Influence of lignin in Reticulitermes santonensis: symbiotic interations investigated through proteomics

in Symbiosis (2013)

The gut of lower termites is populated by numerous microbial species belonging to prokaryotes, fungi, yeasts and protists. These micro-organisms are organized in a complex symbiotic system, interacting ... [more ▼]

The gut of lower termites is populated by numerous microbial species belonging to prokaryotes, fungi, yeasts and protists. These micro-organisms are organized in a complex symbiotic system, interacting together and with the insect host. Their likely ability to degrade ligno-cellulosic compounds could lead to improvements in second generation biofuels production. Lignin elimination represents a critical point as this polymer significantly interferes with industrial process of cellulose. Although host produces its own lignin-degrading enzymes, some symbionts may participate in digestion of lignin and its degradation products in termite gut. Here, we compared gut proteomes from R. santonensis after rearing on artificial diets composed of cellulose with and without lignin. The effect of lignin in artificial diets on different parts of the digestive tract was compared through liquid chromatography associated with tandem mass spectrometry (LC-MS/MS) experiments. Enzymatic assays were performed to characterize activities present in R. santonensis digestive tract after feeding on artificial diets. Microscopic observations of microbial communities provided some information on population balances after feeding experiment. [less ▲]

Termites as a tool to improve lignocellulose biomass valorization : study of enzymatic complex in termites and its common symbionts by comprehensive metabolite profiling

Conference (2012, November 16)

Termites artificially-fed on unusual diet and resulting enzymatic switches

Poster (2012, August)

Wood-feeding termites as Reticulitermes santonensis generally feed on cellulose, hemicelluloses and lignin. However, these opportunistic insects are also able to degrade other carbohydrates, such as ... [more ▼]

Wood-feeding termites as Reticulitermes santonensis generally feed on cellulose, hemicelluloses and lignin. However, these opportunistic insects are also able to degrade other carbohydrates, such as starch. The production of putative endogenous α - amylase has been previously shown in R. flavipes, as the disappearance of the major symbiotic flagellates from the hindgut. Here, we compared enzymatic activities (CMCase, MCCase, xylanase, amylase, α- and β-glucosidase) between different fractions of the digestive tract of starch-, cellulose-, and wood-fed termites. Main compounds of the artificial diets, namely starch or MCC, resulted in differential enzymatic activity. Even the substitution of wood by artificial diets itself seemed to induce changes in enzymatic activities, regardless of the main substrate in the diet, as we observed strong midgut α-glucosidase activity only for artificially-fed termites. Preliminary assays to isolate and characterize enzymes were performed using proteomic methods. [less ▲]

GCxGC-TOFMS for Bioanalytical Applications

Scientific conference (2012, August)

Enhanced Characterization of the Smell of Death by Comprehensive Two-Dimensional Gas Chromatography-Time-of-Flight Mass Spectrometry (GCxGC-TOFMS)

in PLoS ONE (2012), 7(6), 39005

Soon after death, the decay process of mammalian soft tissues begins and leads to the release of cadaveric volatile compounds in the surrounding environment. The study of postmortem decomposition products ... [more ▼]

Soon after death, the decay process of mammalian soft tissues begins and leads to the release of cadaveric volatile compounds in the surrounding environment. The study of postmortem decomposition products is an emerging field of study in forensic science. However, a better knowledge of the smell of death and its volatile constituents may have many applications in forensic sciences. Domestic pigs are the most widely used human body analogues in forensic experiments, mainly due to ethical restrictions. Indeed, decomposition trials on human corpses are restricted in many countries worldwide. This article reports on the use of comprehensive two-dimensional gas chromatography coupled with time-offlight mass spectrometry (GCxGC-TOFMS) for thanatochemistry applications. A total of 832 VOCs released by a decaying pig carcass in terrestrial ecosystem, i.e. a forest biotope, were identified by GCxGC-TOFMS. These postmortem compounds belong to many kinds of chemical class, mainly oxygen compounds (alcohols, acids, ketones, aldehydes, esters), sulfur and nitrogen compounds, aromatic compounds such as phenolic molecules and hydrocarbons. The use of GCxGC-TOFMS in study of postmortem volatile compounds instead of conventional GC-MS was successful. [less ▲]

Termites as a tool to improve lignocellulose biomass valorization: study of enzymatical complex from termites and its common symbionts by comprehensive metabolite profiling.

Conference (2012, May)

Measurement of Trace Level Dechlorane Flame Retardants in Human Blood by GCXGC-NCI-HRTOFMS

Conference (2012, March)

Use of human dried-blood spots as a minimally invasive method to

Poster (2012, March)

Method for the measurement of dechlorane 602 in human serum

Poster (2012, February)

Comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry for the forensic study of cadaveric volatile organic compounds released in soil by buried decaying pig carcasses

in Journal of Chromatography. A (2012), 1255