Photosynthetic purple sulfur bacterium Marichromatium purpuratum RuA2 induces changes in water quality parameters, the occurrence of sulfonamide resistance gene and microbial community structure of marine aquaculture (original) (raw)
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Diversity of Sulfur-Oxidizing Bacteria in Greenwater System of Coastal Aquaculture
Applied Biochemistry and Biotechnology, 2010
Reduced sulfur compounds produced by the metabolism are the one of the major problems in aquaculture. In the present study, herbivorous fishes have been cultured as biomanipulators for secretions of slime, which enhanced the production of greenwater containing beneficial bacteria. The genes encoding soxB which is largely unique to sulfuroxidizing bacteria (SOB) due to its hydrolytic function has been targeted for examining the diversity of SOB in the green water system of coastal aquaculture. Novel sequences obtained based on the sequencing of metagenomic clone libraries for soxB genes revealed the abundance of SOB in green water system. Phylogenetic tree constructed from aligned amino acid sequences demonstrated that different clusters have only 82-93% match with Roseobacter sp., Phaeobacter sp., Roseovarius sp., Sulfitobacter sp., Ruegeria sp., and Oceanibulbus sp. The level of conservation of the soxB amino acid sequences ranged from 42% to 71%. 16S rRNA gene analyses of enrichment culture from green water system revealed the presence of Pseudoxanthomonas sp., which has 97% similarity with nutritionally fastidious Indian strain of Pseudoxanthomonas mexicana-a sulfur chemolithotrophic γ-proteobacterium. Our results illustrate the relevance of SOB in the functioning of the green water system of coastal shrimp aquaculture for oxidation of reduced sulfur compounds, which in turn maintain the sulfide concentration well within the prescribed safe levels.
Abundance of sulphur-oxidizing bacteria in coastal aquaculture using soxB gene analyses
Aquaculture Research, 2010
Molecular techniques based on sequencing of metagenomic clone libraries provide an insight into the diversity of microbial populations. Using nucleic acid-based methods, the diversity of soxB genes was examined to detect and characterize sulphur-oxidizing bacteria in Indian coastal aquaculture environments. Gene-spe-ci¢c degenerate primers were used to amplify various fragments (710,753, 483^503, 280 and 239 bp) of soxB genes. Metagenomic clone libraries were constructed for 753, 483^503 and 239 bp fragments of soxB genes. The abundance of soxB revealed the presence of sulphur-oxidizing organisms. Amino acids in parts of the soxB-encoded proteins were aligned to known conserved amino acid residues. The level of conservation ranged from 23% to 30%. A phylogenetic tree constructed from aligned amino acid sequences of SoxB revealed di¡erent clusters associated with the branches of phototrophic aand g-proteobacteria. In general, soxB is widespread among the various phylogenetic groups, although this does not necessarily mean that the organism can use sulphur compounds. Our results suggest that the chemolithoautotrophy based on sulphur oxidation in coastal aquaculture is primarily sustained by the presence of sulphur oxidizers, which involve the soxB gene. This study aids identi¢cation of the phylogenetic characteristics related to sulphur bioremediation in poorly characterized coastal aquaculture environments.
A rod-shaped, phototrophic, purple sulfur bacterium, strain JA124 T , was isolated in pure culture from a marine aquaculture pond, located near Bhimunipatnam, in a medium that contained 3 % NaCl (w/v). Strain JA124 T is a Gram-negative, motile rod with a single polar flagellum. Strain JA124 T has a requirement for NaCl, with optimum growth at 1.5-8.5 %, and tolerates up to 11 % NaCl. Intracellular photosynthetic membranes are of the vesicular type. Bacteriochlorophyll a and probably carotenoids of the spirilloxanthin series are present as photosynthetic pigments. Strain JA124 T was able to utilize sulfide, sulfate, thiosulfate, sulfite, thioglycollate and cysteine as sulfur sources. Strain JA124 T was able to grow photolithoautotrophically, photolithoheterotrophically and photo-organoheterotrophically. Chemotrophic and fermentative growth could not be demonstrated. Strain JA124 T lacks diazotrophic growth and acetylene reduction activity. Pyridoxal phosphate is required for growth. During growth on reduced sulfur sources as electron donors, sulfur is deposited intermediately as a number of small granules within the cell. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA124 T clusters with species of the genus Marichromatium belonging to the class Gammaproteobacteria. The highest sequence similarities of strain JA124 T were found with the type strains of Marichromatium indicum (98 %), Marichromatium purpuratum (95 %) and Marichromatium gracile (93 %). However, DNA-DNA hybridization with Marichromatium indicum DSM 15907 T revealed relatedness of only 65 % with strain JA124 T . The DNA base composition of strain JA124 T was 67 mol% G+C (by HPLC). Based on 16S rRNA gene sequence analysis, morphological and physiological characteristics and DNA-DNA hybridization studies, strain JA124 T (=ATCC BAA-1316 T =JCM 13911 T ) is sufficiently different from other Marichromatium species to merit its description as the type strain of a novel species, Marichromatium bheemlicum sp. nov.
2021
The sustainability of the shrimp aquaculture depends largely on disease control and the health status of shrimp. Probiotics, which make shrimps healthier and more resistant to pathogens, are promising countermeasure for shrimp diseases. In this study, the effects of the marine purple non-sulfur photosynthetic bacterium (PNSB) Rhodovulum sulfidophilum on Marsupenaeus japonicus (kuruma shrimp) growth and survival were examined in 177 m aquaria (140 tons of water) for 70 days. The shrimp received feed containing 0.01 % fresh weight (10 colony forming unit/g) of R. sulfidophilum cells. The survival rate significantly improved (P < 0.001) (R. sulfidophilum-fed = 81.9 %; control = 71.5 %), the feed conversion rate improved (R. sulfidophilum-fed = 1.83; control = 2.11), and there was no difference in the shrimp average body weight. The approximate bacterial cell cost was 0.003to0.003 to 0.003to0.005 per 1 kg feed, indicating that the R. sulfidophilum approach is economically feasible and a promisin...
Archives of Microbiology, 2013
This study investigated the spatiotemporal abundance and diversity of the a-subunit of the dissimilatory sulfite reductase gene (dsrA) in the meromictic Lake Suigetsu for assessing the sulfur-oxidizing bacterial community. The density of dsrA in the chemocline reached up to 3.1 9 10 6 copies ml-1 in summer by means of quantitative real-time PCR and it was generally higher than deeper layers. Most of the dsrA clones sequenced were related to green sulfur bacteria such as Chlorobium phaeovibrioides, C. limicola, and C. luteolum. Below the chemocline of the lake, we also detected other dsrA clones related to the purple sulfur bacterium Halochromatium salexigens and some branching lineages of diverse sequences that were related to chemotrophic sulfur bacterial species such as Magnetospirillum gryphiswaldense, Candidatus Ruthia magnifica, and Candidatus Thiobios zoothamnicoli. The abundance and community compositions of sulfur-oxidizing bacteria changed depending on the water depth and season. This study indicated that the green sulfur bacteria dominated among sulfur-oxidizing bacterial population in the chemocline of Lake Suigetsu and that certain abiotic environmental variables were important factors that determined sulfur bacterial abundance and community structure.
International Microbiology, 2007
Communities of green sulfur bacteria were studied in selected marine and saline habitats on the basis of gene sequences of 16S rRNA and the Fenna-Matthews-Olson (FMO) protein. The availability of group-specific primers for both 16S rDNA and the fmoA gene, which is unique to green sulfur bacteria, has, for the first time, made it possible to analyze environmental communities of these bacteria by culture-independent methods using two independent genetic markers. Sequence results obtained with fmoA genes and with 16S rDNA were largely congruent to each other. All of the 16S rDNA and fmoA sequences from habitats of the Baltic Sea, the Mediterranean Sea, Sippewissett Salt Marsh (Massachusetts, USA), and Bad Water (Death Valley, California, USA) were found within salt-dependent phylogenetic lines of green sulfur bacteria established by pure culture studies. This strongly supports the existence of phylogenetic lineages of green sulfur bacteria specifically adapted to marine and saline environments and the exclusive occurrence of these bacteria in marine and saline habitats. The great majority of clone sequences belonged to different clusters of the Prosthecochloris genus and probably represent different species. Evidence for the occurrence of two new species of Prosthecochloris was also obtained. Different habitats were dominated by representatives from the Prosthecochloris group and different clusters or species of this genus were found either exclusively or as the clearly dominant green sulfur bacterium at different habitats. [Int Microbiol 2006; 9(4):259-266]
Analysis of Subfossil Molecular Remains of Purple Sulfur Bacteria in a Lake Sediment
1998
Molecular remains of purple sulfur bacteria (Chromatiaceae) were detected in Holocene sediment layers of a meromictic salt lake (Mahoney Lake, British Columbia, Canada). The carotenoid okenone and bacteriophaeophytin a were present in sediments up to 11,000 years old. Okenone is specific for only a few species of Chromatiaceae, including Amoebobacter purpureus, which presently predominates in the chemocline bacterial community of the lake. With a primer set specific for Chromatiaceae in combination with denaturing gradient gel electrophoresis, 16S rRNA gene sequences of four different Chromatiaceae species were retrieved from different depths of the sediment. One of the sequences, which originated from a 9,100-year-old sample, was 99.2% identical to the 16S rRNA gene sequence of A. purpureus ML1 isolated from the chemocline. Employing primers specific for A. purpureus ML1 and dot blot hybridization of the PCR products, the detection limit for A. purpureus ML1 DNA could be lowered to 0.004% of the total community DNA. With this approach the DNA of the isolate was detected in 7 of 10 sediment layers, indicating that A. purpureus ML1 constituted at least a part of the ancient purple sulfur bacterial community. The concentrations of A. purpureus DNA and okenone in the sediment were not correlated, and the ratio of DNA to okenone was much lower in the subfossil sediment layers (2.7 ⅐ 10 ؊6 ) than in intact cells (1.4). This indicates that degradation rates are significantly higher for genomic DNA than for hydrocarbon cell constituents, even under anoxic conditions and at the very high sulfide concentrations present in Mahoney Lake.