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Isolation of
hydrolase producing bacteria from Sua pan solar salterns and
the production of endo-1, 4-b-xylanase
from a newly isolated haloalkaliphilic Nesterenkonia
sp.
Lucretia
Govender, Lureshini Naidoo and Mathabatha Evodia Setati*
Discipline of Microbiology, School of Biochemistry, Genetics
and Microbiology, Faculty of Science and Agriculture,
University of KwaZulu-Natal, Westville Campus, P/Bag X54001,
Durban, 4000, South Africa.
*Corresponding author. E-mail: setatim@ukzn.ac.za. Fax:
+27 31 260 7809.
Accepted 20 July, 2009 |
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Eighty seven bacterial
isolates were obtained from evaporator ponds using culture
enrichment technique and screened for xylanase, mannanase
and cellulase activity. Based on biochemical and phenotypic
characteristics, the isolates were divided into 18 groups.
Thirteen groups were Bacillus species, four were
Halomonas species, while one group belonged to the genus
Nesterenkonia. Four Bacillus isolates,
Sua-BAC005, Sua-BAC012, Sua-BAC017 and Sua-BAC019, as well
as Nesterenkonia sp. Sua-BAC020 were studied further.
Isolate Sua-BAC005 affiliated with Bacillus
amyloliquefaciens secreted 12.6 U/ml and 9.0 U/ml
b-mannanase
and
b-xylanase,
respectively, while isolates Sua-BAC012, Sua-BAC017 and
Sua-BAC019 affiliated with Bacillus licheniformis,
produced less than 2 U/ml of xylanase, cellulase and
mannanase. Nesterenkonia sp. Sua-BAC020
grew at 0 – 20% NaCl with an optimum at 2.5% NaCl, and at pH
7 – 9.5 with an optimum at pH 9. This isolate produced 3.5
U/ml xylanase when cultivated at pH 8 in 10% NaCl. Five
xylanase activity bands were detected on Native-PAGE coupled
with zymogram.
Key words:
Halomonas, xylanase, halophiles, alkaliphiles,
xylanase multiplicity. |
