Exopolysaccharide production by a new Halomonas strain CRSS isolated from saline lake Cape Russell in Antarctica growing on complex and defined media; Poli A et al.; A haloalkalophilic Halomonas strain CRSS, isolated from salt sediments in Antarctica, produced exocellular polysaccharides (EPS) up to 2.9gg(-1) dry cells . Acetate was the most efficient carbon source for EPS production . The composition of media strongly affected the nature of the polymers; a mannan and a xylo-mannan, were obtained when cells were grown on complex media . Acetate was the most efficient carbon source for EPS production and in presence of this substrate, a new polysaccharide, a fructo-glucan, was produced . The EPS fraction was composed by glucose, fructose, glucosamine and galactosamine in relative proportions of 1:0.7:0.3:trace.

Appl Biochem Biotechnol, 1999 Spring, 77-79, 827 - 34Effect of Growth Substrates on Production of New Soluble Glucose 3-Dehydrogenase in Halomonas (Deleya) sp . alpha-15; Kojima K et al.; Halomonas (Deleya) sp . alpha-15 produces new co-factor binding soluble glucose 3-dehydrogenase (G3DH), which oxidizes the third hydroxy group of pyranose . This study investigated the condition of efficient production of G3DH using Halomonas (Deleya) sp . alpha-15 . This enzyme was inducible, and alpha-methyl-D-glucoside, isopropyl-thiogalactopyranoside (IPTG) and lactose were revealed to be suitable carbon sources for G3DH induction . Maximum G3DH production was achieved by using minimal medium containing 0.8% (w/v) lactose with a productivity of 470U/l.

Int J Syst Evol Microbiol, 2004 Jul, 54(Pt 4), 1329 - 32Halomonas anticariensis sp . nov., from Fuente de Piedra, a saline-wetland wildfowl reserve in Malaga, southern Spain; Martinez-Canovas MJ et al.; Three Halomonas strains, FP34, FP35T and FP36, which were isolated from soil samples taken from Fuente de Piedra, a saline wetland in the province of Malaga in southern Spain, are described . Phylogenetic analyses based on 16S rRNA gene sequences show that the three isolates belong to the genus Halomonas in the gamma-Proteobacteria and form an independent genetic line . Phenotypically, they share the characteristics of Halomonas and differ from the most closely related species, Halomonas campisalis, in the following features: they are strictly aerobic and, because of their production of exopolysaccharides, form cream-coloured, mucoid colonies; they produce phosphatase and grow within narrow pH and temperature ranges; and they are susceptible to kanamycin and streptomycin . Their G+C content varies between 60.0 and 61.4 mol% . The name Halomonas anticariensis sp . nov . is proposed for these isolates . Strain FP35T (=LMG 22089T=CECT 5854T) is the type strain . The bacterium grows best in 7.5% (w/v) NaCl and does not require magnesium or

potassium salts for growth, although they do stimulate growth somewhat when present . Its major fatty acids are 18 : 1omega7c, 16 : 0, 16 : 1omega7c, 15 : 0 iso 2-OH, 12 : 0 3-OH, 12 : 0, 10 : 0 and 19 : 0 cyclo omega8c . Its predominant respiratory lipoquinone is ubiquinone with nine isoprene units (Q-9).

Appl Environ Microbiol, 2004 Jul, 70(7), 4151 - 7Effect of substratum surface chemistry and surface energy on attachment of marine bacteria and algal spores; Ista LK et al.; Two series of self-assembled monolayers (SAMs) of omega-substituted alkanethiolates on gold were used to systematically examine the effects of varying substratum surface chemistry and energy on the attachment of two model organisms of interest to the study of marine biofouling, the bacterium Cobetia marina (formerly Halomonas marina) and zoospores of the alga Ulva linza (formerly Enteromorpha linza) . SAMs were formed on gold-coated glass slides from solutions containing mixtures of methyl- and carboxylic acid-terminated alkanethiols and mixtures of methyl- and hydroxyl-terminated alkanethiols . C . marina attached in increasing numbers to SAMs with decreasing advancing water contact angles (theta(AW)), in accordance with equation-of-state models of colloidal attachment . Previous studies of Ulva zoospore attachment to a series of mixed methyl- and hydroxyl-terminated SAMs showed a similar correlation between substratum theta(AW) and zoospore attachment . When the hydrophilic component of the SAMs was changed to carboxylate, however, the profile of attachment of Ulva was significantly different, suggesting that a more complex model of interfacial energetics is required.

J Microbiol Methods, 2004 Aug, 58(2), 289 - 94Rapid and sensitive NMR method for osmolyte determination; Motta A et al.; We propose a rapid and sensitive method for osmolyte determination, based on one-dimensional and two-dimensional 1H NMR spectroscopy applied directly on culture of haloalkalophilic Halomonas pantelleriensis and acidothermophilic archaeon Sulfolobus solfataricus, without any extraction procedure . The osmoprotectants hydroxyectoine, ectoine, glutamate, glycine-betaine and treahalose can easily be quantified by integrating the peak areas with respect to an internal standard, and the concentrations evaluated with this method are in excellent agreement with the values previously reported . Furthermore, trace amount of osmoprotectants, often undetectable after extraction procedures, can also be evaluated.

Can J Microbiol, 2004 May, 50(5), 369 - 74Flagellar motors of marine bacteria Halomonas are driven by both protons and sodium ions; Kita-Tsukamoto K et al.; Bacterial cells in aquatic environments are able to reach or stay near nutrient patches by using motility . Motility is usually attained by rotating

flagellar motors that are energized by electrochemical potential of H+ or Na+ . In this paper, the ion specificity for flagellar rotation of two marine isolates Halomonas spp . strains US172 and US201 was investigated . Both isolates require sodium for growth and possess a respiratory-driven primary sodium pump . They are motile because of lateral flagella regardless of the presence of sodium ions . Their swimming speed under various concentrations of sodium ions with and without carbonylcyanide m-chlorophenylhydrazone, a proton conductor, and with and without phenamil, a specific inhibitor for the sodium-driven flagellar motors, was examined . The effect of carbonylcyanide m-chlorophenylhydrazone on the transmembrane proton gradient was also determined . Our results showed that the flagellar motors of the Halomonas strains were energized by both H+ and Na+ in one cell . The bimodal nature of Halomonas spp . motility with respect to the driving energy source may reflect ecophysiological versatility to adapt to a wide range of salt conditions of the marine environment.

Microbiology, 2004 Jun, 150(Pt 6), 1779 - 84Multiple linear regression analysis of bacterial deposition to polyurethane coatings after conditioning film formation in the marine environment; Bakker DP et al.; Many studies have shown relationships of substratum hydrophobicity, charge or roughness with bacterial adhesion, although bacterial adhesion is governed by interplay of different physico-chemical properties and multiple regression analysis would be more suitable to reveal mechanisms of bacterial adhesion . The formation of a conditioning film of organic compounds adsorbed from seawater affects the properties of substratum surfaces prior to bacterial adhesion, which is a complicating factor in studying the mechanism of bacterial adhesion . In this paper, the impact of conditioning films adsorbed from natural seawater to four polyurethane coatings with different hydrophobicity, elasticity and roughness was studied for three different marine bacterial strains in a multiple linear regression analysis . The water contact angle on hydrophobic coatings decreased on average by 8 degrees and increased on average by the same amount on hydrophilic coatings . These changes were accompanied by increased concentrations of oxygen and nitrogen on the surface as determined by X-ray photoelectron spectroscopy, indicative of adsorption of proteinaceous material . Furthermore, the mean surface roughness increased on average by 4 nm after conditioning film formation . Multiple linear regression analysis revealed that changes in deposition due to conditioning film formation of Marinobacter hydrocarbonoclasticus, Psychrobacter sp . SW5H and Halomonas pacifica in a stagnation-point flow chamber could be explained in a model comprising hydrophobicity and the prevalence of nitrogen-rich components on the surface for the most hydrophobic strain . For the two more hydrophilic strains, deposition was governed by a combination of surface roughness and

hydrophobicity . Elasticity was not a factor in bacterial adhesion to conditioning films.

Appl Environ Microbiol, 2004 May, 70(5), 3130 - 2Functional expression of the ectoine hydroxylase gene (thpD) from Streptomyces chrysomallus in Halomonas elongata; Prabhu J et al.; The formation of hydroxyectoine in the industrial ectoine producer Halomonas elongata was improved by the heterologous expression of the ectoine hydroxylase gene, thpD, from Streptomyces chrysomallus . The efficient conversion of ectoine to hydroxyectoine was achieved by the concerted regulation of thpD by the H . elongata ectA promoter.

Extremophiles, 2004 Apr, 8(2), 133 - 41 Epub 2004 Jan 22.Carbon and energy fluxes during haloadaptation of Halomonas sp . EF11 growing on phenol; Maskow T et al.; The haloalkaliphile Halomonas sp . EF11 can grow on phenol as sole source for carbon and energy, while maintaining an osmotic equilibrium predominantly by adjusting levels of a certain compatible solute . To determine the energy costs of haloadaptation and the fate of substrate-carbon, the strain was grown continuously in an isothermal compensation calorimeter, keeping all conditions constant except salinity . As salinity increased, slight linear reductions in exothermic heat flow and biomass formation occurred, and 1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) synthesis increased linearly . However, beyond a certain salinity threshold the stationary phenol concentration increased exponentially, while heat flow fell sharply, indicating intoxication or wash-out . The clear transition point between the phases, where ectoine formation peaked, suggests that calorimetric measurements could be used to control the conversion of growth-inhibiting substrates (like phenol) into ectoine and to optimize the process . Enthalpy balance and chemical determinations revealed acetate and formate were formed as side products when the C/N ratio in the feed was low, while 2-muconic acid semialdehyde and formate were produced when the ratio was high . These findings indicate that phenol assimilation occurs via the meta pathway . However, enzyme assays implied that assimilation occurs via the ortho and meta pathways at a low C/N ratio and exclusively via the meta pathway at a high C/N ratio.

Biotechnol Lett, 2004 Jan, 26(2), 81 - 6Lipase-producing microorganisms from a Kenyan alkaline soda lake; Vargas VA et al.; Lipolytic enzyme production of 150 isolated strains from samples of Lake Bogoria (Kenya) was examined . Among these, fifteen isolates were selected on the basis of their lipolytic activities and subjected to morphological and 16S rRNA gene sequencing analyses for their identification . All the microorganisms have been selected under culture conditions with

pH ranges between 7-10 and temperatures of 37-55 degrees C . Most of them showed optimal growth at 37 degrees C and tolerated salinity up to 10% (w/v) . Ten of the isolates were Gram-negative, nine of which were closely related to the Pseudomonas cluster and one to the Halomonas cluster sharing high similarity profile with Halomonas desiderata . The remaining Gram-positive isolates were closely related to the Bacillus cluster, and were grouped with Bacillus halodurans, Bacillus alcalophilus and Bacillus licheniformis . Four members of the Bacillus cluster and the Halomonas sp . produced lipolytic activity under alkaline conditions, while others did so at neutral pH values.

Mar Biotechnol (NY), 2001 Sep, 3(5), 454 - 62Characterization of psychrotrophic bacteria in the surface and deep-sea waters from the northwestern Pacific Ocean based on 16S ribosomal DNA analysis; Radjasa OK et al.; Seventy-eight 4 degrees C-culturable bacteria were isolated using ZoBell 2216E medium from surface (0-200 m) and deep-sea (1000-9671 m) waters in the northwestern Pacific Ocean . Growth studies indicated that all 4 degrees C-culturable bacteria were psychrotrophs . Six phylotypes were observed in the surface water samples and 8 phylotypes in the deep-sea waters . Phylogenetic characterization based on 16S ribosomal DNA sequence analysis of the representative phylotypes revealed that some bacterial genera, Pseudoalteromonas, Photobacterium, and Vibrio, were common to surface and deep-sea waters, and others, Pseudomonas and Halomonas, specifically occurred in surface water . Overall, the members of Vibrionaceae appear to be dominant in both habitats.

Mar Biotechnol (NY), 2001 Nov, 3(6), 528 - 35Evaluation of marine bacterial lysogens for development of a marine prophage induction assay; McDaniel L et al.; The demonstrated relationship between carcinogenicity of a chemical compound in mammals and its tendency to cause prophage induction in bacteria provides a method for biologically based carcinogen screening . Because of the need for this type of screening and the abundance of lysogens in the marine environment, 14 isolates were evaluated for the degree of prophage induction in exponentially growing cultures in the presence of a known mutagen (0.5 microg/ml mitomycin C) . Assays were performed both in liquid culture and in microtiter plates . Virus-like particles were enumerated by epifluorescence microscopy after staining with SYBR-Gold . Two isolates designated P94-4B3 (identified as Halomonas aquamarina) and P94-4S3 (identified as Pseudomonas aeruginosa) were further evaluated for potential use . Because of the rapid growth, larger size of its virus-like particles, and linear response to increasing dose of mitomycin C, the P . aeruginosa st . P94-4S3 was determined a better candidate for the marine prophage induction assay (MPIA) . The Pseudomonas isolate

was then used in several experiments for the development and optimization of the MPIA procedure . Initial screenings of the MPIA were also performed with selected environmental pollutants.

Biofouling, 2003 Dec, 19(6), 391 - 7The effect of dissolved organic carbon on bacterial adhesion to conditioning films adsorbed on glass from natural seawater collected during different seasons; Bakker DP et al.; Adhesion of three marine bacterial strains, i.e . Marinobacter hydrocarbonoclasticus, Psychrobacter sp . and Halomonas pacifica with different cell surface hydrophobicities was measured on glass in a stagnation point flow chamber . Prior to bacterial adhesion, the glass surface was conditioned for 1 h with natural seawater collected at different seasons in order to determine the effect of seawater composition on the conditioning film and bacterial adhesion to it . The presence of a conditioning film was demonstrated by an increase in water contact angle from 15 degrees on bare glass to 50 degrees on the conditioned glass, concurrent with an increase in the amount of adsorbed organic carbon and nitrogen, as measured by X-ray photoelectron spectroscopy . Multiple linear regression analysis on initial deposition rates, with as explanatory variables the temperature, salinity, pH and concentration of dissolved organic carbon (DOC) of the seawater at the time of collection, showed that the concentration of DOC was most strongly associated with the initial deposition rates of the three strains . Initial deposition rates of the two most hydrophilic strains to a conditioning film, increased with the concentration of DOC in the seawater, whereas the initial deposition rate of the most hydrophobic strain decreased with an increasing concentration of DOC.

Extremophiles . 2004 Jan 22; {Epub ahead of print}Carbon and energy fluxes during haloadaptation of Halomonas sp . EF11 growing on phenol; Maskow T et al.; The haloalkaliphile Halomonas sp . EF11 can grow on phenol as sole source for carbon and energy, while maintaining an osmotic equilibrium predominantly by adjusting levels of a certain compatible solute . To determine the energy costs of haloadaptation and the fate of substrate-carbon, the strain was grown continuously in an isothermal compensation calorimeter, keeping all conditions constant except salinity . As salinity increased, slight linear reductions in exothermic heat flow and biomass formation occurred, and 1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) synthesis increased linearly . However, beyond a certain salinity threshold the stationary phenol concentration increased exponentially, while heat flow fell sharply, indicating intoxication or wash-out . The clear transition point between the phases, where ectoine formation peaked, suggests that calorimetric measurements could be used to control the conversion of growth-inhibiting

substrates (like phenol) into ectoine and to optimize the process . Enthalpy balance and chemical determinations revealed acetate and formate were formed as side products when the C/N ratio in the feed was low, while 2-muconic acid semialdehyde and formate were produced when the ratio was high . These findings indicate that phenol assimilation occurs via the meta pathway . However, enzyme assays implied that assimilation occurs via the ortho and meta pathways at a low C/N ratio and exclusively via the meta pathway at a high C/N ratio.

Dis Aquat Organ, 2003 Sep 24, 56(2), 105 - 13Bacterial influences on Atlantic halibut Hippoglossus hippoglossus yolk-sac larval survival and start-feed response; Verner-Jeffreys DW et al.; A bacteria-free halibut larval rearing system was used to test 20 bacterial isolates, from British halibut hatcheries, for their toxicity towards halibut yolk-sac larvae under microbially controlled conditions . The isolates tested spanned a range of genera and species (Pseudoalteromonas, Halomonas marina, Vibrio salmonicida-like, Photobacterium phosphoreum and V . splendidus species) . A pathogen of turbot, Scophthalmus maximus, V . anguillarum 91079, and 2 isolates from adult halibut were also included . Isolates were inoculated, at a concentration of 5 x 10(2) cfu ml(-1), into flasks containing 25 recently hatched axenic halibut larvae, using a minimum of 3 flasks for each treatment . Control survivals to 38 d post-hatch for the 3 experiments averaged 84, 51.5 and 49%, respectively . With the exception of V . anguillarum 91079, which was highly pathogenic towards halibut yolk-sac larvae, there was no statistically significant difference in survival between the controls and the different treatments . This suggests that most of the bacteria routinely isolated from halibut hatcheries are not harmful to yolk-sac larvae, even though most flasks contained in excess of 5 x 10(6) cfu m(-1) of the inoculated organism when the experiments were terminated . Three organisms previously shown to inhibit growth of bacteria in vitro were tested for their ability to protect halibut yolk-sac larvae against invasion by V . anguillarum . In 4 separate challenge experiments none of the test isolates, a Pseudoalteromonas strain and 2 Carnobacterium-like organisms, showed any protective effect . To investigate how particular bacteria influence their start-feed response, larvae were fed axenic and gnotobiotic Artemia colonized with a range of different Vibrio spp., and examined after 8 d . There were no statistically significant between-treatment differences in the proportion of Artemia-containing larvae, indicating that bacterial contamination of the live food does not appear to influence initiation of the feeding response.

Environ Sci Technol, 2003 Oct 1, 37(19), 4397 - 402Phenol and catechol biodegradation by the haloalkaliphile Halomonas campisalis: influence of pH and salinity; Alva VA et

al.; Removal of aromatic compounds from alkaline and/or saline industrial wastewater is an environmental concern for industry . In addition, aromatics may be accumulating in soda lakes, unique natural systems, where the fate and toxicity of these contaminants is unknown . To determine the feasibility of aromatic compound biodegradation in saline and alkaline conditions, the effect of pH and salinity on the biodegradation of phenol as a model aromatic waste compound by the haloalkaliphilic bacterium Halomonas campisalis was examined . Phenol was degraded as a source of carbon and energy at pH 8-11 and 0-150 g/L NaCl . Metabolic intermediates catechol, cis,cis-muconate, and (+)-muconolactone were identified, thus indicating that phenol was degraded via the beta-ketoadipate metabolic pathway . Although phenol and catechol were completely degraded in all cases, small amounts of cis,cis-muconate accumulated proportionally to increases in pH . There was no noticeable influence of salinity on cis,cis-muconate accumulation except at 0 g/L NaCl where it was completely degraded . These results indicate that it may be feasible to use haloalkaliphiles forthe treatment of aromatics present in saline and/or alkaline systems . This is the first report of phenol and catechol biodegradation under combined saline and alkaline conditions.

Anal Bioanal Chem, 2003 Sep, 377(1), 203 - 7 Epub 2003 Jul 08.Highly sensitive determination of ectoine and other compatible solutes by anion-exchange chromatography and pulsed amperometric detection; Riis V et al.; In saline media prokaryotes compensate for the osmotic pressure of the surrounding medium by producing osmolytes . Although these osmolytes or osmoprotectors have quite diverse structures, most of them can be determined by anion-exchange chromatography combined with integrated pulsed amperometric detection . This technique offers the advantages of very high sensitivity and new opportunities to determine ectoine and 5-hydroxyectoine-two important osmolytes -after hydrolytic cleavage of the pyrimidine ring . It can even be used to screen bacterial colonies on agar for compatible solutes . Furthermore, it allows amino acids and osmolytes of this type to be determined without derivatization . To test the method we applied it to two halotolerant bacterial strains: Stenotrophomonas rhizophila DSM 14405(T) and Halomonas elongata DSM 2581(T) . The first strain produced trehalose and glucosylglycerol, and the second ectoine, as the main osmotic counterweight . The relationship between the content of these osmolytes in the bacterial biomass and the external salinity is described.

Appl Environ Microbiol, 2003 Jul, 69(7), 4012 - 8Temporal stability and biodiversity of two complex antilisterial cheese-ripening microbial consortia; Maoz A et al.; The temporal stability and diversity of bacterial species composition

as well as the antilisterial potential of two different, complex, and undefined microbial consortia from red-smear soft cheeses were investigated . Samples were collected twice, at 6-month intervals, from each of two food producers, and a total of 400 bacterial isolates were identified by Fourier-transform infrared spectroscopy and 16S ribosomal DNA sequence analysis . Coryneform bacteria represented the majority of the isolates, with certain species being predominant . In addition, Marinolactobacillus psychrotolerans, Halomonas venusta, Halomonas variabilis, Halomonas sp . (10(6) to 10(7) CFU per g of smear), and an unknown, gram-positive bacterium (10(7) to 10(8) CFU per g of smear) are described for the first time in such a consortium . The species composition of one consortium was quite stable over 6 months, but the other consortium revealed less diversity of coryneform species as well as less stability . While the first consortium had a stable, extraordinarily high antilisterial potential in situ, the antilisterial activity of the second consortium was lower and decreased with time . The cause for the antilisterial activity of the two consortia remained unknown but is not due to the secretion of soluble, inhibitory substances by the individual components of the consortium . Our data indicate that the stability over time and a potential antilisterial activity are individual characteristics of the ripening consortia which can be monitored and used for safe food production without artificial preservatives.

Int J Syst Evol Microbiol, 2003 May, 53(Pt 3), 653 - 60Saccharospirillum impatiens gen . nov., sp . nov., a novel gamma-Proteobacterium isolated from hypersaline Ekho Lake (East Antarctica); Labrenz M et al.; Five Gram-negative, motile, aerobic to microaerophilic spirilla were isolated from various depths of the hypersaline, heliothermal and meromictic Ekho Lake (East Antarctica) . The strains are oxidase- and catalase-positive, metabolize a variety of sugars and carboxylic acids and have an absolute requirement for sodium ions . The predominant fatty acids of the organisms are C(16 : 1)omega7c, C(16 : 0) and C(18 : 1)omega7c, with C(10 : 1))3-OH, C(10 : 0) 3-OH, C(12 : 0) 3-OH, C(14 : 1)3-OH, C(14 : 0) 3-OH and C(19 : 1) present in smaller amounts . The main polar lipids are diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylmonomethylamine . The DNA base composition of the strains is 54-55 mol% G + C . 16S rRNA gene sequence comparisons show that the isolates are related to the genera Oceanospirillum, Pseudospirillum, Marinospirillum, Halomonas and Chromohalobacter in the gamma-Proteobacteria . Morphological, physiological and genotypic differences from these previously described genera support the description of a novel genus and species, Saccharospirillum impatiens gen . nov., sp . nov . The type strain is EL-105(T) (=DSM 12546(T) = CECT 5721(T)).

Carbohydr Res, 2003 Mar 14, 338(6), 567 - 70The O-specific chain structure of the major component from the lipopolysaccharide fraction of Halomonas magadii strain 21 MI (NCIMB 13595); de Castro C et al.; An O-specific polysaccharide containing D-galactose and D-glucose, was isolated from the water-soluble lipopolysaccharide fraction of the alkaliphilic bacterium Halomonas magadii . The structure, determined by means of chemical analysis and 1D and 2D NMR spectroscopy, showed a trisaccharide repeating unit, as shown below: {structure: see text}

J Biotechnol, 2003 Mar 20, 101(3), 267 - 74Thermokinetic description of anaerobic growth of Halomonas halodenitrificans using a static microcalorimetric ampoule technique; Maskow T et al.; Efficiency and velocity of growth are key variables to consider when designing any microbial biotechnological process . Selection of the optimal strain and description of environmental effects on growth patterns require rapid information about relevant parameters . Calorimetry is particularly suitable for providing such data, provided it can simultaneously perform many measurements and the apparatus is as simple as possible . The simplest experimental set-up measures the heat flux of microorganisms growing in a static, sealed ampoule . But, how reliable and reproducible are the growth rates and growth yield coefficients obtained from such a system? To answer this question, the strain Halomonas halodenitrificans CCM 286(T) was grown on glycerol with nitrate as the terminal electron acceptor in a multi-channel isothermal heat conduction calorimeter in such a way that growth was predominantly influenced by availability of the oxidant . The time course of the heat fluxes up to the maximum attained was successfully modelled using integrated Monod kinetics . The reproducibility of the specific growth rate obtained was excellent (standard deviation less than 1% for a single measurement and less than 3% for a couple of measurements) and agreed well with figures reported in the literature . An Arrhenius-type model, consisting of one term for the activation and one for the inactivation of the microbial catalyst, was found to fit the whole specific growth rate versus temperature curve.

Extremophiles, 2003 Feb, 7(1), 55 - 61 Epub 2002 Oct 10.Halomonas glaciei sp . nov . isolated from fast ice of Adelie Land, Antarctica; Reddy GS et al.; Eleven psychrophilic bacteria were isolated from a solid layer of fast ice in the middle of Pointe-Geologie Archipelago, Adelie Land, Antarctica . The 11 isolates based on the phenotypic characteristics, chemotaxonomic and phylogenetic analysis have been identified as members of the genus Halomonas . All the isolates at the 16S rDNA sequence level were identical, possessed the 15 conserved nucleotides of the family Halomonadaceae and four nucleotides of the genus Halomonas .

Therefore, the 16S rDNA sequence of DD 39 was used for calculating the evolutionary distances and for phylogenetic analysis . It was observed that DD 39 formed a robust cluster with H . variabilis, from which it differed by 0.7% . Further DNA-DNA hybridization studies indicated low DNA-DNA homology (15%) between H . variabilis and DD 39 . Between the 11 Antarctic isolates the homology was >85% . In addition it was observed that DD 39 was different from H . variabilis in that it was psychrophilic, could tolerate only up to 15% sodium chloride, could not hydrolyse esculin, could not reduce nitrate, was urease negative, could not utilize glycerol as a carbon source, and was resistant to ampicillin and erythromycin and sensitive to nalidixic acid . In addition, it also exhibited distinct differences with respect to high content of C(16:1) and low levels of cyclo-C(17:0) and cyclo-C(19:0) . DD 39 also differed from all the other reported species of Halomonas with respect to many phenotypic characteristics . It is proposed therefore that DD 39 should be placed in the genus Halomonas as a new species that is Halomonas glaciei . The type strain of H . glaciei is DD 39(T) (MTCC 4321; JCM 11692).

J Gen Appl Microbiol, 1997 Feb, 43(1), 49 - 59Polyamine distribution patterns within the families Aeromonadaceae, Vibrionaceae, Pasteurellaceae, and Halomonadaceae, and related genera of the gamma subclass of the Proteobacteria; Hamana K; Polyamines of the four families and the five related genera within the gamma subclass of the class Proteobacteria were analyzed by HPLC with the objective of developing a chemotaxonomic system . The production of putrescine, diaminopropane, cadaverine, and agmatine are not exactly correlated to the phylogenetic genospecies within 36 strains of the genus Aeromonas (the family Aeromonadaceae) lacking in triamines . The occurrence of norspermidine was limited but not ubiquitous within the family Vibrionaceae, including 20 strains of Vibrio, Listonella, Photobacterium, and Salinivibrio . Spermidine was not substituted for the absence of norspermidine in the family . Agmatine was detected only in Photobacterium . Salinivibrio and some strains of Vibrio were devoid of polyamines . Vibrio ("Moritella") marinus contained cadaverine . Within the family Pasteurellaceae, Haemophilus contained cadaverine only and Actinobacillus contained no polyamine . Halomonas, Chromohalobacter, and Zymobacter, belonging to the family Halomonadaceae, ubiquitously contained spermidine and sporadically cadaverine and agmatine . Shewanella contained putrescine and cadaverine; Alteromonas macleodii, putrescine, 2-hydroxyputrescine, cadaverine, 2-hydroxyspermidine, and spermidine; Pseudoalteromonas, putrescine, cadaverine, and spermidine; Marinobacter, spermidine; and Marinomonas, putrescine and spermidine . Their polyamine profiles serve as a chemotaxonomic marker within the gamma subclass.

Appl Microbiol Biotechnol, 2002 Nov, 60(3), 347 - 51 Epub 2002 Sep 26.Characteristics of bioemulsifiers synthesised in crude oil media by Halomonas eurihalina and their effectiveness in the isolation of bacteria able to grow in the presence of hydrocarbons; Calvo C et al.; Halomonas eurihalina strains F2-7, H28, H96, H212 and H214 were capable of producing large amounts of exopolysaccharides (EPS) in MY medium with added crude oil . The biopolymers showed lower carbohydrate and protein content than those synthesised in control medium without oil . Nevertheless, the percentages of uronic acids, acetyls and sulphates were higher . The emulsifying activity of biopolymers was measured; crude oil was the substrate most efficiently emulsified . Furthermore, all the EPS tested emulsified higher volumes of crude oil than the commercial surfactants used as controls . We have also proved the effectiveness of both Halomonas eurihalina strains and their EPS to select indigenous bacteria able to grow in the presence of polycyclic aromatic hydrocarbons (naphthalene, phenanthrene and pyrene) from waste crude oil . The majority of isolated strains belonged to the genus Bacillus.

J Clin Lab Anal, 2002, 16(6), 299 - 303Clinical application of the serum 1,5-anhydroglucitol assay method using glucose 3-dehydrogenase; Hamafuji T et al.; We attempted to develop a novel serum 1,5-anhydroglucitol (1,5-AG) assay kit using glucose 3-dehydrogenase (G3DH) from Halomonas sp . alpha-15 strain . The major advantages of this method are that the 1,5-AG detection requires a very small amount of G3DH, and the enzyme catalyzes a simple reaction . The analytical performances were acceptable for clinical use operated with a clinical automatic analyzer . The correlation with a commercial assay kit against sera of healthy volunteers was y=0.975x+0.008, r=0.993, Sylx=1.32 microg/mL . However, sham-negative specimens were observed in the validation of this method using specimens from hospital patients .

Syst Appl Microbiol, 2002 Aug, 25(2), 207 - 11Proposal of Cobetia marina gen . nov., comb . nov., within the family Halomonadaceae, to include the species Halomonas marina; Arahal DR et al.; At present the family Halomonadaceae consists of four genera and the taxonomic status of all species included in these genera is not equally supported by phylogenetic evidence . Whereas Zymobacter and Carnimonas contain one single species each and form the deeper branch of the family, the genus Halomonas contains currently 22 species, with a maximum 16S/23S rRNA sequence divergence greater than it could be expected for species of the same genus . In addition, we have witnessed during last years an increase in the number of new

species within this group, which makes even more necessary a taxonomic rearrangement . In a previous study (Arahal et al., 2002) we evaluated the phylogenetic status of the family Halomonadaceae based on 23S and 16S rDNA sequence analyses and mentioned that Halomonas marina could eventually be assigned to a new genus . In this study we have emended the description of this species, including new features and propose its placement in a new genus, Cobetia gen . nov . within the family Halomonadaceae . The type strain of Cobetia marina is ATCC 25374T (= DSM 4741T) . Further discussion on the phylogeny of the family Halomonadaceae is provided taking into account the most recent changes.

Biosci Biotechnol Biochem, 2002 May, 66(5), 955 - 62Purification, characterization, and gene sequencing of a catalase from an alkali- and halo-tolerant bacterium, Halomonas sp . SK1; Phucharoen K et al.; An alkali- and halo-tolerant bacterium with high catalase activity was isolated and identified as a new species of the genus Halomonas . Its catalase (HktA) was simply purified by two steps of liquid chromatography . A 71.4% yield of the catalase was obtained with 97% purity on SDS-PAGE . The specific activity of HktA (57,900 U/mg protein) was two times higher than that of bovine liver catalase . The purified enzyme is inhibited by KCN, NH2OH, NaN3, and 3-amino-1,2,4-triazole, active at pH 5.0-11.0, thermo-sensitive, and KCl-tolerant . HktA is suggested to be a typical catalase, a homotetrameric protein containing heme groups in the active sites . The nucleotide sequence of the catalase gene (hktA) comprises 1,530 bp, encoding a protein of 509 amino acid residues . The deduced amino acid sequence of the hktA shares 99% identity with that of Vibrio rumoiensis S-1T.

Appl Environ Microbiol, 2002 Jun, 68(6), 2858 - 68Impact of irradiation and polycyclic aromatic hydrocarbon spiking on microbial populations in marine sediment for future aging and biodegradability studies; Melcher RJ et al.; Experiments were carried out to develop methods to generate well-characterized, polycyclic aromatic hydrocarbon (PAH)-spiked, aged but minimally altered sediments for fate, biodegradation, and bioavailability experiments . Changes in indigenous bacterial populations were monitored in mesocosms constructed of relatively clean San Diego Bay sediments, with and without exposure to gamma radiation, and then spiked with five different PAHs and hexadecane . While phenanthrene and chrysene degraders were present in the unspiked sediments and increased during handling, PAH spiking of nonirradiated sediments led to dramatic increases in their numbers . Phenotypic characterization of isolates able to grow on phenanthrene or chrysene placed them in several genera of marine bacteria: Vibrio, Marinobacter or Cycloclasticus, Pseudoalteromonas, Marinomonas, and HALOMONAS: This is the

first time that marine PAH degraders have been identified as the latter two genera, expanding the diversity of marine bacteria with this ability . Even at the highest irradiation dose (10 megarads), heterotrophs and endospore formers reappeared within weeks . However, while bacteria from the unirradiated sediments had the capacity to both grow on and mineralize 14C-labeled phenanthrene and chrysene, irradiation prevented the reappearance of PAH degraders for up to 4 months, allowing spikes to age onto the sediments, which can be used to model biodegradation in marine sediments.

Microb Ecol, 2002 Mar, 43(2), 242 - 9 Epub 2002 Jan 02.Two species of culturable bacteria associated with degradation of brown algae Fucus evanescens; Ivanova EP et al.; The heterotrophic microbial enrichment community established during degradation of brown algae Fucus evanescens was characterized . A two-species bacterial community of marine culturable gamma-proteobacteria consisted of Pseudoalteromonas and Halomonas . The first member of the community, Pseudoalteromonas sp., was highly metabolically active, had bacteriolytic and hemolytic activities, produced proteinases (gelatinase and caseinase), lipases, DNases, and fucoidanhydrolases, laminaranases, alginases, pustulanases, beta-glucosidases, beta-galactosidases, beta-N-acetylglucosaminidases, and beta-xylosidases . The second member of the community, Halomonas marina, produced only caseinase and DNase, and it did not hydrolyze algal polysaccharides . Both members of the studied bacterial community utilized a range of easily assimilable monosaccharides and other low molecular weight organic substances . The results provide an evidence of the complex metabolic interrelations between two members of this culturable community . One of them Pseudoalteromonas sp., most likely plays the major role in the initial stages of algal degradation; the other one, H . marina, resistant to the bacteriolytic activity of the former, is able to utilize the products of degradation of polysaccharides.

Curr Microbiol, 2002 May, 44(5), 357 - 62Tolerance to cadmium of free-living and associated with marine animals and eelgrass marine gamma-proteobacteria; Ivanova EP et al.; The tolerance to Cd2+ and possible mechanisms of Cd2+ detoxification by 178 free-living bacteria isolated from sea water, associated with marine animals (a mussel Crenomytilus grayanus, a scallop Patinopecten yessoensis), and eelgrass Zostera marina collected in The Sea of Japan and The Sea of Okhotsk have been studied . The concentrations of 25 and 50 mg Cd2+/L were highly toxic and inhibited the growth from 54% to 78% of the total bacteria studied . The free-living bacteria isolated from seawater samples (up to 50%) were tolerant to high concentrations of cadmium . Marine gamma-proteobacteria tolerated Cd2+ by the

activation of different detoxifying mechanisms . The strain Halomonas sp . KMM 734 isolated from seawater prevented the uptake of Cd2+ into bacterial cells . The chromosomal cadmium resistance system of Pseudoalteromonas citrea KMM 461 and Marinobacter sp . KMM 181 was found to be similar to class III metallothioneins (also known as phytochelatins).

DNA Seq, 2001 Dec, 12(5-6), 455 - 61Analysis and expression of algL, which encodes alginate lyase in Pseudomonas syringae Pv . syringae; Preston LA et al.; Pseudomonas syringae produces alginate, an exopolysaccharide that contributes to the virulence and epiphytic fitness of this phytopathogenic bacterium . P . syringae also produces the algL-encoded alginate lyase, which cleaves the alginate biopolymer via a beta-elimination reaction . The algL gene from P . syringae maps to a 1134 bp region within the alginate biosynthetic operon, and is similar to algL from Halomonas marina, P . aeruginosa, Azotobacter chroococcum, and A . vinelandii . algL from P . syringae was over expressed in Escherichia coli; two periplasmic forms of AlgL were overproduced (40 and 37 kDa) . Both forms were enzymatically active and recognized by antibodies raised against AlgL from P . aeruginosa . Analysis of the regions flanking algL revealed significant homology to algX and algI, genes previously identified in the biosynthetic operon of other alginate-producing bacteria.

Int J Syst Evol Microbiol, 2002 Jan, 52(Pt 1), 241 - 9Phylogeny of the family Halomonadaceae based on 23S and 165 rDNA sequence analyses; Arahal DR et al.; In this study, we have evaluated the phylogenetic status of the family Halomonadaceae, which consists of the genera Halomonas, Chromohalobacter and Zymobacter, by comparative 23S and 16S rDNA analyses . The genus Halomonas illustrates very well a situation that occurs often in bacterial taxonomy . The use of phylogenetic tools has permitted the grouping of several genera and species believed to be unrelated according to conventional taxonomic techniques . In addition, the number of species of the genus Halomonas has increased as a consequence of new descriptions, particularly during the last few years, but their features are too heterogeneous to justify their placement in the same genus and, therefore, a re-evaluation seems necessary . We have determined the complete sequences (about 2900 bases) of the 23S rDNA of 18 species of the genera Halomonas and Chromohalobacter and resequenced the complete 16S rDNA sequences of seven species of Halomonas . The results of our analysis show that two phylogenetic groups (respectively containing five and seven species) can be distinguished within the genus Halomonas . Six other species cannot be assigned to either of the above-mentioned groups . Furthermore, Halomonas marina forms a separate branch at a deeper level than the other species of the

genus Halomonas, which suggests that it should be ascribed to a separate genus . The genus Chromohalobacter forms a monophyletic group constituted by Chromohalobacter marismortui, the recently reclassified species Chromohalobacter canadensis and Chromohalobacter israelensis and the recently proposed species Chromohalobacter salexigens . Finally, we propose to include the genus Carnimonas, with its single species Carnimonas nigrificans, in the family Halomonadaceae.