An efficient process for the transformation of betulin to betulinic acid by a strain of bacillus megaterium
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Date
2017
Authors
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Journal ISSN
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Publisher
3 Biotech
Abstract
Betulinic acid as a derivative of betulin is widely
reported for its anti-HIV and antitumor activities. Betulin
has three most significant positions, i.e., primary hydroxyl
group at position C-28, secondary hydroxyl group at
position C-3, and alkene moiety at position C-20, where
chemical modifications were performed to yield pharmacologically
more active derivatives. Bioconversion optimization
was performed for the enhancement in the
percentage of conversion using statistical approach by
opting temperature, pH and betulin concentration as independent
variables. Three hundred fifty isolates were
screened from natural sources under selective medium
containing up to 3 g/l of betulin for their tolerance and
bioconversion efficiency. Isolate KD235 was found to grow
in 3 g/l betulin with 23.34 ± 0.57 g/l biomass and
0.67 ± 0.06 g/l betulinic acid production. New isolate
KD235 was characterized by molecular analysis and
named as Bacillus megaterium KD235. Molecular characterization
of a potentially active isolate for the transformation
of betulin to betulinic acid was suggested as isolate
Bacillus megaterium KD235. Maximum bioconversion
(22 ± 1.5%) was found at optimized conditions, i.e., pH
6.5, temperature 30 C and at 3 g/l betulin. Validations of
experiments as*11% more bioconversion i.e., 1 ± 0.1 g/l
betulinic acid were obtained using 5 l lab fermenter as
compared to shake flask.
Description
Keywords
Bacillus megaterium Betulin Biotransformation Pharmacological properties HPLC Betulinic acid