Characterization of extracellular polymers synthesized by tropical intertidal biofilm bacteria.
OBJECTIVE
This study was performed to determine the potential of tropical intertidal biofilm bacteria as a source of novel exopolymers (EPS).


RESULTS
A screening procedure was implemented to detect EPS-producing biofilm bacteria. Isolates MC3B-10 and MC6B-22, identified respectively as a Microbacterium species and Bacillus species by 16S rDNA and cellular fatty acids analyses, produced different EPS, as evidenced by colorimetric and gas chromatographic analyses. The polymer produced by isolate MC3B-10 displays significant surfactant activity, and may chelate calcium as evidenced by spectroscopic analysis.


CONCLUSIONS
Polymer MC3B-10 appears to be a glycoprotein, while EPS MC6B-22 seems to be a true polysaccharide dominated by neutral sugars but with significant concentrations of uronic acids and hexosamines. EPS MC3B-10 possesses a higher surfactant activity than that of commercial surfactants, and given its anionic nature, may chelate cations thus proving useful in bioremediation. The chemical composition of polymer MC6B-22 suggests its potential biomedical application in tissue regeneration.


CONCLUSIONS
This is the first report of a Microbacterium species producing EPS with surfactant properties, which expands our knowledge of the micro-organisms capable of producing these biomolecules. Furthermore, this work shows that tropical intertidal environments are a nonpreviously recognized habitat for bioprospecting EPS-producing bacteria, and that these molecules might be involved in ecological roles protecting the cells against dessication.
Ortega-Morales
B O
BO
Departamento de Microbiología Ambiental y Biotecnología, Programa de Corrosión del Golfo de México, Universidad Autónoma de Campeche Av., Campeche, México. beortega@uacam.mx
Santiago-García
J L
JL
Chan-Bacab
M J
MJ
Moppert
X
X
Miranda-Tello
E
E
Fardeau
M L
ML
Carrero
J C
JC
Bartolo-Pérez
P
P
Valadéz-González
A
A
Guezennec
J
J
D001407:Bacillus / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D001426:Bacterial Proteins / Q000032:analysis; D001483:Base Sequence; D018441:Biofilms; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics; D006023:Glycoproteins / Q000032:analysis; D008969:Molecular Sequence Data; D009005:Monosaccharides / Q000032:analysis; D009161:Mycobacterium / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D010802:Phylogeny; D011108:Polymers / Q000737:chemistry / Q000378:metabolism*; D011134:Polysaccharides / Q000032:analysis; D013055:Spectrophotometry, Infrared / Q000379:methods; D013501:Surface-Active Agents / Q000032:analysis; D014329:Tropical Climate
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D006023:Glycoproteins; D009005:Monosaccharides; D011108:Polymers; D011134:Polysaccharides; D013501:Surface-Active Agents