scholarly journals Novel [NiFe]- and [FeFe]-Hydrogenase Gene Transcripts Indicative of Active Facultative Aerobes and Obligate Anaerobes in Earthworm Gut Contents

2011 ◽  
Vol 77 (17) ◽  
pp. 5842-5850 ◽  
Author(s):  
Oliver Schmidt ◽  
Pia K. Wüst ◽  
Susanne Hellmuth ◽  
Katharina Borst ◽  
Marcus A. Horn ◽  
...  
Keyword(s):  
Alimentary Canal ◽  
Redox Conditions ◽  
Gut Contents ◽  
Redox Potentials ◽  
Gut Content ◽  
Content Type ◽  
Hydrogenase Gene ◽  
Group 4 ◽  
Gene Transcripts ◽  
Earthworm Gut

ABSTRACTThe concomitant occurrence of molecular hydrogen (H2) and organic acids along the alimentary canal of the earthworm is indicative of ongoing fermentation during gut passage. Fermentative H2production is catalyzed by [FeFe]-hydrogenases and group 4 [NiFe]-hydrogenases in obligate anaerobes (e.g.,Clostridiales) and facultative aerobes (e.g.,Enterobacteriaceae), respectively, functional groups that might respond differently to contrasting redox conditions. Thus, the objectives of this study were to assess the redox potentials of the alimentary canal ofLumbricus terrestrisand analyze the hydrogenase transcript diversities of H2producers in glucose-supplemented gut content microcosms. Although redox potentials in the core of the alimentary canal were variable on an individual worm basis, average redox potentials were similar. The lowest redox potentials occurred in the foregut and midgut regions, averaging 40 and 110 mV, respectively. Correlation plots between hydrogenase amino acid sequences and 16S rRNA gene sequences indicated that closely related hydrogenases belonged to closely related taxa, whereas distantly related hydrogenases did not necessarily belong to distantly related taxa. Of 178 [FeFe]-hydrogenase gene transcripts, 177 clustered in 12Clostridiales-affiliated operational taxonomic units, the majority of which were indicative of heretofore unknown hydrogenases. Of 86 group 4 [NiFe]-hydrogenase gene transcripts, 79% and 21% were affiliated with organisms in theEnterobacteriaceaeandAeromonadaceae, respectively. The collective results (i) suggest that fermenters must cope with variable and moderately oxidative redox conditions along the alimentary canal, (ii) demonstrate that heretofore undetected hydrogenases are present in the earthworm gut, and (iii) corroborate previous findings implicatingClostridiaceaeandEnterobacteriaceaeas active fermentative taxa in earthworm gut content.

scholarly journals Differential Engagement of Fermentative Taxa in Gut Contents of the EarthwormLumbricus terrestris

2017 ◽  
Vol 84 (5) ◽  
Author(s):  
Anja B. Meier ◽  
Sindy Hunger ◽  
Harold L. Drake
Keyword(s):  
16S Rrna ◽  
Alimentary Canal ◽  
Alimentary Tract ◽  
Anaerobic Growth ◽  
Gut Contents ◽  
Content Type ◽  
Earthworm Gut ◽  
The Impact ◽  
Rrna Sequences ◽  
16S Rrna Sequences

ABSTRACTThe earthworm gut is an anoxic, saccharide-rich microzone in aerated soils. The apparent degradation of diverse saccharides in the alimentary canal of the model earthwormLumbricusterrestrisis concomitant with the production of diverse organic acids, indicating that fermentation is an ongoing process in the earthworm gut. However, little is known about how different gut-associated saccharides are fermented. The hypothesis of this investigation was that different gut-associated saccharides differentially stimulate fermentative microorganisms in gut contents ofL. terrestris. This hypothesis was addressed by (i) assessing the fermentation profiles of anoxic gut content microcosms that were supplemented with gut-associated saccharides and (ii) the concomitant phylogenic analysis of 16S rRNA sequences. Galactose, glucose, maltose, mannose, arabinose, fucose, rhamnose, and xylose stimulated the production of fermentation products, including H2, CO2, acetate, lactate, propionate, formate, succinate, and ethanol. Fermentation profiles were dependent on the supplemental saccharide (e.g., glucose yielded large amounts of H2and ethanol, whereas fucose did not, and maltose yielded large amounts of lactate, whereas mannose did not). Approximately 1,750,000 16S rRNA sequences were affiliated with 37 families, and phylogenic analyses indicated that a respective saccharide stimulated a subset of the diverse phylotypes. AnAeromonas-related phylotype displayed a high relative abundance in all treatments, whereas keyEnterobacteriaceae-affiliated phylotypes were stimulated by some but not all saccharides. Collectively, these results reinforce the likelihood that (i) different saccharides stimulate different fermentations in gut contents of the earthworm and (ii) facultative aerobes related toAeromonadaceaeandEnterobacteriaceaecan be important drivers of these fermentations.IMPORTANCEThe feeding habits of earthworms influence the turnover of elements in the terrestrial biosphere. The alimentary tract of the earthworm constitutes an anoxic saccharide-rich microzone in aerated soils that offers ingested microbes a unique opportunity for anaerobic growth. The fermentative activity of microbes in the alimentary tract are responsible for thein situproduction of (i) organic compounds that can be assimilated by the earthworm and (ii) H2that is subject toin vivoemission by the earthworm and can be trophically linked to secondary microbial events in soils. To gain insight on how fermentative members of the gut microbiome might respond to the saccharide-rich alimentary canal, this study examines the impact of diverse gut-associated saccharides on the differential activation of fermentative microbes in gut contents of the model earthwormL. terrestris.

scholarly journals N2O-Producing Microorganisms in the Gut of the Earthworm Aporrectodea caliginosa Are Indicative of Ingested Soil Bacteria

2003 ◽  
Vol 69 (3) ◽  
pp. 1655-1661 ◽  
Author(s):  
Julian Ihssen ◽  
Marcus A. Horn ◽  
Carola Matthies ◽  
Anita Gößner ◽  
Andreas Schramm ◽  
...  
Keyword(s):  
Gene Sequence ◽  
Sequence Similarity ◽  
Garden Soil ◽  
Gut Contents ◽  
Rrna Gene ◽  
Aporrectodea Caliginosa ◽  
Gut Content ◽  
Terminal Electron Acceptor ◽  
Gram Positive Bacteria ◽  
Earthworm Gut

ABSTRACT The main objectives of this study were (i) to determine if gut wall-associated microorganisms are responsible for the capacity of earthworms to emit nitrous oxide (N2O) and (ii) to characterize the N2O-producing bacteria of the earthworm gut. The production of N2O in the gut of garden soil earthworms (Aporrectodea caliginosa) was mostly associated with the gut contents rather than the gut wall. Under anoxic conditions, nitrite and N2O were transient products when supplemental nitrate was reduced to N2 by gut content homogenates. In contrast, nitrite and N2O were essentially not produced by nitrate-supplemented soil homogenates. The most probable numbers of fermentative anaerobes and microbes that used nitrate as a terminal electron acceptor were approximately 2 orders of magnitude higher in the earthworm gut than in the soil from which the earthworms originated. The fermentative anaerobes in the gut and soil displayed similar physiological functionalities. A total of 136 N2O-producing isolates that reduced either nitrate or nitrite were obtained from high serial dilutions of gut homogenates. Of the 25 representative N2O-producing isolates that were chosen for characterization, 22 isolates exhibited >99% 16S rRNA gene sequence similarity with their closest cultured relatives, which in most cases was a soil bacterium, most isolates were affiliated with the gamma subclass of the class Proteobacteria or with the gram-positive bacteria with low DNA G+C contents, and 5 isolates were denitrifiers and reduced nitrate to N2O or N2. The initial N2O production rates of denitrifiers were 1 to 2 orders of magnitude greater than those of the nondenitrifying isolates. However, most nondenitrifying nitrate dissimilators produced nitrite and might therefore indirectly stimulate the production of N2O via nitrite-utilizing denitrifiers in the gut. The results of this study suggest that most of the N2O emitted by earthworms is due to the activation of ingested denitrifiers and other nitrate-dissimilating bacteria in the gut lumen.

scholarly journals Protein- and RNA-Enhanced Fermentation by Gut Microbiota of the EarthwormLumbricus terrestris

2018 ◽  
Vol 84 (11) ◽  
Author(s):  
Lydia Zeibich ◽  
Oliver Schmidt ◽  
Harold L. Drake
Keyword(s):  
Fatty Acids ◽  
Plant Growth ◽  
Soil Fertility ◽  
Microbial Cell ◽  
Gut Contents ◽  
Gut Content ◽  
Content Type ◽  
Cell Lysate ◽  
Gut Passage ◽  
Product Profile

ABSTRACTEarthworms are a dominant macrofauna in soil ecosystems and have determinative effects on soil fertility and plant growth. These invertebrates feed on ingested material, and gizzard-linked disruption of ingested fungal and bacterial cells is conceived to provide diverse biopolymers in the anoxic alimentary canals of earthworms. Fermentation in the gut is likely important to the utilization of ingested biopolymer-derived compounds by the earthworm. This study therefore examined the fermentative responses of gut content-associated microbes of the model earthwormLumbricus terrestristo (i) microbial cell lysate (to simulate gizzard-disrupted cells) and (ii) dominant biopolymers of such biomass, protein, and RNA. The microbial cell lysate augmented the production of H2, CO2, and diverse fatty acids (e.g., formate, acetate, propionate, succinate, and butyrate) in anoxic gut content microcosms, indicating that the cell lysate triggered diverse fermentations. Protein and RNA also augmented diverse fermentations in anoxic microcosms of gut contents, each yielding a distinct product profile (e.g., RNA yielded H2and succinate, whereas protein did not). The combined product profile of protein and RNA treatments was similar to that of cell lysate treatments, and 16S rRNA-based analyses indicated that many taxa that responded to cell lysate were similar to taxa that responded to protein or RNA. In particular, protein stimulatedPeptostreptococcaceae,Clostridiaceae, andFusobacteriaceae, whereas RNA stimulatedAeromonadaceae. These findings demonstrate the capacity of gut-associated obligate anaerobes and facultative aerobes to catalyze biopolymer-driven fermentations and highlight the potential importance of protein and RNA as substrates linked to the overall turnover dynamics of organic carbon in the alimentary canal of the earthworm.IMPORTANCEThe subsurface lifestyle of earthworms makes them an unnoticed component of the terrestrial biosphere. However, the propensity of these invertebrates to consume their home, i.e., soil and litter, has long-term impacts on soil fertility, plant growth, and the cycling of elements. The alimentary canals of earthworms can contain up to 500 ml anoxic gut content per square meter of soil, and ingested soil may contain 109or more microbial cells per gram dry weight, considerations that illustrate that enormous numbers of soil microbes are subject to anoxia during gut passage. Feeding introduces diverse sources of biopolymers to the gut, and the gut fermentation of biopolymers could be important to the transformation of matter by the earthworm and its capacity to utilize fermentation-derived fatty acids. Thus, this study examined the capacity of microbes in earthworm gut contents to ferment protein and RNA, dominant biopolymers of cells that become disrupted during gut passage.

scholarly journals Microbial Functional Gene Diversity with a Shift of Subsurface Redox Conditions duringIn SituUranium Reduction

2012 ◽  
Vol 78 (8) ◽  
pp. 2966-2972 ◽  
Author(s):  
Yuting Liang ◽  
Joy D. Van Nostrand ◽  
Lucie A. N′Guessan ◽  
Aaron D. Peacock ◽  
Ye Deng ◽  
...  
Keyword(s):  
Functional Diversity ◽  
Field Experiments ◽  
Gene Diversity ◽  
Functional Gene ◽  
Redox Conditions ◽  
Functional Genes ◽  
Microbial Functional Diversity ◽  
Content Type ◽  
Microbial Functional Gene

ABSTRACTTo better understand the microbial functional diversity changes with subsurface redox conditions duringin situuranium bioremediation, key functional genes were studied with GeoChip, a comprehensive functional gene microarray, in field experiments at a uranium mill tailings remedial action (UMTRA) site (Rifle, CO). The results indicated that functional microbial communities altered with a shift in the dominant metabolic process, as documented by hierarchical cluster and ordination analyses of all detected functional genes. The abundance ofdsrABgenes (dissimilatory sulfite reductase genes) and methane generation-relatedmcrgenes (methyl coenzyme M reductase coding genes) increased when redox conditions shifted from Fe-reducing to sulfate-reducing conditions. The cytochrome genes detected were primarily fromGeobactersp. and decreased with lower subsurface redox conditions. Statistical analysis of environmental parameters and functional genes indicated that acetate, U(VI), and redox potential (Eh) were the most significant geochemical variables linked to microbial functional gene structures, and changes in microbial functional diversity were strongly related to the dominant terminal electron-accepting process following acetate addition. The study indicates that the microbial functional genes clearly reflect thein situredox conditions and the dominant microbial processes, which in turn influence uranium bioreduction. Microbial functional genes thus could be very useful for tracking microbial community structure and dynamics during bioremediation.

scholarly journals Isolation and characterization of bacteria residing in the oral, gut, and fecal samples of different pheasant species

2023 ◽  
Vol 83 ◽  
Author(s):  
M. Mushtaq ◽  
S. M. Bukhari ◽  
S. Ahmad ◽  
A. Khattak ◽  
M. B. Chattha ◽  
...  
Keyword(s):  
Bacterial Species ◽  
Gut Contents ◽  
Phasianus Colchicus ◽  
Gut Content ◽  
E Coli ◽  
Colony Forming Unit ◽  
Isolation And Characterization ◽  
Staphylococcus Spp ◽  
Campylobacter Spp

Abstract There is a paucity of research conducted on microbial prevalence in pheasants. The microbiota of captive birds has zoonotic significance and must be characterize. Present study is therefore planned to assess the microbiota from oral, fecal and gut content of captive avian species. It will be helpful in characterization of harmful microbes. Different samples taken from oral, gut and feces of ring-necked pheasants (Phasianus colchicus), green pheasants (Phasianus versicolor), golden pheasant (Chrysolophus pictus) and silver pheasant (Lophura nycthemera). Samples were collected, diluted, and inoculated onto different agar plates (MacConkey, SS agar, MSA and nutrient agar) for cultivation of bacterial species. Colonies of E.coli, Staphylococcus spp. Brachyspira spp. and Campylobacter spp were observed based on colony morphology. Colony forming unit showed E. coli as frequently found bacteria in fecal, oral and gut contents of all the above pheasants. The overall significance difference was found among bacterial species of golden pheasants, green pheasant, ring-necked pheasant, and silver pheasants. It was concluded that E.coli is predominant isolated from heathy pheasants followed by Campylobacter, Staphylococcus and Brachyspira.

Transport of Food Through the Alimentary Camals of Aquatic Annelids

1948 ◽  
Vol s3-89 (5) ◽  
pp. 47-51
Author(s):  
JEAN HANSON
Keyword(s):  
Alimentary Canal ◽  
Anterior Part ◽  
Gut Contents ◽  
Ciliated Epithelium ◽  
Gut Epithelium ◽  
The University ◽  
Anterior Direction ◽  
Metachronal Waves ◽  
Muscle Coat ◽  
Made In

1. In most serpulids and sabellids the only muscle coat in the wall of the alimentary canal lies outside the blood sinus which envelops it. In a few sabellids there is another muscle coat, of unknown function, between the sinus and the gut epithelium. 2. The muscles outside the sinus contract antiperistaltically and tend to hinder the transport of the gut contents towards the anus. 3. The contents of the alimentary canal are transported by its cilia which beat towards the anus. The metachronal waves of the ciliated epithelium travel in a postero-anterior direction. The ‘ascending ciliary current’ of Stephenson (1913) does not exist. 4. The food boli of serpulids and sabellids rotate as they move down the gut. In Salmacina incrustans the rotation is imparted by cilia in the anterior part of the gut. These observations were made in the Zoological Station of Naples. I wish to record my gratitude to the staff of the Station, to the British Association for the Advancement of Science for the use of its Table, and to the University of London for a grant towards travelling expenses.

Assessment of Redox Conditions in the Near Field of Nuclear Waste Repositories: Application to the Swiss high-level and intermediate level waste disposal concept

2003 ◽  
Vol 807 ◽  
Author(s):  
Paul Wersin ◽  
Lawrence H. Johnson ◽  
Bernhard Schwyn
Keyword(s):  
Solid Phase ◽  
Near Field ◽  
Intermediate Level ◽  
Redox Conditions ◽  
High Level Waste ◽  
Redox Potentials ◽  
Spent Fuel ◽  
Reducing Conditions ◽  
High Level ◽  
Waste Repositories

ABSTRACTRedox conditions were assessed for a spent fuel and high-level waste (SF/HLW) and an intermediate-level waste (ILW) repository. For both cases our analysis indicates permanently reducing conditions after a relatively short oxic period. The canister-bentonite near field in the HLW case displays a high redox buffering capacity because of expected high activity of dissolved and surface-bound Fe(II). This is contrary to the cementitious near field in the ILW case where concentrations of dissolved reduced species are low and redox reactions occur primarily via solid phase transformation processes.For the bentonite-canister near field, redox potentials of about -100 to -300 mV (SHE) are estimated, which is supported by recent kinetic data on U, Tc and Se interaction with reduced iron systems. For the cementitious near field, redox potentials of about -200 to -800 mV are estimated, which reflects the large uncertainties related to this alkaline environment.

Experimental model of posttraumatic syringomyelia: the role of adhesive arachnoiditis in syrinx formation

1994 ◽  
Vol 80 (1) ◽  
pp. 133-139 ◽  
Author(s):  
Ki Hong Cho ◽  
Yoshinobu Iwasaki ◽  
Hiroyuki Imamura ◽  
Kazutoshi Hida ◽  
Hiroshi Abe
Keyword(s):  
Normal Saline ◽  
Subarachnoid Space ◽  
Saline Solution ◽  
Traumatic Injury ◽  
Content Type ◽  
Group 4 ◽  
Kaolin Injection ◽  
Group 3 ◽  
Group 2

✓ An experimental model was devised to elucidate the role of spinal blockade in posttraumatic syringomyelia. Thirty-eight Japanese White rabbits, each weighing about 3 kg, were used in this study. The animals were divided into four groups: in Group 1, eight animals received traumatic injury only; in Group 2, 12 animals received traumatic injury following injection of 100 mg kaolin suspended in 1 cc normal saline solution into the subarachnoid space at the site of trauma; in Group 3, nine animals received traumatic injury following injection of 200 mg kaolin in 1 cc normal saline solution into the subarachnoid space at the site of trauma; and in Group 4, nine animals without traumatic injury received an injection of 200 mg kaolin in 1 cc normal saline solution into the subarachnoid space. The subjective criteria for syrinx formation were the presence of a definite round cyst having a smooth margin and an upper or lower extension of more than 2 cm from the injured site. Syrinx formation was seen in 12.5% (one of eight rabbits) in Group 1, 41.7% (five of 12 animals) in Group 2, 55.5% (five of nine rabbits) in Group 3 and 0% (none of nine animals) in Group 4 (p < 0.05). There was a tendency for the combined trauma/kaolin injection groups to be more prone to develop a syrinx. In the kaolin injection only group (Group 4), no animal showed a definite cyst or an extending cavity during the experimental period. The results suggest that kaolin enhances the extension of multiple small cavities that have already formed at the time of initial injury. The difference between the frequency of syrinx formation and the time of survival was statistically significant well beyond the 0.05% level. The overall difference, relating to the frequency of syrinx development, group, and duration of survival, was also statistically significant. In summary, subarachnoid block secondary to adhesive arachnoiditis is important in initiating the extension of the syringomyelia cavity.

scholarly journals Catecholamine-Modulated Novel Surface-Exposed Adhesin LIC20035 ofLeptospiraspp. Binds Host Extracellular Matrix Components and Is Recognized by the Host during Infection

2017 ◽  
Vol 84 (6) ◽  
Author(s):  
Karukriti Kaushik Ghosh ◽  
Aman Prakash ◽  
Vinayagamurthy Balamurugan ◽  
Manish Kumar
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Membrane Surface ◽  
Outer Membrane Proteins ◽  
Extracellular Matrices ◽  
Content Type ◽  
Extracellular Matrix Components ◽  
Gene Transcripts ◽  
Host Tissues

ABSTRACTIn this study, the effect of the host stress hormone catecholamine onLeptospiragene transcripts encoding outer membrane proteins was investigated. There was no impact of catecholamine supplementation on thein vitrogrowth pattern ofLeptospira interrogans; however, 7 genes out of 41 were differentially transcribed, and the effect was reversed to the basal level in the presence of the antagonist propranolol. Comprehensive analysis of one of the differentially regulated proteins, LIC20035 (in serovar Copenhageni)/LB047 (in serovar Lai) (due to catecholamine supplementation), revealed immunogenicity and ability to adhere to host extracellular matrices. Protease accessibility assay and phase partition of integral membrane proteins ofLeptospirashowed LIC20035/LB047 to be an outer membrane surface-exposed protein. The recombinant LIC20035 protein can be serologically detected using human/bovine sera positive for leptospirosis. Moreover, the recombinant LIC20035 can bind to diverse host extracellular matrices, with a higher affinity toward collagen and chondroitin sulfate.IMPORTANCELeptospirosis is a neglected tropical disease of global importance. This study aimed to identify outer membrane proteins of pathogenicLeptospiraresponding to host chemical signals like catecholamines, with the potential to serve as virulence factors, new serodiagnostic antigens, and vaccine candidates. This study mimicked the plausible means by whichLeptospiraduring infection and hormonal stress intercepts host catecholamines to disseminate in host tissues.

scholarly journals Food and Feeding Habits of the Mola Carplet Amblypharyngodon mola (Hamilton, 1822) in Rice Field Ecosystem with Consideration of Water Quality Parameters

Our Nature ◽  
2013 ◽  
Vol 11 (1) ◽  
pp. 61-75 ◽  
Author(s):  
Md. Mostafizur Rahman Mondol ◽  
Dil Afroz Nahar ◽  
Somen Dewan ◽  
Md. Mosaddequr Rahman ◽  
Saleha Jasmine ◽  
...  
Keyword(s):  
Water Quality ◽  
Rice Field ◽  
Feeding Habits ◽  
Quality Parameters ◽  
Gut Contents ◽  
Gut Content Analysis ◽  
Gut Content ◽  
Field Ecosystem ◽  
Food And Feeding ◽  
Plankton Population

The present investigation was conducted in the Agronomy field laboratory of Bangladesh Agricultural University, Mymensingh, Bangladesh during May 1999 to August 1999 to reveal the food and feeding habits of Amblypharyngodon mola in the rice field ecosystem. Percentage of frequency of occurrence and percentage in number methods were used for the qualitative and quantitative estimation of plankton population. Results showed that, during the present study, the water quality parameters were within the suitable range for optimal fish growth and plankton population was abundant in the water of the rice plots. Gut content analysis of A. mola revealed a sum of 32 genera of phytoplankton belonging to Chlorophyceae (17), Euglenophyceae (2), Cyanophyceae (7) and Bacillariophyceae (6) and 8 genera of zooplankton under Rotifera (3), Cladocera (2) and Copepoda (3). In general, Navicula, Fragilaria, Chlorella, Chrysococcus, Closterium, Oscillatoria and Gomphosphaeria were found abundant both in the water of the rice plots and in the gut contents of A. mola indicating that, these genera are preferred food of this fish in the rice field ecosystem. Gut content analysis also exposed that, phytoplankton was the major food item constituting 94.38% of the gut contents’ composition of A. mola whereas zooplankton comprised only 5.62%. The results of this study conclude that, the A. mola is planktivorous in nature, feeding mostly on phytoplankton and could be a suitable species for integrated rice-fish farming.DOI: http://dx.doi.org/10.3126/on.v11i1.8245 Our Nature Vol.11(1) 2013: 61-75

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