Effects of live feed manipulation with algal‐derived antimicrobial metabolites on fish larvae microbiome assembly: A molecular‐based assessment

2021 ◽  
Author(s):  
Gracinda M. M. Sanches‐Fernandes ◽  
Gianmaria Califano ◽  
Sara Castanho ◽  
Florbela Soares ◽  
Laura Ribeiro ◽  
...  

2016 ◽  
Author(s):  
Regina Melianawati ◽  
Rarastoeti Pratiwi ◽  
Nyoman Puniawati ◽  
Pudji Astuti


2018 ◽  
Author(s):  
Eva C. Sonnenschein ◽  
Christopher Broughton William Phippen ◽  
Mikkel Bentzon-Tilia ◽  
Silas Anselm Rasmussen ◽  
Kristian Fog Nielsen ◽  
...  

SummaryThe Roseobacter-group species Phaeobacter inhibens produces the antibacterial tropodithietic acid (TDA) and the algaecidal roseobacticides with both compound classes sharing part of the same biosynthetic pathway. The purpose of this study was to investigate the production of roseobacticides more broadly in TDA-producing roseobacters and to compare the effect of producers and non-producers on microalgae. Of 33 roseobacters analyzed, roseobacticide production was a unique feature of TDA-producing P. inhibens, P. gallaeciensis and P. piscinae strains. One TDA-producing Phaeobacter strain, 27-4, was unable to produce roseobacticides, possibly due to a transposable element. TDA-producing Ruegeria mobilis and Pseudovibrio did not produce roseobacticides. Addition of roseobacticide-containing bacterial extracts affected the growth of the microalgae Rhodomonas salina, Thalassiosira pseudonana and Emiliania huxleyi, while growth of Tetraselmis suecica was unaffected. During co-cultivation, growth of E. huxleyi was initially stimulated by the roseobacticide producer DSM 17395, while the subsequent decline in algal cell numbers during senescence was enhanced. Strain 27-4 that does not produce roseobacticides had no effect on algal growth. Both bacterial strains, DSM 17395 and 27-4, grew during co-cultivation presumably utilizing algal exudates. Furthermore, TDA-producing roseobacters have potential as probiotics in marine larviculture and it is promising that the live feed Tetraselmis was unaffected by roseobacticides-containing extracts.Originality-significance statementSome Roseobacter-group bacteria produce the antibacterial compound tropodithetic acid (TDA) and have potential as probiotics in marine aquaculture. However, a few of these strains additionally produce algaecidal compounds, the roseobacticides, which would restrict their use in marine larviculture where algae are used as live feed for fish larvae. We herein found that roseobacticides are limited to TDA-producing Phaeobacter strains and were not biosynthesized by TDA-producers outside this genus. Roseobacticides affected several strains of microalgae, but not the chlorophyte that is used as live feed in the aquaculture industry. Thus, the application of Roseobacter strains as probiotics is not hampered. Furthermore, these results demonstrate how Roseobacter-group strains act as gardeners of microalgae and thereby would be involved in environmental processes on a larger scale.



2020 ◽  
Vol 86 (14) ◽  
Author(s):  
Karen K. Dittmann ◽  
Bastian Barker Rasmussen ◽  
Jette Melchiorsen ◽  
Eva C. Sonnenschein ◽  
Lone Gram ◽  
...  

ABSTRACT The Phaeobacter genus has been explored as probiotics in mariculture as a sustainable strategy for the prevention of bacterial infections. Its antagonistic effect against common fish pathogens is predominantly due to the production of the antibacterial compound tropodithietic acid (TDA), and TDA-producing strains have repeatedly been isolated from mariculture environments. Despite many in vitro trials targeting pathogens, little is known about its impact on host-associated microbiomes in mariculture. Hence, the purpose of this study was to investigate how the addition of a TDA-producing Phaeobacter inhibens strain affects the microbiomes of live feed organisms and fish larvae. We used 16S rRNA gene sequencing to characterize the bacterial diversity associated with live feed microalgae (Tetraselmis suecica), live feed copepod nauplii (Acartia tonsa), and turbot (Scophthalmus maximus) eggs/larvae. The microbial communities were unique to the three organisms investigated, and the addition of the probiotic bacterium had various effects on the diversity and richness of the microbiomes. The structure of the live feed microbiomes was significantly changed, while no effect was seen on the community structure associated with turbot larvae. The changes were seen primarily in particular taxa. The Rhodobacterales order was indigenous to all three microbiomes and decreased in relative abundance when P. inhibens was introduced in the copepod and turbot microbiomes, while it was unaffected in the microalgal microbiome. Altogether, the study demonstrates that the addition of P. inhibens in higher concentrations, as part of a probiotic regime, does not appear to cause major imbalances in the microbiome, but the effects were specific to closely related taxa. IMPORTANCE This work is an essential part of the risk assessment of the application of roseobacters as probiotics in mariculture. It provides insights into the impact of TDA-producing Phaeobacter inhibens on the commensal bacteria related to mariculture live feed and fish larvae. Also, the study provides a sequencing-based characterization of the microbiomes related to mariculture-relevant microalga, copepods, and turbot larvae.



2017 ◽  
Vol 49 (3) ◽  
pp. 1274-1283
Author(s):  
Benni W Hansen ◽  
Emil Boesen ◽  
Ole B Brodnicke ◽  
Natasja L Corfixen ◽  
Per M Jepsen ◽  
...  
Keyword(s):  


2020 ◽  
Vol 367 (2) ◽  
Author(s):  
Emre Turgay ◽  
Terje Marken Steinum ◽  
Kamil Mert Eryalçın ◽  
Remziye Eda Yardımcı ◽  
Süheyla Karataş

ABSTRACT Live-feed is indispensable to commercial fish larviculture. However, high bacterial loads in rotifers could pose a biosecurity risk. While this may be true, live-feed associated bacteria could also be beneficial to fish larvae through improved feed utilization or pathogen inhibition following host microbiota modification. The study objective was to elucidate the largely unexplored microbiota of rotifers propagated on five different diets through bacterial community profiling by 16S rRNA gene amplicon sequencing. Investigated rotifer samples had a median observed alpha-diversity of 338 ± 87 bacterial species. Alpha- and Gamma-Proteobacteria dominated the rotifer microbiota followed by members of classes Flavobacteriia, Cytophagia, Mollicutes, Phycisphaerae and Bacteroidia. Different diets significantly altered the bacterial communities associated with rotifers according to PERMANOVA test results and beta dispersion calculations. A common core rotifer microbiome included 31 bacterial species present in relative abundances over 0.01%. We discuss the functional role of some microbiome members. Our data suggested the presence of several known fish pathogens in stock rotifers. However, we found no evidence for increased loads of these presumptive taxa in propagated live-feed rotifers during this field trial.



2005 ◽  
Vol 4 (2) ◽  
pp. 1-7
Author(s):  
B. Victor ◽  
M. Mannar Mannan ◽  
M. Maridass ◽  
P. Murphy Alexander ◽  
J. M. A. P. Arachi

Feeding experiment conducted under laboratory conditions, to determine the suitability of live feed for the larvae of ornamental fish Puntius dorsalis, shows the increase of specific growth rate and weight gain when they were fed with mosquito larvae( 3.284 and 8.04%/day),chironomus larvae(3.308 and 6.24%/day),chopped earthworm (2.618 and 4.39%/day). The maximum growth rate,0.614g was observed in mosquito larvae feed followed by chironomus larvae(0.522 g),chopped earthworm(0.411g) and plankton(0.405g). The present study indicates that mosquito larvae could be used as a suitable live feed for feeding Puntius dorsalis larval fishes.



Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 505
Author(s):  
Luz Hurtado ◽  
Claudio D. Miranda ◽  
Rodrigo Rojas ◽  
Félix A. Godoy ◽  
Mark A. Añazco ◽  
...  

The culture of red cusk eel Genypterus chilensis is currently considered a priority for Chilean aquaculture but low larval survival rates have prompted the need for the continuous use of antibacterials. The main aim of this study was to evaluate the role of live feed as a source of antibacterial-resistant bacteria in a commercial culture of G. chilensis. Samples of rotifer and Artemia cultures used as live feed were collected during the larval growth period and culturable bacterial counts were performed using a spread plate method. Rotifer and Artemia cultures exhibited high levels of resistant bacteria (8.03 × 104 to 1.79 × 107 CFU/g and 1.47 × 106 to 3.50 × 108 CFU/g, respectively). Sixty-five florfenicol-resistant isolates were identified as Vibrio (81.5%) and Pseudoalteromonas (15.4%) using 16S rRNA gene sequence analysis. A high incidence of resistance to streptomycin (93.8%), oxytetracycline (89.2%), co-trimoxazole (84.6%), and kanamycin (73.8%) was exhibited by resistant isolates. A high proportion of isolates (76.9%) carried the florfenicol-resistance encoding genes floR and fexA, as well as plasmid DNA (75.0%). The high prevalence of multiresistant bacteria in live feed increases the incidence of the resistant microbiota in reared fish larvae, thus proper monitoring and management strategies for live feed cultures appear to be a priority for preventing future therapy failures in fish larval cultures.



2020 ◽  
pp. 342-366
Author(s):  
Per Meyer Jepsen ◽  
Kristian Syberg ◽  
Guillaume Drillet ◽  
Benni Winding Hansen

The cultivation of planktonic crustaceans as live feed is of paramount importance for the aquaculture and aquarium industries. The use of live cladocerans as feed for freshwater fish is limited to the aquarium industry, whereas Artemia and copepods are used to feed edible marine fish larvae with small mouth gape. Live feed production is expensive and time consuming; therefore, it is only used for fish that cannot be fed an inert diet directly, and only until they are ready for weaning to an inert diet. High-quality planktonic crustacean cultures are furthermore used to conduct environmental risk assessments for hazardous chemicals. Cladocerans are widely used for ecotoxicology testing, but Artemia and copepods are emerging as new model species. The present chapter reviews the culturing procedures of these important planktonic crustaceans: Artemia, cladocerans, and copepods. It discusses their use as live feed and as test organisms for environmental risk assessments. The culturing procedures are categorized into three complexity levels: Extensive, semi-extensive, and intensive. In general, the pros for Artemia and cladocerans are that they are easier to culture than copepods. Copepods are often more difficult in term of culture requirements and feeding. Nevertheless, copepods have the advantage of being in either freshwater or saline water, whereas cladocerans are limited to freshwater and Artemia to seawater. Artemia cysts and copepod eggs have a well-defined protocol for storage and distribution to aquaculture end users. Cladocerans, however, have the potential for the ephippia stage, although this is not well developed. For toxicological testing, three species are used: Artemia franciscana, Daphnia magna, and Acartia tonsa, with Artemia and A. tonsa in seawater testing, D. magna in freshwater testing. The chapter concludes with a comparative analysis of these organisms from use and culturing capability and demonstrates that there are strong similarities and challenges across these taxa.



2020 ◽  
Vol 12 (1) ◽  
pp. 3-7
Author(s):  
Lidiia Khuda ◽  
Mykola Spivak ◽  
Oleksandr Demchenko ◽  
Oksana Karucheru ◽  
Olha Frunza ◽  
...  

The anthibiotics use in aquaculture these days is severely restricted by European standarts of marketable fish products quality. According to this, one of the most efficient alternatives are probiotics. So the search of applicable probiotic microorganisms that can be applied in aquaculture is relevant. On the other side, probiotics introduction into the fish body is usually accomplished in composition with dry feed as a biofilm. But a lot of fish larvae are not capable of consuming dry artificial feed due to numerous reasons. For their transmission for endogenic nourishment from exogenic live feeds are used in aquaculture, which have a higher level of digestibility compared to granulated feed. One more advantage of live feed is that they can be used as vectors to provide the targeted delivery of probiotics into fish body. In this work Lactobacillus casei IMV 7280 was firsly tested for the needs of aquaculture. It is shown that the usage of this probiotic during the growing of carp whitebaits stimulates it growth and leads to unwanted microflora suppresion in water as well as in fish bodies. The optimal schedule of L. сasei UCM 7280 bioencapsulation into live feed with Daphnia magna as an example is designed and suggested. It is shown that bioencapsulation procedure realization does not repress D. magna΄s normal mocrobiome, provides the increase of proteins and lipids level for 1,2 and 1,4 times accordingly and spends up the increasing of density level of fodder organisms.



2018 ◽  
Vol 68 (2) ◽  
pp. 181 ◽  
Author(s):  
J. A. THEODOROU

Secondary feeding with commercial lipids enrichments such as the microencapsulated diets Diet A (33.42±3.00%) and Diet B (55.88±3.5%) compared with the marine yeast type product Diet C(8.59±1.0%) as a method of increasing the total lipids and ω-3 PUFA content of rotifers, hence enhancing their nutritional value as live feed prey for fish larvae in hatcheries. The total lipids the rotifers was affected analogous to the levels of these components in the feeds showing its maximum percentage uptake within 4 hours from the enrichment (20.27±3.52, 26.64±3.91, 11.31±2.30 respectively). There was not any significant toxicity to the animals due to the diets during the 16 hours experiment. The DHA/EPA for Diet A(1.31), Diet B(0.42) and Diet C(absent) as well as the DHA/EPA/ARA ratios for Diet A(10.70 ± 1.60 / 8.18 ± 1.10 / 2.08 ± 0.20), Diet B(6.20 ± 2.30 / 14.60 ±1.00 / 1.12 ± 0.40) and Diet C (0 / 5.14 ± 3.40 / 1.30 ± 1.10) indicates that Diet A is closer to the suggested DHA/EPA/ARA optimal value 10/5/1 for marine fish larval growth.



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