Isolation, Identification and In-Vitro Fermentation Activity of Cellulolytic Bacteria from the Gut of Termites
Termites are known for their ability to digest high lignocellulolytic compounds, such as wood and fiber materials. Ruminants with the aid of their microorganisms are able to digest fiber materials, however the percentage of digestion is not so high. Therefore, the main objectives of this study we...
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| Format: | Thesis |
| Language: | English English |
| Published: |
2008
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/10696/1/FP_2008_29.pdf |
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| Summary: | Termites are known for their ability to digest high lignocellulolytic
compounds, such as wood and fiber materials. Ruminants with the aid of their
microorganisms are able to digest fiber materials, however the percentage of
digestion is not so high. Therefore, the main objectives of this study were to
isolate and identify cellulolytic bacteria from the termites gut and to
determine the ability of these bacteria to improve the digestibility of fibrous
feed materials by the rumen microflora using the in-vitro gas production
technique. In this study, cellulolytic bacteria isolated from the gut of termites
were used to mix with the rumen microflora on fiber material digestion.
Termites were obtained from decayed plant materials and nests from different
locations in the vicinity of Universiti Putra Malaysia (UPM). They were
identified as the lower termite Coptotermes curvignathus (Holmgren) and the
higher termite Macrotermes gilvus (Hagen). Cellulolytic bacteria from the gut
of the lower termite; Coptotermes curvignathus (Holmgren) was isolated. The isolates were cultured aerobically in a medium containing carboxymethylcellulose
(CMC) at temperature of 30°C. The five isolates obtained were
identified based on the Biolog reader chemical test, Bergy' s Manual and 1 6S
rRNA sequence homology. The species were identified as: Bacillus cereus
(isolate 1), Acinetobacter baumanni (isolate 5), Enterobacter aerogenes
(isolate 2), Enterobacter cloacae (isolate 3) and Chryseobacterium
kwangyangense (isolate 4). The Gene Bank NCBI/EMBL accession numbers
for the bacterial isolates are EU294508, EU332791, EU305608, EU305609,
and EU 169201 respectively. Acinetobacter baumanni isolate 5 is an aerobic
bacterium, while the other four species are facultative anaerobes. The first invitro
experiment by the gas production technique was conducted to examine
the digestion and volatile fatty acid production by the five bacterial species
grown in the rice straw medium. There were significant differences (P<0.05)
in dry matter loss (DM) of rice straw and acetic acid concentration among the
five bacterial species. A cinetobacter baumanni isolate 5 showed the highest
fermentation activity (7.76 mM). The second in-vitro experiment also by gas
production technique, which was conducted to determine the effect of adding
rumen fluid microflora on rice straw digestion. The bacterial cultures were
standardized to an OD of 0.5 (108 CFU/ml) before adding to the rumen fluid
micro flora. Rumen fluid was obtained from a fistulated cattle maintained on a
grass diet. The facultative bacteria tested were C. kwangyangense isolate 4, E.
cloacae isolate 3 and E. aerogenes isolate 2. Digestion of rice straw by rumen
fluid microflora was determined with or without adding individual cultures of
termites gut bacterial species. |
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