Polyphenols isolated from antiradical extracts of Mallotus metcalfianus

Six flavonoids including two new flavones, luteolin 7-O-(4″-O-(E)-coumaroyl)-β-glucopyranoside), chrysoeriol-7-O-(4″-O-(E)-coumaroyl)-β-glucopyranoside) and a mixture of two pairs of diastereoisomeric flavonolignans, (±)-hydnocarpin 7-O-(4″-O-(E)-coumaroyl)-β-glucopyranoside)/(±)-hydnocarpin-D 7-O-(4″-O-(E)-coumaroyl)-β-glucopyranoside) with a 2:1 ratio were isolated from the whole plant of Mallotus metcalfianus Croizat, in addition to 10 known compounds. Their structures were evaluated on the basis of different spectroscopic methods, including extensive 1D and 2D NMR spectroscopy. Some extracts have moderate antimicrobial properties and interesting antiradical (DPPH) activity, as well as some compounds isolated from this species. Tannins were also identified in some active extracts.     

Carotenoids found in Littorina littorea and their relationship to parasitic infection by larva trematodes

Littorina littorea from Long Island Sound feed primarily on algae: Chlorophyceae (three species) and Rhodophyceae (two species). Carotenoids from the algae accumulate in tissues of the snail in either an unchanged or a metabolized state. β-Carotene, the major pigment of green and red algae, was isolated from the foot, hepatopancreas, and nephridium of these snails. Six oxygenated carotenoids, not completely identified, were isolated from the same tissues. The snails show a variation in foot color from white to brown to red. L. littorea is parasitized by trematode larvae of Cryptocotyle lingua and Cercaria parvicaudata from which β-carotene and one oxygenated carotenoid were isolated. Contrary to previous work, there is no relation between foot color of the snail and parasitic infection. Neither age nor sex appears to have any relation to foot color. Although carotenoid pigments are known to cause the variation in foot color, the reasons or factors for their accumulation in the snail tissue have not been established. Some hypothetical explanations are discussed.     

Uncharted Diversity and Ecology of Saprolegniaceae (Oomycota) in Freshwater Environments

The fungal-like family Saprolegniaceae (Oomycota), also called “water mold,” includes mostly aquatic saprophytes as well as notorious aquatic animal pathogens. Most studies on Saprolegniaceae have been biased toward pathogenic species that are important to aquaculture rather than saprotrophic species, despite the latter’s crucial roles in carbon cycling of freshwater ecosystems. Few attempts have been made to study the diversity and ecology of Saprolegniaceae; thus, their ecological role is not well-known. During a survey of oomycetes between 2016 and 2021, we investigated the diversity and distribution of culturable Saprolegniaceae species in freshwater ecosystems of Korea. In the present study, members of Saprolegniaceae were isolated and identified at species level based on their cultural, morphological, and molecular phylogenetic analyses. Furthermore, substrate preference and seasonal dynamics for each were examined. Most of the species were previously reported as animal pathogens; however, in the present study, they were often isolated from other freshwater substrates, such as plant debris, algae, water, and soil sediment. The relative abundance of Saprolegniaceae was higher in the cold to cool season than that in the warm to hot season of Korea. This study enhances our understanding of the diversity and ecological attributes of Saprolegniaceae in freshwater ecosystems.     

Fusarium falciforme Infection of Foot in a Patient with Type 2 Diabetes Mellitus: A Case Report and Review of the Literature

Fungal infections of foot in patients with diabetes are not uncommon; however, foot infection due to Fusarium species has been rarely reported. We report here a case of a 50-year-old male with type 2 diabetes who developed multiple spontaneous nodular lesions on right foot without any systemic symptoms and signs for 6 months. The lesions were unresponsive to broad-spectrum antibacterial treatment. Fine needle aspiration cytology of nodular lesions revealed the presence of fungal hyphae, and Fusarium species was isolated from the same sample which was identified as Fusarium solani species complex: Fusarium falciforme. Radiological investigations and blood culture ruled out any dissemination of the disease. The lesions healed after voriconazole therapy for 3 months. No relapse was noted at the end of the next 6-month follow-up. All reported cases of Fusarium infection of foot in patients with diabetes in English and non-English literature since 1970 have been reviewed.     

Comparative properties of ferredoxins from a marine and freshwater species of Porphyridium

Ferredoxins were isolated from the freshwater red alga Porphyridium aerugineut, and from Porphyridium cruentum, a related marine species. A sin     

Poly-3-hydroxyalkanoates from marine and freshwater cyanobacteria

Polyesters of (R)-3-hydroxybutanoic and (R)-3-hydroxypentanoic acids have been isolated from Aphanothece species, a freshwater cyanobacteri     

The Microbiota of Freshwater Fish and Freshwater Niches Contain Omega-3 Fatty Acid-Producing Shewanella Species

Approximately 30 years ago, it was discovered that free-living bacteria isolated from cold ocean depths could produce polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) (20:5n-3) or docosahexaenoic acid (DHA) (22:6n-3), two PUFA essential for human health. Numerous laboratories have also discovered that EPA- and/or DHA-producing bacteria, many of them members of the Shewanella genus, could be isolated from the intestinal tracts of omega-3 fatty acid-rich marine fish. If bacteria contribute omega-3 fatty acids to the host fish in general or if they assist some bacterial species in adaptation to cold, then cold freshwater fish or habitats should also harbor these producers. Thus, we undertook a study to see if these niches also contained omega-3 fatty acid producers. We were successful in isolating and characterizing unique EPA-producing strains of Shewanella from three strictly freshwater native fish species, i.e., lake whitefish (Coregonus clupeaformis), lean lake trout (Salvelinus namaycush), and walleye (Sander vitreus), and from two other freshwater nonnative fish, i.e., coho salmon (Oncorhynchus kisutch) and seeforellen brown trout (Salmo trutta). We were also able to isolate four unique free-living strains of EPA-producing Shewanella from freshwater habitats. Phylogenetic and phenotypic analyses suggest that one producer is clearly a member of the Shewanella morhuae species and another is sister to members of the marine PUFA-producing Shewanella baltica species. However, the remaining isolates have more ambiguous relationships, sharing a common ancestor with non-PUFA-producing Shewanella putrefaciens isolates rather than marine S. baltica isolates despite having a phenotype more consistent with S. baltica strains.     

A new species of mammalian trypanosome,Trypanosoma (Megatrypanum) bubalisi sp. nov., found in the freshwater leech Hirudinaria manillensis

Leeches have long been considered potential vectors for the aquatic lineage of trypanosomes, while bloodsucking insects are generally considered as the vectors for the terrestrial lineage of trypanosomes. The freshwater leech, Hirudinaria manillensis, is a widely distributed species in southern China and could potentially act as the vector for trypanosomes. Prior to this study, no trypanosomes had been reported from this leech. However, in this study, leeches were collected from three different places in Guangdong province, China, and a large number of flagellates were isolated and successfully cultured in vitro. Based on morphology, these flagellates looked like a typical trypanosome species. Analysis was carried out on the molecular sequences of the 18S rRNA gene and the glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) gene. To our surprise, these flagellates were identified as likely to be a mammalian trypanosome belonging to the clade containing Trypanosoma (Megatrypanum) theileri but they are significantly different from the typical TthI and TthII stocks. Analyses of blood composition indicated that the source of the blood meal in these leeches was from the water buffalo (Bubalus bubalis). To further test if this flagellate from the freshwater leech was indeed a mammalian trypanosome, we transferred the trypanosomes cultured at 27–37 °C and they were able to successfully adapt to this mammalian body temperature, providing further supporting evidence. Due to the significant genetic differences from other related trypanosomes in the subgenus Megatrypanum, we propose that this flagellate, isolated from H. manillensis, is a new species and have named it Trypanosoma bubalisi. Our results indicate that freshwater leeches may be a potential vector of this new mammalian trypanosome.     

Isolation and identification of herbivorous ciliates from contaminated microalgal cultures

Ciliates are a common but understudied group of grazers that can invade microalgal cultures. To estimate the potential impact of ciliates on microalgal culture productivity, the identification of species that can invade these cultures is essential. Furthermore, isolation of these herbivorous ciliates allows to use them in experiments that investigate the impact of ciliate grazing on the productivity of microalgal cultures. The main aims of this study were to isolate and identify ciliates that invade cultures of the freshwater microalgae Chlorella and Chlamydomonas, and to establish a live collection of these ciliates for usage in future experiments. To this end, we optimized a method for isolating ciliates from contaminated microalgal cultures and we developed a new PCR primer set for amplifying the partial 18S rDNA of ciliates belonging to the classes Spirotrichea, Oligohymenophorea and Colpodea. As a result, we isolated 11 ciliates from microalgal enrichment cultures inoculated with non-sterile dust and various freshwater sources. Of these 11 species, 7 were found to be feeding on Chlamydomonas. Ciliate species that fed on Chlorella could not be isolated in this study. Ciliate species feeding on Chlamydomonas were identified based on a combination of morphological observations and molecular analyses of partial 18S rDNA sequences.     

Planctopirus ephydatiae,a novel Planctomycete isolated from a freshwater sponge

The microbiome of freshwater sponges is rarely studied, and not a single novel bacterial species has been isolated and subsequently characterized from a freshwater sponge to date. A previous study showed that 14.4% of the microbiome from Ephydatia fluviatilis belong to the phylum Planctomycetes. Therefore, we sampled an Ephydatia sponge from a freshwater lake and employed enrichment techniques targeting bacteria from the phylum Planctomycetes. The obtained strain spb1^T was subject to genomic and phenomic characterization and found to represent a novel planctomycetal species proposed as Planctopirus ephydatiae sp. nov. (DSM 106606 = CECT 9866). In the process of differentiating spb1^T from its next relative Planctopirus limnophila DSM 3776^T, we identified and characterized the first phage – Planctopirus phage vB_PlimS_J1 – infecting planctomycetes that was only mentioned anecdotally before. Interestingly, classical chemotaxonomic methods would have failed to distinguish Planctopirus ephydatiae strain spb1^T from Planctopirus limnophila DSM 3776^T. Our findings demonstrate and underpin the need for whole genome-based taxonomy to detect and differentiate planctomycetal species.     

Characterisation of Host Growth after Infection with a Broad-Range Freshwater Cyanopodophage

Freshwater cyanophages are poorly characterised in comparison to their marine counterparts, however, the level of genetic diversity that exists in freshwater cyanophage communities is likely to exceed that found in marine environments, due to the habitat heterogeneity within freshwater systems. Many cyanophages are specialists, infecting a single host species or strain; however, some are less fastidious and infect a number of different host genotypes within the same species or even hosts from different genera. Few instances of host growth characterisation after infection by broad host-range phages have been described. Here we provide an initial characterisation of interactions between a cyanophage isolated from a freshwater fishing lake in the south of England and its hosts. Designated ΦMHI42, the phage is able to infect isolates from two genera of freshwater cyanobacteria, Planktothrix and Microcystis. Transmission Electron Microscopy and Atomic Force Microscopy indicate that ΦMHI42 is a member of the Podoviridae, albeit with a larger than expected capsid. The kinetics of host growth after infection with ΦMHI42 differed across host genera, species and strains in a way that was not related to the growth rate of the uninfected host. To our knowledge, this is the first characterisation of the growth of cyanobacteria in the presence of a broad host-range freshwater cyanophage.     

Polyphenolic compounds in the fruits of Egyptian medicinal plants (Terminalia bellerica, Terminalia chebula and Terminalia horrida): Characterization, quantitation and determination of antioxidant capacities

Thirty-four polyphenolic substances in methanol extracts of the fruits of Terminalia bellerica, Terminalia chebula and Terminalia horrida, three plants used in Egyptian folk medicine, were initially identified by HPLC-ESI-MS and quantitated by analytical HPLC after column chromatography on Sephadex LH-20. After purification by semi-preparative HPLC the compounds were identified by their mass and fragmentation patterns using ESI-MS-MS. For several compounds detailed ¹H/¹³C NMR analysis at 600 MHz was performed. Two polyphenolics, namely 4-O-(4″-O-galloyl-α-l-rhamnopyranosyl)ellagic acid and 4-O-(3″,4″-di-O-galloyl-α-l-rhamnopyranosyl)ellagic acid were identified by NMR. Antioxidant capacities of the raw fruit extracts and the major isolated substances were determined using the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), oxygen radical absorbance capacity (ORAC) and ferric reducing ability of plasma (FRAP) in vitro assays and indicated that chebulic ellagitannins have high activity which may correlate with high potential as cancer chemopreventive agents. Therefore, further studies (metabolism, bioavailability and toxicity) of the polyphenolics in Terminalia species using preclinical models and in vivo human intervention trials are warranted.     

Comparison of freshwater discrimination ability in three species of sea kraits (Laticauda semifasciata, L. laticaudata and L. colubrina)

Three species of amphibious sea kraits (Laticauda spp.) require drinking freshwater to regulate water balance. The extent of terrestriality is known to differ among them. Species with higher extent of terrestriality would drink freshwater accumulated on land, whereas less terrestrial species would rely totally on freshwater that runs into the sea. Consequently, we predicted that the latter species might have a better ability to follow the flow of freshwater or lower salinity water in the sea than the former. We investigated the freshwater discrimination ability of three sea krait species, using a Y-maze apparatus. We found that Laticauda semifasciata and Laticauda laticaudata, less terrestrial species, followed freshwater significantly more frequently than seawater, whereas Laticauda colubrina, more terrestrial species, unbiasedly selected freshwater and seawater. This result supports our prediction and suggests that less terrestrial sea kraits more efficiently access freshwater sources in the sea than highly terrestrial sea kraits. It is likely that behavioral rehydration systems vary among sea kraits in relation to their terrestrial tendency.     

MALDI-TOF mass spectrometry for the identification of freshwater snails from Senegal,including intermediate hosts of schistosomes

Freshwater snails of the genera Biomphalaria, Bulinus, and Oncomelania are intermediate hosts of schistosomes that cause human schistosomiasis, one of the most significant infectious neglected diseases in the world. Identification of freshwater snails is usually based on morphology and potentially DNA-based methods, but these have many drawbacks that hamper their use. MALDI-TOF MS has revolutionised clinical microbiology and has emerged in the medical entomology field. This study aims to evaluate MALDI-TOF MS profiling for the identification of both frozen and ethanol-stored snail species using protein extracts from different body parts. A total of 530 field specimens belonging to nine species (Biomphalaria pfeifferi, Bulinus forskalii, Bulinus senegalensis, Bulinus truncatus, Bulinus globosus, Bellamya unicolor, Cleopatra bulimoides, Lymnaea natalensis, Melanoides tuberculata) and 89 laboratory-reared specimens, including three species (Bi. pfeifferi, Bu. forskalii, Bu. truncatus) were used for this study. For frozen snails, the feet of 127 field and 74 laboratory-reared specimens were used to validate the optimised MALDI-TOF MS protocol. The spectral analysis yielded intra-species reproducibility and inter-species specificity which resulted in the correct identification of all the specimens in blind queries, with log-score values greater than 1.7. In a second step, we demonstrated that MALDI-TOF MS could also be used to identify ethanol-stored snails using proteins extracted from the foot using a specific database including a large number of ethanol preserved specimens. This study shows for the first time that MALDI-TOF MS is a reliable tool for the rapid identification of frozen and ethanol-stored freshwater snails without any malacological expertise.     

Are Cristaria herculea (Middendorff, 1847) and Cristaria plicata (Leach, 1815) (Bivalvia,Unionidae) separate species?

The number of species in the freshwater mussel genus Cristaria Schumacher, 1817 recognized from Far East Russia has varied over the last several decades. While some authors consider the occurrence of only one species, Cristaria plicata (Leach, 1815), widespread in East Asia, others, recognize two separate species Cristaria herculea (Middendorff, 1847) and Cristaria tuberculata Schumacher, 1817 from Far East Russia, distinct from C. plicata. For the present study, freshwater mussels, identified as C. herculea, were collected in the Upper Amur basin (Transbaikalia, Russia). The shell morphology and the whole soft body anatomy were analysed in detail and compared with previously published information on other Cristaria spp.. Additionally, a cytochrome oxidase subunit 1 (CO1) gene fragment was sequenced from foot tissue samples of selected animals, collected from the same region, and compared with published data. Based upon morphological similarities of glochidia and adult morphology and anatomy as well as the mitochondrial DNA sequence analysis, we consider C. herculea as a synonym of C. plicata. Further analysis of Far East Russia C. herculea and C. tuberculata specimens using both molecular and morphological characters should be carried in the future to enhance our knowledge about the taxonomy within the Cristaria genus. Moreover, a comprehensive revision of the genus Cristaria is needed, restricting the type locality and comparing topotypic specimens for both C. plicata and C. tuberculata, and including all recognized Cristaria species.     

First description of an euryoecious acanthoecid choanoflagellate species,Enibas tolerabilis gen. et sp. nov. from a salar in the Chilean Andes based on morphological and transcriptomic data

In general, acanthoecid choanoflagellates have been described to occur exclusively in brackish water to marine habitats. Only recently, two studies have proven their existence in inland waters. One of them has shown, that an acanthoecid species from a small lake (near Apia on the island of Upolu, Samoa) is strictly freshwater adapted, not able to tolerate even brackish water. In this study, we present the first euryoecious acanthoecid species, able to live and reproduce in freshwater as well as under hypersaline conditions. The new species, Enibas tolerabilis gen. et sp. nov. was isolated in 2017 from the Salar de Ascotán in the Altiplano at 3750 m a. s. l., Northern Chile. The salinity at the time of sampling was 6 PSU. A series of autecological experiments have revealed a salinity tolerance from freshwater up to 70 PSU. In our phylogenetic analysis, E. tolerabilis gen. et sp. nov. clustered within the family of Acanthoecidae, forming a well-supported sister clade together with two other, environmental choanoflagellate sequences. We erected a new genus, Enibas gen. nov. and described the morphology, molecular biology and autecology for E. tolerabilis gen. et sp. nov. which has a stephanoecid-like lorica morphology. We emphasize that the definition of the genus Stephanoeca, being polyphyletic, is in urgent need of revision as we showed that this morphology is present in both acanthoecid families.     

Molecular phylogeny of the genus Capoeta (Teleostei: Cyprinidae) in Anatolia,Turkey

Phylogeny of Capoeta genus distributed in Anatolia were carried out by analysing mitochondrial cytochrome b gene (1140 bp) sequences from 332 samples representing 59 populations of 15 species across their geographical distribution. Haplotype network and phylogenetic analysis (neighbor-joining, maximum-likelihood, maximum parsimony, and bayesian inference) of the 103 cytochrome b haplotypes detected in Capoeta species resulted in similar tree topologies including four distinct clades, in congruent with taxonomic classification of Capoeta based on morphological characteristics such as scale size, mouth shape, and body spotting. Based on cyt b nucleotide sequences, the present study suggests that four undescribed Capoeta species may exist in Anatolia freshwater; one species in the Kizilirmak River, the second species in the Dirgine River, the third species B. Menderes River, and the fourth species in the some Yesilirmak tributaries that run into the Black Sea Basin. Capoeta taxa distributed in the rivers of Anatolian freshwater basins are isolated from each other during middle Miocene (Serravallian)-late Pleistocene (Ionian) (about 13.75–0.41 million years). This suggests that distribution and presence of Capoeta species were shaped under paleogeographic conditions such as Pleistocene climate changes in Quarternary period as well as tectonic uplift and faulting, which probably has not changed up to now.     

Morphology and phylogeny of Vannella croatica n. sp. (Amoebozoa,Discosea, Vannellida)

We isolated and described a new species of freshwater vannellid amoeba from Krka natural reserve in Croatia – Vannella croatica n. sp. This species has certain morphological differences from all known vannellids and differs at the level of SSU sequence. It resembles in size and morphology Vannella lata; to facilitate direct comparison we publish images of V. lata CCAP 1589/12 strain (type strain, which is now lost) taken in 1999. Vannela croatica feeds on bacteria and can be easily grown in large amount in relatively pure culture and thus is suitable for molecular and biochemical studies requiring large amounts of material.     

Anthocyanins with unusual furanose sugar (apiose) from leaves of Synadeniumgrantii (Euphorbiaceae)

Four anthocyanins, cyanidin 3-O-(2″-(5?-(E-p-coumaroyl)-β-apiofuranosyl)-β-xylopyranoside)-5-O-β-glucopyranoside, cyanidin 3-O-(2″-(5?-(E-p-coumaroyl)-β-apiofuranosyl)-β-xylopyranoside), cyanidin 3-O-(2″-(5?-(E-caffeoyl)-β-apiofuranosyl)-β-xylopyranoside) and cyanidin 3-O-(2″-(5?-(E-feroyl)-β-apiofuranosyl)-β-xylopyranoside) were isolated from leaves of African milk bush, (Synadeniumgrantii Hook, Euphorbiaceae) together with the known cyanidin 3-O-β-xylopyranoside-5-O-β-glucopyranoside and cyanidin 3-O-β-xyloside. The four former pigments are the first reported anthocyanins containing the monosaccharide apiose, and the three 5?-cinnamoyl derivative-2″-(β-apiosyl)-β-xyloside subunits have previously not been reported for any compound.