Show simple item record

dc.contributor.authorŠustr, Vladimír
dc.contributor.authorStingl, Ulrich
dc.contributor.authorBrune, Andreas
dc.date.accessioned2015-08-03T12:05:53Z
dc.date.available2015-08-03T12:05:53Z
dc.date.issued2014-08
dc.identifier.issn00221910
dc.identifier.doi10.1016/j.jinsphys.2014.06.007
dc.identifier.urihttp://hdl.handle.net/10754/563675
dc.description.abstractThe saprophagous larvae of bibionid flies harbor bacteria in their alkaline intestinal tracts, but little is known about the contribution of the gut microbiota to the digestion of their recalcitrant diet. In this study, we measured oxygen and hydrogen partial pressure, redox potential and pH in the midgut, gastric caeca and hindgut of larvae of the bibionid fly Penthetria holosericea with Clark-type O2 and H2 microsensors, platinum redox microelectrodes, and LIX-type pH microelectrodes. The center of the midgut lumen was anoxic, whereas gastric caeca and hindgut were hypoxic. However, redox potential profiles indicated oxidizing conditions throughout the gut, with lowest values in the midgut (+20 to +60mV). Hydrogen production was not detected. The midgut was extremely alkaline (pH around 11), whereas hindgut and gastric caeca were neutral to slightly alkaline. While HPLC analysis showed high concentrations of glucose in the midgut (15mM) and gastric caeca (27mM), the concentrations of microbial fermentation products such as lactate (2-4mM), acetate (<1mM) and succinate (<0.5mM) were low in all gut regions, suggesting that the contribution of microorganisms to the digestive process, particularly in the alkaline midgut, is only of minor importance. We conclude that the digestive strategy of the saprophytic larva of P. holosericea, which feeds selectively on decomposed leaves and its own microbe-rich faeces, differs fundamentally from those of detritivorous and humivorous insects, which host a highly active, fermentative microbiota in their alkaline midgut or hindgut compartments. © 2014 Elsevier Ltd.
dc.publisherElsevier BV
dc.subjectDipteran larvae
dc.subjectGut pH
dc.subjectHydrogen partial pressure
dc.subjectOxygen partial pressure
dc.subjectRedox potential
dc.titleMicroprofiles of oxygen, redox potential, and pH, and microbial fermentation products in the highly alkaline gut of the saprophagous larva of Penthetria holosericea (Diptera: Bibionidae)
dc.typeArticle
dc.contributor.departmentRed Sea Research Center (RSRC)
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Division
dc.contributor.departmentMarine Science Program
dc.contributor.departmentMarine Microbial Ecology Research Group
dc.identifier.journalJournal of Insect Physiology
dc.contributor.institutionInstitute of Soil Biology, Biology Centre, Academy of Sciences of the Czech Republic, Na Sádkách 7, 37005 České Budějovice, Czech Republic
dc.contributor.institutionMikrobielle Ökologie, Fachbereich Biologie, Universität Konstanz, 78434 Konstanz, Germany
dc.contributor.institutionDepartment of Biogeochemistry, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, 35043 Marburg, Germany
kaust.personStingl, Ulrich


This item appears in the following Collection(s)

Show simple item record