Extracellular Polysaccharides of Algae: Effects on Life-Support Systems

Moore, Brian G.; Tischer, R. G.

doi:10.1126/science.145.3632.586

Cited by 100 publications

(48 citation statements)

References 8 publications

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“…Moore and Tischer (1964) reported that the EPS of Anabaena flos-aquae and Palmella mucosa were derived from their water-soluble cellular polysaccharides that had the same composition. However, the EPS of N. sphaeroides examined in the present study contained very little carbohydrate and thus could not be considered a polysaccharide.…”

Section: Discussionmentioning

confidence: 99%

STUDIES ON POLYSACCHARIDES FROM THREE EDIBLE SPECIES OF NOSTOC (CYANOBACTERIA) WITH DIFFERENT COLONY MORPHOLOGIES: COMPARISON OF MONOSACCHARIDE COMPOSITIONS AND VISCOSITIES OF POLYSACCHARIDES FROM FIELD COLONIES AND SUSPENSION CULTURES

Liu

Paulsen

Klaveness

1998

Journal of Phycology

112

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Section: Discussionmentioning

confidence: 99%

STUDIES ON POLYSACCHARIDES FROM THREE EDIBLE SPECIES OF NOSTOC (CYANOBACTERIA) WITH DIFFERENT COLONY MORPHOLOGIES: COMPARISON OF MONOSACCHARIDE COMPOSITIONS AND VISCOSITIES OF POLYSACCHARIDES FROM FIELD COLONIES AND SUSPENSION CULTURES

Liu

Paulsen

Klaveness

1998

Journal of Phycology

112

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“…Aquatic plants, such as algae, are able to secrete many organic compounds, such as amino acids and polysaccharides, which are in turn used by bacteria as substrates for growth (14,19,20,23). For example, low-molecular-mass products (Ͻ700 Da) are an important source of carbon for heterotrophic bacteria (19).…”

Section: Discussionmentioning

confidence: 99%

Aquatic Plants Stimulate the Growth of and Biofilm Formation by Mycobacterium ulcerans in Axenic Culture and Harbor These Bacteria in the Environment

Marsollier

Stinear

Aubry

et al. 2004

Appl Environ Microbiol

140

131

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Mycobacterium ulcerans is the causative agent of Buruli ulcer, one of the most common mycobacterial diseases of humans. Recent studies have implicated aquatic insects in the transmission of this pathogen, but the contributions of other elements of the environment remain largely unknown. We report here that crude extracts from two green algae added to the BACTEC 7H12B culture medium halved the doubling time of M. ulcerans and promoted biofilm formation. Using the 7H12B medium, modified by the addition of the algal extract, and immunomagnetic separation, we also demonstrate that M. ulcerans is associated with aquatic plants in an area of the Ivory Coast where Buruli ulcer is endemic. Genotype analysis showed that plant-associated M. ulcerans had the same profile as isolates recovered in the same region from both aquatic insects and clinical specimens. These observations implicate aquatic plants as a reservoir of M. ulcerans and add a new potential link in the chain of transmission of M. ulcerans to humans.Mycobacterium ulcerans is an emerging environmental pathogen (2). It is the etiologic agent of Buruli ulcer, a necrotic skin disease highly prevalent in many countries throughout west Africa and one of the most common mycobacterial diseases in humans after tuberculosis and leprosy (2). M. ulcerans is the only mycobacterium known to produce a toxin, a polyketide-derived macrolide called mycolactone (10, 11). The infection begins with a painless nodule or papule that spreads over the surrounding tissue. Ischemic and necrotized tissue disappears and is replaced by centralized ulceration of the limb. At present, the only effective treatment consists of excision of the lesions, and this is often followed by extensive skin grafting (6).Until very recently M. ulcerans had never been isolated in culture from the environment. Indirect evidence from epidemiological studies suggests that M. ulcerans is an environmental mycobacterium present in swampy areas. Humans are thought to be infected through minor wounds or skin abrasions via contact with mycobacterium-containing water (33). In a previous study we demonstrated that aquatic insects are a possible mode of transmission of M. ulcerans to humans. We showed that, in an experimental mouse model, aquatic insects (Naucoridae) were able to transmit an infection by biting, thereby inoculating bacilli that had accumulated in the salivary glands of the insects (16). We were then able to isolate in pure culture M. ulcerans from the salivary glands of Naucoridae captured in a region of endemicity in the Ivory Coast. However it seems unlikely that these insects are the only environmental source of M. ulcerans. In another recent study, data gathered using an M. ulcerans-specific PCR to survey environments of endemicity in southeastern Australia identified aquatic plants as a possible reservoir of this pathogen (30).In this report, we test the hypothesis that M. ulcerans is associated with aquatic plants by studying the effects of crude aquatic plant extracts on the growth of M. ulcer...

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“…This AOM can be considered representative of the various compounds that could be released by any algae because the composition and the metabolism of the algal cells are relatively similar among the various groups of algae, especially in the Chlorophyceae group (5,13). Indeed, because of their metabolism (photosynthesis), algae produce large quantities of organic compounds, such as monosaccharides and polysaccharides, uronic acids, peptides, and amino acids (32,40,41), that are likely to be released during oxidation. The reserve substances are always composed of polysaccharides-glucanes (glucose polymeres) belonging to the family of starches or laminarines.…”

Section: Discussionmentioning

confidence: 99%

Escherichia coli Behavior in the Presence of Organic Matter Released by Algae Exposed to Water Treatment Chemicals

Bouteleux

Saby²,

Tozza

et al. 2005

Appl Environ Microbiol

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When exposed to oxidation, algae release dissolved organic matter with significant carbohydrate (52%) and biodegradable (55 to 74%) fractions. This study examined whether algal organic matter (AOM) added in drinking water can compromise water biological stability by supporting bacterial survival. Escherichia coli (1.3 ؋ 10 5 cells ml ؊1 ) was inoculated in sterile dechlorinated tap water supplemented with various qualities of organic substrate, such as the organic matter coming from chlorinated algae, ozonated algae, and acetate (model molecule) to add 0.2 ؎ 0.1 mg of biodegradable dissolved organic carbon (BDOC) liter ؊1 . Despite equivalent levels of BDOC, E. coli behavior depended on the source of the added organic matter. The addition of AOM from chlorinated algae led to an E. coli growth equivalent to that in nonsupplemented tap water; the addition of AOM from ozonated algae allowed a 4-to 12-fold increase in E. coli proliferation compared to nonsupplemented tap water. Under our experimental conditions, 0.1 mg of algal BDOC was sufficient to support E. coli growth, whereas the 0.7 mg of BDOC liter ؊1 initially present in drinking water and an additional 0.2 mg of BDOC acetate liter ؊1 were not sufficient. Better maintenance of E. coli cultivability was also observed when AOM was added; cultivability was even increased after addition of AOM from ozonated algae. AOM, likely to be present in treatment plants during algal blooms, and thus potentially in the treated water may compromise water biological stability.In spite of the disinfection processes, bacterial proliferation can be observed in drinking water distribution network systems (20,26,37,42) proving that certain bacterial populations are able to adapt, transiently or permanently, to the oligotrophic conditions of distribution networks (16,17). This phenomenon has been described for fecal indicators such as coliform bacteria, particularly Escherichia coli (16), and poses the problem of compliance with water quality health regulations.Although multiple factors certainly affect microbial growth phenomena, organic matter in treated waters, mainly the biodegradable fraction, has a determining effect since it provides a carbon and energy source essential to the growth of heterotrophic bacteria, including coliforms (16,19,25,38,39,42). Atypical events (algal bloom, swelling, rainfall, etc.) capable of modifying the quality of the organic matter in raw and treated waters have been suggested to be a catalyst for coliform growth (3, 18, 23). Lake et al. (15) showed that there is a strong link between the end of the algal bloom and the presence of coliforms in the distribution system, leading to a situation incompatible with health standards. Algal products in the treated water were suspected of providing a good nutritional source for bacterial regrowth in the distribution system. In addition to the natural capacity of algae to secrete organic compounds, massive contamination at the inlet of a treatment plant using preoxidation can lead to algal cell lysis and re...

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Extracellular Polysaccharides of Algae: Effects on Life-Support Systems

Cited by 100 publications

References 8 publications

STUDIES ON POLYSACCHARIDES FROM THREE EDIBLE SPECIES OF NOSTOC (CYANOBACTERIA) WITH DIFFERENT COLONY MORPHOLOGIES: COMPARISON OF MONOSACCHARIDE COMPOSITIONS AND VISCOSITIES OF POLYSACCHARIDES FROM FIELD COLONIES AND SUSPENSION CULTURES

STUDIES ON POLYSACCHARIDES FROM THREE EDIBLE SPECIES OF NOSTOC (CYANOBACTERIA) WITH DIFFERENT COLONY MORPHOLOGIES: COMPARISON OF MONOSACCHARIDE COMPOSITIONS AND VISCOSITIES OF POLYSACCHARIDES FROM FIELD COLONIES AND SUSPENSION CULTURES

Aquatic Plants Stimulate the Growth of and Biofilm Formation by Mycobacterium ulcerans in Axenic Culture and Harbor These Bacteria in the Environment

Escherichia coli Behavior in the Presence of Organic Matter Released by Algae Exposed to Water Treatment Chemicals

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