Pavlos Makridis - Academia.edu (original) (raw)

Papers by Pavlos Makridis

Research paper thumbnail of Food size selectivity of Artemia franciscana at three developmental stages

Journal of Plankton Research, Nov 1, 1999

Food size selectivity was examined in Artemia franciscana metanauplii at three different developm... more Food size selectivity was examined in Artemia franciscana metanauplii at three different developmental stages. Clearance rates were determined in short-term experiments either by measuring the decrease in concentration of live particles and plastic beads, or by measuring the radioactivity accumulated in animals that grazed 14 C-labelled live particles. The maximum clearance rate of A.franciscana metanauplii increased during development and was measured at 50-63 µl ind.-1 h-1 , 254 µl ind.-1 h-1 and 1.48-2.10 ml ind.-1 h-1 in 2-, 4-and 7-day-old metanauplii, respectively. A preference for particles with a diameter of 4-8 µm was observed at all three developmental stages. The ability of A.franciscana metanauplii to graze bacterial particles was also demonstrated, although the efficiency in grazing such small particles was low compared to microalgae (28, 20 and 9% of the maximum clearance rate in 2-, 4-and 7-day-old metanauplii, respectively). Electron microscopy showed that the inter-setular distance in antennae and thoracopods was 0.20 ± 0.07, 0.16 ± 0.05 and 0.18 ± 0.04 µm in 2-, 4-and 7-day-old metanauplii, respectively, and accordingly independent of stage.

Research paper thumbnail of The Probiotic Phaeobacter inhibens Provokes Hypertrophic Growth via Activation of the IGF-1/Akt Pathway during the Process of Metamorphosis of Greater Amberjack (Seriola dumerili, Risso 1810)

Animals, Jun 29, 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

Research paper thumbnail of Use of Phaeobacter sp. probiotic bacteria for the rearing of sea bass larvae (Dicentrarchus labrax)

Research paper thumbnail of Use of microalgae bioencapsulated in Artemia during the weaning of Senegalese sole (Solea senegalensis Kaup)

Aquaculture, Jul 1, 2009

The microalgae species Chlorella minutissima and Tetraselmis chuii were bioencapsulated in Artemi... more The microalgae species Chlorella minutissima and Tetraselmis chuii were bioencapsulated in Artemia metanauplii and used during the weaning of Senegalese sole, Solea senegalensis post-larvae. We evaluated the effect of microalgae on:(i) survival and growth ...

Research paper thumbnail of Antimicrobial activity in bacteria isolated from Senegalese sole, Solea senegalensis, fed with natural prey

Aquaculture Research, Dec 1, 2005

... The alignments of the sequences have been made using the Software Clustal X (Thompson, Gibson... more ... The alignments of the sequences have been made using the Software Clustal X (Thompson, Gibson, Plewniak, Jeanmougin & Higgins 1997), and ... with H. diversicolor differentiate from the microbial communities present in the sediments of their natural habitat (Lucas, Bertru & ...

Research paper thumbnail of Bioenergetic changes in the microalgal photosynthetic apparatus by extremely high CO<sub>2</sub>concentrations induce an intense biomass production

Physiologia Plantarum, Mar 1, 2008

Unicellular green alga Chlorella minutissima, grown under extreme carbon dioxide concentrations (... more Unicellular green alga Chlorella minutissima, grown under extreme carbon dioxide concentrations (0.036-100%), natural temperature and light intensities (Mediterranean conditions), strongly increase the microalgal biomass through photochemical and non-photochemical changes in the photosynthetic apparatus. Especially, CO 2 concentrations up to 10% enhance the density of active reaction centers (RC/CS o), decrease the antenna size per active reaction center (ABS/RC), decrease the dissipation energy (DI o /RC) and enhance the quantum yield of primary photochemistry (F v /F m). Higher CO 2 concentrations (20-25%) combine the above-mentioned photochemical changes with enhanced non-photochemical quenching of surplus energy, which leads to an enhanced steady-state fraction of 'open' (oxidized) PSII reaction centers (q p), and minimize the excitation pressure of PSII (1 2 q p) under very high light intensities (approximately 1700 mmol m 22 s 21 maximal value), avoiding the photoinhibition and leading to an enormous biomass production (approximately 2500%). In conclusion, these extreme CO 2 concentrations-about 1000 times higher than the ambient one-can be easily metabolized from the unicellular green alga to biomass and can be used, on a local scale at least, for the future development of microalgal photobioreactors for the mitigation of the factory-produced carbon dioxide.

Research paper thumbnail of Application of multi-species of Bacillus in sea bream larviculture

Aquaculture, Jul 1, 2010

To date, probiotics can be considered a valid alternative to the use of antibiotics in aquacultur... more To date, probiotics can be considered a valid alternative to the use of antibiotics in aquaculture and in particular, in fish larviculture, to prevent high mortality and to improve welfare and promote growth. In the two last decades, many studies reported promising results using a single beneficial bacterial strain in the culture of many finfish species. Looking for innovative ways to improve fish larviculture, we tested a mixture of Bacillus probiotic bacteria in the gilthead sea bream (Sparus aurata) larviculture focusing on their effects on survival, growth and general welfare. The mixture, composed of three Bacillus strains, Bacillus subtilis, Bacillus licheniformis and Bacillus pumilus was provided via rotifers and Artemia nauplia and added to the water (group 1) or supplied exclusively via live prey (group 2). The Bacillus mixture significantly increased growth in terms of standard length and body weight in both experimental groups, at larval and juvenile stages, 47 and 75 days after hatching, respectively, with the highest values obtained from Group 2 treatment. In addition, the expression of genes involved in growth metabolism (Insulin-like Growth Factors I and Myostatin) and animal welfare (70 KDa-Heat Shock Protein and Glucocorticoid Receptor) were analysed. The morphometric analysis was supported by molecular results which clearly evidenced higher expression of IGFI and lower levels of myostatin in groups fed on probiotics. In addition, a better tolerance to farming conditions was also found as evidenced by the lower expression of HSP70 and Glucocorticoid Receptor, suggesting beneficial effects of the supplied Bacillus mixture on fish welfare. The data generated in this study provide scientific and technical support for the implementation of sustainable development of sea bream aquaculture.

Research paper thumbnail of Microbial conditions and antimicrobial activity in cultures of two microalgae species, Tetraselmis chuii and Chlorella minutissima, and effect on bacterial load of enriched Artemia metanauplii

Aquaculture, May 1, 2006

The microbial conditions and antimicrobial activity were determined in batch cultures of two micr... more The microbial conditions and antimicrobial activity were determined in batch cultures of two microalgae species, Tetraselmis chuii and Chlorella minutissima. The number of bacteria associated with the microalgae cultures showed an exponential growth 2, 10, and 16 days after inoculation, and they were higher in T. chuii in all three sampling points compared with C. minutissima. No presumptive Vibrio strains were observed in any of the samples, as measured by the growth on TCBS agar. A total of 17 and 30 bacterial strains were isolated from C. minutissima and T. chuii, respectively. A high percentage of Gram-positive strains was detected among the bacterial strains isolated, as Gram-positive strains constituted 82% (14 / 17) and 73% (22 / 30) of the total numbers of isolates in C. minutissima and T. chuii, respectively. The isolated bacteria were screened in vitro for inhibition against two pathogenic strains, and nine of the 34 strains tested (26%) showed inhibition in vitro against either Photobacterium damselae, susp. piscicida or Vibrio anguillarum. Incubation of enriched Artemia in cultures of the two microalgae for 30 min resulted in a significant decrease of the bacterial load in Artemia (P b 0.05), and a significant decrease of the level of presumptive Vibrio in Artemia homogenates (P b 0.05). The results of this study demonstrate a simple and practical approach to decrease the microbial load and at the same time reduce the percentage of Vibrio among the bacteria associated with enriched Artemia.

Research paper thumbnail of Control of the bacterial flora of Brachionus plicatilis and Artemia franciscana by incubation in bacterial suspensions

Aquaculture, May 1, 2000

The accumulation of bacteria in Brachionus plicatilis and Artemia franciscana during a Ž. short-t... more The accumulation of bacteria in Brachionus plicatilis and Artemia franciscana during a Ž. short-term incubation was quantified using immunocolony blot ICB and an enzyme-linked Ž. immunosorbent assay ELISA. Four bacterial strains, isolated from turbot and halibut, were Ž 7

Research paper thumbnail of Oxygenation of European seabass (Dicentrarchus labrax L.) in cages through aeration and effect on lipid metabolism

Fish Physiology and Biochemistry, Feb 22, 2023

Research paper thumbnail of Influence of Microalgae Supernatant, and Bacteria Isolated from Microalgae Cultures, on Microbiology, and Digestive Capacity of Larval Gilthead Seabream, Sparus aurata, and Senegalese Sole, Solea senegalensis

Journal of the World Aquaculture Society, Oct 1, 2010

This study aimed at investigating addition of microalgae in the rearing of marine fish larvae (gr... more This study aimed at investigating addition of microalgae in the rearing of marine fish larvae (green water technique). Addition of microalgae supernatant, or bacteria isolated from microalgae cultures, to the rearing tanks of larval Senegalese sole, Solea senegalensis, and gilthead seabream, Sparus aurata, had no significant (P < 0.05) influence on survival or growth of the larvae. Addition of four bacterial strains isolated from microalgae decreased however the numbers of presumptive Vibrio in gilthead seabream larvae and seawater were compared with the control treatment 7 d after hatching (P < 0.05). No such effects were shown on the numbers of presumptive Vibrio in the rearing of sole larvae. Addition of bacteria improved the digestive capacity of gilthead seabream larvae, as the total activity (U/larva) of trypsin, amylase, and alkaline phosphatase in the treatment with added bacteria were significantly higher (P < 0.05) than in larvae from the control treatment 10 d after hatching. No such effects were shown in the case of sole larvae. The present results indicated that bacteria associated with microalgae may play an important role for the inhibition of proliferation of Vibrio and improvement of digestive capacity during the first days of feeding of gilthead seabream larvae, but does not appear to be beneficial for larvae of Senegalese sole.

Research paper thumbnail of Isolation of Phaeobacter sp. from Larvae of Atlantic Bonito (Sarda sarda) in a Mesocosmos Unit, and Its Use for the Rearing of European Seabass Larvae (Dicentrarchus labrax L.)

Microorganisms, Jan 8, 2021

Phaeobacter sp. from Larvae of Atlantic Bonito (Sarda sarda) in a Mesocosmos Unit, and Its Use fo... more Phaeobacter sp. from Larvae of Atlantic Bonito (Sarda sarda) in a Mesocosmos Unit, and Its Use for the Rearing of European Seabass Larvae (Dicentrarchus labrax L.).

Research paper thumbnail of Evaluation of candidate probiotic strains for gilthead sea bream larvae (Sparus aurata) using an in vivo approach

Letters in Applied Microbiology, Apr 1, 2005

The aim of this study was to evaluate the effect of six bacterial strains on gilthead sea bream l... more The aim of this study was to evaluate the effect of six bacterial strains on gilthead sea bream larvae (Sparus aurata). Methods and Results: Six bacterial strains isolated from well-performing live food cultures were identified by sequencing fragments of their 16s rDNA genome to the genus level as Cytophaga sp., Roseobacter sp., Ruergeria sp., Paracoccus sp., Aeromonas sp. and Shewanella sp. Survival rates of gilthead sea bream larvae transferred to seawater added these bacterial strains at concentrations of 6 ± 0AE3 • 10 5 bacteria ml)1 were similar to those of larvae transferred to sterilized seawater and showed an average of 86% at 9 days after hatching, whereas, survival rates of larvae transferred to filtered seawater were lower (P < 0AE05), and showed an average of 39%, 9 days after hatching. Conclusion: Several bacterial strains isolated from well-performing live food cultures showed a positive effect for sea bream larvae when compared with filtered seawater. Significance and Impact of the Study: The approach used in this study could be applied as an in vivo evaluation method of candidate probiotic strains used in the rearing of marine fish larvae.

Research paper thumbnail of Antibacterial activity of essential oils from plants of the genus Origanum

Food Control, Dec 1, 2013

ABSTRACT In this study, three plant species, members of the family of Lamiaceae and the genus Ori... more ABSTRACT In this study, three plant species, members of the family of Lamiaceae and the genus Origanum, namely, Origanum vulgare subsp. hirtum, Origanum onites L., and Origanum marjorana L. were studied for their chemical composition and antibacterial activity. Essential oils of these plants were received by means of micro-steam distillation and their components were analyzed by gas chromatography and mass spectrometry (GC–EIMS). The major components identified in all three species are carvacrol and thymol. The oils were assayed as potential food control antimicrobial agents. In vitro studies showed that the essential oils showed strong antimicrobial activity against 5 bacterial and 1 yeast strains.

Research paper thumbnail of Microbiology and immunology of larviculture

HAL (Le Centre pour la Communication Scientifique Directe), Oct 5, 2010

Research paper thumbnail of Effects of rearing conditions on skeletal anomalies typology and frequency in gilthead seabream Sparus auratus juveniles

This study analyzed different lots of gilthead seabream juveniles outcoming from the same egg bat... more This study analyzed different lots of gilthead seabream juveniles outcoming from the same egg batch, but reared under different (intensive vs semi-intensive) conditions aimed at: (1) quantitatively and qualitatively analyzing whether differences in skeletal elements (shape and number) arise; (2) to investigate if a relationship between skeletal bone tissue/ossification and some environmentally-induced malformation exists; and (3) identifying the best practices for seabream larval rearing in order to obtain lower deformity rates. A total of 981 reared juveniles of gilthead seabream were analysed, among which 721 were from a commercial hatchery located in Northern Italy (Valle Figheri, Venice, Italy), and other 260 were obtained from the Hellenic Center for Marine Research (Iraklion, Crete, Greece). These individuals were from 4 different eggs batches (Groups 1-4), for a total of 10 different lots. Each egg batch/group was split after hatching in two lots, and reared with two differen...

Research paper thumbnail of The aquaculture supply chain in the time of covid-19 pandemic: Vulnerability, resilience, solutions and priorities at the global scale

Environmental Science & Policy, 2022

The COVID-19 global pandemic has had severe, unpredictable and synchronous impacts on all levels ... more The COVID-19 global pandemic has had severe, unpredictable and synchronous impacts on all levels of perishable food supply chains (PFSC), across multiple sectors and spatial scales. Aquaculture plays a vital and rapidly expanding role in food security, in some cases overtaking wild caught fisheries in the production of high-quality animal protein in this PFSC. We performed a rapid global assessment to evaluate the effects of the COVID-19 pandemic and related emerging control measures on the aquaculture supply chain. Socio-economic effects of the pandemic were analysed by surveying the perceptions of stakeholders, who were asked to describe potential supply-side disruption, vulnerabilities and resilience patterns along the production pipeline with four main supply chain components: a) hatchery, b) production/processing, c) distribution/logistics and d) market. We also assessed different farming strategies, comparing land- vs. sea-based systems; extensive vs. intensive methods; and with and without integrated multi-trophic aquaculture, IMTA. In addition to evaluating levels and sources of economic distress, interviewees were asked to identify mitigation solutions adopted at local / internal (i.e., farm-site) scales, and to express their preference on national / external scale mitigation measures among a set of a priori options. Survey responses identified the potential causes of disruption, ripple effects, sources of food insecurity, and socio-economic conflicts. They also pointed to various levels of mitigation strategies. The collated evidence represents a first baseline useful to address future disaster-driven responses, to reinforce the resilience of the sector and to facilitate the design reconstruction plans and mitigation measures, such as financial aid strategies.

Research paper thumbnail of The Synergistic Impacts of Anthropogenic Stressors and COVID-19 on Aquaculture: A Current Global Perspective

Reviews in Fisheries Science & Aquaculture, 2021

The rapid, global spread of COVID-19, and the measures intended to limit or slow its propagation,... more The rapid, global spread of COVID-19, and the measures intended to limit or slow its propagation, are having major impacts on diverse sectors of society. Notably, these impacts are occurring in the context of other anthropogenic-driven threats including global climate change. Both anthropogenic stressors and the COVID-19 pandemic represent significant economic challenges to aquaculture systems across the globe, threatening the supply chain of one of the most important sources of animal protein, with potential disproportionate impacts on vulnerable communities. A web survey was conducted in 47 countries in the midst of the COVID-19 pandemic to assess how aquaculture activities have been affected by the pandemic, and to explore how these impacts compare to those from climate change. A positive correlation between the effects of the two categories of drivers was detected, but analysis suggests that the pandemic and the anthropogenic stressors affect different parts of the supply chain. The immediate measurable reported losses varied with aquaculture typology (land vs. marine, and intensive vs. extensive). A comparably lower impact on farmers reporting the use of integrated multitrophic aquaculture (IMTA) methods suggests that IMTA might enhance resilience to multiple stressors by providing different market options under the COVID-19 pandemic. Results emphasize the importance of assessing detrimental effects of COVID-19 under a multiple stressor lens, focusing on areas that have already locally experienced economic loss due to anthropogenic stressors in the last decade. Holistic policies that simultaneously address other ongoing anthropogenic stressors, rather than focusing solely on the acute impacts of COVID-19, are needed to maximize the long-term resilience of the aquaculture sector.

Research paper thumbnail of Co-Culturing Microalgae with Roseobacter Clade Bacteria as a Strategy for Vibrionaceae Control in Microalgae-Enriched Artemia

Microorganisms

Bacterial communities associated with fish larvae are highly influenced by the microbiota of live... more Bacterial communities associated with fish larvae are highly influenced by the microbiota of live prey used as feed (rotifers or Artemia), generally dominated by bacterial strains with a low degree of specialization and high growth rates, (e.g., Vibrionaceae), which can be detrimental to larvae. Co-cultivation of microalgae used in the enrichment of Artemia (e.g., Phaeodactylum tricornutum, or Chlorella minutissima) with Vibrio-antagonistic probiotics belonging to the Roseobacter clade bacteria (e.g., Phaeobacter spp. or Ruegeria spp.) was studied. The introduction of the probiotics did not affect microalgae growth or significantly modify the composition of bacterial communities associated with both microalgae, as revealed by DGGE analysis. The inoculation of P. tricornutum with Ruegeria ALR6 allowed the maintenance of the probiotic in the scale-up of the microalgae cultures, both in axenic and non-axenic conditions. Using Ruegeria-inoculated P. tricornutum cultures in the enrichmen...

Research paper thumbnail of Characterization of Host-Associated Microbiota and Isolation of Antagonistic Bacteria from Greater Amberjack (Seriola dumerili, Risso, 1810) Larvae

Microorganisms

Greater amberjack (Seriola dumerili) is a new species in marine aquaculture with high mortalities... more Greater amberjack (Seriola dumerili) is a new species in marine aquaculture with high mortalities at the larval stages. The microbiota of amberjack larvae was analyzed using 16S rDNA sequencing in two groups, one added copepod nauplii (Acartia tonsa) in the diet, and one without copepods (control). In addition, antagonistic bacteria were isolated from amberjack larvae and live food cultures. Proteobacteria was the most abundant phylum followed by Bacteroidota in amberjack larvae. The composition and diversity of the microbiota were influenced by age, but not by diet. Microbial community richness and diversity significantly increased over time. Rhodobacteraceae was the most dominant family followed by Vibrionaceae, which showed the highest relative abundance in larvae from the control group 31 days after hatching. Alcaligenes and Thalassobius genera exhibited a significantly higher relative abundance in the copepod group. Sixty-two antagonistic bacterial strains were isolated and scr...

Research paper thumbnail of Food size selectivity of Artemia franciscana at three developmental stages

Journal of Plankton Research, Nov 1, 1999

Food size selectivity was examined in Artemia franciscana metanauplii at three different developm... more Food size selectivity was examined in Artemia franciscana metanauplii at three different developmental stages. Clearance rates were determined in short-term experiments either by measuring the decrease in concentration of live particles and plastic beads, or by measuring the radioactivity accumulated in animals that grazed 14 C-labelled live particles. The maximum clearance rate of A.franciscana metanauplii increased during development and was measured at 50-63 µl ind.-1 h-1 , 254 µl ind.-1 h-1 and 1.48-2.10 ml ind.-1 h-1 in 2-, 4-and 7-day-old metanauplii, respectively. A preference for particles with a diameter of 4-8 µm was observed at all three developmental stages. The ability of A.franciscana metanauplii to graze bacterial particles was also demonstrated, although the efficiency in grazing such small particles was low compared to microalgae (28, 20 and 9% of the maximum clearance rate in 2-, 4-and 7-day-old metanauplii, respectively). Electron microscopy showed that the inter-setular distance in antennae and thoracopods was 0.20 ± 0.07, 0.16 ± 0.05 and 0.18 ± 0.04 µm in 2-, 4-and 7-day-old metanauplii, respectively, and accordingly independent of stage.

Research paper thumbnail of The Probiotic Phaeobacter inhibens Provokes Hypertrophic Growth via Activation of the IGF-1/Akt Pathway during the Process of Metamorphosis of Greater Amberjack (Seriola dumerili, Risso 1810)

Animals, Jun 29, 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

Research paper thumbnail of Use of Phaeobacter sp. probiotic bacteria for the rearing of sea bass larvae (Dicentrarchus labrax)

Research paper thumbnail of Use of microalgae bioencapsulated in Artemia during the weaning of Senegalese sole (Solea senegalensis Kaup)

Aquaculture, Jul 1, 2009

The microalgae species Chlorella minutissima and Tetraselmis chuii were bioencapsulated in Artemi... more The microalgae species Chlorella minutissima and Tetraselmis chuii were bioencapsulated in Artemia metanauplii and used during the weaning of Senegalese sole, Solea senegalensis post-larvae. We evaluated the effect of microalgae on:(i) survival and growth ...

Research paper thumbnail of Antimicrobial activity in bacteria isolated from Senegalese sole, Solea senegalensis, fed with natural prey

Aquaculture Research, Dec 1, 2005

... The alignments of the sequences have been made using the Software Clustal X (Thompson, Gibson... more ... The alignments of the sequences have been made using the Software Clustal X (Thompson, Gibson, Plewniak, Jeanmougin &amp;amp; Higgins 1997), and ... with H. diversicolor differentiate from the microbial communities present in the sediments of their natural habitat (Lucas, Bertru &amp;amp; ...

Research paper thumbnail of Bioenergetic changes in the microalgal photosynthetic apparatus by extremely high CO<sub>2</sub>concentrations induce an intense biomass production

Physiologia Plantarum, Mar 1, 2008

Unicellular green alga Chlorella minutissima, grown under extreme carbon dioxide concentrations (... more Unicellular green alga Chlorella minutissima, grown under extreme carbon dioxide concentrations (0.036-100%), natural temperature and light intensities (Mediterranean conditions), strongly increase the microalgal biomass through photochemical and non-photochemical changes in the photosynthetic apparatus. Especially, CO 2 concentrations up to 10% enhance the density of active reaction centers (RC/CS o), decrease the antenna size per active reaction center (ABS/RC), decrease the dissipation energy (DI o /RC) and enhance the quantum yield of primary photochemistry (F v /F m). Higher CO 2 concentrations (20-25%) combine the above-mentioned photochemical changes with enhanced non-photochemical quenching of surplus energy, which leads to an enhanced steady-state fraction of 'open' (oxidized) PSII reaction centers (q p), and minimize the excitation pressure of PSII (1 2 q p) under very high light intensities (approximately 1700 mmol m 22 s 21 maximal value), avoiding the photoinhibition and leading to an enormous biomass production (approximately 2500%). In conclusion, these extreme CO 2 concentrations-about 1000 times higher than the ambient one-can be easily metabolized from the unicellular green alga to biomass and can be used, on a local scale at least, for the future development of microalgal photobioreactors for the mitigation of the factory-produced carbon dioxide.

Research paper thumbnail of Application of multi-species of Bacillus in sea bream larviculture

Aquaculture, Jul 1, 2010

To date, probiotics can be considered a valid alternative to the use of antibiotics in aquacultur... more To date, probiotics can be considered a valid alternative to the use of antibiotics in aquaculture and in particular, in fish larviculture, to prevent high mortality and to improve welfare and promote growth. In the two last decades, many studies reported promising results using a single beneficial bacterial strain in the culture of many finfish species. Looking for innovative ways to improve fish larviculture, we tested a mixture of Bacillus probiotic bacteria in the gilthead sea bream (Sparus aurata) larviculture focusing on their effects on survival, growth and general welfare. The mixture, composed of three Bacillus strains, Bacillus subtilis, Bacillus licheniformis and Bacillus pumilus was provided via rotifers and Artemia nauplia and added to the water (group 1) or supplied exclusively via live prey (group 2). The Bacillus mixture significantly increased growth in terms of standard length and body weight in both experimental groups, at larval and juvenile stages, 47 and 75 days after hatching, respectively, with the highest values obtained from Group 2 treatment. In addition, the expression of genes involved in growth metabolism (Insulin-like Growth Factors I and Myostatin) and animal welfare (70 KDa-Heat Shock Protein and Glucocorticoid Receptor) were analysed. The morphometric analysis was supported by molecular results which clearly evidenced higher expression of IGFI and lower levels of myostatin in groups fed on probiotics. In addition, a better tolerance to farming conditions was also found as evidenced by the lower expression of HSP70 and Glucocorticoid Receptor, suggesting beneficial effects of the supplied Bacillus mixture on fish welfare. The data generated in this study provide scientific and technical support for the implementation of sustainable development of sea bream aquaculture.

Research paper thumbnail of Microbial conditions and antimicrobial activity in cultures of two microalgae species, Tetraselmis chuii and Chlorella minutissima, and effect on bacterial load of enriched Artemia metanauplii

Aquaculture, May 1, 2006

The microbial conditions and antimicrobial activity were determined in batch cultures of two micr... more The microbial conditions and antimicrobial activity were determined in batch cultures of two microalgae species, Tetraselmis chuii and Chlorella minutissima. The number of bacteria associated with the microalgae cultures showed an exponential growth 2, 10, and 16 days after inoculation, and they were higher in T. chuii in all three sampling points compared with C. minutissima. No presumptive Vibrio strains were observed in any of the samples, as measured by the growth on TCBS agar. A total of 17 and 30 bacterial strains were isolated from C. minutissima and T. chuii, respectively. A high percentage of Gram-positive strains was detected among the bacterial strains isolated, as Gram-positive strains constituted 82% (14 / 17) and 73% (22 / 30) of the total numbers of isolates in C. minutissima and T. chuii, respectively. The isolated bacteria were screened in vitro for inhibition against two pathogenic strains, and nine of the 34 strains tested (26%) showed inhibition in vitro against either Photobacterium damselae, susp. piscicida or Vibrio anguillarum. Incubation of enriched Artemia in cultures of the two microalgae for 30 min resulted in a significant decrease of the bacterial load in Artemia (P b 0.05), and a significant decrease of the level of presumptive Vibrio in Artemia homogenates (P b 0.05). The results of this study demonstrate a simple and practical approach to decrease the microbial load and at the same time reduce the percentage of Vibrio among the bacteria associated with enriched Artemia.

Research paper thumbnail of Control of the bacterial flora of Brachionus plicatilis and Artemia franciscana by incubation in bacterial suspensions

Aquaculture, May 1, 2000

The accumulation of bacteria in Brachionus plicatilis and Artemia franciscana during a Ž. short-t... more The accumulation of bacteria in Brachionus plicatilis and Artemia franciscana during a Ž. short-term incubation was quantified using immunocolony blot ICB and an enzyme-linked Ž. immunosorbent assay ELISA. Four bacterial strains, isolated from turbot and halibut, were Ž 7

Research paper thumbnail of Oxygenation of European seabass (Dicentrarchus labrax L.) in cages through aeration and effect on lipid metabolism

Fish Physiology and Biochemistry, Feb 22, 2023

Research paper thumbnail of Influence of Microalgae Supernatant, and Bacteria Isolated from Microalgae Cultures, on Microbiology, and Digestive Capacity of Larval Gilthead Seabream, Sparus aurata, and Senegalese Sole, Solea senegalensis

Journal of the World Aquaculture Society, Oct 1, 2010

This study aimed at investigating addition of microalgae in the rearing of marine fish larvae (gr... more This study aimed at investigating addition of microalgae in the rearing of marine fish larvae (green water technique). Addition of microalgae supernatant, or bacteria isolated from microalgae cultures, to the rearing tanks of larval Senegalese sole, Solea senegalensis, and gilthead seabream, Sparus aurata, had no significant (P < 0.05) influence on survival or growth of the larvae. Addition of four bacterial strains isolated from microalgae decreased however the numbers of presumptive Vibrio in gilthead seabream larvae and seawater were compared with the control treatment 7 d after hatching (P < 0.05). No such effects were shown on the numbers of presumptive Vibrio in the rearing of sole larvae. Addition of bacteria improved the digestive capacity of gilthead seabream larvae, as the total activity (U/larva) of trypsin, amylase, and alkaline phosphatase in the treatment with added bacteria were significantly higher (P < 0.05) than in larvae from the control treatment 10 d after hatching. No such effects were shown in the case of sole larvae. The present results indicated that bacteria associated with microalgae may play an important role for the inhibition of proliferation of Vibrio and improvement of digestive capacity during the first days of feeding of gilthead seabream larvae, but does not appear to be beneficial for larvae of Senegalese sole.

Research paper thumbnail of Isolation of Phaeobacter sp. from Larvae of Atlantic Bonito (Sarda sarda) in a Mesocosmos Unit, and Its Use for the Rearing of European Seabass Larvae (Dicentrarchus labrax L.)

Microorganisms, Jan 8, 2021

Phaeobacter sp. from Larvae of Atlantic Bonito (Sarda sarda) in a Mesocosmos Unit, and Its Use fo... more Phaeobacter sp. from Larvae of Atlantic Bonito (Sarda sarda) in a Mesocosmos Unit, and Its Use for the Rearing of European Seabass Larvae (Dicentrarchus labrax L.).

Research paper thumbnail of Evaluation of candidate probiotic strains for gilthead sea bream larvae (Sparus aurata) using an in vivo approach

Letters in Applied Microbiology, Apr 1, 2005

The aim of this study was to evaluate the effect of six bacterial strains on gilthead sea bream l... more The aim of this study was to evaluate the effect of six bacterial strains on gilthead sea bream larvae (Sparus aurata). Methods and Results: Six bacterial strains isolated from well-performing live food cultures were identified by sequencing fragments of their 16s rDNA genome to the genus level as Cytophaga sp., Roseobacter sp., Ruergeria sp., Paracoccus sp., Aeromonas sp. and Shewanella sp. Survival rates of gilthead sea bream larvae transferred to seawater added these bacterial strains at concentrations of 6 ± 0AE3 • 10 5 bacteria ml)1 were similar to those of larvae transferred to sterilized seawater and showed an average of 86% at 9 days after hatching, whereas, survival rates of larvae transferred to filtered seawater were lower (P < 0AE05), and showed an average of 39%, 9 days after hatching. Conclusion: Several bacterial strains isolated from well-performing live food cultures showed a positive effect for sea bream larvae when compared with filtered seawater. Significance and Impact of the Study: The approach used in this study could be applied as an in vivo evaluation method of candidate probiotic strains used in the rearing of marine fish larvae.

Research paper thumbnail of Antibacterial activity of essential oils from plants of the genus Origanum

Food Control, Dec 1, 2013

ABSTRACT In this study, three plant species, members of the family of Lamiaceae and the genus Ori... more ABSTRACT In this study, three plant species, members of the family of Lamiaceae and the genus Origanum, namely, Origanum vulgare subsp. hirtum, Origanum onites L., and Origanum marjorana L. were studied for their chemical composition and antibacterial activity. Essential oils of these plants were received by means of micro-steam distillation and their components were analyzed by gas chromatography and mass spectrometry (GC–EIMS). The major components identified in all three species are carvacrol and thymol. The oils were assayed as potential food control antimicrobial agents. In vitro studies showed that the essential oils showed strong antimicrobial activity against 5 bacterial and 1 yeast strains.

Research paper thumbnail of Microbiology and immunology of larviculture

HAL (Le Centre pour la Communication Scientifique Directe), Oct 5, 2010

Research paper thumbnail of Effects of rearing conditions on skeletal anomalies typology and frequency in gilthead seabream Sparus auratus juveniles

This study analyzed different lots of gilthead seabream juveniles outcoming from the same egg bat... more This study analyzed different lots of gilthead seabream juveniles outcoming from the same egg batch, but reared under different (intensive vs semi-intensive) conditions aimed at: (1) quantitatively and qualitatively analyzing whether differences in skeletal elements (shape and number) arise; (2) to investigate if a relationship between skeletal bone tissue/ossification and some environmentally-induced malformation exists; and (3) identifying the best practices for seabream larval rearing in order to obtain lower deformity rates. A total of 981 reared juveniles of gilthead seabream were analysed, among which 721 were from a commercial hatchery located in Northern Italy (Valle Figheri, Venice, Italy), and other 260 were obtained from the Hellenic Center for Marine Research (Iraklion, Crete, Greece). These individuals were from 4 different eggs batches (Groups 1-4), for a total of 10 different lots. Each egg batch/group was split after hatching in two lots, and reared with two differen...

Research paper thumbnail of The aquaculture supply chain in the time of covid-19 pandemic: Vulnerability, resilience, solutions and priorities at the global scale

Environmental Science & Policy, 2022

The COVID-19 global pandemic has had severe, unpredictable and synchronous impacts on all levels ... more The COVID-19 global pandemic has had severe, unpredictable and synchronous impacts on all levels of perishable food supply chains (PFSC), across multiple sectors and spatial scales. Aquaculture plays a vital and rapidly expanding role in food security, in some cases overtaking wild caught fisheries in the production of high-quality animal protein in this PFSC. We performed a rapid global assessment to evaluate the effects of the COVID-19 pandemic and related emerging control measures on the aquaculture supply chain. Socio-economic effects of the pandemic were analysed by surveying the perceptions of stakeholders, who were asked to describe potential supply-side disruption, vulnerabilities and resilience patterns along the production pipeline with four main supply chain components: a) hatchery, b) production/processing, c) distribution/logistics and d) market. We also assessed different farming strategies, comparing land- vs. sea-based systems; extensive vs. intensive methods; and with and without integrated multi-trophic aquaculture, IMTA. In addition to evaluating levels and sources of economic distress, interviewees were asked to identify mitigation solutions adopted at local / internal (i.e., farm-site) scales, and to express their preference on national / external scale mitigation measures among a set of a priori options. Survey responses identified the potential causes of disruption, ripple effects, sources of food insecurity, and socio-economic conflicts. They also pointed to various levels of mitigation strategies. The collated evidence represents a first baseline useful to address future disaster-driven responses, to reinforce the resilience of the sector and to facilitate the design reconstruction plans and mitigation measures, such as financial aid strategies.

Research paper thumbnail of The Synergistic Impacts of Anthropogenic Stressors and COVID-19 on Aquaculture: A Current Global Perspective

Reviews in Fisheries Science & Aquaculture, 2021

The rapid, global spread of COVID-19, and the measures intended to limit or slow its propagation,... more The rapid, global spread of COVID-19, and the measures intended to limit or slow its propagation, are having major impacts on diverse sectors of society. Notably, these impacts are occurring in the context of other anthropogenic-driven threats including global climate change. Both anthropogenic stressors and the COVID-19 pandemic represent significant economic challenges to aquaculture systems across the globe, threatening the supply chain of one of the most important sources of animal protein, with potential disproportionate impacts on vulnerable communities. A web survey was conducted in 47 countries in the midst of the COVID-19 pandemic to assess how aquaculture activities have been affected by the pandemic, and to explore how these impacts compare to those from climate change. A positive correlation between the effects of the two categories of drivers was detected, but analysis suggests that the pandemic and the anthropogenic stressors affect different parts of the supply chain. The immediate measurable reported losses varied with aquaculture typology (land vs. marine, and intensive vs. extensive). A comparably lower impact on farmers reporting the use of integrated multitrophic aquaculture (IMTA) methods suggests that IMTA might enhance resilience to multiple stressors by providing different market options under the COVID-19 pandemic. Results emphasize the importance of assessing detrimental effects of COVID-19 under a multiple stressor lens, focusing on areas that have already locally experienced economic loss due to anthropogenic stressors in the last decade. Holistic policies that simultaneously address other ongoing anthropogenic stressors, rather than focusing solely on the acute impacts of COVID-19, are needed to maximize the long-term resilience of the aquaculture sector.

Research paper thumbnail of Co-Culturing Microalgae with Roseobacter Clade Bacteria as a Strategy for Vibrionaceae Control in Microalgae-Enriched Artemia

Microorganisms

Bacterial communities associated with fish larvae are highly influenced by the microbiota of live... more Bacterial communities associated with fish larvae are highly influenced by the microbiota of live prey used as feed (rotifers or Artemia), generally dominated by bacterial strains with a low degree of specialization and high growth rates, (e.g., Vibrionaceae), which can be detrimental to larvae. Co-cultivation of microalgae used in the enrichment of Artemia (e.g., Phaeodactylum tricornutum, or Chlorella minutissima) with Vibrio-antagonistic probiotics belonging to the Roseobacter clade bacteria (e.g., Phaeobacter spp. or Ruegeria spp.) was studied. The introduction of the probiotics did not affect microalgae growth or significantly modify the composition of bacterial communities associated with both microalgae, as revealed by DGGE analysis. The inoculation of P. tricornutum with Ruegeria ALR6 allowed the maintenance of the probiotic in the scale-up of the microalgae cultures, both in axenic and non-axenic conditions. Using Ruegeria-inoculated P. tricornutum cultures in the enrichmen...

Research paper thumbnail of Characterization of Host-Associated Microbiota and Isolation of Antagonistic Bacteria from Greater Amberjack (Seriola dumerili, Risso, 1810) Larvae

Microorganisms

Greater amberjack (Seriola dumerili) is a new species in marine aquaculture with high mortalities... more Greater amberjack (Seriola dumerili) is a new species in marine aquaculture with high mortalities at the larval stages. The microbiota of amberjack larvae was analyzed using 16S rDNA sequencing in two groups, one added copepod nauplii (Acartia tonsa) in the diet, and one without copepods (control). In addition, antagonistic bacteria were isolated from amberjack larvae and live food cultures. Proteobacteria was the most abundant phylum followed by Bacteroidota in amberjack larvae. The composition and diversity of the microbiota were influenced by age, but not by diet. Microbial community richness and diversity significantly increased over time. Rhodobacteraceae was the most dominant family followed by Vibrionaceae, which showed the highest relative abundance in larvae from the control group 31 days after hatching. Alcaligenes and Thalassobius genera exhibited a significantly higher relative abundance in the copepod group. Sixty-two antagonistic bacterial strains were isolated and scr...