Pseudoalteromonas Issachenkonii Research Articles

Scientific Investigation of Antifouling Activity from Biological Agents and Distribution of Marine Foulers-Coastal Areas of Tamil Nadu.

Biofouling is the result of a biological process that is the accumulation of micro- and macro-organisms on the surfaces of the ship which causes serious environmental problems. The consequence of biofouling includes modifying the hydrodynamic response, affecting heat exchange, can make structures heavier, accelerate or generating corrosion, biodegradation, increasing the fatigue of certain materials, and blocking mechanical functions. It causes severe problems for the objects in the water such as ships and buoys. Also, its impact on shellfish and other aquaculture was sometimes devastating. The main scope of this study is to review the currently available biocides from biological agents for marine submerged foulants and marine foulers that are present around the coastal areas of Tamil Nadu. Biological anti-fouling methods are preferred than that of the chemical and physical anti-fouling methods as it have some toxic effects on the non targeted marine biodiversity. This study focuses on the marine foulers that are present around the coastal areas of Tamil Nadu which will be helpful for the researchers to discover the suitable anti-foulers from a biological source, which will be very useful to protect the marine ecosystem and marine economy. A total of 182 antifouling compounds from marine biological sources were discovered. The marine microbes, Penicillium sp. and Pseudoalteromonas issachenkonii, were reported to possess EC50. The survey results obtained from this study show that Chennai coastal region has a lot of barnacles, and 8 different species were present in Pondicherry region.

Purified proteases of two Antarctic bacteria: from screening to characterization

AbstractProteases are widely used in industrial processes, and the discovery of new, more kinetically efficient proteases can have a positive impact on industry. Enzymes from Antarctic microorganisms exhibit cold-adaptive properties, making them useful in biotechnology. The cold and harsh environment of Antarctica makes it a valuable source for new biotechnologically related enzymes. In this study, we characterized two cold-adapted proteases purified from Pseudoalteromonas issachenkonii P14M1-4 and Flavobacterium frigidimaris ANT34-7, isolated from King George Island, Antarctica, and compared these with proteases from the non-cold-adapted bacteria Bacillus licheniformis and Geobacillus stearothermophilus. The best temperature growing conditions were used for protease purification and characterization. The protease from P. issachenkonii P14M1-4 was identified as a 40–43 kDa metal-dependent subtilisin-like serine protease and the protease from F. frigidimaris ANT34-7 was identified as a 28 kDa metalloprotease. The enzymes showed an optimum temperature of between 35°C and 40°C and an optimum pH in the neutral to alkaline range. Their activation energies, catalytic constants and growth capacities at different temperatures categorize them as cold-adapted enzymes. We conclude that the characteristics exhibited by these proteases make them useful for biotechnological purposes requiring high activity at low temperatures. Moreover, to the best of our knowledge, this is the first characterization of a cold-adapted protease from F. frigidimaris.

Genetic diversity of the causative agent of ice-ice disease of the seaweed Kappaphycus alvarezii from Karimunjawa island, Indonesia

An essential step in investigating the bacterial role in the occurrence of diseases in Kappaphycus alvarezii is the characterization of bacteria associated with this seaweed. A molecular characterization was conducted on the genetic diversity of the causative agents of ice-ice disease associated with K. alvarezii widely known as the main source of kappa carrageenan. K. alvrezii infected with ice-ice were collected from the Karimunjawa island, North Java Sea, Indonesia. Using Zobell 2216E marine agar medium, nine bacterial species were isolated from the infected seaweed. The molecular characterizations revealed that the isolated bacteria causing ice-ice disease were closely related to the genera of Alteromonas, Bacillus, Pseudomonas, Pseudoalteromonas, Glaciecola, Aurantimonas, and Rhodococcus. In order to identify the symptoms causative organisms, the isolated bacterial species were cultured and were evaluated for their pathogenity. Out of 9 species, only 3 isolates were able to cause the ice-ice symptoms and consisted of Alteromonas macleodii, Pseudoalteromonas issachenkonii and Aurantimonas coralicida. A. macleodii showed the highest pathogenity.

Characterization of β-N-acetylglucosaminidase from a marine Pseudoalteromonas sp. for application in N-acetyl-glucosamine production

ABSTRACTThe psychrotolerant Pseudoalteromonas issachenkonii PAMC 22718 was isolated for its high exo-acting chitinase activity in the Kara Sea, Arctic. An exo-acting chitinase (W-Chi22718) was homogeneously purified from the culture supernatant of PAMC 22718, the molecular weight of which was estimated to be approximately 112 kDa. Due to its β-N-acetylglucosaminidase activity, W-Chi22718 was able to produce N-acetyl-D-glucosamine (GlcNAc) monomers from chitin oligosaccharide substrates. W-Chi22718 displayed chitinase activity from 0 to 37°C (optimal temperature of 30°C) and maintained activity from pH 6.0 to 9.0 (optimal pH of 7.6). W-Chi22718 exhibited a relative activity of 13 and 35% of maximal activity at 0 and 10°C, respectively, which is comparable to the activities of previously characterized, cold-adapted bacterial chitinases. W-Chi22718 activity was enhanced by K+, Ca2+, and Fe2+, but completely inhibited by Cu2+ and SDS. We found that W-Chi22718 can produce much more (GlcNAcs) from colloidal chitin, working together with previously characterized cold-active endochitinase W-Chi21702. Genome sequencing revealed that the corresponding gene (chi22718_IV) was 2,856 bp encoding a 951 amino acid protein with a calculated molecular weight of approximately 102 kDa.

Complete genome of brown algal polysaccharides-degrading Pseudoalteromonas issachenkonii KCTC 12958T (=KMM 3549T)

Pseudoalteromonas issachenkonii is a Gram-negative, rod-shaped, flagellated, aerobic, chemoorganotrophic marine bacterium that was isolated from the thallus of Fucus evanescens (marine brown macroalgae) sampled from the Kraternaya Bight of the Kurile Islands in the Pacific Ocean. Here, we report the complete genome of P. issachenkonii KCTC 12958T (=KMM 3549T=LMG 19697T=CIP 106858T), which consists of 4,131,541bp (G+C content of 40.3%) with two chromosomes, 3538 protein-coding genes, 102 tRNAs and 8 rRNA operons. Several genes related to glycoside hydrolases, proteases, and bacteriolytic- and hemolytic activities were detected in the genome that help explain how the strain mediates degradation of algal cell wall and decomposes algal polysaccharides into industrially applicable products.

A new approach for discovering cold-active enzymes in a cell mixture of pure-cultured bacteria

To overcome the intrinsic problems of conventional approaches, such as the unavailability of source microorganisms in metagenomic libraries and the production of inactive aggregates, a new method was tested for discovering new enzymes (e.g. cold-active chitinase). A metagenome-like library was constructed using genomes extracted from a cell mixture of pure-cultured chitinolytic bacteria, followed by activity-based screening for Escherichia coli clones that exhibit chitinase activity on selective medium. Within one positive chitinolytic clone, one chitinase gene (chi22718_III) was detected and assigned to the arctic marine bacterium, Pseudoalteromonas issachenkonii PAMC 22718, by colony-PCR with chi22718_III-specific primers. When expressed in E. coli, recombinant R-Chi22718_III lost 85 % of its enzyme activity when pre-incubated at 40 °C for 1 h, whereas its mesophilic counterpart R-ChiK only lost 10 % of its activity under the same conditions indicating that R-Chi22718_III is thermolabile, a characteristic of cold-active enzymes.

Isolation and Identification of Agarose-degrading Bacterium, Pseudoalteromonas sp. GNUM08122.

This study's aim was to isolate microorganisms producing agarase with a high activity, with possible applications in improving the performance of the pretreatment processes for bioethanol production. Marine algaes were collected from the south coast of Korea, from which three kinds of microorganisms were isolated. After a 4-day culture of these strains at , crude enzymes were obtained from culture supernatant or cell-free extract by ammonium sulfate precipitation and membrane dialysis. Agarase activity was observed in these crude enzymes. Notably higher specific activity was observed in the crude enzyme obtained from the culture supernatant rather than that from the cell-free extract. This indicates that a secreted enzyme has a much greater activity than a cellular enzyme. Crude enzymes from the GNUM08122 strain were inferred to have -agarase activity because release of p-nitrophenol was observed, possibly due to the cleavage of p-nitrophenyl--D-galactopyranoside. The 16S rRNA sequence of GNUM08122 showed a close relationship to Pseudoalteromonas issachenkonii KMM 3549 (99.8%) and Pseudoalteromonas tetraodonis IMA 14160 (99.7%), which led us to assign it to the genus Pseudoalteromonas. Biochemical and physiological study revealed that this strain can grow well at under a wide range of pH (pH 4~8) in high-salt conditions (10% NaCl).

Novel Antifoulants: Inhibition of Larval Attachment by Proteases

We investigated the effect of commercially available enzymes (alpha-amylase, alpha-galactosidase, papain, trypsin, and lipase) as well as proteases from deep-sea bacteria on the larval attachment of the bryozoan Bugula neritina L. The 50% effective concentrations (EC(50)) of the commercial proteases were 10 times lower than those of other enzymes. Crude proteases from six deep-sea Pseudoalteromonas species significantly decreased larval attachment at concentrations of 0.03 to 1 mIU ml(-1). The EC(50) of the pure protease from the bacterium Pseudoalteromonas issachenkonii UST041101-043 was close to 1 ng ml(-1) (0.1 mIU ml(-1)). The protease and trypsin individually incorporated in a water-soluble paint matrix inhibited biofouling in a field experiment. There are certain correlations between production of proteases by bacterial films and inhibition of larval attachment. None of the bacteria with biofilms that induced attachment of B. neritina produced proteolytic enzymes, whereas most of the bacteria that formed inhibitive biofilms produced proteases. Our investigation demonstrated the potential use of proteolytic enzymes for antifouling defense.

The complete structure of the lipooligosaccharide from the halophilic bacterium Pseudoalteromonas issachenkonii KMM 3549 T

Novel lipooligosaccharide components were isolated and identified from the lipooligosaccharide fraction of the halophilic marine bacterium Pseudoalteromonas issachenkonii type strain KMM 3549 T. The complete structure was achieved by chemical analysis, 2D NMR spectroscopy and MALDI mass spectrometry as the following: All sugars are d-pyranoses. Hep is l- glycero- d- manno-heptose, Kdo is 3-deoxy- d- manno-oct-2-ulosonic acid, P is phosphate, residues and substituents in italic are not stoichiometrically linked. In addition, by MALDI mass spectrometry of the intact LOS, the lipid A moiety was also identified as a mixture of penta-, tetra- and triacylated species.

Low-molecular-weight, biologically active compounds from marine Pseudoalteromonas species.

We have examined the ability of marine Proteobacteria from the Pseudoalteromonas genus and Alteromonas macleodii to produce low-molecular-weight, biologically active compounds with antimicrobial and surface-active properties. A new marine bacterium, Pseudoalteromonas issachenkonii, exhibited a high level of biological activity and produced antifungal and hemolytic compounds. A detailed spectroscopic investigation based on UV, IR, high-resolution mass spectrometry, and 2D 1H and 13C nuclear magnetic resonance revealed that the former was indole-2,3-dione (isatin). The chemical structure of red-brown pigment (C9H7N3OS3) responsible for hemolytic activity remained unclear. Four of the 15 strains studied (P. luteoviolacea, P. rubra, P. undina, and P. issachenkonii) produced cell-bound, two (P. elaykovii and P. carrageenovora) produced extracellular, and one strain (P. citrea) produced cell-bound and extracellular fatty acids and phospholipids with surface activity. Neither peptides nor glycolipids with surface activity were detected.

Impact of cultivation conditions on haemolytic activity of Pseudoalteromonas issachenkonii KMM 3549T.

The present work aimed to study the effects of cultivation conditions on the haemolytic activities of Pseudoalteromonas issachenkonii. The kinetics of growth and haemolytic activities was investigated on sea-salts and NaCl-based nutrient media supplemented with either starch, or KBr over a period of 140 h. The first haemolytic activity occurred when bacterial cells reached the late stationary phase. The second haemolytic activity was observed in marine broth (MB) after 110 h of incubation. Addition of Fe to the culture medium neither affected bacterial growth nor reduced the haemolytic activity. However, the activity was enhanced in the presence of iron chelator. The second haemolytic activity was not affected by Ca2+, or inhibited by chymotrypsin or EDTA. The production of haemolysins by P. issachenkonii was greater on MB and was dependent on both the medium composition and time of incubation. The second haemolytic activity was heat stable, nonproteinaceous, calcium-independent and was regulated by Fe. The results demonstrated the importance of optimization of both the media composition and monitoring the haemolytic activity over a prolonged cultivation time to detect different types of haemolysins.

Optimization of glycosidases production by Pseudoalteromonas issachenkonii KMM 3549(T).

The present work aimed to design an optimized medium to yield a higher production of glycosides by Pseudoalteromonas issachenkonii KMM 3549(T). Higher levels of fucoidan hydrolase, alginase, laminaranase and b-N-acetylglucosaminidase production were obtained with peptone concentrations ranging from 2.5 g l(-1) to 10 g l(-1), while the presence of both yeast extract and glucose did not affect enzyme production. The activity of fucoidan hydrolase and laminaranase increased up to 4.83 microM h(-1) mg(-1) and 19.23 microM h(-1) mg(-1) protein, respectively, in growth media containing xylose (1.0 g l(-1)), laminarin (0.5 g l(-1)) or alginate (0.5 g l(-1)), and production of b-N-acetylglucosaminidase substantially increased in the presence of fucoidan (0.5 g l(-1)) or galactose (1 g l(-1)). All polysaccharides tested in concentrations of 0.5 g l(-1) fucoidan and 0.2 g l(-1) fucose induced production of alginase (up to 5.06 microM h(-1) mg-1 protein). The production of glycosidases is not only stimulated by the presence of algal polysaccharides, but may also be stimulated by monosaccharides (e.g. xylose). The production of glycosidases by Pseudoalteromonas issachenkonii KMM 3549(T) was significantly improved by using a simple nutrient medium containing peptone (2.5 g l(-1)) and xylose (5.0 g l(-1)) in 100% natural seawater.

Pseudoalteromonas issachenkonii sp. nov., a bacterium that degrades the thallus of the brown alga Fucus evanescens.

Eleven non-pigmented strains of gram-negative, aerobic, marine bacteria with polar flagella were isolated from the thallus of the brown alga Fucus evanescens collected in the Kraternaya Bight of the Kurile Islands in the Pacific Ocean. These organisms were conspecific and exhibited high levels of genetic relatedness (up to 91%). The G+C contents of the DNAs of these strains were 42.9-43.3 mol%. These halophilic bacteria had bacteriolytic, proteolytic and haemolytic activities and degraded algal polysaccharides, synthesizing a number of glycoside hydrolases (fucoidanases, laminaranases, alginases, agarases, pullulanases, beta-glucosidases, beta-galactosidases, beta-N-acetylglucosaminidases and beta-xylosidases). By 16S rDNA analysis, the bacteria were shown to belong to the genus Pseudoalteromonas, a member of the gamma-subclass of the Proteobacteria. DNA from the strains isolated from the brown alga showed 27-54% genetic relatedness with respect to DNAs of other type strains of the genus Pseudoalteromonas. The phenotypic characteristics, together with the genetic evidence, indicate that this group of epiphytic bacteria represents a distinct species, Pseudoalteromonas issachenkonii sp. nov., for which the type strain is KMM 3549T (= LMG 19697T = CIP 106858T).