Determination of the Chemical Form of Fluorine in Tea Infusions by 19F-NMR

A novel marine ice-nucleating bacterium, KUIN-5, was isolated from a marine algae, Monostroma latissum. Strain KUIN-5 was identified as a Pseudomonas sp. from its characteristics and taxonomies; the optimum temperature and pH for its growth were 25°C and 6.0, respectively. When strain KUIN-5 was aerobically cultured in Carlucci-Pramer medium (pH 6.0) for 50 h at 25°C, the highest ice-nucleating activity of the cells among the media for marine bacteria was obtained, and the ice-nucleating temperature, T₅₀, was indicated to be ? 3.2°C. Also, the optimum concentration of NaCl for the growth in this medium, which was prepared with distilled water instead of seawater, was 2.0% (w/v) and then the ice-nucleating activity was inversely proportional to the NaCl concentration. Moreover, when strain KUIN-5 was cultured in Davis medium under optimum conditions, it produced insoluble polysaccharide (IPS) in the culture. The maximum amount of IPS production by strain KUIN-5 was 84.5 mg/ml of medium under optimum conditions. Therefore, this IPS was isolated and could be identified as cellulose, based on TLC or HPLC of the acid hydrolysate, and GC-MS of the acetylated polyalcohol prepared by periodate oxidation and Smith degradation of this polysaccharide. This is the first report of cellulose production by a marine ice-nucleating bacterium.     

Three species of Lagenidiales isolated from the eggs and zoeae of the marine crabPortunus pelagicus

Three species of Lagenidiales were isolated from the eggs and zoeae of the marine crabPortunus pelagicus. One of them,Lagenidium callinectes, is reported for the first time in Japan, with fungal infection in the eggs.Haliphthoros milfordensis was discovered from a zoea of the crab.Atkinsiella okinawaensis was also isolated from a zoea of the crab and described as a new species. Growth temperature range and optimum temperature of the fungi were examined. All of the isolates grew at various concentrations of NaCl or KCl, and optimum growth was observed on PYGS agar containing seawater. Pathogenicity to zoeae of the swimming crabPortunus trituberculatus was demonstrated by using a zoospore suspension of each fungus at 25°C.     

Isolation and characterization of a marine methanogenic bacterium from the biofilm of a shiphull in Los Angeles harbor

A marine mesophilic, irregular coccoid methanogen, which shows close resemblance toMethanococcus sp., was isolated from the biofilm of shiphulls docked in Los Angeles harbor. Hydrogen plus carbon dioxide or formate served as substrates for methanogenesis in a mineral salt medium. The isolate did not use acetate and methanol as sole source of carbon and energy. The organism had an optimal pH range of 6.8–7.0 and a temperature optimum of 37°C. Elevated levels of sodium chloride were required for optimum growth. Optimum levels of total sulfide and magnesium chloride for growth were 1.0mm and 10mm respectively. The isolate used ammonia as nitrogen source. The concentration of 30mm ammonium chloride supported maximum growth of the isolate.     

Comparing temperature sensitivity of bacterial growth in Antarctic marine water and soil

The western Antarctic Peninsula is an extreme low temperature environment that is warming rapidly due to global change. Little is known, however, on the temperature sensitivity of growth of microbial communities in Antarctic soils and in the surrounding oceanic waters. This is the first study that directly compares temperature adaptation of adjacent marine and terrestrial bacteria in a polar environment. The bacterial communities in the ocean were adapted to lower temperatures than those from nearby soil, with cardinal temperatures for growth in the ocean being the lowest so far reported for microbial communities. This was reflected in lower minimum (T_min) and optimum temperatures (T_opt) for growth in water (?17 and +20°C, respectively) than in soil (?11 and +27°C), with lower sensitivity to changes in temperature (Q₁₀; 0–10°C interval) in Antarctic water (2.7) than in soil (3.9). This is likely due to the more stable low temperature conditions of Antarctic waters than soils, and the fact that maximum in situ temperatures in water are lower than in soils, at least in summer. Importantly, the thermally stable environment of Antarctic marine water makes it feasible to create a single temperature response curve for bacterial communities. This would thus allow for calculations of temperature‐corrected growth rates, and thereby quantifying the influence of factors other than temperature on observed growth rates, as well as predicting the effects of future temperature increases on Antarctic marine bacteria.     

Characterization of marine microalga, Scenedesmus sp. strain JPCC GA0024 toward biofuel production

A marine microalga, strain JPCC GA0024 was selected as high amount of neutral lipid producers from marine microalgal culture collection toward biofuel production. The strain was tentatively identified as Scenedesmus rubescens by 18S rDNA analysis. The growth of strain JPCC GA0024 was influenced by artificial seawater concentrations. The optimum growth of 0.79 g/l was obtained at 100% artificial seawater. The lipid accumulation reached 73.0% of dry cell weight at 100% artificial seawater without additional nutrients for 11 days. Gas chromatography/mass spectrometry analysis indicates that lipid fraction mainly contained hydrocarbons including mainly hexadecane (C₁₆ H₃₄) and 1-docosene (C₂₂ H₄₄). Furthermore, calorimetric analysis revealed that the energy content of strain JPCC GA0024 was 6,160 kcal/kg (25.8 MJ/kg) of calorific value, which was equivalent to the coal engery. The strain JPCC GA0024, S. rubescens, will become a promising resource that can grow as a dominant species in the seawater for the production of both liquid and solid biofuels.     

Effects of Ultraviolet Radiation on the Gram-Positive Marine Bacterium <Emphasis Type="Italic">Microbacterium maritypicum</Emphasis>

Although extensive information is available on the effect ultraviolet (UV) radiation has on Gram-negative marine bacteria, there is a scarcity of data concerning UV radiation and Gram-positive marine bacteria. The focus of this paper is on Microbacterium maritypicum, with the Gram-negative Vibrio natriegens being used as a standard of comparison. M. maritypicum exhibited growth over a NaCl range of 0–1000 mM, with optimum growth occurring between 0 and 400 mM NaCl. In contrast, V. natriegens grew over a NaCl span of 250–1000 mM, with best growth being observed between 250 and 600 mM NaCl. UV radiation experiments were done using the medium with 250 mM NaCl. For solar (UV-A and B) radiation and log-phase cells, M. maritypicum was determined to be three times more resistant than V. natriegens. For germicidal (UV-C) radiation, the pattern of resistance of the log-phase cells to the lethal effects of the radiation was even more pronounced, with the Gram-positive bacterium being more than 12 to 13 times more resistant. Similar data to the solar and germicidal log-phase UV kill curves were obtained for stationary-phase cells of both organisms. Photoreactivation was observed for both types of cells exposed to UV-C but none for cells treated with UV-A and B. When log phase cells of M.maritypicum were grown at 0.0 and 0.6 M NaCl and exposed to UV-C radiation, no difference in survivorship patterns was noted from that of 0.25 M NaCl grown cells. Although this study has only focused on two marine bacteria, our results indicate that the Gram-positive M. maritypicum could have a built-in advantage for survival in some marine ecosystems.     

Thermococcus alcaliphilus sp. nov., a new hyperthermophilic archaeum growing on polysulfide at alkaline pH

A novel coccoid-shaped, hyperthermophilic, heterotrophic member of the archaea was isolated from a shallow marine hydrothermal system at Vulcano Island, Italy. The isolate grew between 56 and 90° C with an optimum around 85° C. The pH range for growth was 6.5 to 10.5, with an optimum around 9.0. Polysulfide and elemental sulfur were reduced to H₂S. Sulfur stimulated the growth rate. The isolate fermented yeast extract, peptone, meat extract, tryptone, and casein. Isovalerate, isobutyrate, propionate, acetate, CO₂, NH₃, and H₂S (in the presence of S°) were detected as end products. Growth was not inhibited by H₂. Based on DNA-DNA hybridization and 16S rRNA partial sequences, the new isolate represents a new species of Thermococcus, which we named Thermococcus alcaliphilus. The type strain is isolate AEDII12 (DSM 10322) Received: 7 July 1995 / Accepted: 25 August 1995     

Characterization of Aspergillus sydowii (Thom et Church), a fungal pathogen of Caribbean sea fan corals

In the Caribbean, the fungus Aspergillus sydowii is currently causing an epizootic among sea fan corals (Gorgonia spp.). To elucidate potential factors that may have facilitated the emergence of this disease, we characterized and compared temperature requirements, susceptibility to coral crude extracts, and metabolic profiles of pathogenic (marine) and non-pathogenic (terrestrial) strains of A. sydowii. Growth of all A. sydowii strains were observed at all temperatures tested (22–36 °C) with an optimum of approximately 30 °C. Sea fan crude extracts inhibited growth of A. sydowii but were less effective at higher temperatures. Thus, temperature is likely to have a strong influence on the dynamics of the Gorgonia–Aspergillus interaction by promoting the growth of the pathogen while reducing the efficacy of host resistance. Metabolically, marine A. sydowii strains pathogenic to sea fans were distinct from non-pathogenic terrestrial strains.     

Ammonia assimilation enzymes in a thermophilicBacillus sp. of marine origin

The physiology of ammonia assimilation enzymes was examined inBacillus sp. FE-1, a thermophilic marine bacterium. Glutamine synthetase (GS) and glutamate synthase (GOGAT) activities varied with the nitrogen source present in the medium, ranging as much as 10-fold for the former and 2.5-fold for the latter. Glutamate dehydrogenase (GDH) was detected but, under the growth conditions studied, levels were not affected by the nitrogen source. Anaerobic growth in the presence of nitrate yielded enzyme levels that were not significantly different from those measured under aerobic growth. Partially purified GS exhibited a temperature optimum between 65° and 75°C. The enzyme's Mn²⁺-dependent reverse transferase activity was stimulated by K₂SO₄ and demonstrated some tolerance to NaCl. Hyperbolic kinetics were observed for ammonium, with an apparentK _M of 1.0mm.     

Isolation and characterization of Methanoplanus endosymbiosus sp. nov., an endosymbiont of the marine sapropelic ciliate Metopus contortus quennerstedt

Epifluorescence microscopy revealed the presence of a methanogenic bacterium as an endosymbiont in the sapropelic marine ciliate Metopus contortus. The in situ methanogenic activity of the symbiont could be demonstrated. The isolated endosymbiont was an irregular, disc-shaped bacterium with a diameter of 1.6–3.4 m. It had a generation time of 7 or 12 hours on growth on H₂/CO₂ or formate, respectively. The temperature range for growth was between 16 and 36°C with an optimum at 32°C. The optimal pH range for growth was 6.8 to 7.3. Salts, with an optimum concentration of 0.25 M, and tungsten were required for growth. The mol% G+C was 38.7%. The cell envelope consisted of proteins and a glycoprotein with an apparent molecular weight of 110,000. Morphology, antigenic relationship and the G+C content established the isolate MC1 as a new species of the genus Methanoplanus, and the name Methanoplanus endosymbiosus is proposed.Abbreviations G+C Guanine+cytosine - SDS sodium dodecylsulfate - PIPES piperazine-N,N-bis (2-ethane) sulfonic acid     

<Emphasis Type="Italic">Hoeflea siderophila</Emphasis> sp. nov., a new neutrophilic iron-oxidizing bacterium

A new representative of neutrophilic iron-oxidizing bacteria was isolated from the iron-containing sediments of the brackish low-temperature iron-rich spring of the Staraya Russa Resort (Novgorod region, Russia). The cells of strain Hf1 were thin, slightly curved rods, motile by means of a single polar flagellum. The bacterium reproduced by binary division and was capable of producing rosettes. Optimal growth was observed within the pH range of 6.2–8.5 (with an optimum at 7.5), at 9–38°C (with an optimum at 30°C), and in the salinity range of 0.1–8.5% NaCl (with an optimum at 1%). The organism was a facultative anaerobe. The strain was capable of mixotrophic and organoheterotrophic growth. Fe(II) oxidation occurred under anaerobic conditions via reduction of NO₃⁻ and N₂O, or under microaerobic conditions with oxygen as an electron acceptor. According to phylogenetic analysis based on the comparison of the 16S rRNA gene sequences, the strain was closest to the organotrophic marine bacterium Hoeflea phototrophica (98.5% similarity). The level of DNA-DNA homology with the type species of the genus Hoeflea was 19%. The DNA G + C base content was 57.5 mol %. According to its phenotypic and chemotaxonomic properties, as well as to the results of phylogenetic analysis, strain Hf1 was classified into the genus Hoeflea of the family Phyllobacteriaceae, order Rhizobiales of the phylum Alphaproteobacteria as a novel species, Hoeflea siderophila sp. nov. The type strain is Hf1^T (=DSM 21587 = VKM A7094). The GenBank accession number for the 16S rRNA gene sequences of strain Hf1^T is EU670237.     

Nutritional effect of freshwater Chlorella on growth of the rotifer Brachionus plicatilis

Mass production of Brachionus plicatilis is usually accomplished by feeding so-called marine Chlorella (Nannochloropsis oculata) to the rotifers in marine fish hatcheries. If the marine Chlorella are in short supply, baker's yeast is usually used as a supplementary food. Recently, a condensed suspension of freshwater Chlorella (Chlorella vulgaris, k-22) was commercially developed as another supplementary food. We have evaluated the dietary value of this freshwater Chlorella for growth of the rotifer by means of individual and batch cultures. Rotifers cultured with the freshwater Chlorella suspension under almost bacteria-free conditions, showed very suppressed growth. However if the Chlorella was supplemented with vitamin B₁₂ by adding the vitamin solution into the suspension or by culturing the Chlorella in a medium containing vitamin B₁₂, the nutritional value of freshwater Chlorella was greatly improved and almost at the same level as that of marine Chlorella. Condensed Chlorella may therefore be effective as a supplementary food if vitamin B₁₂ is supplied.     

Morphological variation and nutrition of a new monocentric marine fungus

Summary The life cycle of a new marine Phycomycete, Thraustochytrium aureum, is described based on its development on pollen in sea water. Comparisons are made with the amoeboid habit of the fungus on nutrient agar and an hypothesis as to the cause of the phenomenon is discussed. Inoculation studies suggest that T. aureum may be primarily a saprophyte of vascular plant debris. The fungus is obligately marine and apparently euryhaline. Maximal growth occurs with 2.0% NaCl not replaceable by KCl. The omission of KCl from media does not affect yields. The salinity optimum does not vary with temperature and the organism grows best at 12–25°C. It can utilize the nitrogen in (NH₄)₂SO₄ but optimal harvests are obtained with glutamate as the source of that element and with carbon supplied as glucose, maltose, or soluble starch.     

The salt relations of Dunaliella

Dunaliella tertiolecta (marine) and D. viridis (halophilic) were each trained by serial transfer to growth at salt concentrations previously regarded as the other's domain. D. viridis then had a salt optimum at 1.0–1.5 M sodium chloride whereas that for D. tertiolecta was less than 0–2 M. Nevertheless D. tertiolecta grew faster than the halophil at all salt concentrations up to 3.5 M, the highest at which they were compared.Both species accumulate glycerol, which is necessary for growth at elevated salinities and which responds in its content to water activity (a _w ) rather than specifically to salt concentration. Variation in glycerol content is a metabolic process which occurs in the dark from accumulated starch as well as photosynthetically. Regulation of glycerol content by a _w does not require protein synthesis. The NADP-specific glycerol dehydrogenase of each of the algae is likely to be directly involved in the regulation of glycerol content. Kinetic studies, together with those described in an earlier publication, show that the enzyme has regulatory properties, and that both glycerol and dihydroxyacetone act as effectors as well as reactants. A mechanism of the reaction is tentatively proposed.     

Temperature preferences of bacteria isolated from seawater collected in Kandalaksha Bay,White Sea,Russia

Fifty-two bacteria were isolated from seawater collected in Kandalaksha Bay, White Sea, Russia, and classified by 16S rDNA sequencing. Most of the strains belonged to ubiquitous microorganisms. Pseudomonas was the most abundant genus (21 strains), including species of P. fluorescens, P. putida and P. syringae. Serratia was also common (10 strains) with species S. plymuthica and S. proteamaculans. Sphingobacterium, Flavobacterium and Pantoea were less represented (5, 3 and 2 strains, respectively). The only typical bacterium of marine Arctic regions was Shewanella baltica. The strains were tested for their optimal growth temperature in the range 0–45°C. The majority appeared to be psychrotolerant (42%) or mesophilic-psychrotolerant (40%). In addition, one strain (Bacillus pumilus) showed a rather narrow mesophilic profile. No true psychrophilic bacteria were found. Most of the strains showed a classical curve with fast growth decrease above the optimum; some others displayed uncommon flat curves with scarce differences between maximum and minimum of growth in a wide range of temperatures. Moreover, few strains presented an unusual profile being, in relation to the optimum, more tolerant to high rather than low temperatures. Preferences of the Kandalaksha Bay strains are generally different from those reported in literature for the same species: optima were at lower temperatures and, sometimes, ranges were broader showing increased eurythermism. This could indicate adaptation to the wide temperature variations recorded in this peculiar environment.     

Expression of yellow tail (Seriola quinqueradiata) fish growth hormone cDNA in the marine photosynthetic bacterium Rhodobacter SP NKPB 0021

Summary A full length cDNA encoding yellow tail (Seriola quinqueradiata) growth hormone has been cloned into an expression vector, pUK319, which contains a Rhodobacter specific replicon. The resulting plasmid, pKGH319 was introduced by transformation into the marine photosynthetic bacterium Rhodobacter sp. strain NKPB0021. The plasmid was maintained as an autonomous replicon and showed good stability in the absence of antibiotics. Fish growth hormone was purified by HPLC from yellow tail pituitary glands and used to raise polyclonal antibodies for immuno blot analysis of Rhodobacter recombinants. Recombinant growth hormone was immunoreactive to mouse antiserum against natural yellow tail hormone. Our results suggest that the fish growth hormone gene was expressed under the lac promoter of Escherichia coli to levels suitable for the use of recombinant photosynthetic bacteria as a marine fish feed supplement.     

THE ACCLIMATED RESPONSE OF GROWTH,PHOTOSYNTHESIS, COMPOSITION,AND CARBON BALANCE TO TEMPERATURE IN THE PSYCHROPHILIC ICE DIATOM NITZSCHIA SERIATA1

Nitzschia seriata Cleve, a common member of marine bottom ice communities in the Arctic, was grown in unialgal batch cultures to test for compensatory mechanisms for the low temperatures (?1.8° C) typical of its natural habitat. The upper lethal limit for growth was between 12° and 15°C, and the optimum was between 6° and 12° C. The Arrhenius function adequately (R²= 73%) fitted the relationship between growth rate and temperature from – 1.6° up to 10° C, with an average Q₁₀ of 1.9 over the entire range. Light-saturated and light-limited rates of photosynthesis (normalized to chlorophyll a or cell carbon) showed complete compensation from 12° to 4° C. Photosynthetic rates, especially at light saturation, declined rapidly at temperatures below 4° C. Susceptibility to photoinhibition was greatest at the lowest growth temperatures. Cellular composition (chlorophyll a, protein, polysaccharide, and lipid contents) was not systematically related to temperature in any simple way, although cell size (carbon per cell) was maximal at the lowest growth temperature. Dark respiration was unmeasurably low (<0.015 day^?1) at all growth temperatures. The strategy of adaptation in N. seriata may be characterized as optimizing efficiency and compensation, rather than maximization, of growth rate.     

The endemic kelp Lessonia corrugata is being pushed above its thermal limits in an ocean warming hotspot

Kelps are in global decline due to climate change, which includes ocean warming. To identify vulnerable species, we need to identify their tolerances to increasing temperatures and determine whether tolerances are altered by co-occurring drivers such as inorganic nutrient levels. This is particularly important for those species with restricted distributions, which may already be experiencing thermal stress. To identify thermal tolerance of the range-restricted kelp Lessonia corrugata, we conducted a laboratory experiment on juvenile sporophytes to measure performance (growth, photosynthesis) across its thermal range (4–22°C). We determined the upper thermal limit for growth and photosynthesis to be ~22–23°C, with a thermal optimum of ~16°C. To determine if elevated inorganic nitrogen availability could enhance thermal tolerance, we compared the performance of juveniles under low (4.5 μmol · d⁻¹) and high (90 μmol · d⁻¹) nitrate conditions at and above the thermal optimum (16–23.5°C). Nitrate enrichment did not enhance thermal performance at temperatures above the optimum but did lead to elevated growth rates at the thermal optimum. Our results indicate L. corrugata is likely to be extremely susceptible to moderate ocean warming and marine heatwaves. Peak sea surface temperatures during summer in eastern and northeastern Tasmania can reach up to 20–21°C, and climate projections suggest that L. corrugata's thermal limit will be regularly exceeded by 2050 as southeastern Australia is a global ocean-warming hotspot. By identifying the upper thermal limit of L. corrugata, we have taken a critical step in predicting the future of the species in a warming climate.     

Production of hydrogen from marine macro-algae biomass using anaerobic sewage sludge microflora

Hydrogen was produced from various marine macro-algae (seaweeds) through anaerobic fermentation using an undefined bacterial consortium. In this study, anaerobic fermentation from various marine macro-algae for Ulva lactuca, Porphyra tenera, Undaria pinnatifida, and Laminaria japonica was studied. From this analysis Laminaria japorica was determined to be the optimum substrate for hydrogen production. When L. japornica was used as the carbon source for enhanced hydrogen production, the optimum fermentation temperature, substrate concentration, initial pH, and pretreatment condition were determined to be 35°C, 5%, 7.5, and BT120 (Ball mill and thermal treatments at 120°C for 30 min), respectively. In addition, hydrogen production was improved when the sludge was heat-treated at 65°C for 20 min. Under these conditions, about 4,164 mL of hydrogen was produced from 50 g/L of dry algae (L. japonica) for 50 h, with a hydrogen concentration around 34.4%. And the maximum hydrogen production rate and yield were found to be 70 mL/L·h and 28 mL/g dry algae, respectively.     

A Method for the Detection of Weak Lipolysis of Dairy Lactic Acid Bacteria on Double-Layered Agar Plates

A marine bacterium, strain 7-246-6, isolated from sea water was found to elaborate aerobically an extracellular enzyme specific for native collagen and gelatin. The strain was identified as Pseudomonas marinoglutinosa from the morphological and physiological characteristics, though the strain 7-246-6 slightly differs from the latter in the following points; the shape of the colony on the plate culture, the optimum growth temperature, the presence of granule by granular staining, the utilization of carbohydrates and the number of flagellum.