scholarly journals Roles of Verrucomicrobia in lower termite hindgut

2016 ◽  
Vol 15 (2) ◽  
pp. 103-119
Author(s):  
Jantiya Isanapong
Keyword(s):  
Lower Termite ◽  
Termite Hindgut

scholarly journals Characterization of efficient xylanases from industrial-scale pulp and paper wastewater treatment microbiota

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jia Wang ◽  
Jiawei Liang ◽  
Yonghong Li ◽  
Lingmin Tian ◽  
Yongjun Wei
Keyword(s):  
Wastewater Treatment ◽  
Xylanase Activity ◽  
Pulp And Paper ◽  
Optimal Conditions ◽  
Paper Wastewater ◽  
Termite Hindgut ◽  
Uncultured Microorganisms ◽  
Metagenomic Approach ◽  
Gh10 Family

AbstractXylanases are widely used enzymes in the food, textile, and paper industries. Most efficient xylanases have been identified from lignocellulose-degrading microbiota, such as the microbiota of the cow rumen and the termite hindgut. Xylanase genes from efficient pulp and paper wastewater treatment (PPWT) microbiota have been previously recovered by metagenomics, assigning most of the xylanase genes to the GH10 family. In this study, a total of 40 GH10 family xylanase genes derived from a certain PPWT microbiota were cloned and expressed in Escherichia coli BL21 (DE3). Among these xylanase genes, 14 showed xylanase activity on beechwood substrate. Two of these, PW-xyl9 and PW-xyl37, showed high activities, and were purified to evaluate their xylanase properties. Values of optimal pH and temperature for PW-xyl9 were pH 7 and 60 ℃, respectively, while those for PW-xyl37 were pH 7 and 55 ℃, respectively; their specific xylanase activities under optimal conditions were 470.1 U/mg protein and 113.7 U/mg protein, respectively. Furthermore, the Km values of PW-xyl9 and PW-xyl37 were determined as 8.02 and 18.8 g/L, respectively. The characterization of these two xylanases paves the way for potential application in future pulp and paper production and other industries, indicating that PPWT microbiota has been an undiscovered reservoir of efficient lignocellulase genes. This study demonstrates that a metagenomic approach has the potential to screen efficient xylanases of uncultured microorganisms from lignocellulose-degrading microbiota. In a similar way, other efficient lignocellulase genes might be identified from PPWT treatment microbiota in the future.

scholarly journals Rapid Acyl-Homoserine Lactone Quorum Signal Biodegradation in Diverse Soils

2005 ◽  
Vol 71 (3) ◽  
pp. 1291-1299 ◽  
Author(s):  
Ya-Juan Wang ◽  
Jared Renton Leadbetter
Keyword(s):  
Homoserine Lactone ◽  
Most Probable Number ◽  
Acyl Homoserine Lactone ◽  
Protein Synthesis Inhibitors ◽  
Probable Number ◽  
Signal Decay ◽  
Soil Activity ◽  
Final Extent ◽  
Termite Hindgut ◽  
Quorum Sensing Signals

ABSTRACT Signal degradation impacts all communications. Although acyl-homoserine lactone (acyl-HSL) quorum-sensing signals are known to be degraded by defined laboratory cultures, little is known about their stability in nature. Here, we show that acyl-HSLs are biodegraded in soils sampled from diverse U.S. sites and by termite hindgut contents. When amended to samples at physiologically relevant concentrations, 14C-labeled acyl-HSLs were mineralized to 14CO2 rapidly and, at most sites examined, without lag. A lag-free turf soil activity was characterized in further detail. Heating or irradiation of the soil prior to the addition of radiolabel abolished mineralization, whereas protein synthesis inhibitors did not. Mineralization exhibited an apparent Km of 1.5 μM acyl-HSL, ca. 1,000-fold lower than that reported for a purified acyl-HSL lactonase. Under optimal conditions, acyl-HSL degradation proceeded at a rate of 13.4 nmol · h−1 · g of fresh weight soil−1. Bioassays established that the final extent of signal inactivation was greater than for its full conversion to CO2 but that the two processes were well coupled kinetically. A most probable number of 4.6 × 105 cells · g of turf soil−1 degraded physiologically relevant amounts of hexanoyl-[1-14C]HSL to 14CO2. It would take chemical lactonolysis months to match the level of signal decay achieved in days by the observed biological activity. Rapid decay might serve either to quiet signal cross talk that might otherwise occur between spatially separated microbial aggregates or as a full system reset. Depending on the context, biological signal decay might either promote or complicate cellular communications and the accuracy of population density-based controls on gene expression in species-rich ecosystems.

scholarly journals Supercooling Differences in the Eastern Subterranean Termite (Isoptera: Rhinotermitidae)

2004 ◽  
Vol 39 (4) ◽  
pp. 525-536 ◽  
Author(s):  
Brian J. Cabrera ◽  
Shripat T. Kamble
Keyword(s):  
Atmospheric Pressure ◽  
Reticulitermes Flavipes ◽  
Biochemical Properties ◽  
Subterranean Termite ◽  
Control Groups ◽  
Supercooling Point ◽  
Ice Nucleators ◽  
Laboratory Workers ◽  
Eastern Subterranean Termite ◽  
Termite Hindgut

Supercooling points were determined for untreated field-collected and untreated laboratory-maintained Reticulitermes flavipes (Kollar) workers and soldiers. Workers treated with antibiotics or had their hindgut-protozoa removed by exposing them to oxygen under pressure to determine the effects of absence of the hindgut fauna on supercooling. Supercooling points were compared between live and freshly-killed workers to determine whether supercooling in this species might be simply due to the biochemical properties of body fluids. Laboratory-maintained workers were also subjected to desiccation, starvation, or atmospheric pressure to determine their effects on supercooling. Supercooling points were lowest for laboratory workers treated with antibiotics and those that fed on brown paper-toweling for 7 d. Untreated field-collected workers had significantly higher supercooling points than untreated laboratory-maintained workers (−6.06 ± 0.79°C vs −9.29 ± 2.38°C, P < 0.0001). Both untreated field-collected and laboratory soldiers had significantly lower supercooling points than their respective workers (−7.39 ± 2.01°C vs −6.06 ± 0.79°C, P < 0.0001; and −11.60 ± 2.53°C vs −9.29 ± 2.38°C, P< 0.0001, respectively). There was no significant association between termite body mass and supercooling points for both laboratory and field termites (P= 0.0523 and P = 0.6242) or water content of laboratory termites and supercooling points (P = 0.1425). Defaunated workers had significantly lower supercooling points (−10.34 ± 2.38°C) than normally faunated workers (−9.48 ± 1.85°C)(P= 0.0095) suggesting that the symbiotic fauna may have higher supercooling points and act as ice nucleators in the termite hindgut. Starved and desiccated workers had significantly lower supercooling points (−10.38 ± 2.70°C and −10.39 ± 2.38°C, respectively) than their corresponding control groups (−9.87 ± 2.11°C and −9.89 ± 1.94°C; P = 0.0454; P = 0.0234, respectively) and untreated workers (−9.29 ± 2.38°C; P= 0.0021; P= 0.0011) suggesting that some forms of physical stress might lower the supercooling point.

scholarly journals Expanding the Knowledge on Lignocellulolytic and Redox Enzymes of Worker and Soldier Castes from the Lower Termite Coptotermes gestroi

2016 ◽  
Vol 7 ◽  
Author(s):  
João P. L. Franco Cairo ◽  
Marcelo F. Carazzolle ◽  
Flávia C. Leonardo ◽  
Luciana S. Mofatto ◽  
Lívia B. Brenelli ◽  
...  
Keyword(s):  
Redox Enzymes ◽  
Lower Termite ◽  
Coptotermes Gestroi

scholarly journals Physiology and Nutrition of Treponema primitia, an H2/ CO2-Acetogenic Spirochete from Termite Hindguts

2004 ◽  
Vol 70 (3) ◽  
pp. 1307-1314 ◽  
Author(s):  
Joseph R. Graber ◽  
John A. Breznak
Keyword(s):  
Nadh Oxidase ◽  
Natural Habitat ◽  
Biochemical Properties ◽  
Organic Substrates ◽  
Growth And Survival ◽  
Cell Extracts ◽  
Termite Hindgut ◽  
Physiological And Biochemical ◽  
Physiological And Biochemical Properties

ABSTRACT Treponema primitia strains ZAS-1 and ZAS-2, the first spirochetes to be isolated from termite hindguts (J. R. Leadbetter, T. M. Schmidt, J. R. Graber, and J. A. Breznak, Science 283:686-689, 1999), were examined for nutritional, physiological, and biochemical properties relevant to growth and survival in their natural habitat. In addition to using H2 plus CO2 as substrates, these strains were capable of homoacetogenic growth on mono- and disaccharides and (in the case of ZAS-2) methoxylated benzenoids. Cells were also capable of mixotrophic growth (i.e., simultaneous utilization of H2 and organic substrates). Cell extracts of T. primitia possessed enzyme activities of the Wood/Ljungdahl (acetyl coenzyme A) pathway of acetogenesis, including tetrahydrofolate-dependent enzymes of the methyl group-forming branch. However, a folate compound was required in the medium for growth. ZAS-1 and ZAS-2 growing on H2 plus CO2 displayed H2 thresholds of 650 and 490 ppmv, respectively. Anoxic cultures of ZAS-1 and ZAS-2 maintained growth after the addition of as much as 0.5% (vol/vol) O2 to the headspace atmosphere. Cell extracts exhibited NADH and NADPH peroxidase and NADH oxidase activities but neither catalase nor superoxide dismutase activity. Results indicate that (i) T. primitia is able to exploit a variety of substrates derived from the food of its termite hosts and in so doing contributes to termite nutrition via acetogenesis, (ii) in situ growth of T. primitia is likely dependent on secretion of a folate compound(s) by other members of the gut microbiota, and (iii) cells possess enzymatic adaptations to oxidative stress, which is likely to be encountered in peripheral regions of the termite hindgut.

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