The pH of the guts of mites strongly affects their digestive processes. This study was carried out to determine the pH in the guts of 12 species of stored product and house dust mites. Eighteen pH indicators were chosen and offered to the mites in the feeding biotest. Based on the color changes of the indicators, the gut contents of acaridid mites were determined to be within a pH range of 4 to neutral. The gut contents showed a gradient in pH from the anterior to the posterior part. The anterior midgut (ventriculus and caeca) of most species had a pH ranging from 4.5 to 5, or slightly more alkaline for most of the species, while the middle midgut (intercolon/colon) had a pH of 5 to 6. Finally, the pH of the posterior midgut (postcolon) was between 5.5 and 7. Except for Dermatophagoides spp., no remarkable differences in the pH of the gut were observed among the tested species. Dermatophagoides spp. had a more acidic anterior midgut (a pH of 4 to 5) and colon (a pH of 5) with postcolon (a pH of below 6). The results characterizing in vivo conditions in the mite gut offer useful information to study the activity of mite digestive enzymes including their inhibitors and gut microflora.

Crop Research Institute Drnovska 507 Praha 6 Ruzyne CZ 16106 Czechia

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Akimov IA. The biological aspects of digestion of acaroid mites. Akademija Nauk Ukrainskoj RSR; 1985. (in Ukrainian)

Akimov IA, Barabanova VV. The digestive enzymes of acaroid mites. Dopov Akad Nauk Ukr RSR. 1976;6B:547–549.

Akimov IA, Barabanova VV. The influence of the feeding to the activity of the digestive enzymes of acaroid mites. Ekologia. 1978;2:27–31.

Barrow CS, Conrad JW. Assessing the reliability and credibility of industry science and scientists. Environmental Health Perspectives. 2006;114(2):153–155. PubMed PMC

Brdicka R, Dvorak J. Basic physical chemistry. Academia publishing; 1977. (in Czech)

Boudko DY, Moroz LL, Linser PJ, Trimarchi JR, Smith PJS, Harvey WR. In situ analysis of pH gradients in mosquito larvae using noninvasive, self-referencing, pH-sensitive microelectrodes. The Journal of Experimental Biology. 2001;204(4):691–699. PubMed

Brune A, Emerson D, Breznak JA. The termite gut microflora as an oxygen sink: Microelectrode determination of oxygen and pH gradients in guts of lower and higher termites. Applied and Environmental Microbiology. 1995;61(7):2481–2687. PubMed PMC

Carsky J. The preparation of buffers and isotonic solutions. In: Ferencik M, Skarka B, editors. Biochemicke a laboratorne metody. ALFA; 1981. pp. 39–86. (in Slovak)

Dvorak J, Koryta J. The equilibrium in electrolyte solutions. Elektrochemie. In; Academia publishing; 1983. pp. 89–92. (in Czech)

Dahl LK. A simple and sensitive histochemical method for calcium. Proceedings of the Society for Experimental Biology and Medicine. 1952;80(3):474–479. PubMed

Erban T, Hubert J. Digestive function of lysozyme in synanthropic acaridid mites enables utilization of bacteria as a food source. Experimental and Applied Acarology. 2008;44(3):199–212. PubMed

Espinoza-Fuentes FP, Terra WR. Physiological adaptations for digesting bacteria. Water fluxes and distribution of digestive enzymes in Musca domestica larval midgut. Insect Biochemistry. 1987;17(6):809–817.

Funke M, Buchler R, Mahobia V, Schneeberg A, Ramm M, Boland W. Rapid hydrolysis of quorum-sensing molecules in the gut of lepidopteran larvae. ChemBioChem. 2008;9(12):1953–1959. PubMed

Gross EM, Brune A, Walenciak O. Gut pH, redox conditions and oxygen levels in an aquatic caterpillar: Potential effects on the fate of ingested tannins. Journal of Insect Physiology. 2008;54(2):462–471. PubMed

Harrison JF. Insect acid-base physiology. Annual review of Entomology. 2001;46:221–250. PubMed

Holzbecher Z, Churacek J. Analyticka chemie. SNTL — Alfa: 1987. Usage of chemical reactions in analytical chemistry. pp. 50–145. (in Czech)

Hubert J, Doleckova-Maresova L, Hyblova J, Kudlikova I, Stejskal V, Mares M. In vitro and in vivo inhibition of alpha-amylases of stored-product mite Acarus siro. Experimental and Applied Acarology. 2005;35(4):281–291. PubMed

Hubert J, Hyblova J, Munzbergova Z, Pekar S, Krizkova-Kundlikova I, Doleckova-Maresova L, Stejskal V, Mares M. Combined effect of an antifeedant alphaamylase inhibitor and a predator Cheyletus malaccensis in controlling the stored-product mite Acarus siro. Physiological Entomology. 2007;32(1):41–49.

Hughes TE. The physiology of the alimentary canal of Tyrophagus farinae. Quarterly Journal of Microscopical Science. 1950;91(1):54–60. PubMed

Dixon N. Lesson plan Neil Dixon titrations. 2007. Available online: http://tre.ngfl.gov.uk/uploads/materials/24968/

Monteallegre F, Quinones C, Torres N, Goth K. Detection of serine proteases in extracts of the domestic mite Blomia tropicalis. Experimental and Applied Acarology. 2002;26(1–2):87–100. PubMed

Ortego F, Sanchez-Ramoz I, Ruiz M, Castanera P. Characterization of proteases from a stored product mite, Tyrophagus putrescentiae. Archives of Insect Biochemistry and Physiology. 2000;43(3):116–124. PubMed

Sabnis RW. Handbook of acid-base indicators. CRC Press; 2008.

Sanchez-Monge R, Garcia-Casado G, Barber D, Salcedo G. Interaction of allergens from house-dust mite and from cereal flours: Dermatophagoides pteronyssinus α-amylase (Der p 4) and wheat and rice α-amylase inhibitors. Allergy. 1996;51(3):176–180. PubMed

Sanchez-Ramoz I, Hernandez CA, Castanera P, Ortego F. Proteolytic activities in body and faecal extracts of the storage mite, Acarus farris. Medical and Veterinary Entomology. 2004;18(4):378–386. PubMed

Senese F. General Chemistry Online!: Acid-base indicators. 2000. Available online: http://antoine.frostburg.edu/chem/senese/101/acidbase/indicators.shtml.

Shevchenko AM, Kulichenko SA. System of indicators for acid-base titration in surfactant-stabilized emulsions. Journal of Analytical Chemistry. 2005;60(4):336–346.

Skibbe U, Christeller JT, Callaghan PT, Eccles CD, Laing WA. Visualization of pH gradients in the larval midgut of Spodoptera litura using P-31-NMR microscopy. Journal of Insect Physiology. 1996;42(8):777–790.

Sobotnik J, Alberti G, Weyda F, Hubert J. The ultrastructure of digestive tract of Acarus siro. Journal of Morphology. 2008;269(1):54–71. PubMed

Terrra WR, Ferreira C. Insect digestive enzymes: properties, compartmentalization and function. Comparative Biochemistry and Physiology. 1994;109B(1):1–62.

Terra WR, Regel R. pH buffering in Musca domestica midguts. Comparative Biochemistry and Physiology. 1995;112A:559–564.

Terra WR, Ferreira C, Baker J. Compatmentalization of digestion. In: Lehane MJ, Billingsley PF, editors. Biology of the Insect Midgut. Chapman and Hall; 1996. pp. 206–235.

Tovey ER, Chapman MD, Platts-Mills TA. Mite faeces are a major source of house dust allergens. Nature. 1981;289:592–593. PubMed

Tovey ER, Baldo BA. Localization of antigens and allergens in thin sections of the house dust mite, Dermatophagoides pteronyssinus (Acari: Pyroglyphidae). Journal of Medical Entomology. 1990;27(3):368–376. PubMed

Zimmer M, Brune A. Physiological properties of the gut lumen of terrestrial isopods (Isopoda : Oniscidea): Adaptive to digesting lignocellulose? Journal of Comparative Physiology B-Biochemical Systemic and Environmental Physiology. 2005;175(4):275–283. PubMed

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