scholarly journals Phylogenetic distribution of roseobacticides in the Roseobacter group and their effect on microalgae

2018 ◽  
Author(s):  
Eva C. Sonnenschein ◽  
Christopher Broughton William Phippen ◽  
Mikkel Bentzon-Tilia ◽  
Silas Anselm Rasmussen ◽  
Kristian Fog Nielsen ◽  
...  
Keyword(s):  
Fish Larvae ◽  
Algal Cell ◽  
Algal Growth ◽  
Thalassiosira Pseudonana ◽  
Bacterial Strains ◽  
Marine Aquaculture ◽  
Live Feed ◽  
Roseobacter Group ◽  
Enhanced Strain ◽  
Phaeobacter Inhibens

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.

scholarly journals Changes in the Microbiome of Mariculture Feed Organisms after Treatment with a Potentially Probiotic Strain of Phaeobacter inhibens

2020 ◽  
Vol 86 (14) ◽  
Author(s):  
Karen K. Dittmann ◽  
Bastian Barker Rasmussen ◽  
Jette Melchiorsen ◽  
Eva C. Sonnenschein ◽  
Lone Gram ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Fish Larvae ◽  
Antagonistic Effect ◽  
Rrna Gene ◽  
Fish Pathogens ◽  
Content Type ◽  
Live Feed ◽  
The Impact ◽  
Phaeobacter Inhibens

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.

scholarly journals Effect of different kinds of live feed on thyroid structure of marine fish larvae coral trout Plectropomus leopardus (Lacepède, 1802)

2016 ◽  
Author(s):  
Regina Melianawati ◽  
Rarastoeti Pratiwi ◽  
Nyoman Puniawati ◽  
Pudji Astuti
Keyword(s):  
Marine Fish ◽  
Fish Larvae ◽  
Coral Trout ◽  
Live Feed ◽  
Marine Fish Larvae ◽  
Plectropomus Leopardus

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 ◽  
...  
Keyword(s):  
Fish Larvae ◽  
Live Feed ◽  
Antimicrobial Metabolites ◽  
Microbiome Assembly

scholarly journals Chemical Profiling of Volatile Organic Compounds in the Headspace of Algal Cultures as Early Biomarkers of Algal Pond Crashes

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kristen L. Reese ◽  
Carolyn L. Fisher ◽  
Pamela D. Lane ◽  
James D. Jaryenneh ◽  
Matthew W. Moorman ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Biomass Production ◽  
Brachionus Plicatilis ◽  
Solid Phase ◽  
Algal Cell ◽  
Algal Growth ◽  
Gas Chromatography Mass Spectrometry ◽  
Volatile Organic ◽  
Early Indicators

Abstract Algae ponds used in industrial biomass production are susceptible to pathogen or grazer infestation, resulting in pond crashes with high economic costs. Current methods to monitor and mitigate unhealthy ponds are hindered by a lack of early indicators that precede culture crash. We used solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) to identify volatiles emitted from healthy and rotifer infested cultures of Microchloropsis salina. After 48 hours of algal growth, marine rotifers, Brachionus plicatilis, were added to the algae cultures and volatile organic compounds (VOC) were sampled from the headspace using SPME fibers. A GC-MS approach was used in an untargeted analysis of VOCs, followed by preliminary identification. The addition of B. plicatilis to healthy cultures of M. salina resulted in decreased algal cell numbers, relative to uninfected controls, and generated trans-β-ionone and β-cyclocitral, which were attributed to carotenoid degradation. The abundances of the carotenoid-derived VOCs increased with rotifer consumption of algae. Our results indicate that specific VOCs released by infected algae cultures may be early indicators for impending pond crashes, providing a useful tool to monitor algal biomass production and pond crash prevention.

The green hydra symbiosis. VIII. Mechanisms in symbiont regulation

1984 ◽  
Vol 221 (1224) ◽  
pp. 291-319 ◽  
Keyword(s):  
Cell Division ◽  
Algal Cell ◽  
Algal Growth ◽  
Culture Conditions ◽  
Continuous Illumination ◽  
Digestive Cell ◽  
Green Hydra ◽  
European Strain ◽  
Standard Culture ◽  
Feeding Regimes

The relative amount of symbiotic algae and animal tissue in the European strain of green hydra was altered by changes in illumination and feeding regimes. This indicates that the host can regulate the algal population to different sizes depending on external conditions. For animals maintained in continuous illumination, 12 h light: 12 h dark, and continous darkness, each with thrice-weekly feeding, a highly significant regression of algal volume per digestive cell on digestive cell volume was demonstrated, suggesting that the space available for the algae may be one factor that determines the population size of the algal symbionts. Seven strains of Chlorella originally symbiotic with other invertebrates formed stable associations with the European strain of green hydra; this included one strain (NC64A) which released very little maltose at pH 4-5. Althought the relative amounts of algal and host biomass of these experimental associations were very similar under standard culture conditions, large numbers of cells of strain NC64A were regularly expelled from the host. This suggests that the ability of the host to control the growth rate of its symbionts is related to the alga’s capacity for maltose release. The latter characteristic is also correlated with a sensitivity of growth to acid conditions. Of the five cultured strains of symbiotic Chlorella examined, only the two strains that released substantial amounts of maltose at pH 4-5 failed to grow at pH 4.0 and pH 4.5. It is proposed that the regulation of algal cell division in the natural symbiosis is principally mediated through relatively small and temporary changes in the pH of the perialgal vacuole. At more acid values, photosynthetically fixed carbon is primarily directed towards maltose release and little or no algal growth occurs. At higher pH values, maltose release declines sharply and the carbon becomes primarily directed towards symbiont growth. Such a relatively simple hypothetical model, involving stimulation of symbiont growth by temporary alkalinization of the perialgal vacuole, can explain the observed responses to change in environmental conditions, as well as the relation between the timing of symbiont and host cell division.

Interactions between populations of the calanoid copepodAcartia tonsaDana and the harpacticoid copepodTisbe holothuriaeHumes in mixed cultures of live feed for fish 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):  
Fish Larvae ◽  
Mixed Cultures ◽  
Live Feed

scholarly journals Draft Genome Sequences of Seven Bacterial Strains Isolated from a Polymicrobial Culture of Coccolith-Bearing (C-Type) Emiliania huxleyi M217: TABLE 1 

2016 ◽  
Vol 4 (4) ◽  
Author(s):  
Albert Remus R. Rosana ◽  
Fabini D. Orata ◽  
Yue Xu ◽  
Danielle N. Simkus ◽  
Anna R. Bramucci ◽  
...  
Keyword(s):  
Growth Factors ◽  
Draft Genome ◽  
Algal Growth ◽  
Emiliania Huxleyi ◽  
Bacterial Strains ◽  
Genome Sequences ◽  
Symbiotic Interactions ◽  
By Products

Strains of Rhodobacteraceae , Sphingomonadales , Alteromonadales , and Bacteroidetes were isolated from a polymicrobial culture of the coccolith-forming (C-type) haptophyte Emiliania huxleyi strain M217 . The genomes encode genes for the production of algal growth factors and the consumption of their hosts’ metabolic by-products, suggesting that the polymicrobial culture harbors many symbiotic interactions.

scholarly journals Characterization in vitro of new bacterial strains showing potentially probiotic crossed effect against vibriosis in relevant fish species for marine aquaculture

2020 ◽  
Vol 48 (1) ◽  
pp. 553-558
Author(s):  
Ana Gutiérrez-Falcón ◽  
Daniel Padilla ◽  
María José Ramos Sosa ◽  
José Luis Martín Barrasa ◽  
Begoña Acosta-Hernández ◽  
...  
Keyword(s):  
Fish Species ◽  
Bacterial Strains ◽  
Marine Aquaculture

The influence of diet on the microbiota of live-feed rotifers (Brachionus plicatilis) used in commercial fish larviculture

2020 ◽  
Vol 367 (2) ◽  
Author(s):  
Emre Turgay ◽  
Terje Marken Steinum ◽  
Kamil Mert Eryalçın ◽  
Remziye Eda Yardımcı ◽  
Süheyla Karataş
Keyword(s):  
Brachionus Plicatilis ◽  
Fish Larvae ◽  
Bacterial Species ◽  
Alpha Diversity ◽  
Amplicon Sequencing ◽  
Rrna Gene ◽  
Fish Pathogens ◽  
Study Objective ◽  
Commercial Fish ◽  
Live Feed

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.

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