Download - Wiley Online Library

FEMS Microbiology Ecology 30 (1999) 285^293
MiniReview
Marine Pseudoalteromonas species are associated with higher
organisms and produce biologically active extracellular agents
Carola Holmstro«m
b
a;b;
*, Sta¡an Kjelleberg
a;b
a
School of Microbiology and Immunology, The University of New South Wales, Sydney, N.S.W. 2052, Australia
Centre for Marine Biofouling and Bio-Innovation, The University of New South Wales, Sydney, N.S.W. 2052, Australia
Received 13 April 1999; revised 2 August 1999 ; accepted 4 August 1999
Abstract
The newly established genus Pseudoalteromonas contains numerous marine species which synthesize biologically active
molecules. The production of a range of compounds which are active against a variety of target organisms appears to be a
unique characteristic for this genus and may greatly benefit Pseudoalteromonas cells in their competition for nutrients and
colonization of surfaces. Species of Pseudoalteromonas are generally found in association with marine eukaryotes and display
anti-bacterial, bacteriolytic, agarolytic and algicidal activities. Moreover, several Pseudoalteromonas isolates specifically
prevent the settlement of common fouling organisms. While a wide range of inhibitory extracellular agents are produced,
compounds promoting the survival of other marine organisms living in the vicinity of Pseudoalteromonas species have also been
found. ß 1999 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
Keywords : Marine ; Fouling ; Pseudoalteromonas
1. Introduction
Bacteria readily isolated from marine waters are
heterotrophic Gram-negative, £agellated bacteria [1]
and can be divided into two subgroups depending on
their capacity to ferment carbohydrates. Within the
non-fermentative group, the genus designated Alteromonas was revised based on phylogenetic comparisons performed by Gauthier et al. in 1995. Their
revision suggested that the genus Alteromonas should
be divided into two genera, Alteromonas (which now
includes one species only) and a new genus, Pseu-
* Corresponding author. Tel.: +61 (2) 9385 1594;
Fax: +61 (2) 9385 1591; E-mail: [email protected]
doalteromonas [2] (Fig. 1 shows a phylogenetic tree
of the di¡erent species currently assigned to the genus Pseudoalteromonas). This newly created genus
has attracted signi¢cant interest for two reasons.
First, Pseudoalteromonas species are frequently
found in association with eukaryotic hosts in the
marine environment and studies of such associations
will elucidate the mechanisms important in microbehost interactions. Second, many of the species produce biologically active metabolites which target a
range of organisms. The di¡erent extracellular biological activities displayed by Pseudoalteromonas species are listed in Table 1. The aims of this review are
to summarize some of the emerging information pertaining to the genus Pseudoalteromonas and to highlight the ecological relevance and range of biologi-
0168-6496 / 99 / $20.00 ß 1999 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
PII: S 0 1 6 8 - 6 4 9 6 ( 9 9 ) 0 0 0 6 3 - X
FEMSEC 1070 12-11-99
286
C. Holmstro«m, S. Kjelleberg / FEMS Microbiology Ecology 30 (1999) 285^293
Fig. 1. A phylogenetic a¤liation of the genus Pseudoalteromonas based on 16S rRNA gene sequence alignment. An alignment of 1157
characters was used to calculate genetic distances according to the method of Jukes and Cantor (1969). The phenogram was reconstructed
from the pairwise distance matrix using the neighbor-joining method of Saitou and Nei (1996). The scale represents one base substitution
per 10 nucleotide positions.
cally active compounds that are expressed by many
of its member species.
2. Isolation of Pseudoalteromonas species
In the classi¢cation of bacteria, the clear distinc-
tion that exists between marine and non-marine animals and plants is not applicable [3]. Currently, representatives of most culturable bacterial genera can
be isolated both from terrestrial and marine environments. Yet, it is now established that the genus Pseudoalteromonas contains species that exclusively derive from marine waters and that members have
FEMSEC 1070 12-11-99
C. Holmstro«m, S. Kjelleberg / FEMS Microbiology Ecology 30 (1999) 285^293
been isolated from marine locations around the
world [4]. Interestingly, a majority of the Pseudoalteromonas species seem to be associated with eukaryotic hosts. Species have been isolated from various
animals, such as mussels [5,6], pu¡er¢sh [7], tunicates
[8] and sponges [6], as well as from a range of marine
plants [9,10]. Their existence in a variety of habitats
and their world-wide spread suggest that the adaptive and survival strategies expressed by Pseudoalteromonas species are diverse, e¤cient and of great interest for both basic and applied research.
3. Biological activities expressed by
Pseudoalteromonas and Alteromonas species
Recent years have witnessed the generation of considerable novel information on the production of
biologically active metabolites by members of the
genus Pseudoalteromonas and the interactions of
these bacteria with di¡erent host organisms. In particular, many Pseudoalteromonas species have been
demonstrated to produce anti-bacterial products
which appear to aid them in the colonization of surfaces including those of their hosts. The production
of agarases, toxins, bacteriolytic substances and other enzymes by many Pseudoalteromonas species may
assist the bacterial cells in their competition for nutrients and space as well as in their protection
against predators grazing at surfaces. The bacterial
ecology at solid surfaces is complex and many additional factors besides the production of secondary
metabolites and other secreted products a¡ect bacterial responses. For example, Ivanova et al. [11] demonstrated that the degree of hydrophobicity of the
substratum in£uences the production of anti-bacterial metabolites. The highest anti-microbial activity
was found to occur on hydrophilic surfaces despite
the fact that attached Pseudoalteromonas cells were
more abundant on hydrophobic surfaces [11]. This
¢nding may suggest that the expression of the antimicrobial activity may be switched on and o¡ depending on £uctuations and stimuli present in the
immediate environment of the cell.
3.1. Anti-bacterial activity
Pseudoalteromonas species display a broad range
287
of antibiotic e¡ects. Three species, P. aurantia [12],
P. luteoviolacea [13] and P. rubra [14], have been
demonstrated to produce high molecular mass antibacterial compounds [15]. The anti-bacterial activity
displayed by the di¡erent strains of P. luteoviolacea
is particularly interesting and has been suggested to
be due to two classes of compounds. First, cell
bound polyanionic macromolecules, which are partly
di¡usible in culture media, were thought to be acidic
polysaccharides. A later study by McCarthy et al.
demonstrated that these high molecular compounds
are associated with proteins [16]. The second group
of antibiotics produced by P. luteoviolaceus contains
small brominated compounds [17] which are cell
bound and not di¡usible into the media. These brominated compounds are known to have a strong
bactericidal e¡ect [13]. In the production of the different antibiotics, heterogeneity among di¡erent P.
luteoviolaceus strains has been demonstrated. Di¡erent strains have been found to synthesize either the
polysaccharide molecule or the small brominated
metabolites, or both. These variations in the production of anti-bacterial agents may suggest that P. luteoviolaceus strains originally selected di¡erent host
organisms or habitats and with time evolved separately to produce divergent compounds. Self-inhibition has also been observed in P. luteoviolaceus cells
and is suggested to be mediated by the macromolecular antibiotic compound [13]. These polyanionic
carbohydrates have also been demonstrated to be
important in the attachment of bacteria to solid surfaces [18], enabling the bacteria to be highly competitive in the colonization of host organisms [13].
Although auto-inhibition is observed for Pseudoalteromonas species, we demonstrated that it is not a
widely occurring phenomenon in other marine bacteria [19]. The importance of this activity in the marine ecosystem has been questioned, given that the
dilution of compounds in the aqueous phase probably keeps the concentration of extracellular compounds low in the vicinity of cells [17]. Yet, it is
possible that the production of auto-inhibitory compounds in a bacterial population is important for
maintaining the microbial diversity within a microhabitat [20]. Given the recent ¢ndings that extracellular auto-inducer compounds are important in
many bacterial populations [21,22], a role for autoinhibitory molecules can also be envisaged.
FEMSEC 1070 12-11-99
288
C. Holmstro«m, S. Kjelleberg / FEMS Microbiology Ecology 30 (1999) 285^293
Antibiotic activity mediated by a polyanionic antibiotic molecule has also been demonstrated for the
species P. citrea [23]. These polyvalent anions, which
also mediate the antibiotic activity of P. rubra and P.
luteoviolacea, have been found to inhibit bacterial
respiration [13]. Interestingly, it was demonstrated
that the production of such compounds in several
Pseudoalteromonas species was media dependent.
The cells did not express any anti-bacterial activity
when grown on blood-containing media and the expression of the active compounds was very low when
grown on nutrient agar and tryptic soy agar media
containing salt [13,14,24]. Given that speci¢c nutrient conditions may be needed for bacteria to express their extracellular biologically active compounds, it is suggested that some bacteria-host
associations in the marine environments are controlled by available food sources.
3.2. Extracellular enzymes and toxins
Agar is a polysaccharide present in the cell walls
of some red algae. It appears that the bacterial degradation of agar occurs by two mechanisms based on
the speci¢city of the enzymes L-agarase and K-agarase. Cleavage of the polysaccharide chains causes
agar softening so that agarase activity expressed by
bacteria living in association with red algae may help
the bacteria to easily acquire nutrients from the algae, as is the case for the bacterial degradation of the
fronds of green [25] and brown algae [26]. Vera et al.
identi¢ed an agarolytic isolate, P. antarctica strain
N-1, and characterized its extracellular produced
agarase to be an endo L-agarase I [27]. Other agarase
decomposing strains within the genus Pseudoalteromonas are P. agarolyticus, P. sp. strain C-1, P. carrageenovora, P. atlantica [9,27] and P. citrea [6].
Most of the reported agarolytic Pseudoalteromonas
strains have been found to produce extracellular Lagarases while the P. agarolyticus strain was reported
to produce both an K- and a L-agarase.
Other bacteria expressing biological activity
against marine plants include P. bacteriolytica strains
which were isolated from the brown alga Laminaria
japonica and are believed to be the causative agent of
red spot disease in L. japonica [28]. These bacterial
isolates have also been found to have bacteriolytic
activity against both Gram-positive and Gram-neg-
ative bacteria [28]. Given the advantages that bacteriolytic activity provide for the producer strains by
the release of nutritive compounds, this is most likely
a signi¢cant trait for bacteria living in oligotrophic
environments. Bacteriolytic activity may also bene¢t
the producer strain in the competition for space in
the marine environment.
Competitive advantages for Pseudoalteromonas
and Alteromonas bacterial strains in nutritrient aquisition and colonization have been proposed for their
algicidal activities against phytoplankton [29]. In this
case, the ecological relevance of algicidal activity
may also be to control phytoplankton succession in
the marine environment as was shown for Pseudoalteromonas sp. strain Y against blooms of harmful
micro algae [30]. This bacterium was demonstrated
to cause rapid cell lysis and death of species within
the genera Chatonella, Gymnodinium and Heterosigma. A bacterium Pseudoalteromonas sp. A28 was
also demonstrated to lyse marine algae [31]. The active components were proteases and it was suggested
that the protease expression is regulated by the acylated homoserine lactone regulatory system [31].
Several other Pseudoalteromonas species have also
been shown to produce extracellular toxins (see Table 1). These include P. tetraodonis, which produces
the neurotoxin, tetradotoxin, the causative agent of
pu¡er¢sh poisoning [7], and P. piscicidia, which releases a toxin suggested to cause ¢sh mortality [32].
Furthermore, Pseudoalteromonas tunicata cells have
been demonstrated to be toxic against invertebrate
larvae [33] and algal spores [34] and P. denitri¢cans
produces autotoxic substances which kill the bacterial cells and inhibit further growth in dense culture
[4]. Production of toxic compounds may allow for
the bacteria to control large scale processes, in contrast to the more restricted modi¢cation of their microhabitats caused by speci¢c non-toxic extracellular
agents.
3.3. Extracellular polysaccharides
The range of biological activities discussed above
suggests that the expression of bacterial extracellular
compounds allows for the producer to successfully
compete with other organisms. However, bacteria
can also produce compounds which aid in the survival of other marine organisms. For example, the
FEMSEC 1070 12-11-99
C. Holmstro«m, S. Kjelleberg / FEMS Microbiology Ecology 30 (1999) 285^293
289
Table 1
A summary of the biological activities displayed by Pseudoalteromonas species
Bacterium
Biological activity
References
P. aurantia
P. luteoviolacea
P. rubra
P. citrea
Pseudoalteromonas sp. F-420
P. agarolyticus
P. antarctica strain N-1
Pseudoalteromonas sp. strain C-1
P. carrageenovora
P. atlantica
P. bacteriolytica
P. haloplanktis strain S5B
Pseudoalteromonas sp. strain Y
P. piscicidia
P. tetraodonis
P. denitri¢cans
Pseudoalteromonas sp. strain S9
P. colwelliana
P. undina
P. espejiana
P. tunicata
Anti-bacterial activity
Anti-bacterial activity
Anti-bacterial activity
Anti-bacterial, anti-fungal and agarolytic activities
Anti-bacterial activity
Agarolytic activity
Agarolytic activity
Agarolytic activity
Agarolytic activity
Agarolytic activity
Bacteriolytic activity, believed to cause red spot disease of L. japonica
Produces trypsin-like proteases which are believed to cause ¢sh spoilage
Algicidal activity
Produces a toxin which appears to cause ¢sh mortality
Produces a neurotoxin, tetradotoxin, which causes pu¡er¢sh poisoning
Produces autotoxic substances
Promotes the settlement of tunicate larvae
Promotes the settlement of oyster larvae
Anti-bacterial and anti-viral activities
Degrades polymers and also induces metamorphosis of hydroid larvae
Anti-fouling and biocontrol activities against invertebrate larvae, algal spores, bacteria,
fungi and diatoms
[12]
[13]
[14]
[6,23]
[10]
[27]
[27]
[27]
[9]
[9]
[28]
[47]
[30]
[32]
[7]
[4]
[39]
[35]
[48]
[25,49]
[8]
production of exopolysaccharides (EPS) has been
demonstrated to enhance the chances for other organisms to survive in speci¢c marine habitats. Despite this fact, EPS e¡ects have only been examined
in detail in a few instances.
EPS producing bacterial strains are common within the genera Pseudoalteromonas and Alteromonas
[35,36]. Interestingly, Alteromonas sp. strain HYD1545, isolated from tube worms, produces an EPS
containing acidic sugars [37] which were demonstrated to have heavy metal binding properties. The
bacterium is suggested to be important for the survival of its host organism which lives in an environment where the exposure to chemicals (e.g. metallic
sul¢des) is high [37].
Further bene¢cial e¡ects of EPS production by
bacteria on organisms have been demonstrated for
the settlement of invertebrate larvae [35,36]. For example, Pseudoalteromonas sp. strain S9 produces an
EPS both in liquid culture and on surfaces during
the stationary phase of growth [38]. The wild-type
and a transposon-generated mutant de¢cient in the
release of EPS were tested against the settlement of
tunicate larvae [39] and it was demonstrated that the
wild-type resulted in a higher degree of larval settlement and subsequent metamorphosis and development compared to the mutant strain.
The role of EPS production by Pseudoalteromonas
sp. strain S9 in the bacterial cell attachment process
was studied in some detail [38,40,41]. Wrangstadh et
al. demonstrated that an increase in the production
of EPS during starvation conditions correlated with
a decrease in both cell surface hydrophobicity and
adhesion of cells to inanimate surfaces. The increase
in the amount of EPS at the bacterial cell surface
further correlated with an increase in cell detachment
[41]. These responses were triggered by starvation
and were postulated to help the cells to escape nutrient-depleted environments. Following detachment,
the free-living bacterial cells may `search' for other
surfaces to colonize that may provide more suitable
conditions for their proliferation.
It would appear that bacterial EPSs can serve as
anti-bacterial components [13], control bacterial attachment [18,40] and bene¢t the survival of both the
host and other organisms that live in the vicinity of
the producer strain [37,39]. Additionally EPSs can
act as protective barriers against antibiotics, against
FEMSEC 1070 12-11-99
290
C. Holmstro«m, S. Kjelleberg / FEMS Microbiology Ecology 30 (1999) 285^293
predation by protozoa [42], function as enhancers for
nutrient uptake and reduce the di¡usion of some
substances to and from the cells [43]. Many Pseudoalteromonas species employ EPS production and
it is likely that this characteristic provides a range
of survival strategies for the cells.
3.4. Biological activities expressed by P. tunicata
A well studied bacterium within the genus Pseudoalteromonas is P. tunicata (previously designated
D2). This strain was isolated in coastal waters of
Sweden from the surface of an adult tunicate collected at a depth of 10 m [33]. Subsequent studies
demonstrated that P. tunicata-like strains exist on
the green alga Ulva lactuca in Australian waters
[34]. P. tunicata is a dark green-pigmented bacterium
and has been found to produce at least ¢ve extracellular compounds which inhibit other organisms
from establishing themselves in a biofouling community (Fig. 2). The compounds inhibit settlement
of invertebrate larvae and algal spores, growth of
bacteria and fungi and surface colonization by diatoms [34]. The anti-larval component is a heat stable
polar molecule less than 500 Da in size [33]. The
anti-bacterial molecule is a novel large protein (190
kDa) which consists of at least two subunits (80 and
60 kDa in size). The protein inhibits the growth of
most Gram-negative and Gram-positive bacteria isolated from both marine and terrestrial environments
[19]. P. tunicata cells also express auto-inhibition and
cells in the exponential phase of growth are sensitive
to this protein. However, as the cells reach the stationary phase, which is the physiological state in
which the protein is produced, they become resistant.
The ecological role of this anti-bacterial protein in
P. tunicata colonization of surfaces is currently being
studied using strains mutated in the subunit genes.
The anti-spore component is a peptide of around
3 kDa in size [34]. Recent studies indicate that the
anti-fungal molecule may be a cell bound long chain
fatty acid derivative (unpublished data). The anti-diatom compound has not yet been characterized.
The unique features of P. tunicata relate to the
diversity of anti-fouling and inhibitory compounds
that are produced and the fact that each metabolite
has been demonstrated to target speci¢c groups of
organisms (Fig. 2). This phenomenon has not been
Fig. 2. The anti-fouling activities expressed by P. tunicata. The
di¡erent extracellular compounds are active against at least ¢ve
di¡erent groups of organisms. These include invertebrate larvae,
algal spores, bacteria, fungi and diatoms. Each compound targets
a speci¢c group of organisms.
reported for any other bacteria and may suggest that
bacteria displaying such features are not common in
the marine environment, although P. tunicata strains
have been isolated from surfaces of higher organisms
in both waters of the Swedish west coast and around
Sydney. However, the paucity of reports on such
bacteria and characteristics may re£ect that laboratories generally do not have access to broad range
bioassays.
4. Biological control and commercial use of
Pseudoalteromonas species
Biocontrol is based on antagonistic interactions
between microorganisms and between bacteria and
higher organisms. The mode of action may be nontoxic and speci¢c, as displayed by bio¢lm bacteria
that repel fouling macroorganisms. More often however, the microbial biocontrol is based on toxicity as
is generally the case for the control of microbial disease causing organisms. Given that Pseudoalteromonas species express a wide range of biological activities, it has been proposed that this genus includes
valuable biocontrol strains for use in, aquaculture,
anti-fouling technologies and the control of toxic
algal blooms. Indeed, these proposals have been explored in some research programs. The authors of
this minireview developed a method to immobilize
P. tunicata cells into polyacrylamide gels [44] and
FEMSEC 1070 12-11-99
C. Holmstro«m, S. Kjelleberg / FEMS Microbiology Ecology 30 (1999) 285^293
polyvinylalcohol gels [45]. The method was employed
to keep the cells entrapped and alive in a gel matrix
surface coating which allowed for an out£ux of antifouling components. Viable immobilized cells were
demonstrated after more than 2 months in marine
waters in the laboratory [45]. Such a `living paint'
concept may o¡er a novel environmentally friendly
alternative to current toxic marine anti-foulants.
The methods employed for reducing numbers of
pathogenic microorganisms when culturing ¢sh, abalone, oyster and other organisms include ¢ltration
of the water, ozonation, ultraviolet light exposure
and the use of arti¢cial food containing antibiotics.
However, none of these methods has proven e¡ective
in controlling microbial diseases and there is an obvious need to introduce alternative methods. Maeda
et al. [48] investigated the use of an anti-microbial
producing Pseudoalteromonas undina strain as a biocontrol agent and demonstrated that this organism
successfully represses the growth of deleterious bacteria and viruses and improves the growth of farmed
¢sh and crustaceans. Furthermore, the ability of
many Pseudoalteromonas species to degrade polymers and to attach to surfaces was applied in the
degradation of freeze-dried Ulva fronds for a hatchery diet of Artemia nauplii larvae [25]. It was demonstrated that the addition of Pseudoalteromonas espejiana to the fronds enhanced their conversion into
microalgae-like forms. These particles also contained
double the amount of protein, as a result of the
bacterial bio¢lm, in comparison with the particles
that were treated under sterile conditions [25]. This
technology may be applicable in other processes for
the generation of animal food.
5. Fouling control by the Pseudoalteromonas species
in the marine environment
In response to various metabolites or other environmental stimuli, bacterial cells can produce chemical compounds which bene¢t the producer strain
and/or the host organism in their establishment in
suitable marine habitats. Examples include where
host organisms may employ bacterially produced
compounds for their own chemical defence against
fouling organisms as for the green algae Ulva lactuca
and Enteromorpha intestinalis and the tunicate Ciona
291
intestinalis. These organisms are known not to produce any secondary metabolites for their protection
against fouling but have been reported to carry antifouling producing Pseudoalteromonas species [34,46].
We hypothesize that their success in remaining
unfouled in the ¢eld is due to the associated antifouling bacteria.
Acknowledgements
Research in the author's laboratory was funded by
the Australian Research Council, a Vice Chancellor's
post doctoral research fellowship at the University of
New South Wales to C.H. and by the Centre for
Marine Biofouling and Bio-Innovation at UNSW.
We would like to thank Sally James, Suhelen Egan,
Ashley Franks, Torsten Thomas and Harriet Baillie
for assistance and valuable discussions.
References
[1] Baumann, L., Baumann, P., Mandel, M. and Allen, R.D.
(1972) Taxonomy of aerobic marine eubacteria. J. Bacteriol.
110, 402^429.
[2] Gauthier, G., Gauthier, M. and Christen, R. (1995) Phylogenetic analysis of the genera Alteromonas, Shewanella and Moritella using genes coding for small-subunit r RNA sequences
and division of the genus Alteromonas into two genera, Alteromonas (emended) and Pseudoalteromonas gen. nov., and proposal of twelve new species combinations. Int. J. Syst. Bacteriol. 45, 755^761.
[3] Jensen, P.R. and Fenical, W. (1996) Marine bacterial diversity
as a resource for novel microbial products. J. Ind. Microbiol.
17, 346^351.
[4] Enger, O., Nygaard, H., Solberg, M., Schei, G., Nielsen, J.
and Dundas, I. (1987) Characterization of Alteromonas denitri¢cans sp. nov.. Int. J. Syst. Bacteriol. 37, 416^421.
[5] Ivanova, E.P., Kiprianova, E.A., Mikhailov, V.V., Levanova,
G.F., Garagulya, A.D., Gorshkova, N.M., Yumoto, N. and
Yoshikawa, S. (1996) Characterization and identi¢cation of
marine Alteromonas nigrifaciens strains and emendation of
the description. Int. J. Syst. Bacteriol. 46, 223^228.
[6] Ivanova, E.P., Kiprianova, E.A., Mikhailov, V.V., Levanova,
G.F., Garagulya, A.D., Gorschkova, N.M., Vysotskii, M.V.,
Nicolau, D.V., Yumoto, N., Taguchi, T. and Yoshikawa, S.
(1998) Phenotypic diversity of Pseudoalteromonas citrea from
di¡erent marine habitats and emendation of the description.
Int. J. Syst. Bacteriol. 48, 247^256.
[7] Simidu, U., Kita-Tsukamoto, K., Yasumoto, T. and Yotsu,
M. (1990) Taxonomy of four marine bacterial strains that
produce tetrodotoxin. Int. J. Syst. Bacteriol. 40, 331^336.
FEMSEC 1070 12-11-99
292
C. Holmstro«m, S. Kjelleberg / FEMS Microbiology Ecology 30 (1999) 285^293
[8] Holmstro«m, C., James, S., Neilan, B.A., White, D.C. and
Kjelleberg, S. (1998) Pseudoalteromonas tunicata sp. nov., a
bacterium that produces antifouling agents. Int. J. Syst. Bacteriol. 48, 1205^1212.
[9] Akagawa-Matsushita, M., Matsuo, M., Koga, Y. and Yamasato, K. (1992) Alteromonas atlantica sp. nov. and Alteromonas carrageenovora sp. nov., bacteria that compose algal polysaccharides. Int. J. Syst. Bacteriol. 42, 621^627.
[10] Yoshikawa, K., Takadera, T., Adachi, K., Nishijima, M. and
Sano, H. (1997) Koromicin, a novel antibiotic speci¢cally active against marine Gram-negative bacteria, produced by a
marine bacterium. J. Antibiot. 50, 949^953.
[11] Ivanova, E.P., Nicolau, D.V., Yumoto, N., Taguchi, T., Okamoto, K., Tatsu, Y. and Yoshikawa, S. (1998) Impact of
conditions of cultivation and adsorption on antimicrobial activity of marine bacteria. Mar. Biol. 130, 545^551.
[12] Gauthier, M.J. and Breittmayer, V.A. (1979) A new antibiotic-producing bacterium from seawater: Alteromonas aurantia
sp. nov.. Int. J. Syst. Bacteriol. 29, 366^372.
[13] Gauthier, M.J. and Flatau, G.N. (1976) Antibacterial activity
of marine violet-pigmented Alteromonas with special reference
to the production of brominated compounds. Can. J. Microbiol. 22, 1612^1619.
[14] Gauthier, M.J. (1979) Alteromonas rubra sp. nov., a new marine antibiotic-producing bacterium. Int. J. Syst. Bacteriol. 26,
459^466.
[15] Baumann, P., Gauthier, M.J. and Baumann, L. (1984) Bergey's Manual of Determinative Bacteriology. Williams and
Wilkins, Baltimore, MD.
[16] McCarthy, S.A., Johnson, R.M. and Kakimoto, D. (1994)
Characterization of an antibiotic produced by Alteromonas
luteoviolacea Gauthier 1982, 85 isolated from Kinko Bay.
Jpn. J. Appl. Bacteriol. 77, 426^432.
[17] Andersen, R.J., Wolfe, M.S. and Faulkner, D.J. (1974) Autotoxic antibiotic production by a marine Chromobacterium.
Mar. Biol. 27, 281^285.
[18] Fletcher, M. and Floodgate, G.D. (1973) An electron microscopic demonstration of an acidic polysaccharide involved in
the adhesion of a marine bacterium to solid surfaces. J. Gen.
Microbiol. 74, 325^334.
[19] James, S., Holmstro«m, C. and Kjelleberg, S. (1996) Puri¢cation and characterisation of a novel antibacterial protein from
the marine bacterium D2. Appl. Environ. Microbiol. 62,
2783^2788.
[20] DeFreitas, M.J. and Fredrickson, A.G. (1978) Inhibition as a
factor in the maintenance of the diversity of microbial ecosystems. J. Gen. Microbiol. 106, 307^320.
[21] McClean, R.J.C., Whiteley, M., Stickler, D.J. and Fuqua,
W.C. (1997) Evidence of autoinducer activity in naturally occuring bio¢lms. FEMS Microbiol. Lett. 154, 259^263.
[22] Davies, D.G., Parsek, M.R., Pearson, J.P., Iglewski, B.H.,
Costerton, J.W. and Greenberg, E.P. (1998) The involvement
of cell-cell signals in the development of a bacterial bio¢lm.
Science 280, 295^298.
[23] Gauthier, M.J. (1977) Alteromonas citrea, a new Gram-negative, yellow-pigmented species from seawater. Int. J. Syst. Bacteriol. 27, 349^354.
[24] Gauthier, M.J. (1976) Morphological, physiological, and biochemical characteristics of some violet-pigmented bacteria isolated from seawater. Can. J. Microbiol. 22, 138^149.
[25] Uchida, M., Nakata, K. and Maeda, M. (1997) Conversion of
Ulva fronds to a hatchery diet for Artemia nauplii utilizing the
degrading and attaching abilities of Pseudoalteromonas espejiana. J. Allied Phycol. 9, 541^549.
[26] Uchida, M., Nakayama, A. and Abe, S. (1995) Distribution
and characterization of bacteria capable of decomposing
brown algae fronds in waters associated with Laminaria vegetation. Fish. Sci. 61, 117^120.
[27] Vera, J., Alvarez, R., Murano, E., Slebe, J.C. and Leon, O.
(1998) Identi¢cation of a marine agarolytic Pseudoalteromonas
isolate and characterization of its extracellular agarase. Appl.
Environ. Microbiol. 64, 4378^4383.
[28] Sawabe, T., Makino, H., Tatsumi, M., Nakano, K., Tajima,
K., Iqbal, M.M., Yumoto, I., Ezura, Y. and Christen, R.
(1998) Pseudoalteromonas bacteriolytica sp. nov., a marine
bacterium that is the causative agent of red spot disease of
Laminaria japonica. Int. J. Syst. Bacteriol. 48, 769^774.
[29] Imai, I., Ishida, Y., Sakaguchi, K. and Hata, Y. (1995) Algicidal marine bacteria isolated from northern Hiroshima Bay.
Jpn. Fish. Sci. 61, 628^636.
[30] Lovejoy, C., Bowman, J.P. and Hallegrae¡, G.M. (1998) Algicidal e¡ects of a novel marine Pseudoalteromonas isolate
(class Proteobacteria, gamma subdivision) on harmful algal
bloom species of the genera Chattonella, Gymnodinium and
Heterosigma. Appl. Environ. Microbiol. 64, 2806^2813.
[31] Kato, J., Ikeda, T., Kuroda, A., Takiguchi and Ohtake, H.,
(1999) In£uence of Pseudoalteromonas sp. A28 extracellular
products on the synthesis of proteases exhibiting lytic activity
toward marine algae. In: Abstracts of the 99th General Meeting of American Society for Microbiology, Abstract N-104.
Washington, DC.
[32] Bein, S.J. (1954) A study of certain chromogenic bacteria isolated from `red tide' water with a description of a new species.
Bull. Mar. Sci. Gulf Sci. 4, 110^119.
[33] Holmstro«m, C., Rittschof, D. and Kjelleberg, S. (1992) Inhibition of settlement by larvae of Balanus amphitrite and Ciona
intestinalis by a surface-colonizing marine bacterium. Appl.
Environ. Microbiol. 58, 2111^2115.
[34] Holmstro«m, C., James, S., Egan, S. and Kjelleberg, S. (1996)
Inhibition of common fouling organisms by pigmented marine
bacterial isolates. Biofouling 10, 251^259.
[35] Weiner, R.M., Segall, A.M. and Colwell, R.R. (1985) Characterization of a marine bacterium associated with Crassostrea
virginica (the eastern oyster). Appl. Environ. Microbiol. 49,
83^90.
[36] Weiner, R.M., Coyne, V.E., Brayton, P. and Raiken, R.
(1988) Alteromonas colwelliana sp. nov., an isolate from oyster
habitats. Int. J. Syst. Bacteriol. 38, 240^244.
[37] Vincent, P., Pignet, P., Talmont, F., Bozzi, L., Fournet, B.,
Guezennec, J., Jeanthon, C. and Prieur, D. (1994) Production
and characterization of an exopolysaccharide exccreted by a
deep-sea hydrothermal vent bacterium isolated from the polychaeta annelid Alvinella pompejana. Appl. Environ. Microbiol.
60, 4134^4141.
FEMSEC 1070 12-11-99
C. Holmstro«m, S. Kjelleberg / FEMS Microbiology Ecology 30 (1999) 285^293
[38] Wrangstadh, M., Szewzyk, U., Ostling, J. and Kjelleberg, S.
(1990) Starvation speci¢c formation of a peripheral exopolysaccharide by a marine Pseudomonas sp. S9. Appl. Environ.
Microbiol. 56, 2065^2072.
[39] Szewzyk, U., Holmstrom, C., Wrangstadh, M., Samuelsson,
M.O., Maki, J.S. and Kjelleberg, S. (1991) Relevance of the
exopolysaccharide of marine Pseudomonas sp. strain S9 for
attachment of Ciona intestinalis larvae. Mar. Ecol. Prog.
Ser. 75, 259^265.
[40] Wrangstadh, M., Conway, P. and Kjelleberg, S. (1986) The
production and release of an extracellular polysaccharide during starvation of a marine Pseudomonas sp. and the e¡ect
thereof on aadhesion. Arch. Microbiol. 145, 220^227.
[41] Wrangstadh, M., Conway, P.L. and Kjelleberg, S. (1988) The
role of an extracellular polysaccharide produced by the marine
Pseudomonas sp. S9 in cellular detachment during starvation.
Can. J. Microbiol. 35, 309^312.
[42] Costerton, J.W., Cheng, K.J., Geesey, G.G., Ladd, T.I.N.J.C.,
Dasgupta, M. and Marrie, T.J. (1987) Bacterial bio¢lms in
nature and disease. Annu. Rev. Microbiol. 41, 435^464.
[43] Geesey, G.G. (1982) Microbial exopolymers : ecological and
economic considerations. ASM News 48, 9^14.
293
[44] Gatenholm, P., Holmstro«m, C., Maki, J.S. and Kjelleberg, S.
(1995) Toward biological antifouling surface coatings: marine
bacteria immobilized in hydrogel coatings. Biofouling 8, 293^
301.
[45] Holmstro«m, C., Steinberg, P., Christov, V. and Kjelleberg, S.
(1999) Bacteria immobilised in hydrogels : improved methodologies for antifouling and biocontrol applications. Biofouling
(in press).
[46] Lemos, M.L., Toranzo, A.E. and Barja, J.L. (1985) Antibiotic
activity of epiphytic bacteria isolated from intertidal seaweeds.
Microb. Ecol. 11, 149^163.
[47] Odagami, T., Suzuki, S., Takama, K., Azumi, K. and Yokosawa, H. (1993) Characterization of extracellular protease produced by the marine putrefactiva bacteria, Alteromonas haloplanktis S5B. J. Mar. Biotech. 1, 55^58.
[48] Maeda, M., Nogami, K., Kanematsu, M. and Hirayama, K.
(1997) The concept of biological control methods in aquaculture. Hydrobiologia 358, 285^290.
[49] Leitz, T. and Wagner, R.T. (1993) The marine bacterium Alteromonas espejiana induces metamorphosis of the hydroid
Hydractinia echinata. Mar. Biol. 115, 173^178.
FEMSEC 1070 12-11-99