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Changes in fat and moisture contents, and nitrogen fixation in laboratory maintained termites
1984 - IRG/WP 1242
Orphaned groups of termites of Coptotermes acinaciformis and Mastotermes darwiniensis were maintained in the laboratory for several months on two dietary regimes, and changes in their fat contents, moisture contents and nitrogen fixation rates were examined. There were no significant feed or feed time effects for either species. For Coptotermes acinaciformis, there was a highly significant time effect for fat and moisture contents, but this was not the case for Mastotermes darwiniensis. Nitrogen fixation decreased markedly with time for both termite species, irrespective of diets. The time effect for nitrogen fixation for Coptotermes acinaciformis was almost significant, whereas it was significant for Mastotermes darwiniensis. In viewing termite vitality, the importance of conducting concurrent field and laboratory experiments is discussed.
J R J French, P J Robinson, L G Turner, P J Pahl
Effect of nutrient regimes, temperature, pH, and wood sterilization method on performance of selected bioprotectants against wood staining fungi
1992 - IRG/WP 92-1551
The effect of nutrient regimes, incubation temperature, media pH, and wood sterilization method on performance of four potential bioprotectants (Pseudomonas putida, Pseudomonas cepacia, Bacillus subtilis, and Trichoderma harzianum) against wood staining fungi were evaluated using small ponderosa pine samples over a four week period. Incubation at 32°C resulted in slight increases in the degree of fungal stain, but the results were not consistent across treatment groups or bioprotectant species. Bioprotectant performance was altered through the use of different media, but, once again, the results were not consistent across all treatments for a given media. The pH of the media had a substantial effect on bioprotectant performance, with acidic conditions producing the poorest performance of bacterial bioprotectants and alkaline conditions reducing the protective effects of Trichoderma harzianum. The method of wood sterilization produced alterations in both the degree of staining and the composition of the microbial flora of the wood. Unsterile samples were stained to a greater degree than either autoclaved or irradiated specimens and the degree of bioprotection was generally lower. Delays in the interval between bioprotectant application and inoculation with wood staining fungi generally reduced the effectiveness of the bioprotectant, suggesting that bioprotection declined with incubation period. The results illustrate the complexity of developing bioprotectants which can effectively compete under the array of conditions common to freshly sawn lumber and suggest that considerable additional research will be necessary to more fully understand the conditions which assure successful protection.
J J Morrell, C M Secton
Effects of geographical and dietary variation on the symbiotic flagellate protists communities of the subterranean termite Reticulitermes grassei Clément
2015 - IRG/WP 15-10847
Despite their importance on diverse ecosystems, termites may also be considered severe pests of wood in service, and also as agricultural and forestry pests. Subterranean termites’ ability to digest lignocellulose relies not only on their digestive tract physiology, but also on the symbiotic relationships established with flagellate protists and bacteria. In this tripartite lignocellulolytic system, the termite contribute with endogenous cellulases and mechanical processing, flagellate protists phagocyte the wood particles and digest them, and prokaryotes have, among others, an important role in maintaining the physical-chemical equilibrium inside the termite hindgut. The flagellate protist community living inside the termites is rather diverse, as there is a strong division of labour among them to accomplish the intricate process of lignocellulose digestion. The objectives of this work were to: 1) investigate the changes in flagellate protists communities of the termite Reticulitermes grassei in different locations; 2) test the possible effect of different laboratorial diets on diversity and abundance of the flagellate protists. R. grassei termites were captured in four different locations (Évora, Faial Island, Leiria and Sesimbra), in Portugal, and their symbiotic flagellate protist community diversity and abundance was evaluated. Termites belonging to the same colony were submitted to six different diets (natural diet, pine wood, European beech, thermally modified beech, cellulose and starvation) and after the trials their flagellate protist community was also evaluated. The differences between termite colonies from different locations may not be denied, although not considered to be significant. Similar flagellate protists communities were found on non-treated sound woods, while cellulose fed and starving termites had significantly different communities. The flagellate protists community of untreated beech and thermally modified beech fed termites were considered to be significantly different, with three morphotypes missing in the treated wood fed termites. Although the effects of geographical location were not considered significant, the laboratory diets caused major adaptations of the flagellate protists communities. The termite symbiotic flagellate protists community is a dynamic assemblage able to adapt to different conditions and diets.
S Duarte, M Duarte, P A V Borges, L Nunes