The digestive tract sections of the sea cucumber Isostichopus badionotus reveal differences in composition, diversity, and functionality of the gut microbiota.

For the first time, this study analyses the composition and diversity of the gut microbiota of Isostichopus badionotus in captivity, using high-throughput 16S rRNA sequencing, and predicts the metagenomic functions of the microbiota. The results revealed a different composition of the gut microbiota for the foregut (FG) and midgut (MG) compared to the hindgut (HG), with a predominance of Proteobacteria, followed by Actinobacteria, Bacteroidetes, and Firmicutes. The FG and MG demonstrated a greater bacterial diversity compared to the HG. In addition, a complex network of interactions was observed at the genus level and identified some strains with probiotic and bioremediation potentials, such as Acinetobacter, Ruegeria, Streptococcus, Lactobacillus, Pseudomonas, Enterobacter, Aeromonas, Rhodopseudomonas, Agarivorans, Bacillus, Enterococcus, Micrococcus, Bifidobacterium, and Shewanella. Predicting metabolic pathways revealed that the bacterial composition in each section of the intestine participates in different physiological processes such as metabolism, genetic and environmental information processing, organismal systems, and cellular processes. Understanding and manipulating microbe--host-environment interactions and their associated functional capacity could substantially contribute to achieving more sustainable aquaculture systems for I. badionotus.

Protein hydrolysate of poultry by-product and swine liver in the diet of pacific white shrimp / Roteína hidrolisada de subprodutos de frango e fígado suíno na dieta do camarão-branco-do-pacífico

This study aimed to evaluate the use of protein hydrolysate of poultry by-product and swine liver in the diet of Litopenaeus vannamei and its effect on the intestinal microbiota and on the enzymatic activity of the hepatopancreas. Shrimp (10.94 ± 0.90 g) were fed with diets containing 0%, 25%, 50%, 75% and 100% of replacement of salmon by-product meal by protein hydrolysate, in triplicate. The hepatopancreas enzymatic activity and composition of intestinal microbiota was studied. It was observed that the protein hydrolysate in the diet changed the enzymatic activity of the shrimp when compared to the control group (p <0.05). Amylase activity increases directly with the percent of protein replacement in the diet. Metagenomic analysis revealed change in the gut biome of the shrimps. The increasing levels of protein replacement provided greater richness and diversity in gut microbiota in the 75% and 100% treatments, which were mainly related to changes in the abundances in the families Rhodobacteraceae and Flavobacteriaceae. A reduction in the abundance of the Vibrionaceae family was observed with the inclusion of protein hydrolysate in the diet. These results indicate that the protein hydrolysate demonstrated beneficial changes when added at concentrations of 25% in the diet of L. vannamei.(AU)

Este estudo teve como objetivo avaliar a utilização de hidrolisado proteico de subproduto de aves e fígado de suíno na dieta do Litopenaeus vannamei e seu efeito na microbiota intestinal e na atividade enzimática do hepatopâncreas. Camarões (10,94 ± 0,90 g) foram alimentados com dietas contendo 0%, 25%, 50%, 75% e 100% de substituição da farinha de subproduto de salmão pela proteína hidrolisada, em triplicata. A atividade enzimática do hepatopâncreas e a composição da microbiota intestinal foram estudadas. Observou-se que a proteína hidrolisada da dieta alterou a atividade enzimática do camarão quando comparado ao grupo controle (p <0,05). A atividade da amilase aumentou diretamente com a porcentagem de reposição de proteínas na dieta. A análise metagenômica revelou mudança no bioma intestinal dos camarões. Os níveis crescentes de reposição proteica proporcionaram maior riqueza e diversidade no trato digestório nos tratamentos 75% e 100%, estando principalmente relacionadas a mudanças na abundância das famílias Rhodobacteraceae e Flavobacteriaceae. Uma redução na abundância da família Vibrionaceae foi observada com a inclusão do hidrolisado proteico na dieta. Esses resultados indicam que a proteína hidrolisada demonstrou alterações benéficas quando adicionada em concentrações de 25% na dieta do L. vannamei.(AU)

Protein hydrolysate of poultry by-product and swine liver in the diet of pacific white shrimp / Roteína hidrolisada de subprodutos de frango e fígado suíno na dieta do camarão-branco-do-pacífico

This study aimed to evaluate the use of protein hydrolysate of poultry by-product and swine liver in the diet of Litopenaeus vannamei and its effect on the intestinal microbiota and on the enzymatic activity of the hepatopancreas. Shrimp (10.94 ± 0.90 g) were fed with diets containing 0%, 25%, 50%, 75% and 100% of replacement of salmon by-product meal by protein hydrolysate, in triplicate. The hepatopancreas enzymatic activity and composition of intestinal microbiota was studied. It was observed that the protein hydrolysate in the diet changed the enzymatic activity of the shrimp when compared to the control group (p <0.05). Amylase activity increases directly with the percent of protein replacement in the diet. Metagenomic analysis revealed change in the gut biome of the shrimps. The increasing levels of protein replacement provided greater richness and diversity in gut microbiota in the 75% and 100% treatments, which were mainly related to changes in the abundances in the families Rhodobacteraceae and Flavobacteriaceae. A reduction in the abundance of the Vibrionaceae family was observed with the inclusion of protein hydrolysate in the diet. These results indicate that the protein hydrolysate demonstrated beneficial changes when added at concentrations of 25% in the diet of L. vannamei.

Este estudo teve como objetivo avaliar a utilização de hidrolisado proteico de subproduto de aves e fígado de suíno na dieta do Litopenaeus vannamei e seu efeito na microbiota intestinal e na atividade enzimática do hepatopâncreas. Camarões (10,94 ± 0,90 g) foram alimentados com dietas contendo 0%, 25%, 50%, 75% e 100% de substituição da farinha de subproduto de salmão pela proteína hidrolisada, em triplicata. A atividade enzimática do hepatopâncreas e a composição da microbiota intestinal foram estudadas. Observou-se que a proteína hidrolisada da dieta alterou a atividade enzimática do camarão quando comparado ao grupo controle (p <0,05). A atividade da amilase aumentou diretamente com a porcentagem de reposição de proteínas na dieta. A análise metagenômica revelou mudança no bioma intestinal dos camarões. Os níveis crescentes de reposição proteica proporcionaram maior riqueza e diversidade no trato digestório nos tratamentos 75% e 100%, estando principalmente relacionadas a mudanças na abundância das famílias Rhodobacteraceae e Flavobacteriaceae. Uma redução na abundância da família Vibrionaceae foi observada com a inclusão do hidrolisado proteico na dieta. Esses resultados indicam que a proteína hidrolisada demonstrou alterações benéficas quando adicionada em concentrações de 25% na dieta do L. vannamei.

Evaluation of two independent protocols for the extraction of DNA and RNA from different tissues of sea cucumber Isostichopus badionotus.

Isostichopus badionotus is a sea cucumber species of great ecological and economic relevance for Mexico and Central American and Caribbean countries; however, the protocols for the extraction of the nucleic acids have not yet been published. In this study, we describe the first protocols to obtain DNA and RNA from different tissues of I. badionotus, which include the respiratory tree, gonad, longitudinal muscle bands, anterior intestine and cloaca. The extraction of high-quality DNA was performed using the DNeasy Blood & Tissue kit (Qiagen, Valencia, CA, USA) with minor modifications in different points of the protocol. Concerning the RNA, the method of TRIzol was used. This method is particularly advantageous in situations where cells or tissues are enriched for endogenous RNases or when the separation of cytoplasmic RNA from nuclear RNA is impractical. The methodologies used in this study allowed us to obtain DNA and RNA of high quality and integrity in the different tissues of I. badionotus, which will be the basis for future genomic and transcriptomic studies. •The successful extraction of DNA and RNA was achieved in the different tissues of I. badionotus.•The concentrations of DNA and RNA obtained were adequate for a diversity of analyses at a molecular level.

Integrated effect of nutrients from a recirculation aquaponic system and foliar nutrition on the yield of tomatoes Solanum lycopersicum L. and Solanum pimpinellifolium.

The objective of this study was to evaluate the potential of tomato plants to efficiently use the nitrogen (N) of a recirculation aquaponic system (RAS) and to evaluate the effects of foliar fertilization as a complement to the water nutrition on the growth of the two tomato cultivars. The significant effect of six macro- and seven micronutrients was evaluated on the plant growth and on the fruit yield. Two experiments were performed in a nutrient film aquaponic unit. The first experiment was designed to study the effects of foliar fertilization on the seedlings of two tomato cultivars Costoluto Genovese (CG) (Solanum lycopersicum L.) and Currant tomato (Ct) (Solanum pimpinellifolium) with 8% of weekly water exchange (WE8%-RAS). The foliar fertilizer was formulated with N restriction in the last 11 weeks (TF1). In the second experiment, two other foliar fertilization treatments (TF2 and TF3) were applied with a concentration of nutrients twice and triple that in TF1, but with a lower proportion of NPK ratio. These treatments were tested on the cultivar CG in a RAS with zero water exchange (WE0%-RAS). The data from the 1st experiment showed a positive effect of the foliar fertilization on the yield of both cultivars. The fertilization markedly influenced the dry matter weight of the CG; however, this effect was not observed in the Ct. The root length of both cultivars was positively influenced by the P content, whereas the plant height was affected by the excess of Co and S. According to the results from the 2nd experiment, the TF2 plants had the highest number of fruits with a high mean weight. The system was efficient in utilizing N from fish tank; the water K favored the yield of the CG fruit and the foliar K favored the growth of the TF2 plants. With a decrease in the foliar N, the CG plants were able to absorb 27.5% of the NO3- and 7.06% of total ammonia nitrogen from water. The absolute and relative growth rate of Nile tilapia was not affected by the rate of water exchange. Fulton's condition factor of the total length and weight curve indicated that fish from WE8%-RAS had wider bodies than the fish from WE0%-RAS at the same length range. Nitrate and P in the final effluent were lower than the maximum reference values allowed for the discharged water.

Growth kinetics of Escherichia coli O157: H7 on the epicarp of fresh vegetables and fruits

Despite the increasing reports on the incidence of fresh vegetables and fruits as a possible vehicle for human pathogens, there is currently limited knowledge on the growth potential of Escherichia coli O157:H7 on different plant substrates. This study analyzed the selective adhesion and growth of E. coli O157:H7 on chili habanero (Capsicum chinense L.), cucumber (Cucumis sativus), radish (Raphanus sativus), tomato (Lycopersicon esculentum), beet (Beta vulgaris subsp. vulgaris), and onion (Allium cepa L.) under laboratory conditions. The Gompertz parameters were used to determine the growth kinetics. Scanning electron microscopy was used to visualize the adhesion of E. coli O157:H7 on the epicarp of the samples. Predictive models were constructed to compare the growth of E. coli O157:H7 on the samples with different intrinsic factors and to demonstrate the low selectivity of the pathogen. No significant difference was observed in the lag-phase duration (LPD), generation time (GT), and exponential growth rate (EGR) of the pathogen adhered to the samples. The interaction between the microorganism and the substrate was less supportive to the growth of E. coli O157:H7 for onion, whereas for tomato and cucumber, the time for the microorganism to attain the maximum growth rate (M) was significantly longer than that recorded for other samples.(AU)

Growth kinetics of Escherichia coli O157: H7 on the epicarp of fresh vegetables and fruits

ABSTRACT Despite the increasing reports on the incidence of fresh vegetables and fruits as a possible vehicle for human pathogens, there is currently limited knowledge on the growth potential of Escherichia coli O157:H7 on different plant substrates. This study analyzed the selective adhesion and growth of E. coli O157:H7 on chili habanero (Capsicum chinense L.), cucumber (Cucumis sativus), radish (Raphanus sativus), tomato (Lycopersicon esculentum), beet (Beta vulgaris subsp. vulgaris), and onion (Allium cepa L.) under laboratory conditions. The Gompertz parameters were used to determine the growth kinetics. Scanning electron microscopy was used to visualize the adhesion of E. coli O157:H7 on the epicarp of the samples. Predictive models were constructed to compare the growth of E. coli O157:H7 on the samples with different intrinsic factors and to demonstrate the low selectivity of the pathogen. No significant difference was observed in the lag-phase duration (LPD), generation time (GT), and exponential growth rate (EGR) of the pathogen adhered to the samples. The interaction between the microorganism and the substrate was less supportive to the growth of E. coli O157:H7 for onion, whereas for tomato and cucumber, the time for the microorganism to attain the maximum growth rate (M) was significantly longer than that recorded for other samples.

Phenotypic plasticity in gene expression and physiological response in red drum Sciaenops ocellatus exposed to a long-term freshwater environment.

Red drum (Sciaenops ocellatus) is a euryhaline fish commonly found in the Gulf of Mexico and along the Atlantic coast of North America. Because of high commercial demand and its euryhaline characteristics, aquaculture of this species has diversified from marine to low-salinity aquaculture systems. In recent years, interest in the feasibility of producing red drum in inland freshwater systems has grown and this prompted us to investigate its osmoregulatory capacity after rearing for 8 months in a freshwater aquaculture system. We compared the activities of several genes and enzymes involved in the osmoregulatory process in freshwater-acclimatized (FW) and seawater (SW) red drum. The gene expression profiles were variable: the expression of genes encoding Na+/K+-ATPase (NKA) and the cystic fibrosis transmembrane regulator (CFTR) was slightly higher in SW than FW fish, while phosphoenolpyruvate carboxykinase (PEPCK) and the glucocorticoid receptor messenger RNA (mRNA) levels were higher in FW red drum. The total plasma K concentration was 60.3% lower, and gill NKA activity was 63.5% lower in FW than in SW fish. PEPCK activity was twofold higher in FW than in SW red drum. Similarly, liver glycogen was 60% higher in FW fish. In summary, both gene expression and the enzyme activity data support the phenotypic plasticity of red drum and suggest that the limited capacity for ion homeostasis observed, in particular the low plasma K concentration, was due to the composition of freshwater and does not necessarily reflect a physiological inability to osmoregulate.

Growth kinetics of Escherichia coli O157:H7 on the epicarp of fresh vegetables and fruits.

Despite the increasing reports on the incidence of fresh vegetables and fruits as a possible vehicle for human pathogens, there is currently limited knowledge on the growth potential of Escherichia coli O157:H7 on different plant substrates. This study analyzed the selective adhesion and growth of E. coli O157:H7 on chili habanero (Capsicum chinense L.), cucumber (Cucumis sativus), radish (Raphanus sativus), tomato (Lycopersicon esculentum), beet (Beta vulgaris subsp. vulgaris), and onion (Allium cepa L.) under laboratory conditions. The Gompertz parameters were used to determine the growth kinetics. Scanning electron microscopy was used to visualize the adhesion of E. coli O157:H7 on the epicarp of the samples. Predictive models were constructed to compare the growth of E. coli O157:H7 on the samples with different intrinsic factors and to demonstrate the low selectivity of the pathogen. No significant difference was observed in the lag-phase duration (LPD), generation time (GT), and exponential growth rate (EGR) of the pathogen adhered to the samples. The interaction between the microorganism and the substrate was less supportive to the growth of E. coli O157:H7 for onion, whereas for tomato and cucumber, the time for the microorganism to attain the maximum growth rate (M) was significantly longer than that recorded for other samples.

Optimization of the Ultrasound-Assisted Extraction of Phenolic Compounds from Brosimum alicastrum Leaves and the Evaluation of Their Radical-Scavenging Activity.

In order to maximize the yield of the total phenolic content (TPC) and total monomeric anthocyanin (TMA) from Brosimum alicastrum leaf and to study the radical-scavenging activity, a three-level three-factor Box-Behnken design (BBD) was used to determine the optimal points for ultrasound-assisted extraction (UAE). In this study, we analyzed the extraction time (10, 20, and 30 min), temperature (28, 30, and 32 °C), and probe sonication power (40%, 28 W/cm²; 60%, 51 W/cm²; and 80%, 74 W/cm²). Analysis of variance (ANOVA) indicated that the sonication power plays a significant role in the extraction of phenolic compounds. An increase in time and temperature resulted in a decrease in the yield, in particular, of the TMA group. DPPH was found to be a better indicator of radical-scavenging activity than ABTS. The predicted TPC and TMA optimum levels (45.18 mg GAE/g and 15.16 mg CyE/100 g) were obtained at 28 °C, 80%, and 20-10 min. DPPH obtained a maximum value (67.27 µmol TE/g) under same optimization conditions. The RSM confirmed that TPC and TMA enhanced the antioxidant activity when subjected to low temperature (28 °C), extraction time less than 20 min, and higher sonication power (74 W/cm²), and hence achieving the better DPPH scavenging activity.

Physiological changes in the red drum after long-term freshwater acclimation.

The effect of long-term freshwater acclimation on the blood and plasma ion composition of Red Drum Sciaenops ocellatus was investigated with the goal of elucidating the necessity of ion remediation. Four replicates (n = 50) of freshwater-acclimated (FW) fish (1.6 ± 0.2 g) were raised in 25-m(3) tanks supported by 140,000 L of recirculating water. Four replicates (n = 50) of seawater (SW) fish groups were placed in 40-m(3) offshore cages at 32-35 psu. Blood was collected from 100 fish (FW = 578 ± 50 g; SW = 686 ± 45 g) of each group (FW, SW) after 8 months of rearing. During the grow-out phase, the survival of FW and SW fish was 57.5% and 92.2%, respectively. The water ion composition (mainly the Ca(2+)/K(+) [43%] and Ca(2+)/Mg(2+) ratios [1%]) explained 56.6% of the plasmatic ion variability in the fish groups. Freshwater exposure produced significant reductions in osmolality and in several plasma indicators (Na(+), Cl(-), and Mg(2+)); the K(+) levels from FW fish were the most compromised parameter. The water Ca(2+)/Na(+) ratio had a greater influence (44%) on the plasma chemistry parameters, mainly glucose and creatinine. Freshwater-acclimated fish had a higher percentage of hematocrit, hemoglobin, and red blood cells than SW fish, but the water quality explained only 12.5% of the blood parameter variability between the FW and SW groups. The results support the conclusion that Red Drum tolerates salinity variations and can adopt a relatively stable condition for short periods; however, the data suggest that Red Drum have only a limited ability to withstand a hyposmotic environment for long periods due to their limited ability in maintaining K(+) concentrations without external supplementation. Freshwater environments with high Ca(2+)/Na(+), Ca(2+)/K(+), and Ca(2+)/Mg(2+) ratios appear to be a chronic stress factor that should be considered in future experiments.