Papers by Chiara Ceccotti
Aquaculture
Aquaculture is one of the world's fastest growing food-producing sectors, providing more than hal... more Aquaculture is one of the world's fastest growing food-producing sectors, providing more than half of all fish consumed globally for human nutrition. However, to maintain such growth and meet the increasing demand for aquatic food, sustainable raw materials for fish feeds are needed. In this regard, insects represent one of the most promising alternatives to fish meal (FM) protein source for use in aquafeeds. In addition to protein, insects contain bioactive compounds, such as chitin, which is a natural polysaccharide abundantly present in the pupal exuviae of some insects. Studies have shown that dietary chitin or its derivate chitosan acts as a prebiotic thus modulating the gut microbial communities of fish. Accordingly, the present study aimed to evaluate the effect of two waste products rich in chitin, i.e., shrimp head meal (SHM), and insect (Hermetia illucens) pupal exuviae on the gut microbiota of rainbow trout (Oncorhynchus mykiss). Three isoproteic, isolipidic, and isoenergetic diets containing either FM, SHD, or a combination of FM and 1.6% of pupal exuviae meal (PEM) were tested through a 91-day feeding trial. At the end of the experiment, no differences in final mean body weight, specific growth rate, and feed conversion ratio values were observed between fish experimental groups. Mortality was <1% and it did not correlate with diet for the entire duration of the trial. However, a modulatory effect of dietary pupal exuviae on fish gut microbiota was detected. Indeed, gut bacterial species richness improved by including insect exuviae. In particular, Firmicutes and Actinobacteria phyla, mainly represented by Bacillus, Facklamia, Brevibacterium, and Corynebacterium genera, were enriched in trout receiving pupal exuviae. These genera are chitinolytic and shortchain fatty acids (SCFAs)-producing bacteria. SCFAs production was confirmed by gas chromatography analysis, which detected the highest amount of butyrate in feces of trout fed with pupal exuviae meal. Functional inference analysis of intestinal microbiota using PICRUST metagenome prediction tool, showed differences in response to diet. In particular, eleven pathways were significantly different between control fish (FM) and fish fed the PEM diet, whereas twenty functional traits were significantly different between the FM and SHM fish groups. Overall, our data confirmed that chitin from insect's pupal exuviae represents a promising functional ingredient, better than SHM, for positively modulating gut microbiota communities of rainbow trout.
<p>Intestinal morphology parameters of the proximal and distal gilthead sea bream intestine... more <p>Intestinal morphology parameters of the proximal and distal gilthead sea bream intestine.</p
<p>(<b>A</b>) Immunohistochemical co-localization of 5-HT with the neuronal mar... more <p>(<b>A</b>) Immunohistochemical co-localization of 5-HT with the neuronal marker HuC/D and with calbindin (CB). 5-HT immunoreactivity was detected in the soma and axon of myenteric neurons with a large rounded soma and visible dendrites (arrow). Some 5-HT-IR neurons displayed an elongated soma (arrowheads) with a long axon. The co-localization between 5-HT and CB was almost total. Staining Bars: 50 μm. (<b>B</b>) Percentage of 5-HT-IR neurons in the proximal (empty bar) and distal (slashed bar) sea bream intestine. Values are given as mean ± SEM of 7–11 fields for each intestinal region. Vertical bars indicate SEM. (<b>C</b>) Size distribution of the cell body of 5-HT-IR neurons in the whole, proximal and distal intestine gilthead sea bream intestine.</p
<p>Immunohistochemical co-localization of SP with the neuronal marker HuC/D in whole mounts... more <p>Immunohistochemical co-localization of SP with the neuronal marker HuC/D in whole mounts of the proximal and distal gilthead sea bream intestine. (<b>A</b>) Both in the proximal and distal intestine, SP immunoreactivity was detected in fibers running along the smooth muscle layers (asterisks) and in the soma of sparse neurons displaying either an elongated (arrow) or a rounded soma with short dendrites (arrowhead). Bars: 50 μm. (<b>B</b>) Percentage of SP immunoreactive neurons in the proximal (empty bar) and distal (slashed bar) gilthead sea bream intestine. Values are given as mean ± SEM of 7 fieldsfor each intestinal region. Vertical bars indicate SEM; *<i>P</i>≤0.05 by Student’s t. (<b>C</b>) Size distribution of the cell body of SP neurons in the whole, proximal and distal intestine gilthead sea bream intestine.</p
<p>(<b>A</b>) Immunohistochemical co-localization of ChAT with the neuronal mar... more <p>(<b>A</b>) Immunohistochemical co-localization of ChAT with the neuronal marker HuC/D. Both in the proximal and distal intestine, ChAT immunoreactivity was found in myenteric neurons and in fibers oriented in longitudinal direction. Some ChAT-IR uniaxonal neurons displayed a smaller-medium range size oval soma with smooth contours (arrow). Other neurons in the medium range size had an irregular profile with broad lamellar dendrites (arrowhead), and a small number of neurons had smooth, round or oval cell bodies (asterisk). Bars: 50 μm. (<b>B</b>) Percentage of ChAT-IR neurons in the proximal (empty bar) and distal (slashed bar) gilthead sea bream intestine. Values are given as mean ± SEM of 9–14 fields sections for the proximal and distal region, respectively. Vertical bars indicate SEM, *<i>P</i>≤0.05 by Student’s t test. (<b>C</b>) Size distribution of the cell body of ChAT-IR neurons in the whole, proximal and distal gilthead sea bream intestine.</p
<p>The data were tested by ANOVA followed by Tukey's HSD test to determine whether ther... more <p>The data were tested by ANOVA followed by Tukey's HSD test to determine whether there were any significant differences between different groups. Fish were fed for 8 weeks two different diets, a control diet, and an experimental diet, which was the control diet supplemented with 2g/kg (0.2%) of Na- butyrate. Each histogram shows the mean ± SEM of 105 animals. Different letters indicate significant differences (<i>P</i> < 0.05).</p
Current Issues in Molecular Biology
In aquafeeds in which plant proteins are used to replace fishmeal, exogenous methionine (Met) sou... more In aquafeeds in which plant proteins are used to replace fishmeal, exogenous methionine (Met) sources are demanded to balance the amino acid composition of diets and meet the metabolic fish requirements. Nonetheless, since different synthetic Met sources are commercially available, it is important to determine their bioavailability and efficacy. To address this issue, we conducted a two-month feeding trial with rainbow trout (Oncorhynchus mykiss), which were fed diets supplemented with five different forms of Met: Met-Met, L-Met, HMTBa, DL-Met, and Co DL-Met. No differences in growth performance were found in trout fed with different Met forms, but changes in the whole-body composition were found. In particular, Met-Met and L-Met promoted a significant body lipid reduction, whereas the protein retention was significantly increased in fish fed with HMTBa and Co DL-Met. The latter affected the hepatic Met metabolism promoting the trans-sulfuration pathway through the upregulation of C...
<p>One–dimensional immune-blotting analysis of histones H2A and H3 as well as H3, H4 acetyl... more <p>One–dimensional immune-blotting analysis of histones H2A and H3 as well as H3, H4 acetylated histones is shown. Each column represents individual fish. 3 μg histone protein per lane were loaded for the detection of histones H2A, and H3, and 6 μg per lane for histone H4. Before immunodetection, a reversible Ponceau staining was applied to membranes to test equal loading of gels and protein transfer. After X-ray film exposure, densitometry was used to quantify protein levels on the western blots by means of Quantity One 1-D software (Bio-Rad). Putative isoforms for histone H3 [H3.1 (upper band) and H3.2 (lower band)] were accounted for the densitometry analysis.</p
<p>(<b>A</b>) Immunohistochemical co-localization of nNOS with HuC/D. In both r... more <p>(<b>A</b>) Immunohistochemical co-localization of nNOS with HuC/D. In both regions, nNOS-IR neurons displayed a variable size and morphology. Some neurons displayed a large polygonal soma, one long axon and short dendrites (arrow). Other nNOS-IR neurons were unipolar with a rounded soma and short dendrites (arrowhead). Few neurons displayed an elongated oval soma (asterisk). nNOS-IR was also found in neuronal fibers running along the smooth muscle layer. Bars: 50 μm. (<b>B</b>) Percentage of nNOS immunoreactive neurons in the proximal (empty bar) and distal (slashed bar) gilthead sea bream intestine. Values are given as mean ± SEM of 15 fields for each intestinal region. (C) Size distribution of the cell body of nNOS immunoreactive neurons in the whole, proximal and distal gilthead sea bream intestine.</p
<p>Two-way ANOVA statistical analysis of the expression of genes involved in epigenetic reg... more <p>Two-way ANOVA statistical analysis of the expression of genes involved in epigenetic regulatory mechanisms.</p
Animal Feed Science and Technology
Waste Management, 2022
Research on bioconversion based on insects is intensifying as it addresses the problem of reducin... more Research on bioconversion based on insects is intensifying as it addresses the problem of reducing and reusing food and industrial waste. To reach this goal, we need to find more means of pairing waste to insects. With this goal, brewers' spent grains (BSG)-a food waste of the brewing industry-paired with the oleaginous biomass of the thraustochytrid Schizochytrium limacinum cultivated on crude glycerol-a major waste of biodiesel production-were successfully used to grow Hermetia illucens larvae. Combining BSG and S. limacinum in the diet in an attempt to design the lipid profile of H. illucens larvae to contain a higher percentage of omega-3 fatty acids is novel. Insect larvae were grown on three different substrates: i) standard diet for Diptera (SD), ii) BSG, and iii) BSG + 10% S. limacinum biomass. The larvae and substrates were analyzed for fatty acid composition and larval growth was measured until 25% of insects reached the prepupal stage. Our data showed that including omega-3rich S. limacinum biomass in the BSG substrate promoted an increase in larval weight compared to larvae fed on SD or BSG substrates. Furthermore, it was possible, albeit in a limited way, to incorporate omega-3 fatty acids, principally docosahexaenoic acid (DHA) from BSG + S. limacinum substrate containing 20% of DHA into the larval fat (7% DHA). However, H. illucens with this level of DHA may not be suitable if the aim is to get larvae with high omega-3 lipids to feed carnivorous fish.
Frontiers in Marine Science, 2021
Using a circular economy concept, the present study investigated the use of crude glycerol, a pri... more Using a circular economy concept, the present study investigated the use of crude glycerol, a primary by-product of biodiesel production, as a low-priced nutrient source for heterotrophic cultivation of the fungus-like protist Schizochytrium limacinum SR21 strain. The whole biomass of this oleaginous microorganism, rich in docosahexaenoic acid (DHA) and high-quality proteins, was then paired with a vegetable oil (VO) source and used to replace fish oil (FO) in European sea bass (Dicentrarchus labrax) feeds. Four nutritionally balanced diets were formulated: diet FO (a FO-based diet), diet VO + 0 (a VO-based diet without S. limacinum), and diets VO + 5 and VO + 10 that were VO-based feeds supplemented with 5 and 10% of S. limacinum, respectively. After a 3-month feeding trial, fish of all dietary groups tripled their initial weight, but growth and feeding efficiencies of D. labrax were not significantly different among treatments. Although the formulated diets were balanced for polyu...
Scientific Reports, 2021
Alternative nutrient sources to fishmeal for fish feed, such as insect meals, represent a promisi... more Alternative nutrient sources to fishmeal for fish feed, such as insect meals, represent a promising sustainable supply. However, the consequences for fish digestive function have not been exhaustively investigated. In the present study we evaluated the effect of partial fishmeal substitution with 10% Hermetia illucens (Hi10) larvae meal on the neuromuscular function of proximal and distal intestine in gilthead sea bream. In animals fed with insect meal, weight and growth parameters were similar to controls fed with conventional fishmeal. In addition, no anomalies in intestinal gross morphology and no overt signs of inflammation were observed. The gastrointestinal transit was significantly reduced in Hi10 fed animals. In the proximal and distal intestine longitudinal muscle, Hi10 feeding downregulated the excitatory cholinergic and serotoninergic transmission. Sodium nitroprusside-induced inhibitory relaxations increased in the proximal intestine and decreased in the distal intestine...
PeerJ, 2020
BackgroundIn the last two decades, research has focused on testing cheaper and sustainable altern... more BackgroundIn the last two decades, research has focused on testing cheaper and sustainable alternatives to fish oil (FO), such as vegetable oils (VO), in aquafeeds. However, FO cannot be entirely replaced by VOs due to their lack of omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA), particularly eicosapentaenoic (EPA; 20:5n-3) and docosahexaenoic (DHA; 22:6n-3) acids. The oilseed plant,Camelina sativa, may have a higher potential to replace FO since it can contains up to 40% of the omega-3 precursorsα-linolenic acid (ALA; 18:3n-3) and linoleic acid (LA; 18:2n-6).MethodsA 90-day feeding trial was conducted with 600 gilthead sea bream (Sparus aurata) of 32.92 ± 0.31 g mean initial weight fed three diets that replaced 20%, 40% and 60% of FO with CO and a control diet of FO. Fish were distributed into triplicate tanks per diet and with 50 fish each in a flow-through open marine system. Growth performance and fatty acid profiles of the fillet were analysed. The Illumina MiS...
Animals, 2020
This study investigated, for the first time, the effects of replacement of fishmeal (FM) with ins... more This study investigated, for the first time, the effects of replacement of fishmeal (FM) with insect meal from Hermetia illucens (HI) on the transcript levels of three genes involved in methionine (Met) metabolism in rainbow trout (Oncorhynchus mykiss) liver. Two target genes—betaine-homocysteine S-methyltransferase (BHMT) and S-adenosylhomocysteine hydrolase (SAHH)—are involved in Met resynthesis and the third one—cystathionine β synthase (CBS)—is involved in net Met loss (taurine synthesis). We also investigated the levels of two Met metabolites involved in the maintenance of methyl groups and homocysteine homeostasis in the hepatic tissue: S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH). Three diets were formulated, an FM-based diet (HI0) and two diets in which 25% (HI25) and 50% (HI50) of FM was replaced with HI larvae meal. A 78-day feeding trial involved 360 rainbow trout with 178.9 ± 9.81 g initial average weight. Dietary replacement of up to 50% of FM with HI lar...
Animals, 2019
Taurine (Tau) is an amino sulfonic acid, which is widely distributed in animal tissues, whereas i... more Taurine (Tau) is an amino sulfonic acid, which is widely distributed in animal tissues, whereas it is almost lacking in plants with the exception of certain algae, seaweeds, and few others. In the aquafeed industry, Tau is mainly used as a feed additive to promote growth in marine fish species with limited cysteine sulfinate decarboxylase activity. In particular, Tau supplementation is required in feeds in which fishmeal (FM) is substituted with high percentages of plant-derived protein sources such as soybean meals (SBM) that have much lower levels of Tau than FM. In addition to being a growth promoter, Tau exert powerful antioxidant properties being a scavenger of the reactive oxygen species (ROS). Under sustained swimming conditions, an intracellular increase in ROS production can occur in fish red muscle where the abundance of mitochondria (the main site of ROS formation) is high. Accordingly, this study aimed at investigating the effects of dietary Tau on European seabass (Dice...
Reviews in Fish Biology and Fisheries, 2019
Insects have been identified as an economically sustainable high-value, and safe proteinrich alte... more Insects have been identified as an economically sustainable high-value, and safe proteinrich alternative to fishmeal in compound feeds for farmed fish. Accordingly, the present study aimed to evaluate the effects of substitution of fishmeal with insect meal from Hermetia illucens in the diet of rainbow trout (Oncorhynchus mykiss), on fish growth performance, and gut microbiota composition. For this purpose, three diets, with increasing levels of insect prepupae meal inclusion (10%, 20% and 30%) in partial substitution of fishmeal and a control diet without insect meal were tested in a 12-weeks feeding trial. Fish growth and feed conversion ratio were evaluated. The Illumina MiSeq platform for high-throughput amplicon sequencing of 16S rRNA gene and QIIME pipeline were used to analyse and characterize the whole microbiome associated to aquafeeds, and fish gut. The number of reads taxonomically classified according to the Greengenes database was 1,140,534. We identified 450 OTUs at 97% identity in trout fecal samples; 62 OTUs constituted the core gut microbiota. Actinobacteria, Firmicutes and Proteobacteria represented the dominant phyla in both experimental groups. Among them, the abundance of Actinobacteria and Proteobacteria was significantly influenced by including insect meal in the diet. In summary, our findings clearly indicated that insect meal positively modifies fish gut microbiota, increasing its richness and diversity and in particular, increasing the amount of beneficial lactic acid-and butyrate-producing bacteria, which contribute to the global health of the host. In addition, based on our present and previous studies, we believe that the prebiotic effect of insect meal is principally due to fermentable chitin. Keywords Aquaculture Á Gut microbiota Á Hermetia illucens Á Insect meal Á Metagenomics Á Rainbow trout Genciana Terova and Simona Rimoldi have contributed equally to this work.
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Papers by Chiara Ceccotti