Bacteria, with γ-irradiation at doses which do not inhibit cellular growth or cell multiplication. Special emphasis is on the ability of γ-radiation to stimulate cell metabolism, one applicative task being the synthesis of useful compounds both for the cells and for practical applications, such as biotechnological and medical uses.
“Agriculture for Life, Life for Agriculture” Conference Proceedings
In the last decade there is an increased interest in selecting photosynthetic microorganisms with... more In the last decade there is an increased interest in selecting photosynthetic microorganisms with higher lipid content useful for biotechnological applications. In this paper we present our original results concerning: i) the selection of naturally occurring photosynthetic microorganisms with higher lipid content; ii) the use of these isolates as biological material subject of randomly induced mutagenesis; iii) selection by iodine vapour method of clones with decreased polysaccharides content and expected higher lipid content) as well as iv) genetic analysis of most promising strains in order to check the if they are true mutants or not. The results thus obtained argue the importance of the selection of naturally occurring photosynthetic microorganisms with higher lipid content as well as the use of random mutagenesis as a valuable tool to improve the genetic diversity of photosynthetic microorganisms in order to increase their ability to synthesize lipids for further biodiesel prod...
Uploads
Papers by Ana Ardelean