scholarly journals Functional metagenomics reveals differential chitin degradation and utilization features across free-living and host-associated marine microbiomes

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
I. Raimundo ◽  
R. Silva ◽  
L. Meunier ◽  
S. M. Valente ◽  
A. Lago-Lestón ◽  
...  
Keyword(s):  
Marine Invertebrates ◽  
Marine Invertebrate ◽  
Marine Sponges ◽  
Free Living ◽  
Chitin Degradation ◽  
Taxonomic Assignments ◽  
Chitinase Genes ◽  
Chitin Binding Protein ◽  
Encoding Genes

AbstractBackgroundChitin ranks as the most abundant polysaccharide in the oceans yet knowledge of shifts in structure and diversity of chitin-degrading communities across marine niches is scarce. Here, we integrate cultivation-dependent and -independent approaches to shed light on the chitin processing potential within the microbiomes of marine sponges, octocorals, sediments, and seawater.ResultsWe found that cultivatable host-associated bacteria in the generaAquimarina,Enterovibrio,Microbulbifer,Pseudoalteromonas,Shewanella, andVibriowere able to degrade colloidal chitin in vitro. Congruent with enzymatic activity bioassays, genome-wide inspection of cultivated symbionts revealed thatVibrioandAquimarinaspecies, particularly, possess several endo- and exo-chitinase-encoding genes underlying their ability to cleave the large chitin polymer into oligomers and dimers. Conversely,Alphaproteobacteriaspecies were found to specialize in the utilization of the chitin monomer N-acetylglucosamine more often. Phylogenetic assessments uncovered a high degree of within-genome diversification of multiple, full-length endo-chitinase genes forAquimarinaandVibriostrains, suggestive of a versatile chitin catabolism aptitude. We then analyzed the abundance distributions of chitin metabolism-related genes across 30 Illumina-sequenced microbial metagenomes and found that the endosymbiotic consortium ofSpongia officinalisis enriched in polysaccharide deacetylases, suggesting the ability of the marine sponge microbiome to convert chitin into its deacetylated—and biotechnologically versatile—form chitosan. Instead, the abundance of endo-chitinase and chitin-binding protein-encoding genes in healthy octocorals leveled up with those from the surrounding environment but was found to be depleted in necrotic octocoral tissue. Using cultivation-independent, taxonomic assignments of endo-chitinase encoding genes, we unveiled previously unsuspected richness and divergent structures of chitinolytic communities across host-associated and free-living biotopes, revealing putative roles for uncultivatedGammaproteobacteriaandChloroflexisymbionts in chitin processing within sessile marine invertebrates.ConclusionsOur findings suggest that differential chitin degradation pathways, utilization, and turnover dictate the processing of chitin across marine micro-niches and support the hypothesis that inter-species cross-feeding could facilitate the co-existence of chitin utilizers within marine invertebrate microbiomes. We further identified chitin metabolism functions which may serve as indicators of microbiome integrity/dysbiosis in corals and reveal putative novel chitinolytic enzymes in the genusAquimarinathat may find applications in the blue biotechnology sector.

scholarly journals The Interactions among Isolates of Lactiplantibacillus plantarum and Dairy Yeast Contaminants: Towards Biocontrol Applications

Fermentation ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 14
Author(s):  
Miloslava Kavková ◽  
Jaromír Cihlář ◽  
Vladimír Dráb ◽  
Olga Bazalová ◽  
Zuzana Dlouhá
Keyword(s):  
Lactic Acid ◽  
Antifungal Activity ◽  
Wide Spectrum ◽  
In Vitro Tests ◽  
In Vitro Production ◽  
Chitinase Genes ◽  
Chitin Binding Protein ◽  
Reconstituted Milk ◽  
Vitro Production

Yeast diversity in the cheese manufacturing process and in the cheeses themselves includes indispensable species for the production of specific cheeses and undesired species that cause cheese defects and spoilage. The control of yeast contaminants is problematic due to limitations in sanitation methods and chemicals used in the food industry. The utilisation of lactic acid bacteria and their antifungal products is intensively studied. Lactiplantibacillus plantarum is one of the most frequently studied species producing a wide spectrum of bioactive by-products. In the present study, twenty strains of L. plantarum from four sources were tested against 25 species of yeast isolated from cheeses, brines, and dairy environments. The functional traits of L. plantarum strains, such as the presence of class 2a bacteriocin and chitinase genes and in vitro production of organic acids, were evaluated. The extracellular production of bioactive peptides and proteins was tested using proteomic methods. Antifungal activity against yeast was screened using in vitro tests. Testing of antifungal activity on artificial media and reconstituted milk showed significant variability within the strains of L. plantarum and its group of origin. Strains from sourdoughs (CCDM 3018, K19-3) and raw cheese (L12, L24, L32) strongly inhibited the highest number of yeast strains on medium with reconstituted milk. These strains showed a consistent spectrum of genes belonging to class 2a bacteriocins, the gene of chitinase and its extracellular product 9 LACO Chitin-binding protein. Strain CCDM 3018 with the spectrum of class 2a bacteriocin gene, chitinase and significant production of lactic acid in all media performed significant antifungal effects in artificial and reconstituted milk-based media.

scholarly journals Ecology and Biotechnological Potential of Bacteria Belonging to the GenusPseudovibrio

2018 ◽  
Vol 84 (8) ◽  
Author(s):  
Stefano Romano
Keyword(s):  
Marine Invertebrates ◽  
Marine Sponges ◽  
Nutrient Cycles ◽  
Free Living ◽  
Associated Bacteria ◽  
Biotechnological Potential ◽  
Content Type ◽  
Tropical Regions ◽  
Marine Systems ◽  
Major Nutrient

ABSTRACTMembers of the genusPseudovibriohave been isolated worldwide from a great variety of marine sources as both free-living and host-associated bacteria. So far, the available data depict a group of alphaproteobacteria characterized by a versatile metabolism, which allows them to use a variety of substrates to meet their carbon, nitrogen, sulfur, and phosphorous requirements. Additionally,Pseudovibrio-related bacteria have been shown to proliferate under extreme oligotrophic conditions, tolerate high heavy-metal concentrations, and metabolize potentially toxic compounds. Considering this versatility, it is not surprising that they have been detected from temperate to tropical regions and are often the most abundant isolates obtained from marine invertebrates. Such an association is particularly recurrent with marine sponges and corals, animals that play a key role in benthic marine systems. The data so far available indicate that these bacteria are mainly beneficial to the host, and besides being involved in major nutrient cycles, they could provide the host with both vitamins/cofactors and protection from potential pathogens via the synthesis of antimicrobial secondary metabolites. In fact, the biosynthetic abilities ofPseudovibriospp. have been emerging in recent years, and both genomic and analytic studies have underlined how these organisms promise novel natural products of biotechnological value.

scholarly journals Identification of Fromiamycalin and Halaminol A from Australian Marine Sponge Extracts with Anthelmintic Activity against Haemonchus contortus

Marine Drugs ◽  
2019 ◽  
Vol 17 (11) ◽  
pp. 598 ◽  
Author(s):  
H. Herath ◽  
Sarah Preston ◽  
Abdul Jabbar ◽  
Jose Garcia-Bustos ◽  
Aya Taki ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Marine Invertebrates ◽  
Anthelmintic Activity ◽  
Marine Sponges ◽  
Parasitic Nematodes ◽  
Natural Ecosystems ◽  
Bioassay Guided Fractionation ◽  
Guanidine Alkaloids ◽  
Nematocidal Activity

There is an urgent need to discover and develop new anthelmintics for the treatment of parasitic nematodes of veterinary importance to circumvent challenges linked to drug resistant parasites. Being one of the most diverse natural ecosystems, the marine environment represents a rich resource of novel chemical entities. This study investigated 2000 extracts from marine invertebrates, collected from Australian waters, for anthelmintic activity. Using a well-established in vitro bioassay, these extracts were screened for nematocidal activity against Haemonchus contortus — a socioeconomically important parasitic nematode of livestock animals. Extracts (designated Mu-1, Ha-1 and Ha-2) from two marine sponges (Monanchora unguiculata and Haliclona sp.) each significantly affected larvae of H. contortus. Individual extracts displayed a dose-dependent inhibition of both the motility of exsheathed third-stage larvae (xL3s) and the development of xL3s to fourth-stage larvae (L4s). Active fractions in each of the three extracts were identified using bioassay-guided fractionation. From the active fractions from Monanchora unguiculata, a known pentacyclic guanidine alkaloid, fromiamycalin (1), was purified. This alkaloid was shown to be a moderately potent inhibitor of L4 development (half-maximum inhibitory concentration (IC50) = 26.6 ± 0.74 µM) and L4 motility (IC50 = 39.4 ± 4.83 µM), although it had a relatively low potency at inhibiting of xL3 motility (IC50 ≥ 100 µM). Investigation of the active fractions from the two Haliclona collections led to identification of a mixture of amino alcohol lipids, and, subsequently, a known natural product halaminol A (5). Anthelmintic profiling showed that 5 had limited potency at inhibiting larval development and motility. These data indicate that fromiamycalin, other related pentacyclic guanidine alkaloids and/or halaminols could have potential as anthelmintics following future medicinal chemistry efforts.

Production of Novel Bioactive Compounds by the Bacteria Associated with Some Marine Sponges of Gulf of Mannar and Palk Bay, Southeast Coast of India

2018 ◽  
Vol 6 (8) ◽  
pp. 183
Author(s):  
V. Ramadas ◽  
G. Chandralega
Keyword(s):  
Bioactive Compounds ◽  
Bacterial Species ◽  
Marine Sponges ◽  
Marine Organisms ◽  
Gulf Of Mannar ◽  
Bacterial Symbionts ◽  
Palk Bay ◽  
Excellent Source

Sponges, exclusively are aquatic and mostly marine, are found from the deepest oceans to the edge of the sea. There are approximately 15,000 species of sponges in the world, of which, 150 occur in freshwater, but only about 17 are of commercial value. A total of 486 species of sponges have been identified in India. In the Gulf of Mannar and Palk Bay a maximum of 319 species of sponges have been recorded. It has been proved that marine organisms are excellent source of bioactive secondary metabolites and number of compounds of originated from marine organisms had been reported to possess in-vitro and in-vivo immuno stimulatory activity. Extracts from 20 sponge species were tested for bacterial symbionts and bioactive compounds were isolated from such associated bacterial species in the present study.

scholarly journals Neurotoxicity in Marine Invertebrates: An Update

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 161
Author(s):  
Irene Deidda ◽  
Roberta Russo ◽  
Rosa Bonaventura ◽  
Caterina Costa ◽  
Francesca Zito ◽  
...  
Keyword(s):  
Nervous System ◽  
Marine Invertebrates ◽  
Marine Pollution ◽  
Marine Invertebrate ◽  
High Sensitivity ◽  
Model Systems ◽  
Neural Genes ◽  
Chemical Agents ◽  
Neurotoxic Effects ◽  
Invertebrate Model

Invertebrates represent about 95% of existing species, and most of them belong to aquatic ecosystems. Marine invertebrates are found at intermediate levels of the food chain and, therefore, they play a central role in the biodiversity of ecosystems. Furthermore, these organisms have a short life cycle, easy laboratory manipulation, and high sensitivity to marine pollution and, therefore, they are considered to be optimal bioindicators for assessing detrimental chemical agents that are related to the marine environment and with potential toxicity to human health, including neurotoxicity. In general, albeit simple, the nervous system of marine invertebrates is composed of neuronal and glial cells, and it exhibits biochemical and functional similarities with the vertebrate nervous system, including humans. In recent decades, new genetic and transcriptomic technologies have made the identification of many neural genes and transcription factors homologous to those in humans possible. Neuroinflammation, oxidative stress, and altered levels of neurotransmitters are some of the aspects of neurotoxic effects that can also occur in marine invertebrate organisms. The purpose of this review is to provide an overview of major marine pollutants, such as heavy metals, pesticides, and micro and nano-plastics, with a focus on their neurotoxic effects in marine invertebrate organisms. This review could be a stimulus to bio-research towards the use of invertebrate model systems other than traditional, ethically questionable, time-consuming, and highly expensive mammalian models.

scholarly journals The Culturable Mycobiome of Mesophotic Agelas oroides: Constituents and Changes Following Sponge Transplantation to Shallow Water

2021 ◽  
Vol 7 (7) ◽  
pp. 567
Author(s):  
Eyal Ben-Dor Cohen ◽  
Micha Ilan ◽  
Oded Yarden
Keyword(s):  
Microbial Community ◽  
Shallow Water ◽  
Mediterranean Sea ◽  
Hyphal Growth ◽  
Marine Sponges ◽  
The Core ◽  
The Mediterranean ◽  
Dynamic Components ◽  
In Vitro Interactions

Marine sponges harbor a diverse array of microorganisms and the composition of the microbial community has been suggested to be linked to holo-biont health. Most of the attention concerning sponge mycobiomes has been given to sponges present in shallow depths. Here, we describe the presence of 146 culturable mycobiome taxa isolated from mesophotic niche (100 m depth)-inhabiting samples of Agelas oroides, in the Mediterranean Sea. We identify some potential in vitro interactions between several A. oroides-associated fungi and show that sponge meso-hyl extract, but not its predominantly collagen-rich part, is sufficient to support hyphal growth. We demonstrate that changes in the diversity of culturable mycobiome constituents occur following sponge transplantation from its original mesophotic habitat to shallow (10 m) waters, where historically (60 years ago) this species was found. We conclude that among the 30 fungal genera identified as associated with A. oroides, Aspergillus, Penicillium and Trichoderma constitute the core mycobiome of A. oroides, and that they persist even when the sponge is transplanted to a suboptimal environment, indicative of the presence of constant, as well as dynamic, components of the sponge mycobiome. Other genera seemed more depth-related and appeared or disappeared upon host’s transfer from 100 to 10 m.

scholarly journals Effect of Gaseous Ozone on Listeria monocytogenes Planktonic Cells and Biofilm: An In Vitro Study

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1484
Author(s):  
Felice Panebianco ◽  
Selene Rubiola ◽  
Francesco Chiesa ◽  
Tiziana Civera ◽  
Pierluigi Aldo Di Ciccio
Keyword(s):  
Listeria Monocytogenes ◽  
In Vitro Study ◽  
Planktonic Cells ◽  
Free Living ◽  
Biofilm Inhibition ◽  
Additional Tool ◽  
Complete Inactivation ◽  
Gaseous Ozone ◽  
Food Borne

Among food-borne pathogens, Listeria monocytogenes continues to pose concerns to food business operators due to its capacity to form biofilm in processing environments. Ozone may be an eco-friendly technology to control microbial contaminations, but data concerning its effect on Listeria monocytogenes biofilm are still limited. In this study, the effect of gaseous ozone at 50 ppm on planktonic cells and biofilm of reference and food-related Listeria monocytogenes strains was evaluated. Ozone caused a reduction in microbial loads of 3.7 ± 0.4 and 3.9 ± 0.4 Log10 CFU/mL after 10 and 30 min, respectively. A complete inactivation of planktonic cells after 6 h of treatment was observed. Biofilm inhibition and eradication treatments (50 ppm, 6 h) resulted in a significant decrease of the biofilm biomass for 59% of the strains tested, whilst a slight dampening of live cell loads in the biofilm state was observed. In conclusion, gaseous ozone is not sufficient to completely counteract Listeria monocytogenes biofilm, but it may be useful as an additional tool to contrast Listeria monocytogenes free-living cells and to improve the existing sanitization procedures in food processing environments.

On the Chemical Form of Mercury in Edible Fish and Marine Invertebrate Tissue

1992 ◽  
Vol 49 (5) ◽  
pp. 1010-1017 ◽  
Author(s):  
Nicolas S. Bloom
Keyword(s):  
Total Mercury ◽  
Marine Invertebrates ◽  
Marine Invertebrate ◽  
Chemical Form ◽  
Weight Basis ◽  
Atomic Fluorescence Spectrometry ◽  
Atomic Fluorescence ◽  
Saltwater Fish ◽  
Relative Standard ◽  
Wet Weight

Total mercury, monomethylmercury (CH3Hg), and dimethylmercury ((CH3)2Hg) in edible muscle were examined in 229 samples, representing seven freshwater and eight saltwater fish species and several species of marine invertebrates using ultraclean techniques. Total mercury was determined by hot HNO3/H2SO4/BrClldigestion, SnCl2 reduction, purging onto gold, and analysis by cold vapor atomic fluorescence spectrometry (CVAFS). Methylmercury was determined by KOH/methanol digestion using aqueous phase ethylation, cryogenic gas chromatography, and CVAFS detection. Total mercury and CH3Hg concentrations varied from 0.011 to 2.78 μg∙g−1 (wet weight basis, as Hg) for all samples, while no sample contained detectable (CH3)2Hg (<0.001 μg∙g−1 as Hg). The observed proportion of total mercury (as CH3Hg) ranged from 69 to 132%, with a relative standard deviation for quintuplicate analysis of about 10%; nearly all of this variability can be explained by the analytical variability of total mercury and CH3Hg. Poorly homogenized samples showed greater variability, primarily because total mercury and CH3Hg were measured on separate aliquots, which vary in mercury concentration, not speciation. I conclude that for all species studied, virtually ail (>95%) of the mercury present is as CH3Hg and that past reports of substantially lower CH3Hg fractions may have been biased by analytical and homogeneity variability.

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