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1.
PLoS One ; 15(8): e0238167, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857792

RESUMO

The ciliated protozoan Cryptocaryon irritans infects a wide range of marine fish and causes the highly lethal white spot disease. This parasite possesses three morphologically and physiologically distinct life stages: an infectious theront, a parasitic trophont, and an asexually reproductive tomont. In the past few years, several attempts have been made to help elucidate how C. irritans transforms from one stage to another using transcriptomic or proteomic approaches. However, there has been no research studying changes in transcription profiles between different time points of a single C. irritans life stage-the development of this parasite. Here we use RNA-seq and compare gene expression profiles of theront cells collected by 1 and 10 hrs after they emerged from tomonts. It has been shown that infectivity of theront cells declines 6-8 hours post-emergence, and we used this characteristic as a physiological marker to confirm the aging of theront cells. We identified a total of 41 upregulated and 90 downregulated genes that were differentially expressed between young and aging theront cells. Using Blast2Go to further analyze functions of these genes, we show that genes related to energy production are downregulated, but quite surprisingly many genes involved in transcription/translation processes are upregulated. We also show that expression of all nine detectable agglutination/immobilization antigen genes, with great sequence divergence, is invariably downregulated. Functions of other differentially expressed genes and indications are also discussed in our study.


Assuntos
Envelhecimento/metabolismo , Cilióforos/metabolismo , Cilióforos/patogenicidade , Animais , Cilióforos/genética , Cilióforos/crescimento & desenvolvimento , Infecções por Cilióforos/veterinária , Doenças dos Peixes/parasitologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Perciformes , Análise de Sequência de RNA , Transcriptoma
2.
J Eukaryot Microbiol ; 67(1): 54-65, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31356708

RESUMO

The morphology and morphogenesis of a new ciliate species, Neobakuella aenigmatica n. sp., which was discovered in an estuary in Korea, were investigated, using live observation, protargol impregnation, and scanning electron microscopy. This new species is characterized by a large (185-300 × 55-105 µm in vivo), elongate-ellipsoidal, flexible but not contractile body. It has ellipsoidal, yellowish cortical granules, 1.3 × 1.0 µm in size. The species has invariably 3 frontal and 2 frontoterminal cirri, about 5-10 buccal and 1-6 parabuccal cirri, 7 midventral rows, and 1 right and 2-4 left marginal rows. The outer left marginal row(s) consists of 1-7 short rows of cirri. The nuclear apparatus comprises 130 macronuclear nodules and 2 spherical micronuclei on average. The dorsal ciliature consists of 3 dorsal kineties. The leftmost left marginal row(s) likely develops from anlagen originating from both the rightmost and leftmost left marginal row(s). The molecular phylogenetic tree based on SSU rDNA suggests the nonmonophyly of the genus Neobakuella.


Assuntos
Cilióforos/classificação , Cilióforos/citologia , Cilióforos/crescimento & desenvolvimento , Cilióforos/ultraestrutura , DNA de Protozoário/análise , DNA Ribossômico/análise , Microscopia , Microscopia Eletrônica de Varredura , Filogenia , República da Coreia , Rios/parasitologia , Análise de Sequência de DNA
3.
Sci Rep ; 9(1): 15081, 2019 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-31636334

RESUMO

Evolutionary theory predicts potential shifts between cooperative and uncooperative behaviour under fluctuating environmental conditions. This leads to unstable benefits to the partners and restricts the evolution of dependence. High dependence is usually found in those hosts in which vertically transmitted symbionts provide nutrients reliably. Here we study host dependence in the marine, giant colonial ciliate Zoothamnium niveum and its vertically transmitted, nutritional, thiotrophic symbiont from an unstable environment of degrading wood. Previously, we have shown that sulphidic conditions lead to high host fitness and oxic conditions to low fitness, but the fate of the symbiont has not been studied. We combine several experimental approaches to provide evidence for a sulphide-tolerant host with striking polyphenism involving two discrete morphs, a symbiotic and an aposymbiotic one. The two differ significantly in colony growth form and fitness. This polyphenism is triggered by chemical conditions and elicited by the symbiont's presence on the dispersing swarmer. We provide evidence of a single aposymbiotic morph found in nature. We propose that despite a high fitness loss when aposymbiotic, the ciliate has retained a facultative life style and may use the option to live without its symbiont to overcome spatial and temporal shortage of sulphide in nature.


Assuntos
Bactérias/metabolismo , Cilióforos/microbiologia , Interações Hospedeiro-Patógeno , Sulfetos/farmacologia , Simbiose , Bactérias/efeitos dos fármacos , Teorema de Bayes , Cilióforos/efeitos dos fármacos , Cilióforos/crescimento & desenvolvimento , Cilióforos/ultraestrutura , Filogenia , RNA Ribossômico 16S/genética , RNA Ribossômico 18S/genética , Simbiose/efeitos dos fármacos
4.
Int. microbiol ; 22(3): 355-361, sept. 2019. ilus, graf, tab
Artigo em Inglês | IBECS | ID: ibc-184842

RESUMO

The effect of oxygen on anaerobic protozoa was studied in anaerobic batch reactors inoculated with sludge and protozoa cultures. Among the protozoa genera, Metopus, Brachonella, Plagiopyla, Trepomonas, and Vanella were more sensitive to oxygen compared to other genera. Protozoa genera Menoidium, Rhynchomonas, Cyclidium, Spathidium, and Amoeba were found to survive under aerobic conditions, and the growth rate was slightly higher or similar to anaerobic condition. O2 tension resulted in the loss of free and endosymbiotic methanogens in anaerobic system, while methanogens were observed inside the protozoan cysts. Survival of anaerobic protozoa declined considerably when the O2 tension exceeded 1% atm. sat. and showed chemosensory behavior in response to O2 exposure. Superoxide dismutase activity was detected in survived protozoa cells under O2 tension. Facultative anaerobic protozoa with SOD activity can provide a mechanism to overcome possible occurrence of oxygen toxicity in the treatment of wastewater in anaerobic reactor


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Assuntos
Amoeba/efeitos dos fármacos , Cilióforos/efeitos dos fármacos , Meios de Cultura/química , Euglênidos/efeitos dos fármacos , Kinetoplastida/efeitos dos fármacos , Oxigênio/toxicidade , Aerobiose , Amoeba/crescimento & desenvolvimento , Amoeba/metabolismo , Anaerobiose , Reatores Biológicos/parasitologia , Cilióforos/crescimento & desenvolvimento , Cilióforos/metabolismo , Euglênidos/crescimento & desenvolvimento , Euglênidos/metabolismo , Kinetoplastida/crescimento & desenvolvimento , Kinetoplastida/metabolismo , Metano/metabolismo , Sobrevivência Celular
5.
J Appl Microbiol ; 127(3): 670-682, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31165532

RESUMO

AIMS: Experiments were designed to determine the effects of different chemical inhibitors of lysozyme and peptidases on rumen protozoa and the associated prokaryotes, and in vitro fermentation using Entodinium caudatum as a model protozoan species. METHODS AND RESULTS: Imidazole (a lysozyme inhibitor), phenylmethylsulphonyl fluoride (PMSF, a serine peptidase inhibitor) and iodoacetamide (IOD, a cysteine peptidase inhibitor) were evaluated in vitro both individually and in two- and three-way combinations using E. caudatum monocultures with respect to their ability to inhibit the protozoan and their effect on feed digestion, fermentation and the microbiota. All the three inhibitors, both individually and in combination, decreased E. caudatum counts (P < 0·001), and IOD and its combinations with the other inhibitors significantly (P < 0·01) decreased ammonia concentration, with the two- and three-way combinations showing additive effective. Feed digestion was not affected, but fermentation and microbial diversity were affected mostly by PMSF, IOD and their combinatorial treatments potentially due to the overgrowth of Streptococcus luteciae accompanying with the disappearance of host ciliates. CONCLUSIONS: Entodinium caudatum depends on lysozyme and peptidase for digestion and utilization of the engulfed microbes and specific inhibition of these enzymes can inhibition E. caudatum without adversely affecting feed digestion or fermentation even though they changed the microbiota composition in the cultures. SIGNIFICANCE AND IMPACT OF THE STUDY: The peptidase inhibitors may have the potential to be used in controlling rumen protozoa to improve ruminal nitrogen utilization efficiency.


Assuntos
Cilióforos/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Muramidase/antagonistas & inibidores , Inibidores de Proteases/farmacologia , Amônia/metabolismo , Animais , Cilióforos/enzimologia , Cilióforos/crescimento & desenvolvimento , Cilióforos/microbiologia , Digestão/efeitos dos fármacos , Fermentação/efeitos dos fármacos , Imidazóis/farmacologia , Iodoacetamida/farmacologia , Microbiota/efeitos dos fármacos , Fluoreto de Fenilmetilsulfonil/farmacologia , Rúmen/parasitologia
6.
J Eukaryot Microbiol ; 66(5): 740-751, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30746815

RESUMO

Two new soil oxytrichids, Australocirrus rubrus n. sp. and Notohymena gangwonensis n. sp., were discovered from South Korea. Morphologically, A. rubrus shares many features with A. australis, and these two species form a single clade in a molecular tree based on nuclear small subunit ribosomal RNA (SSU rRNA) gene sequences. Australocirrus rubrus mainly differs from A. australis in the color (citrine color vs. reddish) and distribution of the cortical granules. Additionally, we confirm that the genus Australocirrus is not a monophyletic group, as A. shii is separated from the clade comprising the other Australocirrus species, being clustered instead with other taxa. Notohymena gangwonensis n. sp. mainly differs from its congeners by the following combination of features: irregularly distributed cortical granules (vs. arranged in groups associated with cirri and dorsal kineties), variable four or five (usually four) transverse cirri (vs. invariable five), and the anteriormost pretransverse cirrus V/2 on 13.2-16.1% of cell length (vs. on or above 18.9% of cell length). Currently, there are no available gene sequences for members of the genus Notohymena, thus we provide SSU rRNA gene sequences from the new species of Notohymena, as well as detailed morphological descriptions of the novel species.


Assuntos
Cilióforos/crescimento & desenvolvimento , Cilióforos/isolamento & purificação , Filogenia , Cilióforos/classificação , Cilióforos/genética , DNA de Protozoário/genética , RNA Ribossômico 18S/genética , República da Coreia , Solo/parasitologia
7.
Int Microbiol ; 22(3): 355-361, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30811001

RESUMO

The effect of oxygen on anaerobic protozoa was studied in anaerobic batch reactors inoculated with sludge and protozoa cultures. Among the protozoa genera, Metopus, Brachonella, Plagiopyla, Trepomonas, and Vanella were more sensitive to oxygen compared to other genera. Protozoa genera Menoidium, Rhynchomonas, Cyclidium, Spathidium, and Amoeba were found to survive under aerobic conditions, and the growth rate was slightly higher or similar to anaerobic condition. O2 tension resulted in the loss of free and endosymbiotic methanogens in anaerobic system, while methanogens were observed inside the protozoan cysts. Survival of anaerobic protozoa declined considerably when the O2 tension exceeded 1% atm. sat. and showed chemosensory behavior in response to O2 exposure. Superoxide dismutase activity was detected in survived protozoa cells under O2 tension. Facultative anaerobic protozoa with SOD activity can provide a mechanism to overcome possible occurrence of oxygen toxicity in the treatment of wastewater in anaerobic reactor.


Assuntos
Amoeba/efeitos dos fármacos , Cilióforos/efeitos dos fármacos , Meios de Cultura/química , Euglênidos/efeitos dos fármacos , Kinetoplastida/efeitos dos fármacos , Oxigênio/toxicidade , Aerobiose , Amoeba/crescimento & desenvolvimento , Amoeba/metabolismo , Anaerobiose , Reatores Biológicos/parasitologia , Sobrevivência Celular , Cilióforos/crescimento & desenvolvimento , Cilióforos/metabolismo , Euglênidos/crescimento & desenvolvimento , Euglênidos/metabolismo , Kinetoplastida/crescimento & desenvolvimento , Kinetoplastida/metabolismo , Metano/metabolismo
8.
J Eukaryot Microbiol ; 66(5): 694-706, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30657224

RESUMO

A new hypotrichous ciliate, Schmidtiella ultrahalophila gen. nov., spec. nov., was isolated from a solar saltern on the island of Sal, Cape Verde. The possession of only one short dorsal kinety clearly distinguishes S. ultrahalophila from other known hypotrichous genera and species. Further diagnostic characters include: a flexible and slender body, an average size of 85 × 15 µm in vivo; a bipartite adoral zone with two hypertrophied frontal adoral membranelles and nine to twelve ventral adoral membranelles; three frontal, one parabuccal, two frontoventral, two or three postoral ventral, and two or three frontoterminal cirri; and marginal cirral rows variable in number, usually one on each side. Ontogenetic data indicate the following: the frontal-ventral cirri originate from six or five anlagen; the proter inherits the parental adoral zone; the frontal and ventral cirri originate from five or six anlagen; and the marginal cirral rows and the dorsal kinety tend to originate intrakinetally. Additional marginal rows are rarely derived from de novo anlagen. Based on its morphology, morphogenesis and its SSU rRNA phylogenetic placement, the new species should be assigned to the order Sporadotrichida Fauré-Fremiet, 1961. Due to low taxon sampling, however, its exact position in this order remains enigmatic.


Assuntos
Cilióforos/crescimento & desenvolvimento , Cilióforos/isolamento & purificação , Filogenia , Cabo Verde , Cilióforos/classificação , Cilióforos/genética , Ilhas , Morfogênese
9.
Environ Sci Pollut Res Int ; 26(3): 2592-2602, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30474813

RESUMO

To evaluate the water quality status using ecological features of the periphytic ciliate communities, a 1-year (Jan. to Dec., 2016) investigation was conducted in coastal waters of the Yellow Sea, northern China. Four trophic-functional groups (TFgrs) were recorded from a total of 141 species-abundance dataset: algivores (A); bacterivores (B); non-selectives (N); and predators (R), comprising of 65, 34, 26, and 16 species, respectively. In terms of species number, TFgr A was predominant in clean areas while TFgrs B and N were dominant in heavy polluted areas and TFgr R was dominant in slightly polluted area. The trophic-functional patterns of the periphytic ciliate communities showed a clear spatial variation within the pollution gradient. Trophic-functional trait diversity measures represented a clear increasing trend from polluted stations to the clean area regarding the pollution gradients. Multivariate correlation and best matching analysis revealed that the spatial pattern of the trophic-functional groupings were significantly shaped by environmental variable nutrients and chemical oxygen demand, alone or in combination with pH, dissolved oxygen, salinity, and transparency. Thus, we suggest that the ecological features based on the trophic-functional patterns of periphytic ciliate communities might be used for bioassessment of water quality in marine ecosystems.


Assuntos
Cilióforos/crescimento & desenvolvimento , Água do Mar/química , Biodiversidade , Análise da Demanda Biológica de Oxigênio , China , Cilióforos/metabolismo , Ecologia , Ecossistema , Monitoramento Ambiental , Oxigênio/metabolismo , Salinidade , Água do Mar/parasitologia , Qualidade da Água
10.
Appl Environ Microbiol ; 85(3)2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30446561

RESUMO

Copper and alloys containing >60% copper by weight are antimicrobial. In aquaculture, copper alloys are used as part of corrosion-resistant cages or as part of copper coating. To test whether a copper alloy surface prevents the outbreak of parasitosis in the aquaculture of Larimichthys crocea, we covered the bottom of the aquaculture tank with sheets of copper alloy containing 74% to 78% copper, and we cultured L. crocea juveniles that had been artificially infected with the protozoan parasite Cryptocaryon irritans Our results showed that these copper alloy sheets effectively blocked the infectious cycle of C. irritans within a 1-week period and significantly reduced the number of C. irritans trophonts and tomonts, thereby decreasing the mortality rate of L. crocea In in vitro assays, the cytoplasmic membranes of protomonts disintegrated and the cytoplasm overflowed after just 5 minutes of contact with copper alloy surfaces. Although the same cytoplasmic membrane disintegration was not observed in tomonts, the tomonts completely lost their capacity for proliferation and eventually died following direct contact with copper alloy sheets for 1 h; this is likely because C. irritans tomonts took in >100 times more copper ions following contact with the copper alloy sheets than within the control aquaculture environment. Exposure to copper alloy sheets did not lead to excessive heavy metal levels in the aquacultured fish or in the culture seawater.IMPORTANCE Cryptocaryon irritans, a parasitic ciliate that penetrates the epithelium of the gills, skin, and fins of marine fish, causes acute suffocation and death in cultured fish within days of infection. Much of the existing research centers around the prevention of C. irritans infection, but no cure has been found. Studies demonstrate that copper has strong antimicrobial properties, and fish grown in copper-containing cages have lower rates of C. irritans infection, compared to those grown in other currently used aquaculture cages. In this study, we found that an alloy containing 74% to 78% copper by weight effectively killed C. irritans cells and prevented cryptocaryoniasis outbreaks within a 1-week period. These findings offer a new perspective on the prevention and control of cryptocaryoniasis.


Assuntos
Ligas/farmacologia , Antiprotozoários/farmacologia , Infecções por Cilióforos/veterinária , Cilióforos/efeitos dos fármacos , Cobre/farmacologia , Doenças dos Peixes/parasitologia , Ligas/química , Animais , Antiprotozoários/química , Aquicultura/instrumentação , Cilióforos/crescimento & desenvolvimento , Infecções por Cilióforos/parasitologia , Cobre/química , Doenças dos Peixes/prevenção & controle , Estágios do Ciclo de Vida/efeitos dos fármacos , Perciformes/parasitologia
11.
Toxins (Basel) ; 10(12)2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30513751

RESUMO

Kleptoplastic mixotrophic species of the genus Dinophysis are cultured by feeding with the ciliate Mesodinium rubrum, itself a kleptoplastic mixotroph, that in turn feeds on cryptophytes of the Teleaulax/Plagioselmis/Geminigera (TPG) clade. Optimal culture media for phototrophic growth of D. acuminata and D. acuta from the Galician Rías (northwest Spain) and culture media and cryptophyte prey for M. rubrum from Huelva (southwest Spain) used to feed Dinophysis, were investigated. Phototrophic growth rates and yields were maximal when D. acuminata and D. acuta were grown in ammonia-containing K(-Si) medium versus f/2(-Si) or L1(-Si) media. Dinophysis acuminata cultures were scaled up to 18 L in a photobioreactor. Large differences in cell toxin quota were observed in the same Dinophysis strains under different experimental conditions. Yields and duration of exponential growth were maximal for M. rubrum from Huelva when fed Teleaulax amphioxeia from the same region, versus T. amphioxeia from the Galician Rías or T. minuta and Plagioselmis prolonga. Limitations for mass cultivation of northern Dinophysis strains with southern M. rubrum were overcome using more favorable (1:20) Dinophysis: Mesodinium ratios. These subtleties highlight the ciliate strain-specific response to prey and its importance to mass production of M. rubrum and Dinophysis cultures.


Assuntos
Cilióforos/crescimento & desenvolvimento , Dinoflagelados/crescimento & desenvolvimento , Técnicas Microbiológicas , Reatores Biológicos , Cilióforos/genética , Meios de Cultura , DNA , Dinoflagelados/genética , Luz
12.
Sci Rep ; 8(1): 17189, 2018 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-30464297

RESUMO

Mesodinium spp. are commonly found in marine and brackish waters, and several species are known to contain red, green, or both plastids that originate from cryptophyte prey. We observed the seasonal succession of Mesodinium spp. in a Japanese brackish lake, and we analysed the origin and diversity of the various coloured plastids within the cells of Mesodinium spp. using a newly developed primer set that specifically targets the cryptophyte nuclear 18S rRNA gene. Mesodinium rubrum isolated from the lake contained only red plastids originating from cryptophyte Teleaulax amphioxeia. We identified novel Mesodinium sp. that contained only green plastids or both red and green plastids originating from cryptophytes Hemiselmis sp. and Teleaulax acuta. Although the morphology of the newly identified Mesodinium sp. was indistinguishable from that of M. rubrum under normal light microscopy, phylogenetic analysis placed this species between the M. rubrum/major species complex and a well-supported lineage of M. chamaeleon and M. coatsi. Close associations were observed in cryptophyte species composition within cells of Mesodinium spp. and in ambient water samples. The appearance of suitable cryptophyte prey is probably a trigger for succession of Mesodinium spp., and the subsequent abundance of Mesodinium spp. appears to be influenced by water temperature and dissolved inorganic nutrients.


Assuntos
Cilióforos/crescimento & desenvolvimento , Cilióforos/parasitologia , Criptófitas/classificação , Criptófitas/crescimento & desenvolvimento , Cilióforos/classificação , Cilióforos/genética , Análise por Conglomerados , Criptófitas/genética , DNA de Algas/química , DNA de Algas/genética , DNA de Protozoário/química , DNA de Protozoário/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Japão , Lagos/parasitologia , Filogenia , RNA Ribossômico 18S/genética , Estações do Ano , Análise de Sequência de DNA
13.
Harmful Algae ; 78: 95-105, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30196930

RESUMO

Previous studies indicate differences in bloom magnitude and toxicity between regional populations, and more recently, between geographical isolates of Dinophysis acuminata; however, the factors driving differences in toxicity/toxigenicity between regions/strains have not yet been fully elucidated. Here, the roles of prey strains (i.e., geographical isolates) and their associated attributes (i.e., biovolume and nutritional content) were investigated in the context of growth and production of toxins as a possible explanation for regional variation in toxicity of D. acuminata. The mixotrophic dinoflagellate, D. acuminata, isolated from NE North America (MA, U.S.) was offered a matrix of prey lines in a full factorial design, 1 × 2 × 3; one dinoflagellate strain was fed one of two ciliates, Mesodinium rubrum, isolated from coastal regions of Japan or Spain, which were grown on one of three cryptophytes (Teleaulax/Geminigera clade) isolated from Japan, Spain, or the northeastern USA. Additionally, predator: prey ratios were manipulated to explore effects of the prey's total biovolume on Dinophysis growth or toxin production. These studies revealed that the biovolume and nutritional status of the two ciliates, and less so the cryptophytes, impacted the growth, ingestion rate, and maximum biomass of D. acuminata. The predator's consumption of the larger, more nutritious prey resulted in an elevated growth rate, greater biomass, and increased toxin quotas and total toxin per mL of culture. Grazing on the smaller, less nutritious prey, led to fewer cells in the culture but relatively more toxin exuded from the cells on per cell basis. Once the predator: prey ratios were altered so that an equal biovolume of each ciliate was delivered, the effect of ciliate size was lost, suggesting the predator can compensate for reduced nutrition in the smaller prey item by increasing grazing. While significant ciliate-induced effects were observed on growth and toxin metrics, no major shifts in toxin profile or intracellular toxin quotas were observed that could explain the large regional variations observed between geographical populations of this species.


Assuntos
Cilióforos/fisiologia , Dinoflagelados/química , Dinoflagelados/crescimento & desenvolvimento , Cadeia Alimentar , Toxinas Marinhas/química , Cilióforos/crescimento & desenvolvimento , Proliferação Nociva de Algas
14.
FEMS Microbiol Ecol ; 94(10)2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30124812

RESUMO

Meta-communities are assembled along an ecological scale that determines local and regional diversity. Spatial patterns have been detected in planktonic bacterial communities at distances <20 m, but little is known about the occurrence of similar variation for other microbial groups and changes in microbial meta-community assembly at different levels of a meta-community. To examine this variation, the biofilm of eight saline ponds were used to investigate processes shaping diversity within ponds (ß) and between ponds (δ). Bacterial and ciliate communities were assessed using ARISA and T-RFLP respectively, while diversity partitioning methods were used to examine the importance of taxonomic turnover and variation partitioning was used to distinguish spatial from environmental determinants. The results show that turnover is important for determining ß- and δ-diversity of biofilms. Spatial factors are important drivers of bacterial ß-diversity but were unimportant for ciliate ß-diversity. Environmental variation was a strong determinant of bacterial and ciliate δ-diversity, suggesting sorting processes are important for assembling pond communities. Determinants of diversity in bacteria are not universal for ciliates, suggesting higher functional redundancy of bacteria or the greater niche breadth of ciliates may be important in discriminating assembly processes between the two organisms.


Assuntos
Bactérias/classificação , Biofilmes/classificação , Cilióforos/classificação , Lagos/microbiologia , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Biodiversidade , Biofilmes/crescimento & desenvolvimento , Cilióforos/genética , Cilióforos/crescimento & desenvolvimento , Lagos/química , Plâncton , Salinidade , Microbiologia da Água
15.
J Microbiol Methods ; 152: 186-193, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30142357

RESUMO

Rumen protozoa, primarily ciliates, are one of the important groups of strictly anaerobic microbes living in the rumen. Despite their ubiquitous occurrence in the rumen and significant contribution to host animals, it is still poorly understood why they live only in the rumen and similar environment. Because rumen protozoa require strict anaerobic conditions to sustain their viability and grow, only a few laboratories equipped with protozoology expertise and anaerobic facilities can grow rumen protozoa in laboratory. Also for the same reason, only a few species have been grown and maintained as laboratory cultures for research. Prompted by a recent study, we hypothesized that anaerobic rumen protozoa could also be cultivated aerobically if antioxidants were included in the media. Indeed, our experiments showed that the cultures of both Entodinium caudatum and Epidinium caudatum, two major rumen protozoal species, could be cultured successfully in aerobic media supplemented with ascorbic acid, glutathione and α-ketoglutarate as antioxidants. Anaerobic fermentation was maintained through the fermentation characteristics and microbial populations were altered to some extent under aerobic conditions. The antioxidants also enhanced the revival of cryopreserved stock cultures of both rumen protozoal species. The results of this study may facilitate and promote future research in which rumen protozoa need to be cultured in laboratory.


Assuntos
Técnicas de Cultura de Células/métodos , Cilióforos/crescimento & desenvolvimento , Rúmen/parasitologia , Anaerobiose , Animais , Antioxidantes , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Cilióforos/classificação , Meios de Cultura/química , Fermentação , Genes de Protozoários , RNA Ribossômico 16S/genética , Rúmen/microbiologia , Ruminantes/microbiologia , Ruminantes/parasitologia
16.
J Vis Exp ; (136)2018 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-29985325

RESUMO

Cells need to be able to regenerate their parts to recover from external perturbations. The unicellular ciliate Stentor coeruleus is an excellent model organism to study wound healing and subsequent cell regeneration. The Stentor genome became available recently, along with modern molecular biology methods, such as RNAi. These tools make it possible to study single-cell regeneration at the molecular level. The first section of the protocol covers establishing Stentor cell cultures from single cells or cell fragments, along with general guidelines for maintaining Stentor cultures. Culturing Stentor in large quantities allows for the use of valuable tools like biochemistry, sequencing, and mass spectrometry. Subsequent sections of the protocol cover different approaches to inducing regeneration in Stentor. Manually cutting cells with a glass needle allows studying the regeneration of large cell parts, while treating cells with either sucrose or urea allows studying the regeneration of specific structures located at the anterior end of the cell. A method for imaging individual regenerating cells is provided, along with a rubric for staging and analyzing the dynamics of regeneration. The entire process of regeneration is divided in three stages. By visualizing the dynamics of the progression of a population of cells through the stages, the heterogeneity in regeneration timing is demonstrated.


Assuntos
Cilióforos/crescimento & desenvolvimento , Técnicas Histológicas/métodos , Regeneração/fisiologia , Animais , Cilióforos/patogenicidade
17.
Sci Total Environ ; 635: 618-628, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29679834

RESUMO

The determinants of microeukaryotic biogeography in coastal waters at a regional scale remain largely unclear. The coastal northern Zhejiang (in the East China Sea) is a typical subtropical marine ecosystem with multiple environmental gradients that has been extensively perturbed by anthropogenic activities. Thus, it is a valuable region to investigate the key drivers that shape microbial biogeography. We investigated microeukaryotic communities in surface waters from 115 stations in this region using 18S ribosomal RNA gene amplicon sequencing. The microeukaryotic communities were mainly comprised of Dinoflagellata, Ciliophora, Protalveolata, Rhizaria, Stramenopiles and Cryptophyceae. The top abundant operational taxonomic units (OTUs) were highly specific for distinct habitat types, exhibiting significant environment-conditioned features; however, the cosmopolitan OTUs were not strongly correlated with the measured environmental variables. Total phosphorus and suspended particles were major environmental determinants of microeukaryotic α-diversity. Environmental variables, particularly temperature, salinity, pH and silicate concentration, were strongly associated with the microeukaryotic community composition. Overall, environmental and spatial factors explained 55.92% of community variation in total with 34.03% of the variation shared, suggesting that spatially structured environmental variations mainly conditioned the microeukaryotic biogeography in this region. Additionally, dispersal limitation, as indicated by the great pure spatial effect and distance-decay pattern, was another important factor. In summary, our results reveal that spatially structured environmental variation and dispersal limitation mainly conditioned the microeukaryotic biogeography. The results may provide useful distribution patterns of microeukaryotes to determine sources of microbes from marine ecosystems that may facilitate the utilization of coastal resources.


Assuntos
Organismos Aquáticos/classificação , Monitoramento Ambiental , Organismos Aquáticos/crescimento & desenvolvimento , China , Cilióforos/classificação , Cilióforos/crescimento & desenvolvimento , Dinoflagelados/classificação , Dinoflagelados/crescimento & desenvolvimento , Ecossistema , Água do Mar/microbiologia
18.
Mar Pollut Bull ; 129(1): 207-211, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29680539

RESUMO

Owing to the environmental sensitivity of ciliate species, the monitoring and assessment of these communities can indicate the health of the aquatic environment. Sampling for loricate ciliates was carried out during different seasons at three different locations in the estuarine and coastal waters of Kochi, Southwest coast of India. The loricate ciliate community comprising of 27 species belonging to 10 genera revealed significant differences among the three sampling locations. The maximum numerical abundance and less species diversity of loricate ciliates were recorded at the estuarine locations whereas the minimum abundance and more species diversity were encountered in the coastal waters. Multivariate statistical analyses revealed that Tintinnopsis beroidea and Tintinnopsis uruguayensis were correlated positively with nutrients in the estuarine environment, which receives large amount of anthropogenic inputs. Thus, we propose that these two loricate ciliates may be considered as a potential bioindicator of eutrophication status in marine ecosystems.


Assuntos
Cilióforos/classificação , Cilióforos/crescimento & desenvolvimento , Monitoramento Ambiental/métodos , Ecossistema , Eutrofização , Índia , Dinâmica Populacional , Estações do Ano , Qualidade da Água
19.
J Eukaryot Microbiol ; 65(5): 679-693, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29498766

RESUMO

The morphology and phylogeny of four oligotrichid ciliates, Parallelostrombidium paraellipticum sp. n., P. dragescoi sp. n., P. jankowskii (Xu et al. 2009) comb. n., and P. kahli (Xu et al. 2009) comb. n., are described or redescribed based on live observation, protargol stained material, and SSU rRNA gene sequences. The new species P. paraellipticum sp. n. is characterized by its obovoidal cell shape, adoral zone composed of 17-21 collar, 9-11 buccal, and two thigmotactic membranelles, and extrusomes attached in one row along the girdle kinety. The new species P. dragescoi sp. n. is distinguished from its congeners by its obovoidal cell shape and a lack of thigmotactic membranelles. Based on ciliary patterns recognizable in the original slides, Omegastrombidium jankowskii Xu et al. 2009 and O. kahli Xu et al. 2009 should be transferred to the genus Parallelostrombidium Agatha 2004. Phylogenetic analyses based on SSU rRNA gene sequence data demonstrate that all four new sequences cluster with previously described congeners. The genus Parallelostrombidium is separated into two clusters, suggesting its non-monophyly and probably corresponding to the two subgenera proposed by Agatha and Strüder-Kypke (2014), as well as their morphological difference (cell dorsoventrally flattened vs. unflattened).


Assuntos
Cilióforos/classificação , Cilióforos/crescimento & desenvolvimento , Filogenia , China , Cilióforos/genética , DNA de Protozoário/genética , DNA Ribossômico/genética
20.
J Eukaryot Microbiol ; 65(5): 705-708, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29532600

RESUMO

Protargol staining is a crucial method to reveal the infraciliature of ciliates, which is the most important morphological character for species identification. In the present study, Wilbert's protocol of protargol staining was emended mainly toward the highly happened improper bleaching. Through reciprocal treatments, both insufficient and excessive bleachings were much eliminated from the protargol protocol and the tests performed with four different species of ciliates established that the stainings were considerably improved and more reliable with optimized bleaching. Compared to the original protocol, the optimized method was proved to be more suitable for the groups difficult to stain, and it is also friendlier for the beginners and researchers in related fields.


Assuntos
Cilióforos/química , Proteínas de Protozoários/química , Proteínas de Prata/química , Coloração e Rotulagem/métodos , Cilióforos/crescimento & desenvolvimento
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