Analysis and characterization of cultivable extremophilic hydrolytic bacterial community in heavy-metal-contaminated soils from the Atacama Desert and their biotechnological potentials.
OBJECTIVE
To isolate and characterize the cultivable community of hydrolase producers (amylase, protease, lipase, DNase, xylanase and pullulanase) inhabiting heavy-metal-contaminated soils in extreme conditions from the Atacama Desert.


RESULTS
A total of 25 bacterial strains showing hydrolytic activities have been selected including halotolerants, extremely halotolerants and moderate halophiles. Most hydrolase producers were assigned to the family B acillaceae, belonging to the genera Bacillus (nine strains), Halobacillus (seven strains) and Thalassobacillus (five strains) and four isolates were related to members of the families Pseudomonadaceae, Halomonadaceae and Staphylococcaceae. The selected strains were then characterized for their tolerance pattern to six heavy metals, measured as minimal inhibitory concentrations (MICs).


CONCLUSIONS
The diversity found in the cultivable bacterial community analysed is more limited than that detected in other ecological studies owing to the restrictive conditions used in the screening. The dominant bacteria were Firmicutes and particularly, species related to the genus Bacillus.


CONCLUSIONS
This study is focused on the characterization of extremophilic hydrolytic bacteria, providing candidates as a source of novel enzymes with biotechnological applications.
Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, Sevilla, Spain.
M L
ML
Moreno
F
F
Piubeli
M R L
MR
Bonfá
M T
MT
García
L R
LR
Durrant
E
E
Mellado
D001407:Bacillus / Q000145:classification / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification; D001419:Bacteria / Q000145:classification / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification*; D002677:Chile; D004269:DNA, Bacterial / Q000235:genetics; D003889:Desert Climate; D006867:Hydrolases / Q000096:biosynthesis*; D019216:Metals, Heavy; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D012989:Soil Pollutants
D004269:DNA, Bacterial; D019216:Metals, Heavy; D012336:RNA, Ribosomal, 16S; D012989:Soil Pollutants; D006867:Hydrolases