Academic literature on the topic 'Synechoccoccus'

Pangasius catfish rearing ponds and swamp waters are types of stagnant waters (lentic) that are commonly found in the South Sumatra region. Cyanobacter is a group of phytoplankton that plays an important role in the management of aquatic area, but it is not widely known which species is the most dominant in swamp waters. This study aims to determine the types of cyanobacter that are abundant in the swamps and Pangasius catfish cultivation ponds in Ogan Olir, South Sumatra. This research has been carried out by cyanobacter isolation from the swamp water and the pond, isolate liquid cultivation, DNA isolation, 16S rRNA gene amplification and DNA amplicon sequencing. The sequencing results were analyzed using BLAST (Basic local alignment search tool-nucleotide) and MEGA 6 with the help of NCBI gene bank data to obtain a phylogenetic tree for predicting the identity of the cyanobacter isolates. Based on the morphological characters, it is suspected that the pond isolates are similar to Synechoccocus and swamp isolates similar to Microcystis genera. The amplification of cyanobacter DNA using the PCR method with the universal 16S rRNA 63F (Forward) and 1387 R (Reverse) resulted 1302-1307 base pairs. Analysis using BLAST showed that the cyanobacter isolates from ponds have 91% similar to Uncultured Synechoccocus sp. from Australia, while the swamp isolates have 86% similar to Microcystis sp. from China. Key words : Cyanobacteria, Microcystis, PCR, Phylogenetic, Synechococcus

The relationships between the structure of the phytoplankton community and the bio-optical properties of surface waters were studied during the TransPEGASO cruise along a transect across the Atlantic Ocean that covered seven biogeographical provinces, from the Alborán Sea (SW Mediterranean) to the Patagonian Shelf. We characterized the composition of the phytoplankton community by means of high-performance liquid chromatography and CHEMTAX pigment analyses applied to whole water and two filtration size classes (< 3 and ≥ 3 μm), flow cytometric determinations and microscopic observations. Additionally, the study was complemented by measurements of the absorption of particulate matter and coloured dissolved organic matter (CDOM). The size class distribution of the chlorophyll a (Chl a) obtained from the size-fractionated filtration (SFF) was compared with that resulting from the diagnostic pigment algorithms (VU) developed by Vidussi et al. (2001) and Uitz et al. (2006), and the total Chl a–based expressions (HI) of Hirata et al. (2011). The seven provinces crossed by the transect could be divided into an oligotrophic group with Chl a < 0.25 mg m-3 comprising the tropical and subtropical Atlantic (including the Canary Current Coastal Province), and a eutrophic group (Chl a > 0.5 mg m-3) with a single Mediterranean (MEDI) sample and those from the southwestern Atlantic Shelf (SWAS). According to CHEMTAX, the most important taxa in the tropical and subtropical Atlantic were Prochlorococcus, haptophytes and Synechoccoccus, while the MEDI and SWAS were dominated by diatoms and haptophytes. Both the VU and HI algorithms, which are based on pigment composition or Chl a concentration, predicted for SWAS a high proportion of nano- and microphytoplankton, while the SFF indicated dominance of the < 3 μm size class. In addition, the CHEMTAX results indicated a high average diatom contribution in this province. However, at several SWAS stations with relatively high values of diatom Chl a estimated by CHEMTAX, the microscopic observations found only small concentrations of nano- or microplankton-sized cells. This discrepancy appeared to be due to the presence, confirmed by scanning electron microscopy, of picoplankton-sized cells of the diatom Minidiscus sp. and of Parmales (a group sharing the pigment composition with the diatoms). These findings caution against a routine assignment of diatom pigments to the microplankton size class. The total non-water absorption in the water column was dominated by CDOM. The average contribution of phytoplankton absorption for the different provinces ranged from 19.3% in the MEDI to 45.7% in the SWAS and 47% in the western tropical Atlantic (WTRA). The Chl a–specific phytoplankton absorption [aph*(443), m2 mg-1] was lower in the MEDI and SWAS than in the oligotrophic provinces. aph*(443) was negatively correlated with the first principal component derived from a principal component analysis based on the concentration of the main pigments and was not correlated with indicators of phytoplankton community size structure such as the proportion of Chl a in the < 3 μm class or a size index derived from the VU size class distribution. These findings indicate that the variability observed in aph*(443) was mainly related to differences in pigment composition and possibly to photoacclimation processes, and that any package effects due to cell size were probably masked by other factors, an outcome that may be related to the relatively small influence of size within the narrow range of Chl a concentrations (all ≤ 2.4 mg m-3) considered in our study.

ABSTRACT The analysis of host immunity to mycobacteria and the development of discriminatory diagnostic reagents relies on the characterization of conserved and species-specific mycobacterial antigens. In this report, we have characterized the Mycobacterium avium homolog of the highly immunogenic M. leprae 35-kDa protein. The genes encoding these two proteins were well conserved, having 82% DNA identity and 90% identity at the amino acid level. Moreover both proteins, purified from the fast-growing host M. smegmatis, formed multimeric complexes of around 1000 kDa in size and were antigenically related as assessed through their recognition by antibodies and T cells from M. leprae-infected individuals. The 35-kDa protein exhibited significant sequence identity with proteins from Streptomyces griseus and the cyanobacterium Synechoccocus sp. strain PCC 7942 that are up-regulated under conditions of nutrient deprivation. The 67% amino acid identity between the M. avium 35-kDa protein and SrpI of Synechoccocus was spread across the sequences of both proteins, while the homologous regions of the 35-kDa protein and the P3 sporulation protein of S. griseus were interrupted in the P3 protein by a divergent central region. Assessment by PCR demonstrated that the gene encoding the M. avium35-kDa protein was present in all 30 M. avium clinical isolates tested but absent from M. intracellulare,M. tuberculosis, or M. bovis BCG. Mice infected with M. avium, but not M. bovis BCG, developed specific immunoglobulin G antibodies to the 35-kDa protein, consistent with the observation that tuberculosis patients do not recognize the antigen. Strong delayed-type hypersensitivity was elicited by the protein in guinea pigs sensitized with M. avium.

Abstract. We report the transient population dynamic response of the osmotrophic community initiated by a nutrient pulse in mesocosms exposed to different pCO2 levels as well as quantitative variations in phytoplankton and heterotrophic bacteria created by the difference in CO2 exposure. Coastal seawater was enclosed in floating mesocosms (27 m3) and nutrients were supplied initially in order to stimulate growth of microbial organisms, including the coccolitophorid Emiliania huxleyi. The mesocosms were modified to achieve 350 μatm (1×CO2), 700 μatm (2×CO2) and 1050 µatm (3×CO2) CO2 pressure. The temporal dynamics was related to the nutrient conditions in the enclosures. Numerically small osmotrophs (picoeukaryotes and Synechoccocus sp.) dominated initially and towards the end of the experiment, whereas intermediate sized osmotrophs bloomed as the initial bloom of small sized osmotrophs ceased. Maximum concentrations of E. huxleyi were approximately 4.6×103 cells ml−1 whereas other intermediate sized osmotrophs reached approximately twice as high concentrations. Osmotrophic succession pattern did not change, and we were not able to detect differences with regard to presence or absence of specific osmotrophic taxa as a consequence of altered atmospheric CO2 concentration. Quantitative effects on the microbial communities associated with the CO2 treatment were, however, observed towards the end of the experiment.

Abstract. We report the transient population dynamic response of the osmotrophic community initiated by a nutrient pulse in mesocosms exposed to different pCO2 levels. Differences in phytoplankton and heterotrophic bacteria abundances associated with the CO2 treatment are also described. Coastal seawater was enclosed in floating mesocosms (27 m3) and nutrients were supplied initially in order to stimulate growth of microbial organisms, including the coccolitophorid Emiliania huxleyi. The mesocosms were modified to achieve 350 μatm (1×CO2), 700 μatm (2×CO2) and 1050 μatm (3×CO2) CO2 pressure. The temporal dynamics was related to nutrient conditions in the enclosures. Numerically small osmotrophs (picoeukaryotes and Synechoccocus sp.) dominated initially and towards the end of the experiment, whereas intermediate sized osmotrophs bloomed as the initial bloom of small sized osmotrophs ceased. Maximum concentrations of E. huxleyi were approximately 4.6×103 cells ml−1 whereas other intermediate sized osmotrophs reached approximately twice as high concentrations. The osmotrophic succession pattern did not change, and neither were we able to detect differences with regard to presence or absence of specific osmotrophic taxa as a consequence of altered pCO2. Towards the end of the experiment we did, however, record significantly higher picoeukaryotic- and lower Synechococcus-abundances in the higher CO2 treatments. Slightly increased cell concentrations of E. huxleyi and other nanoeukaryotes were also recorded at elevated pCO2 on certain days.

AbstractStudies of the diversity and distribution of freshwater cyanophages are generally limited to the small geographical areas, in many cases including only one or few lakes. Data from dozens of various lakes distributed at a larger distance are necessary to understand their spatial distribution and sensitivity to biotic and abiotic factors. Thus, the objective of this study was to analyze the diversity and distribution of cyanophages within the infected cells using marker genes (psbA, nblA, and g91) in 21 Polish and Lithuanian lakes. Physicochemical factors that might be related to them were also analyzed. The results demonstrated that genetic markers representing cyanophages were observed in most lakes studied. The frequently detected gene was psbA with 88% of cyanophage-positive samples, while nblA and g91 were found in approximately 50% of lakes. The DNA sequence analyses for each gene demonstrated low variability between them, although the psbA sequences branched within the larger cluster of marine Synechoccocuss counterparts. The principal component analysis allowed to identify significant variation between the lakes that presented high and low cyanobacterial biomass. The lakes with high cyanobacterial biomass were further separated by country and the different diversity of cyanobacteria species, particularly Planktothrix agardhii, was dominant in the Polish lakes and Planktolyngbya limnetica in the Lithuanian lakes. The total phosphorous and the presence of cyanophage genes psbA and nblA were the most important factors that allowed differentiation for the Polish lakes, while the pH and the genes g91 and nblA for the Lithuanian lakes.

Salah satu upaya untuk meningkatkan produksi dan mutu benih di lahan salin yaitu melalui penggunaan metode ratun dengan penambahan bakteri sintetik Synechoccocus sp. Penelitian ini bertujuan untuk mengetahui produksi dan mutu benih padi ratun yang tercekam salinitas dengan penambahan bakteri sintetik Synechoccocus sp. Penelitian dilaksanakan pada bulan Juli - Desember 2015 di Desa Suco, Kecamatan Mumbul Sari Jember dan Laboratorium Teknologi Benih Politeknik Negeri Jember. Rancangan percobaan yang digunakan adalah Rancangan Acak Kelompok Faktorial (RAK) dengan 2 faktor dan 3 ulangan. Faktor pertama adalah cekaman Salinitas (S) yang terdiri dari 5 taraf, S1 = tanpa cekaman (kontrol), S2 = cekaman salinitas 1000 ppm, S3 = cekaman salinitas 2000 ppm, S4 = cekaman salinitas 3000 ppm, S5 = cekaman salinitas 4000 ppm. Faktor kedua inokulasi bakteri sintetik Synechoccocus sp. (B), yang terdiri dari 2 taraf, B1 = tanpa inokulasi bakteri (kontrol), B2 = Inokulasi sintetik Synechoccocus sp. Data dianalisis menggunakan uji F (ANOVA) dan dilanjutkan dengan perhitungan Duncan’s Multiple Range Test (DMRT). Hasil penelitian menunjukan perlakuan salinitas 1000 ppm (S2) menghasilkan jumlah anakan ratun produktif tertinggi yaitu 19,33 anakan. Cl- mempunyai fungsi utama dalam reaksi fotosintesis sehingga cekaman salintas pada perlakuan 1000 ppm (S2) dapat ditoleran oleh tanaman padi varietas Ciherang pada fase vegetatif. Pemberian Bakteri (B) Synechococcus sp. mampu menghasilkan tunas ratun tertinggi pada fase vegetatif yaitu 40,10 cm. Interaksi dari dua perlakuan menunjukan hasil yang nyata pada parameter jumlah gabah bernas yaitu cekaman salinitas 4000 ppm dengan inokulasi bakteri (B2S5) menghasilkan gabah bernas yang paling tinggi sebesar 99,06 butir. Inokulasi tanaman dengan Synechococcus sp. mampu meningkatkan kandungan nitrogen dan kandungan klorofil dalam jaringan tanaman. Interaksi antara cekaman salinitas 1000 ppm dengan inokulasi bakteri (B2S2) menghasilkan produksi per Ha yang paling tinggi yaitu 1,389 ton dan potensi produksi per Ha tertinggi yaitu 1.66 ton/ha.