The Role of Epibionts of Bacteria of the Genus <Emphasis Type="Italic">Pseudoalteromonas</Emphasis> and Cellular Proteasomes in the Adaptive Plasticity of Marine Cold-Water Sponges

It was found that cells of different color morphs of the cold-water marine sponges Halichondria panicea (Pallas, 1766) of the class Demospongiae differ in the content of epibionts of bacteria of the genus Pseudoalteromonas. The sponge cells with elevated levels of epibionts of bacteria of the genus Pseudoalteromonas showed an increased expression of Hsp70 proteins but had a reduced level of the proteasomal catalytic beta 5 subunit, which was accompanied by a change in their activity. Probably, epibionts of bacteria of the genus Pseudoalteromonas may affect the ubiquitin–proteasome system in the cells of cold-water marine sponges and, thereby, ensure their adaptive plasticity.     

北戴河海洋沉积物中L-半胱氨酸脱硫细菌的多样性及其特性

【背景】脱硫细菌对有机硫的脱硫作用在硫的生物地球化学循环以及脱硫工业中都起着重要的作用。【目的】了解海洋沉积物中可分解有机物产生硫化氢的细菌多样性。【方法】对我国北戴河海洋沉积物中可培养的L-半胱氨酸脱硫细菌进行分离与筛选,通过对其16SrRNA基因序列测定与分析,构建系统发育树,并对其脱硫、脱氮能力进行检验。【结果】从海洋沉积物中分离得到97株细菌,从以L-半胱氨酸为硫源的培养基中筛选出62株有机脱硫专一型细菌。根据脱硫细菌的形态及其特征,从中选取12株作为典型代表做进一步分析,它们分别属于芽孢杆菌属(Bacillus)、赖氨酸芽孢杆菌属(Lysinibacillus)、动性球菌属(Planococcus)和红球菌属(Rhodococcus)。结果表明,这12株细菌均可产生半胱氨酸脱巯基酶,能够将半胱氨酸分解为丙酮酸、硫化氢和氨,即同时具备脱硫与脱氮的能力。其中有5株菌脱硫能力较强,分别属于赖氨酸芽孢杆菌属、动性球菌属和芽孢杆菌属。【结论】海洋沉积物中存在着丰富的L-半胱氨酸脱硫细菌,为进一步研究海洋中硫的生物地球化学循环提供了素材。     

Correlation of taxonomic criteria for a collection of marine bacteria

Numerical taxonomy was done on 208 strains of marine bacteria. The collection was segregated into eight groups, seven of which contained Vibrio sp. Nucleic acid base ratio studies on a typical Vibrio sp. from each group and other genera were done. The phenotypically different Vibrio sp. had a narrow range of base ratios. The other genera had base ratios more similar to the base ratios reported for their genus than to each other as marine bacteria. The taxonomic groups are compared with generic classification and the strains' sources of isolations.     

Structure and Arrangement of Flagella in Species of the Genus Beneckea and Photobacterium fischeri

Species of marine bacteria belonging to the genus Beneckea and strains of Photobacterium fischeri were negatively stained and examined by means of the electron microscope to determine the structure and arrangement of their flagella. All of the species of the genus Beneckea had single, polar, sheathed flagella when grown in liquid medium. When grown on solid medium, most strains of B. campbellii and B. neptuna and all strains of B. alginolytica and B. parahaemolytica had unsheathed, peritrichous flagella in addition to the single, sheathed, polar flagellum. The remaining species, B. nereida, B. pelagia, and B. natriegens, had a single, polar, sheathed flagellum when grown on solid medium. Strains of P. fischeri had sheathed flagella arranged in polar tufts. Only one group (B-2) of marine bacteria included in this study was found to have polar, unsheathed flagella.     

The phylogeny of marine and freshwater caulobacters reflects their habitat.

Caulobacter is a distinctive genus of prosthecate bacteria. Because caulobacters adhere to surfaces and are found in diverse locales, their role in oligotrophic environments and bacterial biofilm communities is of interest. The phylogenetic relationships of a group of marine and freshwater caulobacters were examined in part to address whether the taxonomic grouping of these bacteria (based primarily on morphological characters) was consistent with 16S rRNA sequence divergence. The caulobacters examined (9 marine and 11 freshwater species or strains) were affiliated with the alpha proteobacteria. They made up a diverse yet, with the possible exception of a strain of Caulobacter subvibrioides, coherent assemblage. The diversity was most apparent in a comparison of freshwater and marine isolates; an early divergence within the main caulobacter lineage generally corresponded to strains isolated from freshwater and marine habitats. The marine caulobacter assemblage was not exclusive; it also embraced strains of marine hyphomonads and Rhodobacter capsulatus. We hypothesize that these genera are derived from more ancestral caulobacters. Overall, the data are consistent with the interpretation that all of the caulobacters examined, with the possible exception of C. subvibrioides, are ancestrally related, albeit anciently, and that most often division by terrestrial and marine habitats corresponds to an early evolutionary divergence within the genus.     

Identification of Bacterial Strains Isolated from the Mediterranean Sea Exhibiting Different Abilities of Biofilm Formation

The Mediterranean Sea has rarely been investigated for the characterization of marine bacteria as compared to other marine environments such as the Atlantic or Pacific Ocean. Bacteria recovered from inert surfaces are poorly studied in these environments, when it has been shown that the community structure of attached bacteria can be dissimilar from that of planktonic bacteria present in the water column. The objectives of this study were to identify and characterize marine bacteria isolated from biofilms developed on inert surfaces immersed in the Mediterranean Sea and to evaluate their capacity to form a biofilm in vitro. Here, 13 marine bacterial strains have been isolated from different supports immersed in seawater in the Bay of Toulon (France). Phylogenetic analysis and different biological and physico-chemical properties have been investigated. Among the 13 strains recovered, 8 different genera and 12 different species were identified including 2 isolates of a novel bacterial species that we named Persicivirga mediterranea and whose genus had never been isolated from the Mediterranean Sea. Shewanella sp. and Pseudoalteromonas sp. were the most preponderant genera recovered in our conditions. The phenotypical characterization revealed that one isolate belonging to the Polaribacter genus differed from all the other ones by its hydrophobic properties and poor ability to form biofilms in vitro. Identifying and characterizing species isolated from seawater including from Mediterranean ecosystems could be helpful for example, to understand some aspects of bacterial biodiversity and to further study the mechanisms of biofilm (and biofouling) development in conditions approaching those of the marine environment.     

Molecular analyses of the sediment of the 11000-m deep Mariana Trench

We have obtained sediment samples from the world's deepest sea-bottom, the Mariana Trench challenger point at a depth of 10 898 m, using the new unmanned submersible Kaiko. DNA was extracted from the sediment, and DNA fragments encoding several prokaryotic ribosomal RNA small-subunit sequences and pressure-regulated gene clusters, typically identifed in deep-sea adapted bacteria, were amplifed by the polymerase chain reaction. From the sequencing results, at least two kinds of bacterial 16S rRNAs closely related to those of the genus Pseudomonas and deep-sea adapted marine bacteria, and archaeal 16S rRNAs related to that of a planktonic marine archaeon were identifed. The sequences of the amplifed pressure-regulated clusters were more similar to those of deep-sea barophilic bacteria than those of barotolerant bacteria. These results suggest that deep-sea adapted barophilic bacteria, planktonic marine archaea, and some of the world's most widespread bacteria (the genus Pseudomonas) coexist on the world's deepest sea-bottom. Received: October 10, 1996 / Accepted: March 3, 1997     

Deoxyribonucleic acid hybridizations among some vibrio-like marine bacteria (author's transl)]

The genotypic relationships established by DNA/DNA hybridization in vitro confirm the results obtained by earlier phenotypic analyses of certain vibrio-like marine bacteria. These strains are closely related to the species Photobacterium fischeri, and do not belong to the genus Vibrio. The group of marine, vibrio-like bacteria that require Na+ for growth is genotypically very heterogeneous.     

A new family of Alteromonadaceae fam. nov., including the marine proteobacteria species Alteromonas, Pseudoalteromonas, Idiomarina i Colwellia

The taxonomic position of the marine genera Alteromonas, Pseudoalteromonas, Idiomarina, and Colwellia within the gamma subclass of the class Proteobacteria were specified on the basis of their phenotypic, genotypic, and phylogenetic characteristics. Gram-negative aerobic bacteria of the genera Alteromonas, Pseudoalteromonas, and Idiomarina and facultatively anaerobic bacteria of the genus Colwellia were found to form a phylogenetic cluster with a 16S rRNA sequence homology of 90% or higher. The characteristics of these genera presented in this paper allow their reliable taxonomic identification. Based on the analysis of our experimental data and analyses available in the literature, we propose to combine the genera Alteromonas, Pseudoalteromonas, Idiomarina, and Colwellia into a new family, Alteromonadaceae fam. nov., with the type genus Alteromonas.     

Isolation of myxobacteria from the marine environment

In an attempt to isolate indigenous marine myxobacteria from coastal samples, we obtained two swarm forming bacteria. Both isolates formed cell aggregates which, at least in one isolate, developed to fruiting body-like structures consisting of a mass of myxospore-like cells. The optimum NaCl concentrations for their growth were between 2 and 3%, comparable to the NaCl concentration of seawater. This growth characteristic strongly suggests that the two isolates are specific marine bacteria. The 16S rDNA sequence studies indicated that the two isolates were related to the genus Nannocystis. Based on the phylogenetic distances between branches, we concluded that the isolates should be assigned to two new myxobacterial genera.     

Protective Efficacy of a Pseudoalteromonas Strain in European Abalone,Haliotis tuberculata,Infected with Vibrio harveyi ORM4

Probiotics and Antimicrobial Proteins - The hemolymph of healthy marine invertebrates is known to harbor antibiotic-producing bacteria belonging to the genus Pseudoalteromonas. Such strains are...     

Oxidation of short-chain fatty acids by sulfate-reducing bacteria in freshwater and in marine sediments

Colony counts of acetate-, propionate- and l-lactate-oxidizing sulfate-reducing bacteria in marine sediments were made. The vertical distribution of these organisms were equal for the three types considered. The highest numbers were found just beneath the border of aerobic and anaerobic layers.Anaerobic mineralization of acetate, propionate and l-lactate was studied in the presence and in the absence of sulfate. In freshwater and in marine sediments, acetate and propionate were oxidized completely with concomitant reduction of sulfate. l-Lactate was always fermented. Lactate-oxidizing, sulfate-reducing bacteria, belonging to the species Desulfovibrio desulfuricans, and lactate-fermenting bacteria were found in approximately equal amounts in the sediments. Acetate-oxidizing, sulfate-reducing bacteria could only be isolated from marine sediments, they belonged to the genus Desulfobacter and oxidized only acetate and ethanol by sulfate reduction. Propionate-oxidizing, sulfate-reducing bacteria belonged to the genus Desulfobulbus. They were isolated from freshwater as well as from marine sediments and showed a relatively large range of usable substrates: hydrogen, formate, propionate, l-lactate and ethanol were oxidized with concomitant sulfate reduction. l-Lactate and pyruvate could be fermented by most of the isolated strains.     

海南西海岸真红树内生细菌多样性及其延缓衰老活性研究

该文设计9种分离培养基,采用稀释涂布法从14份真红树植物的46份组织样品中分离纯化内生细菌。并基于菌株形态学特征和16S rRNA基因序列确定分离菌株的种属及分析其物种多样性,采用秀丽隐杆线虫模型筛选菌株延缓衰老活性。结果表明:(1)通过基因序列去重复后从46份真红树植物组织样品中获得32株海洋细菌,基于菌株16S rRNA基因序列信息分析,覆盖12科17属,其中芽孢杆菌属(Bacillus)为优势菌属,并获得1株疑似橙单胞菌属(Aurantimonas)新种,16S rRNA基因序列相似性低于97%;(2)经过秀丽隐杆线虫粗筛发现3株海洋细菌具有显著延缓线虫衰老的活性(P0.05)。以上结果表明海南西海岸真红树内生细菌具有物种多样性,部分菌株具有延缓线虫衰老活性。     

海洋放线菌盐孢菌属研究进展

1991年,Jensen等从热带及亚热带海洋样品中分离获得了放线菌目专性海洋放线菌类群MAR1。根据形态学特征、生理生化特征及16S rRNA基因分析,提议该类群为新属——盐孢菌属(Salinospora)。2005年,盐孢菌属被正式报道,并将Salinospora更正为Salinispora。盐孢菌属是放线菌目第一个被报道的专性海洋微生物属,可以产生丰富的活性次级代谢产物,使盐孢菌属成为海洋微生物研究的热点。短短几年内,相继报道了许多研究成果。本文从盐孢菌属的建立过程、属及所含种的分类特征、生理生态学研究、次级代谢产物和分子生物学研究等方面对盐孢菌属的研究进展进行综述。     

Salinity decreases nitrite reductase gene diversity in denitrifying bacteria of wastewater treatment systems

Investigation of the diversity of nirK and nirS in denitrifying bacteria revealed that salinity decreased the diversity in a nitrate-containing saline wastewater treatment system. The predominant nirS clone was related to nirS derived from marine bacteria, and the predominant nirK clone was related to nirK of the genus ALCALIGENES:     

Hybridation des acides déoxyribonucléiques de certaines bactéries marines vibrioïdes

The genotypic relationships established by DNA/DNA hybridization in vitro confirm the results obtained by earlier phenotypic analyses of certain vibrio-like marine bacteria. These strains are closely related to the species Photobacterium fischeri, and do not belong to the genus Vibrio. The group of marine, vibrio-like bacteria that require Na⁺ for growth is genotypically very heterogeneous.     

Communities of green sulfur bacteria in marine and saline habitats analyzed by gene sequences of 16S rRNA and Fenna-Matthews-Olson protein.

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.     

Distribution of intracellular fucoidan hydrolases among marine bacteria of the family Flavobacteriaceae

A search for fucoidan-degrading enzymes and other O-glycosylhydrolases has been performed among 51 strains of marine bacteria of the family Flavobacteriaceae isolated from red, green, and brown algae, as well as from the sea urchin Strongylocentrotus intermedius and the holothurian Apostichopus japonicus. Over 40% of the studied strains synthesized fucoidanases. The marine bacteria Mesonia algae KMM 3909(T) (an isolate from green alga Acrosiphonia sonderi), as well as Maribacter sp. KMM 6211 and Gramella sp. KMM 6054 (associants of the sea urchin S. intermedius), were the best producers of fucoidanases. Xylose effectively induced the biosynthesis of fucoidanases in these strains. None of the 15 strains of marine bacteria belonging to the genus Arenibacter produced polysaccharide hydrolases.     

Enrichment and characterization of marine anammox bacteria associated with global nitrogen gas production

Microbiological investigation of anaerobic ammonium oxidizing (anammox) bacteria has until now been restricted to wastewater species. The present study describes the enrichment and characterization of two marine Scalindua species, the anammox genus that dominates almost all natural habitats investigated so far. The species were enriched from a marine sediment in the Gullmar Fjord (Sweden) using a medium based on Red Sea salt. Anammox cells comprised about 90% of the enrichment culture after 10 months. The enriched Scalindua bacteria displayed all typical features known for anammox bacteria, including turnover of hydrazine, the presence of ladderane lipids, and a compartmentalized cellular ultrastructure. The Scalindua species also showed a nitrate-dependent use of formate, acetate and propionate, and performed a formate-dependent reduction of nitrate, Fe(III) and Mn(IV). This versatile metabolism may be the basis for the global distribution and substantial contribution of the marine Scalindua anammox bacteria to the nitrogen loss from oxygen-limited marine ecosystems.     

Methylosulfonomonas methylovora gen. nov., sp. nov., and Marinosulfonomonas methylotropha gen. nov., sp. nov.: novel methylotrophs able to grow on methanesulfonic acid

Two novel genera of restricted facultative methylotrophs are described; both Methylosulfonomonas and Marinosulfonomonas are unique in being able to grow on methanesulfonic acid as their sole source of carbon and energy. Five identical strains of Methylosulfonomonas were isolated from diverse soil samples in England and were shown to differ in their morphology, physiology, DNA base composition, molecular genetics, and 16S rDNA sequences from the two marine strains of Marinosulfonomonas, which were isolated from British coastal waters. The marine strains were almost indistinguishable from each other and are considered to be strains of one species. Type species of each genus have been identified and named Methylosulfonomonas methylovora (strain M2) and Marinosulfonomonas methylotropha (strain PSCH4). Phylogenetic analysis using 16S rDNA sequencing places both genera in the α-Proteobacteria. Methylosulfonomonas is a discrete lineage within the α-2 subgroup and is not related closely to any other known bacterial genus. The Marinosulfonomonas strains form a monophyletic cluster in the α-3 subgroup of the Proteobacteria with Roseobacter spp. and some other partially characterized marine bacteria, but they are distinct from these at the genus level. This work shows that the isolation of bacteria with a unique biochemical character, the ability to grow on methanesulfonic acid as energy and carbon substrate, has resulted in the identification of two novel genera of methylotrophs that are unrelated to any other extant methylotroph genera. Received: 19 July 1996 / Accepted: 7 October 1996