An alkali-thermostable xylanase from Bacillus pumilus functionally expressed in Kluyveromyces lactis and evaluation of its deinking efficiency.
This work aimed at studying the recombinant expression of an alkali- and thermo-stable xylanase from Bacillus pumilus in Kluyveromyces lactis and its use in deinking of civic paper waste. Efficient expression with a 3-fold increase in the activity than the native organism was achieved. An inducer concentration of 2.5% and medium pH of 9.0 was the best for enzyme expression. Purified enzyme showed an optimum activity at temperatures 50 and 60°C and pH 9.0 and 10.0, respectively. At pH 12.0, enzyme retained 74% and 26% activity after 2 and 3h of incubation, respectively. After incubation at 50 and 60°C for 1h, the enzyme showed 100% retention of activity, and remained active for 4h at 60°C retaining 23% residual activity. Partially purified recombinant enzyme showed higher deinking efficiency (273%) of laser print waste paper than crude xylanase from Bacillus and commercial acidic enzyme. This xylanase with superior stability characteristics could be a suitable candidate in paper and pulp industries.
Biotechnology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum 695 019, India. Electronic address: layam31@gmail.com.
Leya
L
Thomas
Biotechnology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum 695 019, India.
Mrudula V
MV
Ushasree
Biotechnology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum 695 019, India.
Ashok
A
Pandey
D001407:Bacillus / Q000201:enzymology*; D043364:Endo-1,4-beta Xylanases / Q000378:metabolism*; D004795:Enzyme Stability / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D007281:Ink; D007716:Kluyveromyces / Q000187:drug effects / Q000378:metabolism*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D015203:Reproducibility of Results; D012972:Sodium Hydroxide / Q000494:pharmacology*; D013696:Temperature; D014170:Transformation, Genetic
D012972:Sodium Hydroxide; D043364:Endo-1,4-beta Xylanases
Alkali stability; Bacillus pumilus; Expression; Kluyveromyces lactis; Xylanase