Bioconversion of isoeugenol to vanillin with different straints of pseudomonas aeruginosa
The experiment was conducted at the Faculty of Industrial Sciences and Technology lab at Universiti Malaysia Pahang to investigate the bioconversion of isoeugenol to vanillin. Vanillin is a simple monoterpenoid which is considered as one of the world’s principal flavouring compound used extensive...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
2014
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| Subjects: | |
| Online Access: | http://umpir.ump.edu.my/id/eprint/9462/1/CD8283.pdf |
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| Summary: | The experiment was conducted at the Faculty of Industrial Sciences and Technology
lab at Universiti Malaysia Pahang to investigate the bioconversion of isoeugenol to vanillin.
Vanillin is a simple monoterpenoid which is considered as one of the world’s principal
flavouring compound used extensively in the food, beverage, perfumery, and
pharmaceutical industries. Vanillin can be produced using bioconversion of isoeugenol via
microorganism and it could be used to substitute synthetic vanillin with a natural vanillin
flavor at an affordable price. This study was conducted to screen the Pseudomonas
ruginosa strains for the bioconversion of isoeugenol to vanillin. Initially isoeugenol was
obtained from extraction of crude clove bud oil. Two different methods of extraction were
done to extract the crude clove bud oil which were microwave extraction and steam
distillation. Through microwave extraction of clove bud oil, eugenol can be extracted at
minimum time of 75 minutes with an optimum yield of 9.09% as compared to the steam
distillation technique where it took time to achieve higher yield of eugenol. Purified
ugenol (purity ≥99%) was obtained using 1.2 moles of sodium hydroxide with recycle
water. Ruthenium acetylacetonate was used as catalyst to produce isoeugenol by synthesis.
The conversion was almost 99% but the method is very expensive and cannot be further use
s a substrate in biotransformation process. API-20E test was selected as a biochemical test
to identify the characteristics of Pseudomonas aeruginosa strains P178, U641, S376, B932
nd ETT187. In fact, all Pseudomonas aeruginosa strains were also confirmed using 16S
rRNA gene sequencing and obtained that all the strains were Pseudomonas aeruginosa. In
this study, the subculture of different strains of Pseudomonas aeruginosa was used to
onvert isoeugenol to vanillin by oxidation. Vanillin formation was analyzed directly by
s chromatography mass spectrometry (GCMS). All the strains exhibited good potential as
whole-cell bio-catalysts for direct bioconversion of isoeugenol to vanillin. During
biotransformation screening by whole cell culture of P. aeruginosa strains, P. aeruginosa
ETT187 showing a good vanillin produced which is 2.312±0.006 g/l at only 1% (v/v)
isoeugenol added for 24 hours incubation at 200 rpm agitation. Furthermore, the effect of
nillin production versus time with 1% induction of isoeugenol was observed at 12, 24,
36, 48, 60, 72, 84, and 96 hours. P. aeruginosa P178 demonstrated consist the highest
oduction of vanillin which was 2.97g/l at 72 hours of incubation while the isoeugenol
creased over time. Meanwhile, P. aeruginosa ETT 187 presented the highest amount of
nillin produced in only 24 hours with 2.31 g/l. Furthermore, strains U641, S376 and
932 produced the highest amount of vanillin at maximum of 96 hours with 2.62 g/l, 3.56
g/l and 2.49 g/l respectively. The reaction also produced the following by-products, namely,
isovanillic acid and isovanillin, ethyl vanillate and also vanillyl methyl ketone. As a
onclusion, the P. aeruginosa strains which were P. aeruginosa P178, P. aeruginosa U641,
P. aeruginosa S376, P. aeruginosa B932 and P. aeruginosa ETT187 can be proposed to
pilot scale as bicatalytic to convert isoeugenol to vanillin at a reasonable price. |
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