Symbiont-independent digestion of cellulose and starch in Panesthia cribrata Saussure, an Australian wood-eating cockroach

Scrivener, A.M.; Slaytor, M.; Rose, H. A.

doi:10.1016/0022-1910(89)90016-4

Cited by 57 publications

(38 citation statements)

References 20 publications

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“…This promising approach has also been adopted for the study of enzymes of some terrestrial invertebrates. For example, using antibiotic treatments, Scrivener [179] demonstrated that cellulase activity of the cockroach Panesthia cribrata was symbiont-independent. However, the validity of such results will depend on the effectiveness of the antimicrobial agent in eliminating the gut microbes of the specific invertebrate being studied, and this must be confirmed in each case.…”

Section: The Presence and Nature Of Gut Microflora In Aquatic Invertementioning

confidence: 99%

The presence, nature, and role of gut microflora in aquatic invertebrates: A synthesis

1993

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This review of the literature concerns the gut microbiota of aquatic invertebrates and highlights the questions and processes that merit attention if an understanding of the role of gut microbes in the physiology of host invertebrates and nutrient dynamics of aquatic systems is to be gained. A substantial number of studies report the presence of gut microbes in aquatic invertebrates. Crustacea, Mollusca, and Echinodermata have received the most attention, with few studies involving other invertebrate groups. Different types of associations (e.g., ingestion, contribution of exoenzymes, incubation, parasitism) are reported to occur between gut microbes and aquatic invertebrates, and it is clear that gut bacterial communities cannot be treated as single functional entities, but that individual populations require examination. In addition, gut microbes may be either ingested transients or residents, the presence of which have different implications for the invertebrate. The most commonly reported genera of gut bacteria are Vibrio, Pseudomonas, Flavobacterium, Micrococcus, and Aeromonas. Quite a number of authors report the physiological properties of gut microbes (including enzyme activities and attributes such as nitrogen fixation), while less attention has been given to consideration of the colonization sites within the digestive tract, the density and turnover of gut bacteria, and the factors affecting the presence and nature of gut microflora. In addition, although a few studies have demonstrated a positive relationship between invertebrates and their gut microbiota, particularly with regard to nutrient gain by the invertebrate, very little conclusive evidence exists as to the role of bacteria in the physiology of host invertebrates. This has resulted from a lack of process-oriented studies. The findings for aquatic gut microbes are compared to those of gut bacteria associated with terrestrial invertebrates, where gut microbes contribute significantly to nutrient gain by the host in some environments.

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Section: The Presence and Nature Of Gut Microflora In Aquatic Invertementioning

confidence: 99%

The presence, nature, and role of gut microflora in aquatic invertebrates: A synthesis

1993

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“…Distribution of amylases and several other glycosidases in the midgut was studied only for Panesthia cribrata (Blaberidae). Activity of all tested enzymes was predominant in AM (Scrivener et al, 1989).…”

Section: Introductionmentioning

confidence: 96%

Compartmentalization of proteinases and amylases in Nauphoeta cinerea midgut

Elpidina

Vinokurov

Gromenko

et al. 2001

Arch Insect Biochem Physiol

121

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Compartmentalization of proteinases, amylases, and pH in the midgut of Nauphoeta cinerea Oliv. (Blattoptera:Blaberidae) was studied in order to understand the organization of protein and starch digestion. Total proteolytic activity measured with azocasein was maximal at pH 11.5 both in anterior (AM) and posterior (PM) halves of the midgut, but the bulk of activity (67%) was found in PM. Total AM and PM preparations were fractionated on a Sephadex G-50 column and further analysed by means of activity electrophoresis and specific inhibitors and activators. The major activity in PM was classified as an unusual SH-dependent proteinase with M(r) 24,000 and pH optimum with synthetic substrate BApNA at 10.0. The enzyme was 43-fold activated in the presence of 1 mM DTT, insensitive to synthetic inhibitors of serine (PMSF, TLCK, TPCK) and cysteine (IAA, E-64) proteinases, strongly inhibited by STI, and displayed four active bands on zymograms. In PM, activities of trypsin-like, chymotrypsin-like, subtilisin-like, and cysteine proteinases were observed. Aspartic and metalloproteinases were not detected. In AM, activity of unusual SH-dependent proteinase also dominated and activity of chymotrypsin-like proteinase was observed, but their levels were much lower than in PM. Distribution of amylase activity, exhibiting an optimum at pH 6.0, was quite the opposite. The major part of it (67%) was located in AM. Treatment of amylase preparation with proteinases from AM and PM reduced amylase activity twofold. pH of the midgut contents was 6.0-7.2 in AM, 6.4-7.6 in the first and 8.8-9.3 in the second halves of PM. Thus, pH in AM is in good agreement with the optimal pH of amylase, located in this compartment, but the activity of proteinases, including the ability to degrade amylase, in such an environment is low. Active proteolysis takes place in the second half of PM, where pH of the gut is close to the optimal pH of proteinases.

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“…To date, no animal cellulase genes have been identified and endogenous cellulase production by animals seems exceptional. Indications for the existence of cellulase genes within the animal kingdom have been obtained by measuring cellulase activity in microbe-free digestive tracts of cockroaches, higher termites, grass carps, eri silkworms, and earthworms (7)(8)(9)(10)(11).…”

mentioning

confidence: 99%

Endogenous cellulases in animals: Isolation of β-1,4-endoglucanase genes from two species of plant-parasitic cyst nematodes

Smant

Stokkermans

Yan

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

437

356

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ABSTRACT␤-1,4-Endoglucanases (EGases, EC 3.2.1.4) degrade polysaccharides possessing ␤-1,4-glucan backbones such as cellulose and xyloglucan and have been found among extremely variegated taxonomic groups. Although many animal species depend on cellulose as their main energy source, most omnivores and herbivores are unable to produce EGases endogenously. So far, all previously identified EGase genes involved in the digestive system of animals originate from symbiotic microorganisms. Here we report on the synthesis of EGases in the esophageal glands of the cyst nematodes Globodera rostochiensis and Heterodera glycines. From each of the nematode species, two cDNAs were characterized and hydrophobic cluster analysis revealed that the four catalytic domains belong to family 5 of the glycosyl hydrolases (EC 3.2.1, 3.2.2, and 3.2.3). These domains show 37-44% overall amino acid identity with EGases from the bacteria Erwinia chrysanthemi, Clostridium acetobutylicum, and Bacillus subtilis. One EGase with a bacterial type of cellulose-binding domain was identified for each nematode species. The leucine-rich hydrophobic core of the signal peptide and the presence of a polyadenylated 3 end precluded the EGases from being of bacterial origin. Cyst nematodes are obligatory plant parasites and the identified EGases presumably facilitate the intracellular migration through plant roots by partial cell wall degradation.

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Symbiont-independent digestion of cellulose and starch in Panesthia cribrata Saussure, an Australian wood-eating cockroach

Cited by 57 publications

References 20 publications

The presence, nature, and role of gut microflora in aquatic invertebrates: A synthesis

The presence, nature, and role of gut microflora in aquatic invertebrates: A synthesis

Compartmentalization of proteinases and amylases in Nauphoeta cinerea midgut

Endogenous cellulases in animals: Isolation of β-1,4-endoglucanase genes from two species of plant-parasitic cyst nematodes

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