Papers by Ioannis T Karapanagiotidis
Sustainable Chemistry and Pharmacy, Oct 1, 2023
Comparative Biochemistry and Physiology Part D: Genomics and Proteomics, Dec 1, 2020
A major challenge in fish physiology is to understand the mechanisms underlying the transcriptomi... more A major challenge in fish physiology is to understand the mechanisms underlying the transcriptomic responses of fish brain to food deprivation. Differential gene expression analysis identified in total 2240 transcripts that presented > 2-fold change (adjusted p < 0.01) between each treatment and the control group (C). The identity of the transcripts was obtained with annotation against multiple public databases and they were grouped according to their expression patterns. The gene ontology terms that were substantially affected were identified by functional annotation analysis. Genes related to ion transport, cell cycle and cell adhesion were mainly regulated during fasting and refeeding. These findings contribute to identify key indicators for the molecular basis of brain functions during periods of starvation in gilthead seabream.
The autotropic, heterotrophic and mixotrophic cultivation mode of the microalgae Microchloropsis ... more The autotropic, heterotrophic and mixotrophic cultivation mode of the microalgae Microchloropsis gaditana was studied. Three sets of experiments were carried out: In the first set, six experimental groups were tested; one autotrophic, one heterotrophic and four mixotrophic where cultivation modes carried out and biomass productivities were compared to each other. In the second and in the third set of experiments, the algae were exposed to four or five concentrations of cobalt (Co) or of molybdenum (Mo) respectively; in these sets of experiments the effect of Co and Mo on the biomass productivity and on the lipid content and distribution of M. gaditana was examined. In the 1 st set of experiments, the mixotrophic cultivations, the initial carbon concentration, C(0), was equal to 2.87 g/L, 2.92 g/L, 3.96 g/L and 4.96 g/L and in the heterotrophic cultivation C(0) was equal to 2.24 g/L. Nitrogen initial concentration, Ν(0), was held constant at 77.1 mg/L. For the heterotrophic and the three mixotrophic cultivations, the biomass yield, when expressed as g/(per L-g of added carbon) was highest for the heterotrophic growth. In the 2 nd and 3 rd sets of experiments it was found that both Co and Mo affect biomass productivity and lipid distribution. Co, even at relatively medium concentrations, strongly inhibited the growth. On the other hand, Mo, even at relatively high concentrations, did not affect substantially the growth rate of M. gaditana. The lipid distribution showed that for most treatments with varying concentrations of Co and Mo, MUFA prevailed while, n-3 PUFA up to
Journal of insects as food and feed, Nov 23, 2020
Frontiers in Physiology, Mar 27, 2023
Freshwater crayfish are considered as aquatic products of high quality and high nutritional value... more Freshwater crayfish are considered as aquatic products of high quality and high nutritional value. The increasing demand has led to populations reduction in several locations throughout their range. Thus, the development of appropriate rearing conditions is considered necessary, among which, optimization of their diet is a basic part. Towards this direction, in the present study, a 98-day feeding trial was carried out to evaluate the impact of dietary fishmeal substitution by Hermetia illucens meal on Pontastacus leptodactylus juveniles kept under laboratory conditions. Insect meals represent an environmentally friendly alternative solution, considered as a high-value feed source, rich in nutrients such as protein and fat. Three dietary regimens were utilized with a fishmeal-based without Hermetia meal (HM) defined as the control diet (HM0), and two diets, the first with 50% (HM50) and the second with 100% (HM100) of fishmeal substitution by HM, respectively. Growth performance, whole-body composition, and fatty acid profiles of individuals were studied in the different treatments. At the end of the feeding trial, statistically significant differences were observed in the mean survival rate (SR), specific growth rate (SGR), feed conversion ratio (FCR) and weight gain (WG) values. More specifically, animals fed with HM-based diets had higher mean SR, while the control group performed better regarding FCR and SGR. The HM inclusion in the diet significantly altered the whole-body chemical composition of the crayfish signifying a different metabolic utilization compared to fishmeal (FM). The fatty acid analysis revealed that 16:0 (palmitic acid) was the predominant saturated fatty acid (SFA), 18:1ω9 (oleic acid) was found to be the main monounsaturated fatty acid (MUFA), while 18:2ω6 (linoleic acid) represented the major polyunsaturated fatty acid (PUFA) followed by C20:3 cis ω3 (cis-11-14-17-eicosatrienoate) and C22:6 cis ω3 (cis-4,7,10,13,16,19-Docosahexaenoic) fatty acids. The inclusion of dietary HM significantly reduced the contents of ∑SFAs, ∑PUFAs and ∑ω6 fatty acids, as well as those of C22:6 cis ω3 and increased the ω6/ω3 and hypocholesterolemic to hypercholesterolemic ratios in the body. In parallel with improvements in balanced diets and in culture conditions that need to be optimised for rearing of freshwater crayfish, our study provides new data that enlighten the suitability of insect meals in the nutrition of P. leptodactylus.
Frontiers in Physiology
Freshwater crayfish are considered as aquatic products of high quality and high nutritional value... more Freshwater crayfish are considered as aquatic products of high quality and high nutritional value. The increasing demand has led to populations reduction in several locations throughout their range. Thus, the development of appropriate rearing conditions is considered necessary, among which, optimization of their diet is a basic part. Towards this direction, in the present study, a 98-day feeding trial was carried out to evaluate the impact of dietary fishmeal substitution by Hermetia illucens meal on Pontastacus leptodactylus juveniles kept under laboratory conditions. Insect meals represent an environmentally friendly alternative solution, considered as a high-value feed source, rich in nutrients such as protein and fat. Three dietary regimens were utilized with a fishmeal-based without Hermetia meal (HM) defined as the control diet (HM0), and two diets, the first with 50% (HM50) and the second with 100% (HM100) of fishmeal substitution by HM, respectively. Growth performance, who...
Journal of Applied Phycology, 1990
In this research, the effect of solar irradiance on Chlorella vulgaris cultivated in open bioreac... more In this research, the effect of solar irradiance on Chlorella vulgaris cultivated in open bioreactors under greenhouse conditions was investigated, as well as of ratio of light intensity in the 420-520 nm range to light in the 580-680 nm range (I 420-520 /I 580-680) and of artificial irradiation provided by red and white LED lamps in a closed flat plate laboratory bioreactor on the growth rate and composition. The increase in solar irradiance led to faster growth rates (µ exp) of C. vulgaris under both environmental conditions studied in the greenhouse (in June up to 0.33 d −1 and in September up to 0.29 d −1) and higher lipid content in microalgal biomass (in June up to 25.6% and in September up to 24.7%). In the experiments conducted in the closed bioreactor, as the ratio I 420-520 /I 580-680 increased, the specific growth rate and the biomass, protein and lipid productivities increased as well. Additionally, the increase in light intensity with red and white LED lamps resulted in faster growth rates (the µ exp increased up to 0.36 d −1) and higher lipid content (up to 22.2%), while the protein, fiber, ash and moisture content remained relatively constant. Overall, the trend in biomass, lipid, and protein productivities as a function of light intensity was similar in the two systems (greenhouse and bioreactor).
Fishes
The aim of this study is to investigate the effect of 10 and 20% replacement of fishmeal (FM diet... more The aim of this study is to investigate the effect of 10 and 20% replacement of fishmeal (FM dietary group) with the superworm Zophobas morio larvae meal (ZM10 and ZM20 dietary groups) on the growth performance of sea bass (Dicentrarchus labrax) and lettuce plants (Lactuca sativa) reared in aquaponics. Ninety juvenile sea bass with an average body weight of 21.55 g/individual were placed in aquaponic fish tanks, together with 24 lettuce plants with an average initial height of 8.90 cm/plant and an average number of leaves of 5.75/plant over a 45-day trial period. At the end of that period, all feeding groups exhibited high survival. In fact, ΖΜ10 and ZM20 groups showed similar fish weight gain and specific growth rate (SGR) (p > 0.05), but significantly lower SGR (p < 0.05) than the FM group. Nevertheless, final fish body weight and length were similar (p > 0.05) for all feeding groups. No plant mortality was observed during the 45-day study period. All three aquaponic syst...
HAL (Le Centre pour la Communication Scientifique Directe), Oct 7, 2014
Journal of Insects as Food and Feed, 2021
Much research has been directed towards the optimisation of the mass rearing of the yellow mealwo... more Much research has been directed towards the optimisation of the mass rearing of the yellow mealworm, Tenebrio molitor, in terms of diet and rearing conditions. However, an issue that has not been thoroughly investigated to date is the strain effect on the larval growth and performance of T. molitor. To close this gap, the plasticity in growth and development, as well as the feed conversion efficiency and the nutritional composition of larvae of seven T. molitor strains of different geographic origins (Greece, Italy, Germany, Turkey, Spain and USA) were comparatively evaluated in the present study. Based on the results, there were considerable differences in the performance of the strains tested. Larval weight at harvest was the highest for a strain originated from Germany; however, the higher final body mass was at the cost of longer development time and higher feed intake, the latter having a negative impact in the overall performance and productivity of the strain. No significant ...
Journal of Insects as Food and Feed, 2021
Organic side-streams and agricultural wastes represent a big pool of untapped and underrated reso... more Organic side-streams and agricultural wastes represent a big pool of untapped and underrated resources which could be efficiently exploited for insect rearing. We evaluated the suitability of eleven agricultural by-products, stemming from the production of cotton, sugar beet, sunflower, barley, oats, peas and vetch, for the development of larvae of the yellow mealworm, Tenebrio molitor. In a first bioassay, by-products were screened singly to evaluate their potential to support the development of middle sized (4th-6th instar) larvae. In a second bioassay, by-products were supplemented with carrot, and their potential to support complete larval development (first instar until first pupation) was evaluated. Lastly, a third bioassay was conducted in which the more promising by-products were used as components of isonitrogenous diets for middle sized larvae, at two nitrogen levels (2.7 and 3.2%). Our results show the suitability of several agricultural by-products from Greece for T. mol...
Animals, 2020
Reducing the energy content of broiler diets could lead to the formulation of diets with reduced ... more Reducing the energy content of broiler diets could lead to the formulation of diets with reduced production cost. Dimethylgycine (DMG) has been used as a dietary supplement to enhance dietary fat utilization in poultry. The objective of the present study was to investigate the effects of DMG supplementation in reduced energy diets on performance and nutrient digestibility in broiler chickens. Four hundred and eighty day-old broilers were randomly allocated to three dietary treatments: a standard energy diet (PC treatment), a reduced energy diet by 66 kcal/kg (NC treatment) and the reduced energy diet supplemented with 500 mg/kg of DMG (DMG treatment). Fat digestibility was significantly higher in DMG group, compared to PC and NC groups. Intestines and gizzard lesion scores were found to be lower in the DMG group compared to PC. DMG supplementation resulted in lower jejunum pH and ileum viscosity in broilers. Overall, the present study showed that DMG supplementation in reduced energ...
Euro-Mediterranean Journal for Environmental Integration, 2020
In the era of blue growth, maritime spatial planning (MSP)-especially MSP using a place-based app... more In the era of blue growth, maritime spatial planning (MSP)-especially MSP using a place-based approach-is absolutely essential if the sustainable management of oceans and seas is to be achieved. This paper therefore presents relevant lessons learnt from a study of a pilot marine area of Greece (the Inner Ionian Sea-Corinthian Gulf region). The study showed that, in order to develop and perform efficient place-based MSP in Greece, it is necessary to strengthen cross-border cooperation among countries that share the eastern Mediterranean Sea, to effectively engage the maritime regime and stakeholders in governance schemes, to collect and manage marine geospatial data, and to have a good grasp of the tools and methodologies that can be used in MSP. Moreover, the present paper identifies suitable criteria for defining appropriate MSP management units, considering ecosystem boundaries, management boundaries, geopolitical boundaries, socioeconomic and cultural characteristics, and land-sea interactions. The process of identifying the optimal MSP management units is underway in Greece; this step is crucial to performing place-based MSP and, ultimately, MSP utilizing the ecosystem-based approach.
Applied Sciences, 2020
The simultaneous use of crude glycerol and effluent from anaerobic digestate, both wastes derived... more The simultaneous use of crude glycerol and effluent from anaerobic digestate, both wastes derived from the biofuel industry, were tested in the frame of circular economy concept, as potential low-cost nutrient sources for the cultivation of rich in docosahexaenoic acid (DHA) oil microalgae strain Schizochytrium limacinum SR21. Initially, the optimal carbon and nitrogen concentration levels for high S. limacinum biomass and lipids production were determined, in a culture media containing conventional, high cost, organic nitrogen sources (yeast extract and peptone), micronutrients and crude glycerol at varying concentrations. Then, the effect of a culture media composed of crude glycerol (as carbon source) and effluent digestate at varying proportions on biomass productivity, lipid accumulation, proximate composition, carbon assimilation and fatty acid content were determined. It was shown that the biomass and total lipid content increased considerably with varying effluent concentrat...
Plants, 2019
The effect of different environmental conditions on the growth rate, biomass production, nutrient... more The effect of different environmental conditions on the growth rate, biomass production, nutrient composition, and phenolic content of the microalgae species Chlorella vulgaris, Botryococcus braunii, Chlamydomonas reinhardtii, Euglena gracilis, and Nannochloropsis oculata was investigated. The experiments were conducted in open bioreactors in a greenhouse in three different periods (during October, March, and June), and in a controlled environment in a closed plant growth chamber. It was found that the growth rate and production of C. vulgaris and B. braunii was higher during March, C. reinhardtii and N. oculata grew better in June, and the growth of E. gracilis was similar in March and June. The lipid content of the biomass of all five species increased with increasing light intensity and temperature, while the nitrogen free extractable (NFE) content decreased and the protein, fiber, moisture, and ash content remained relatively unaffected. The phenolic content varied from species ...
Journal of Chemical Technology & Biotechnology, 2018
BACKGROUND: The effects of the initial nitrogen concentration, as well as of twostage and prolong... more BACKGROUND: The effects of the initial nitrogen concentration, as well as of twostage and prolonged cultivation on the growth rate, lipid and protein content of Chlorella vulgaris were examined. Additionally, a kinetic model of specific growth rate in the exponential growth phase (μ exp) was developed as a function of initial nitrogen concentration. RESULTS: As the initial nitrogen concentration in the culture medium increased, the total biomass production and μ exp went through a maximum at 300 mg N L-1 and at 200 mg N L-1 , respectively. The lipid content was found to be highly dependent on the initial nitrogen concentration and increased from 9.0% to 29.6% as the nitrogen concentration varied from 800 mg N L-1 to 10 mg N L-1 , respectively. Cultivation in two stages resulted in an increase of the lipid content of the biomass from 15.4% to 24.9%, while prolonged cultivation led to an increase of the lipid content from 15.4% to 23.0%.
Tilapia in Intensive Co-culture, 2016
Agronomy, 2022
The ability of microalgae, such as the rich in docosahexaenoic acid (DHA) heterotrophic marine mi... more The ability of microalgae, such as the rich in docosahexaenoic acid (DHA) heterotrophic marine microalgae Schizochytrium limacinum SR21, to utilize nutrients in their culture media derived from low-cost nutrient sources makes them a promising low-cost alternative source for the production of useful substances used in aqua feeds. The assessment of culture parameters, one of which is the pH, for every different nutrient growth medium used for microalgae cultivation is important, as they affect the biomass and secondary metabolite microalgae production. This study assessed the effect of different growth medium pH levels (6, 7, 8 and 9), at laboratory and pilot scale systems, on S. limacinum biomass productivity, lipid accumulation, proximate composition, carbon assimilation and DHA. The microalgae were cultivated in growth media containing two different alternative low-cost nutrient sources: (a) crude glycerol derived from biofuel industry as carbon source and (b) effluent digestate fr...
Uploads
Papers by Ioannis T Karapanagiotidis