Digestome of the termite, coptotermes curvignathus holmgren as a source of novel lignocellulases
Researchers have made extensive efforts to determine the lignocellulose degrading potential genes in herbivorous insect, which might assist in reducing the cost of biofuel production via treatment of lignocelluloses. This project was carried out using Coptotermes curvignathus, a subterranean term...
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Published: |
2016
|
| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/78373/1/FSPM%202016%2011%20-%20ir.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Researchers have made extensive efforts to determine the lignocellulose
degrading potential genes in herbivorous insect, which might assist in reducing
the cost of biofuel production via treatment of lignocelluloses. This project was
carried out using Coptotermes curvignathus, a subterranean termite that has an
important impact economically on both agricultural lands and plantations by
causing deaths of crop plants, whether in sapling or mature form. Hence, the
ability of C. curvignathus to feed on living trees and overcome the barriers and
defenses of plants is intriguing. The objectives of this study are to discover the
Carbohydrate-Active enzymes (CAZyme) related genes in C. curvignathus,
illustrate a potential pathway for lignocelluloses degradation in the digestive
system, and discover the genes involved in the defensive system. To achieve
these objectives, a transcriptomic gene library was constructed using digestive
tracts from 200 insects, from which mRNA was isolated to generate a cDNA
library. The cDNA library was sequenced in Next Generation Sequencing via
Illumina HiSeq 2000. Raw data were trimmed and assembled by SolexaQA and
Bowtie before loading into Gene Ontology based data mining software,
Blast2GO (B2G). Assembled transcriptome were loaded into CAZyme analysis
toolkits to identify CAZyme genes present in the data. Data were also analysed
based on insect innate immunity database (IIID). The result from the study
showed the presence of expressed gene encoding lignocellulose of CAZyme
residing in C. curvignathus that fed in different habitat, with about 68% of the
common CAZyme families encoded transcripts from mineral habitat which
were expressed to be higher than peat habitat. As compared to Reticuliformis
flavipes and Coptotermes formosanus, ten CAZyme families (GH16, GH22, GH23,
GH32, GH73, GT90, CE15, CBM3, CBM5 and CBM50) were found only in C. curvignathus. In addition, in this study, expression profile for Auxiliary Activity
(AA) of a new family of CAZyme is presented to show that lignin degradation
is significant in C. curvignathus lignocellulosic digestion. The lignocellulose
degrading pathway was illustrated in this study to show the complex
mechanism on how C. curvignathus digest lignocellulose material. Lastly, this
study has discovered several important expressed genes, such as GH22 and
GH23 that are related to host immune system and detoxification. In conclusion,
this project is hoped to adapt the usage of C. curvignathus CAZyme ability in
industrial lignocellulose degradation and also improve the agricultural sector in
the control of C. curvignathus through the finding of defence related
transcriptome such as GH22 and GH23. It is also recommended to study each of
the ten unique gene found in this study in detail via protein expression, which
will determine the actual function in C. curvignathus. |
|---|