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The red tide-forming microalga Heterosigma akashiwo has been associated with massive events of fish deaths, both wild and cultured. Culture conditions are responsible for the synthesis or accumulation of some metabolites with different interesting bioactivities. H. akashiwo LC269919 strain was grown in a 10 L bubble column photobioreactor artificially illuminated with multi-coloured LED lights. Growth and production of exopolysaccharides, polyunsaturated fatty acids (PUFAs), and carotenoids were evaluated under different culture modes (batch, fed-batch, semicontinuous, and continuous) at two irradiance levels (300 and 700 µE·s−1·m−2). Continuous mode at the dilution rate of 0.2·day−1 and 700 µE·s−1·m−2 provided the highest production of biomass, PUFAs (132.6 and 2.3 mg·L−1·day−1), and maximum fucoxanthin productivity (0.16 mg·L−1·day−1). The fed-batch mode accumulated exopolysaccharides in a concentration (1.02 g·L−1) 10-fold over the batch mode. An extraction process based on a sequential gradient partition with water and four water-immiscible organic solvents allowed the isolation of bioactive fucoxanthin from methanolic extracts of H. akashiwo. Metabolites present in H. akashiwo, fucoxanthin and polar lipids (i.e., eicosapentaenoic acid (EPA)), or probably such as phytosterol (β-Sitosterol) from other microalgae, were responsible for the antitumor activity obtained. [ABSTRACT FROM AUTHOR]

This study investigated the effects of dietary commercial feed (n = 50,025 in triplicate, named group PF for soil dike pond, sampling n = 7; n = 15,000 in triplicate, WF for water tank, n = 8), iced fish (n = 50,025 in triplicate, PI, n = 7), and a combination of both (n = 50,025 in triplicate, PFI, n = 8) on different metabolic parameters of the largemouth bass, Micropterus salmoides (0.67 ± 0.09 g, culture period from June 2017 to July 2018). Throughout the experimental period, different areas of water (including input water of the front, middle of the pond, and from the drain off at the back) and their mixed samples were simultaneously analyzed to find the source of the main infectious bacteria. Various feeding strategies may differentially affect body composition and shape the gut microbiota, but the mode of action has not been determined. Results showed that no significant differences were found in the growth performance except for the product yield using a different culture mode (PFI vs. WF). For muscle composition, the higher ∑SFA, ∑MUFA, ∑n-6PUFA, and 18:3n-3/18:2n-6 levels were detected in largemouth bass fed with iced fish, while enrichment in ∑n-3PUFA and ∑HUFA was detected in largemouth bass fed with commercial feed. For the gut microbiota, Fusobacteria, Proteobacteria, and Firmicutes were the most dominant phyla among all the gut samples. The abundance of Firmicutes and Tenericutes significantly decreased and later increased with iced fish feeding. The relative abundance of species from the Clostridia, Mollicutes, Mycoplasmatales, and families (Clostridiaceae and Mycoplasmataceae) significantly increased in the feed plus iced fish (PFI) group relative to that in the iced fish (PI) group. Pathways of carbohydrate metabolism and the digestive system were enriched in the commercial feed group, whereas infectious bacterial disease resistance-related pathways were enriched in the iced fish group, corresponding to the higher rate of death, fatty liver disease, and frequency and duration of cyanobacteria outbreaks. Feeding with iced fish resulted in more activities in the digestive system and energy metabolism, more efficient fatty acid metabolism, had higher ∑MUFA, and simultaneously had the potential for protection against infectious bacteria from the environment through a change in intestinal microbiota in the pond of largemouth bass culturing. Finally, the difference in feed related to the digestive system may contribute to the significant microbiota branch in the fish gut, and the input and outflow of water affects the intestinal flora in the surrounding water and in the gut, which in turn affects growth and disease resistance. [ABSTRACT FROM AUTHOR]

This study aimed to compare the nutritional composition, digestive enzyme activity, nonspecific immunity, and intestinal microflora of Procambarus clarkii under different culture modes: crayfish and crab coculture, pond intensive farmed culture (PF), rice and crayfish coculture (RC), cement pond culture (CP), and wild-caught. The muscle, hepatopancreas, and intestine of crayfish with a mean weight of 25.35 ± 4.23 g were collected and examined. The results showed that the nutritive value of amino acids and fatty acids in the muscle was higher in the RC group than in the other groups. Moreover, muscle crude protein contents were the highest in the CP group. Trypsin activities in the intestines were significantly higher in the PF and CP groups than in the other groups (P

This study investigated the effects of dietary commercial feed (n = 50,025 in triplicate, named group PF for soil dike pond, sampling n = 7; n = 15,000 in triplicate, WF for water tank, n = 8), iced fish (n = 50,025 in triplicate, PI, n = 7), and a combination of both (n = 50,025 in triplicate, PFI, n = 8) on different metabolic parameters of the largemouth bass, Micropterus salmoides (0.67 ± 0.09 g, culture period from June 2017 to July 2018). Throughout the experimental period, different areas of water (including input water of the front, middle of the pond, and from the drain off at the back) and their mixed samples were simultaneously analyzed to find the source of the main infectious bacteria. Various feeding strategies may differentially affect body composition and shape the gut microbiota, but the mode of action has not been determined. Results showed that no significant differences were found in the growth performance except for the product yield using a different culture mode (PFI vs. WF). For muscle composition, the higher ∑SFA, ∑MUFA, ∑n-6PUFA, and 18:3n-3/18:2n-6 levels were detected in largemouth bass fed with iced fish, while enrichment in ∑n-3PUFA and ∑HUFA was detected in largemouth bass fed with commercial feed. For the gut microbiota, Fusobacteria, Proteobacteria, and Firmicutes were the most dominant phyla among all the gut samples. The abundance of Firmicutes and Tenericutes significantly decreased and later increased with iced fish feeding. The relative abundance of species from the Clostridia, Mollicutes, Mycoplasmatales, and families (Clostridiaceae and Mycoplasmataceae) significantly increased in the feed plus iced fish (PFI) group relative to that in the iced fish (PI) group. Pathways of carbohydrate metabolism and the digestive system were enriched in the commercial feed group, whereas infectious bacterial disease resistance-related pathways were enriched in the iced fish group, corresponding to the higher rate of death, fatty liver disease, and frequency and duration of cyanobacteria outbreaks. Feeding with iced fish resulted in more activities in the digestive system and energy metabolism, more efficient fatty acid metabolism, had higher ∑MUFA, and simultaneously had the potential for protection against infectious bacteria from the environment through a change in intestinal microbiota in the pond of largemouth bass culturing. Finally, the difference in feed related to the digestive system may contribute to the significant microbiota branch in the fish gut, and the input and outflow of water affects the intestinal flora in the surrounding water and in the gut, which in turn affects growth and disease resistance.

The red tide-forming microalga Heterosigma akashiwo has been associated with massive events of fish deaths, both wild and cultured. Culture conditions are responsible for the synthesis or accumulation of some metabolites with different interesting bioactivities. H. akashiwo LC269919 strain was grown in a 10 L bubble column photobioreactor artificially illuminated with multi-coloured LED lights. Growth and production of exopolysaccharides, polyunsaturated fatty acids (PUFAs), and carotenoids were evaluated under different culture modes (batch, fed-batch, semicontinuous, and continuous) at two irradiance levels (300 and 700 µE·s−1·m−2). Continuous mode at the dilution rate of 0.2·day−1 and 700 µE·s−1·m−2 provided the highest production of biomass, PUFAs (132.6 and 2.3 mg·L−1·day−1), and maximum fucoxanthin productivity (0.16 mg·L−1·day−1). The fed-batch mode accumulated exopolysaccharides in a concentration (1.02 g·L−1) 10-fold over the batch mode. An extraction process based on a sequential gradient partition with water and four water-immiscible organic solvents allowed the isolation of bioactive fucoxanthin from methanolic extracts of H. akashiwo. Metabolites present in H. akashiwo, fucoxanthin and polar lipids (i.e., eicosapentaenoic acid (EPA)), or probably such as phytosterol (β-Sitosterol) from other microalgae, were responsible for the antitumor activity obtained.

Amylases are enzymes required for starch degradation and are naturally produced by many microorganisms. These enzymes are used in several fields such as food processing, beverage, and medicine as well as in the formulation of enzymatic detergents proving their significance in modern biotechnology. In this study, a three-stage growth mode was applied to enhance starch production and amylase detection from Chlorella vulgaris. Stress conditions applied in the second stage of cultivation led to an accumulation of proteins (75% DW) and starch (21% DW) and a decrease in biomass. Amylase activities were detected and they showed high production levels especially on day 3 (35 U/ml) and day 5 (22.5 U/ml) of the second and third stages, respectively. The bioinformatic tools used to seek amylase protein sequences from TSA database of C. vulgaris revealed 7 putative genes encoding for 4 α-amylases, 2 β-amylases, and 1 isoamylase. An in silico investigation showed that these proteins are different in their lengths as well as in their cellular localizations and oligomeric states though they share common features like CSRs of GH13 family or active site of GH14 family. In brief, this study allowed for the production and in silico characterization of amylases from C. vulgaris. [ABSTRACT FROM AUTHOR]

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Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To compare the flesh quality of large yellow croaker cultured with three different modes, enclosure culture (EC), cage culture with feeding trash fish (CCF) and cage culture with feeding formula diet (CCD), thirty six fish individuals of EC (484.6 ± 79.8 g), CCF (432.7 ± 87.9 g) and CCD (416.9 ± 49.5 g) were sampled to measure body color, flesh water holding capacity, flesh proximate composition, amino acids and fatty acids composition, and collagen and inosinic acid contents. The analysis showed that there was no significant difference in the yellowness of skin and the contents of crude protein and inosinic acid between CCD and EC (P >0.05), and the two modes showed higher values than CCF ( P < 0.05). Most of the amino acids (AA) in flesh were higher in EC than in CCF ( P < 0.05), but CCD showed no difference in AA composition from the other two modes ( P > 0.05). EC and CCD had higher contents of collagen, free AA and lower drip loss than CC ( P < 0.05). In polyunsaturated fatty acids, EC showed significantly higher levels of C20:5n-3 and C22:6n-3 than CCF and CCD ( P < 0.05), but CCD had significantly higher C18:2n-6 than CCF and EC ( P < 0.05). In conclusion, the flesh quality of CCD fish is similar to EC fish, and these two modes have better flesh quality than CCF. [ABSTRACT FROM AUTHOR]

Virus-like particles (VLPs) are nanostructures that resemble the structures of viruses. They are composed of one or more structural proteins that can be arranged in several layers and can also contain a lipid outer envelope. VLPs trigger a high humoral and cellular immune response due to their repetitive structures. A key factor regarding VLP safety is the lack of viral genomic material, which enhances safety during both manufacture and administration. Contemporary VLP production may take advantage of several systems, including bacterial, yeast, insect and mammalian cells. The choice of production platform depends on several factors, including cost and the need for post-translational modifications (PTMs), which can be essential in generating an optimal immune response. Some VLP-based vaccines designed to prevent several infectious diseases are already approved and on the market, with many others at the clinical trial or research stage. Interest in this technology has recently increased due to its advantages over classical vaccines. This paper reviews the state-of-the-art of VLP production systems and the newest generation of VLP-based vaccines now available. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are prevalent in aquatic environments worldwide, but the occurrence of MPs in different mariculture modes has not been clarified. Four extensively cultured bivalves and ambient surface water were collected to study the MPs pollution characteristics of different mariculture modes. The results indicated that MPs abundance in the inland mode water was 2.5 times higher than that in the marine mode water. The MPs hazard index was evaluated as 655, 390, and 23 in the surface water of the inland, coastal, and marine aquaculture modes, respectively. The MPs abundance in the bivalves in the inland mode was significantly higher than that in the other two modes. There was a positive relationship between the MPs characteristics in the mariculture water and in the cultured bivalves. The abundance of MPs in the four bivalves (calculated items/g) was negatively correlated with soft tissue weight. This study further improves the understanding of MPs pollution characteristics in different aquaculture modes and further highlights the general transmission risk of MPs in various aquaculture systems. [Display omitted] • The MPs abundance in the inland mode water was 2.5 times higher than that in the marine mode water. • The MPs hazard index was evaluated in the surface water of various aquaculture systems. • Of the mariculture modes, the inland mode had the highest MPs abundance. • MPs characteristics in the water and bivalves were consistent. [ABSTRACT FROM AUTHOR]

[Objective] This study aimed to investigate the culture conditions for hairy roots of Aconitum coreanum (Levl.) Raipaies and optimize the amplification culture conditions in bioreactors, thus providing basis for large-scale production of A. coreanum hairy roots. [Method] The effects of different pH, culture modes and culture vessels on the growth of hairy roots were compared to obtain the optimal culture conditions for A. coreanum hairy roots. Moreover, the effects of medium volume and inoculation mode on bioreactor culture of A. coreanum hairy roots were investigated to analyze the feasibility of amplification culture of hairy roots in bioreactor. [Result] After autoclaving, medium pH was reduced slightly and the clarity of medium varied. To be specific, A. coreanum hairy roots cultured in medium at pH 5. 80 exhibited the best growth. A. coreanum hairy roots cultured in liquid medium displayed more rapid growth than hairy roots cultured in solid medium. Medium pH and electrical connuctivity (EC) varied with the extension of culture time. The yield and propagation coefficient of A. coreanum hairy roots were positively correlated with the size of culture vessels. The growth of hairy roots cultured in bioreactors were influenced by medium volumes and inoculation modes. [Conclusion] The growth of A. coreanum hairy roots were significantly influenced by medium pH, culture modes and culture vessels. A. coreanum hairy roots cultured in bioreactor exhibited high yield and large propagation coefficient. According to the results, the relationship between ventilation volume and hairy root density is crucial to the amplification culture of A. coreanum hairy roots. [ABSTRACT FROM AUTHOR]

We investigated the effects of culture mode (intertidal and off-bottom suspended culture) and initial stocking density (5%, 10%, 35% and 70% bottom cover) on survival, growth and condition indices of three size cohorts (16, 22 and 32 mm initial shell length) of the basket cockle, Clinocardium nuttallii, during a second year of grow-out. In addition, we evaluated the effects of depth (2, 4 and 6 m) in suspended culture. All size cohorts demonstrated significantly higher growth rates, soft-tissue biomass and condition indices in the off-bottom suspended system compared to the intertidal one. In suspended culture, however, C. nuttallii exhibited sub-optimal survival, shell deformities and heavy fouling. For all size cohorts, stocking density had a significant effect on most growth and condition parameters, except meat yield indices, in both culture modes. An initial maximum stocking density of 10% cover is recommended for all size cohorts. Culture depth did not have a consistent statistically significant effect on any of the growth or condition parameters. Depending on the grow-out scenario, stocking density and harvestable size chosen, the cumulative harvestable proportion after the second year of grow-out constituted 15.5-63.1% of the seed planted. Our results could be used to develop and improve culture techniques for C. nuttallii and other cockle species. [ABSTRACT FROM AUTHOR]

The basket cockle ( Clinocardium nuttallii) is a candidate species for aquaculture in the northeast Pacific. The aim of the current research was to assess the feasibility of C. nuttallii grow-out, with an emphasis on growth performance and qualities affecting product marketability. In this article, we investigated the combined effects of culture mode (intertidal and off-bottom suspended culture) and initial stocking density (1500, 3000, 10 500 and 21 000 ind m−2) on C. nuttallii survival and growth during the first year of grow-out ( May through October). In intertidal culture, cockles exhibited low survival and poor growth rates. In suspended culture, survival was consistently high (>96%) at all stocking densities tested; growth and condition parameters had the highest values at 1500 and 3000 ind m−2. The edible portion (meat yield) exceeded 40% of the whole wet weight at all stocking densities, occurrences of fouled and deformed cockles were <1% and no commensal species were observed. Depending on the minimum harvestable size and stocking density chosen, harvestable proportions constituted from 1.1% to 15.2% by October of the first grow-out year in the suspended system. The effects of stocking density and depth on second year grow-out performance of C. nuttallii are reported in a companion paper (Dunham et al. in this issue). [ABSTRACT FROM AUTHOR]

Isochrysis is a genus of marine unicellular microalgae that produces docosahexaenoic acid (DHA, C22:6), a very long chain polyunsaturated fatty acid (PUFA) of significant health and nutritional value. Mass cultivation of Isochrysis for DHA production for human consumption has not been established due to disappointing low DHA productivity obtained from commonly used Isochrysis strains. In this study, 19 natural Isochrysis strains were screened for DHA yields and the results showed that the cellular DHA content ranged from 6.8 to 17.0 % of total fatty acids with the highest DHA content occurring in the exponential growth phase. Isochrysis galbana #153180 exhibited the greatest DHA production potential and was selected for further investigation. The effects of different light intensities, forms, and concentrations of nitrogen, phosphorus, and salinity on growth and DHA production of I. galbana #153180 were studied in a bubble column photobioreactor (PBR). Under favorable culture conditions, I. galbana #153180 contained DHA up to 17.5 % of total fatty acids or 1.7 % of cell dry weight. I. galbana #153180 was further tested in outdoor flat-plate PBRs varying in light path length, starting cell density (SCD), and culture mode (batch versus semicontinuous). When optimized, record high biomass and DHA productivity of I. galbana #153180 of 0.72 g L day and 13.6 mg L day, or 26.4 g m day and 547.7 mg m day, respectively, were obtained, suggesting that I. galbana #153180 may be a desirable strain for commercial production of DHA. [ABSTRACT FROM AUTHOR]

Biotechnological production of high-value metabolites and therapeutic proteins by plant in vitro systems has been considered as an attractive alternative of classical technologies. Numerous proof-of-concept studies have illustrated the feasibility of scaling up plant in vitro system-based processes while keeping their biosynthetic potential. Moreover, several commercial processes have been established so far. Though the progress on the field is still limited, in the recent years several bioreactor configurations has been developed (e.g., so-called single-use bioreactors) and successfully adapted for growing plant cells in vitro. This review highlights recent progress and limitations in the bioreactors for plant cells and outlines future perspectives for wider industrialization of plant in vitro systems as 'green cell factories' for sustainable production of value-added molecules. [ABSTRACT FROM AUTHOR]

This study mainly investigated the distribution characteristics and risk assessment of 14 antibiotics in typical marine aquaculture farms surrounding the Bohai Sea. The effects of various culture modes (outdoor pond culture, recirculating water culture, greenhouse pond culture, raft culture, cage culture and bottom sowing culture), and diverse cultured organism species such as fish (grouper, bass, pike and turbot), mollusk (oyster, scallop, conch and mussel) and sea cucumber on the distribution of antibiotics in different mariculture pond matrices (seawater, sediment/biofilm and organism) were studied. In addition, antibiotic pollution levels in various matrices (water, sediment, organism and feed) from different mariculture areas surrounding the Bohai Sea and the Yellow Sea were compared. The biofilm on the inner wall of greenhouse pond was more capable of accumulating antibiotics than the biofilm attached to the rope for raft culture and net for cage culture, and other culture sediments. The antibiotic concentration level in the culture matrices (water, sediment/biofilm and organism) was the highest under greenhouse pond culture mode, and that under the industrial recirculating water culture mode was the lowest. Antibiotic concentration in culture matrices of fish ponds was higher than that of sea cucumber ponds and mollusk ponds. The levels of antibiotics in water and sediment from marine aquaculture farms in Laizhou (Bohai Sea coast) were higher than those in Haiyang and Jimo (Yellow Sea coast). Enrofloxacin in turbot might cause considerable harm to human health, and the risk of antibiotics in other seafood could be ignored. Antibiotic ecological risks and resistance risks were generally low in water. Fluoroquinolones posed medium to high ecological risks in the natural receiving water around the mariculture farm. Trimethoprim and enrofloxacin showed relatively high antibiotic resistance risks in mariculture water and natural water, which might exert selective pressure on the bacterial community in the environment. Unlabelled Image • Antibiotic concentrations were the highest under greenhouse pond among all modes. • For recirculating water culture mode, the antibiotic concentration was the lowest. • More antibiotics were found in fish pond than in sea cucumber pond or mollusk pond. • Antibiotic concentrations were higher in culture matrices of Bohai than Yellow Sea. • Ecological risks and resistance risks of most antibiotics were low in water. [ABSTRACT FROM AUTHOR]

The redclaw crayfish, Cherax quadricarinatus , is a valuable freshwater shrimp species with outstanding advantages and broad prospects for aquaculture. The culture of this crayfish has been gradually rising in the middle and lower sections of the Yangtze Plain. However, several problems such as short cultivation cycles, a lack of cultivation specifications, and low seedling survival rates are encountered when culturing this species in nontropical areas given that this particular crayfish is a tropical species. These conditions have hindered its development in the industry. Therefore, a scientific culture mode must be developed. This study explores the establishment of a culture model suitable for the characteristics of this crayfish: a temporary shelter used in shed and pond culture. The technology is described in terms of pond and shed construction, cleaning and disinfection, fertilization and water quality management, the cultivation of water grass, juvenile crayfish stocking, temporary shed shelter arrangements, pond culture management, disease and pathogen control, and harvesting. Results show that 1) the yield per hectare and survival rate of ponds with sheds were 2739.50 ± 307.53 kg ha−1 and 68.82% ± 4.23%, respectively, exceeding those of ponds with no sheds; 2) the highest yield and survival rate of ponds were measured as 3930.0 kg ha−1 and 77.73%, respectively (the shed area covered 220 m2, the temporary-keeping density was measured as 100 tails m−2, stocking occurred on April 15, 2019, the cultivation cycle lasted 182 days, and stocking density was measured as 87,300 tails ha−1); 3) the crayfish growout season ran from April to November. However, summer was the main growing season for the crayfish. After August, the growth rate decreased. In conclusion, the addition of sheds to temporary shelters provides a clear advantage in terms of both yields and survival rates. This culture model can meet cultivation demand in the middle and lower sections of the Yangtze Plain. Furthermore, the proportion of sheds in ponds should be increased, and stocking (in mid-April or earlier) and saling (appearance on the market in autumn) should occur earlier on. The cultivation cycle should be extended, and shed management should be the primary focus. [ABSTRACT FROM AUTHOR]

• MF promoted algal growth more effectively at lower temperatures (25 °C) in batch mode. • Tribonema sp. biomass productivity was improved markedly in semi-continuous culture. • MF can affect algae biochemical composition and enhance the oil accumulation. • Gradually reducing HRT in semi-continuous mode can remove >90% of nutrients. This paper investigated the effects of temperature and cultivation methods (batch or semi-continuous culture) on the filamentous microalgae Tribonema sp. biomass production and nutrients removal in starch wastewater under low intensity magnetic field (MF) intervention. The MF significantly promoted algal growth in the late logarithmic-phase of batch cultivation, and the effect was even more obvious at lower temperatures. The MF treated group at 30 °C accumulated the highest biomass of 4.44 g/L of batch culture, an increase of 15.0% compared with the control group. The oil content of Tribonema sp. was enhanced with the MF intervention, especially for the batch culture. In the semi-continuous culture under MF intervention, Tribonema sp. reached the high biomass of 18.45 g/L after 25 days. When gradually reducing hydraulic retention time (HRT) to 1 day, the average removal rates for COD, TN, NH 3 -N and TP were all more than 90% in the semi-continuous cultivation. [ABSTRACT FROM AUTHOR]