scholarly journals Identification and antimicrobial properties of bacteria isolated from naturally decaying wood

2020 ◽  
Author(s):  
Tanja R. Scheublin ◽  
Anna M. Kielak ◽  
Marlies van den Berg ◽  
Johannes A. van Veen ◽  
Wietse de Boer
Keyword(s):  
Resource Competition ◽  
General Pattern ◽  
Antimicrobial Properties ◽  
Wood Decay ◽  
Antagonistic Activity ◽  
High Resource ◽  
Wood Rot Fungi ◽  
Decaying Wood

AbstractResearch on wood decay in forest ecosystems has traditionally focused on wood-rot fungi, which lead the decay process through attack of the lignocellulose complex. The role of bacteria, which can be highly abundant, is still unclear. Wood-inhabiting bacteria are thought to be nutritionally dependent on decay activities of wood-rot fungi. Therefore, we hypothesized that these bacteria are not antagonistic against wood-rot fungi whereas antagonistic activity against other bacteria may be high (resource competition). This was examined for decaying wood in temperate forests. We found that the abundance of cultivable bacteria in decaying wood can be highly variable. The general pattern is an increase of bacteria with progressive decay, but we also identified several fungi that were apparently able to exclude bacteria from their woody territory. We established a bacterial collection which is highly representative for decaying wood with typical wood-inhabiting taxa: Xanthomonadaceae, Acetobacteraceae, Caulobacteraceae, Methylovirgula, Sphingomonas, Burkholderia and Granulicella. In vitro antagonistic activity against other bacteria and fungi was evaluated. In contrast to our hypothesis, we found surprisingly low antagonistic activity against bacteria (<2% of isolates), while antagonism against fungi was more prevalent. These results may point at a prominent role of mycophagy (growth at the expense of living fungi) among wood-inhabiting bacteria.

scholarly journals Antagonism and synergism in Gardnerella vaginalis strains isolated from women with bacterial vaginosis

2010 ◽  
Vol 59 (8) ◽  
pp. 891-897 ◽  
Author(s):  
G. S. Teixeira ◽  
K. L. K. Soares-Brandão ◽  
K. M. G. R. Branco ◽  
J. L. M. Sampaio ◽  
R. M. D. Nardi ◽  
...  
Keyword(s):  
Bacterial Vaginosis ◽  
Chemical Nature ◽  
Growth Conditions ◽  
Antagonistic Activity ◽  
Gardnerella Vaginalis ◽  
Ecological Role ◽  
Micro Organisms

Antagonistic and synergistic substances are important for interactions between micro-organisms associated with human body surfaces, either in healthy or in diseased conditions. In the present study, such compounds produced by Gardnerella vaginalis strains isolated from women with bacterial vaginosis (BV) were detected in vitro and the antagonistic ones were partially characterized. Among 11 G. vaginalis strains tested, all showed antagonistic activity against at least one of the 22 indicator bacteria assayed. Interestingly, for some of these strains, antagonism reverted to synergism, favouring one of the indicator strains (Peptostreptococcus anaerobius) when the growth medium was changed. Partial characterization of antagonistic substances suggested a bacteriocin-like chemical nature. Depending on growth conditions, G. vaginalis isolated from women with BV produced antagonistic or synergistic compounds for other bacterial components of the vaginal ecosystem. This is the first report to our knowledge of the production of antagonistic and/or synergistic substances by G. vaginalis. This ability may be a pivotal factor in understanding BV and the ecological role of this bacterium in the vaginal environment.

scholarly journals Intraspecific variation in the diet of the Mexican garter snakeThamnophis eques

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4036 ◽  
Author(s):  
Javier Manjarrez ◽  
Martha Pacheco-Tinoco ◽  
Crystian S. Venegas-Barrera
Keyword(s):  
Intraspecific Variation ◽  
Resource Competition ◽  
Prey Availability ◽  
General Pattern ◽  
Stomach Contents ◽  
Large Prey ◽  
Male And Female ◽  
Males And Females ◽  
Prey Items

The Mexican Garter Snake (Thamnophis eques)is a terrestrial-aquatic generalist that feeds on both aquatic and terrestrial prey. We describe size-related variation and sexual variation in the diet ofT. equesthrough analysis of 262 samples of identifiable stomach contents in snakes from 23 locations on the Mexican Plateau. The snakeT. equeswe studied consumed mostly fish, followed in lesser amounts by leeches, earthworms, frogs, and tadpoles. Correspondence analysis suggested that the frequency of consumption of various prey items differed between the categories of age but not between sex of snakes, and the general pattern was a reduction of prey item diversity with size of snake. Snake length was correlated positively with mass of ingested prey. Large snakes consumed large prey and continued to consume smaller prey. In general, no differences were found between the prey taxa of male and female snakes, although males ate two times more tadpoles than females. Males and females did not differ in the mass of leeches, earthworms, fishes, frogs and tadpoles that they ate, and males and females that ate each prey taxon were similar in length. We discuss proximate and functional determinants of diet and suggest that the observed intraspecific variation inT. equescould be explored by temporal variation in prey availability, proportions of snake size classes and possible sexual dimorphism in head traits and prey dimensions to assess the role of intersexual resource competition.

Presence of chromogranin-derived antimicrobial peptides in plasma during coronary artery bypass surgery and evidence of an immune origin of these peptides

Blood ◽  
2002 ◽  
Vol 100 (2) ◽  
pp. 553-559 ◽  
Author(s):  
Aurélie Tasiemski ◽  
Hamida Hammad ◽  
Franck Vandenbulcke ◽  
Christophe Breton ◽  
Thomas J. Bilfinger ◽  
...  
Keyword(s):  
Artery Bypass ◽  
Antimicrobial Properties ◽  
Microscopic Analysis ◽  
Skin Incision ◽  
Biologically Active ◽  
Chromogranin B ◽  
Positive Role ◽  
Active Peptides

Abstract Chromogranin A (CGA) and chromogranin B (CGB) are acidic proteins stored in secretory organelles of endocrine cells and neurons. In addition to their roles as helper proteins in the packaging of peptides, they may serve as prohormones to generate biologically active peptides such as vasostatin-1 and secretolytin. These molecules derived from CGA and CGB, respectively, possess antimicrobial properties. The present study demonstrates that plasmatic levels of both vasostatin-1 and secretolytin increase during surgery in patients undergoing cardiopulmonary bypass (CPB). Vasostatin-1 and secretolytin, initially present in plasma at low levels, are released just after skin incision. Consequently, they can be added to enkelytin, an antibacterial peptide derived from proenkephalin A, for the panoply of components acting as a first protective barrier against hypothetical invasion of pathogens, which may occur during surgery. CGA and CGB, more commonly viewed as markers for endocrine and neuronal cells, were also found to have an immune origin. RNA messengers coding for CGB were amplified by reverse transcription–polymerase chain reaction in human monocytes, and immunocytochemical analysis by confocal microscopy revealed the presence of CGA or CGB or both in monocytes and neutrophils. A combination of techniques including confocal microscopic analysis, mass spectrometry measurement, and antibacterial tests allowed for the identification of the positive role of interleukin 6 (IL-6) in the secretolytin release from monocytes in vitro. Because IL-6 release is known to be strongly enhanced during CPB, we suggest a possible relationship between IL-6 and the increased level of secretolytin in patients undergoing CPB.

scholarly journals Isolation, Characterization, cDNA Cloning, and Antimicrobial Properties of Two Distinct Subfamilies of α-Defensins from Rhesus Macaque Leukocytes

1999 ◽  
Vol 67 (11) ◽  
pp. 6139-6144 ◽  
Author(s):  
Yi-Quan Tang ◽  
Jun Yuan ◽  
Christopher J. Miller ◽  
Michael E. Selsted
Keyword(s):  
Rhesus Macaque ◽  
Host Defense ◽  
Polymorphonuclear Leukocytes ◽  
Nonhuman Primates ◽  
Antimicrobial Properties ◽  
Posttranslational Processing ◽  
E Coli ◽  
Gram Positive Bacteria

ABSTRACT Experiments to isolate and characterize rhesus macaque myeloid α-defensins (RMADs) were conducted. Seven RMAD peptides were isolated and sequenced, and the cDNAs encoding six of these peptides and one other α-defensin from bone marrow were also characterized. Four of the RMADs were found to be highly similar to human neutrophil α-defensins HNP-1 to HNP-3, while the remaining four peptides were much more similar to human enteric α-defensin HD-5. Two α-defensin pairs differed only by the presence or absence of an additional arginine at the amino termini of their mature peptides, indicative of alternate posttranslational processing. The primary translation products of RMAD-1 to -8 are 94- and 96-amino-acid prepropeptides that are highly similar to those of human α-defensins. Immunolocalization experiments revealed a granular cytoplasmic pattern in the cytoplasms of neutrophils, indistinguishable from the pattern observed after immunostaining of human myeloid α-defensins in polymorphonuclear leukocytes. Each of the purified peptides was tested for its in vitro activities against Staphylococcus aureus 502a,Listeria monocytogenes EGD, Escherichia coliML35, and Cryptococcus neoformans 271A. Several of the peptides were microbicidal for the gram-positive bacteria and C. neoformans at defensin concentrations in the range of 2 to 5 μM. All of the peptides were bacteriostatic against E. coli, but none were bactericidal for this organism. This study is the first to characterize the sequences and activities of α-defensins from nonhuman primates, data that should aid in delineating the role of these peptides in rhesus macaque host defense.

scholarly journals Rikkunshito, a Japanese Kampo Medicine, Ameliorates Decreased Feeding Behavior via Ghrelin and Serotonin 2B Receptor Signaling in a Novelty Stress Murine Model

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Chihiro Yamada ◽  
Yayoi Saegusa ◽  
Koji Nakagawa ◽  
Shunsuke Ohnishi ◽  
Shuichi Muto ◽  
...  
Keyword(s):  
Food Intake ◽  
Feeding Behavior ◽  
Receptor Activation ◽  
Antagonistic Activity ◽  
Acylated Ghrelin ◽  
Receptor Antagonists ◽  
Water Treated Control ◽  
Cumulative Food Intake

We investigated the effects of rikkunshito (RKT), a ghrelin signal enhancer, on the decrease in food intake after exposure to novelty stress in mice. RKT administration (500 mg/kg,per os) improved the decrease in 6 h cumulative food intake. In control mice, the plasma acylated ghrelin levels significantly increased by 24 h fasting. In contrast, the acylated ghrelin levels did not increase by fasting in mice exposed to the novelty stress. RKT administration to the novelty stress mice showed a significant increase in the acylated ghrelin levels compared with that in the distilled-water-treated control mice. Food intake after administering serotonin 2B (5-HT2B) receptor antagonists was evaluated to clarify the role of 5-HT2Breceptor activation in the decrease in feeding behavior after novelty stress. SB215505 and SB204741, 5-HT2Breceptor antagonists, significantly improved the decrease in food intake after exposure to novelty stress. A component of RKT, isoliquiritigenin, prevented the decrease in 6 h cumulative food intake. Isoliquiritigenin showed 5-HT2Breceptor antagonistic activityin vitro.In conclusion, the results suggested that RKT improves the decrease in food intake after novelty stress probably via 5-HT2Breceptor antagonism of isoliquiritigenin contained in RKT.

scholarly journals Isolation and Characterisation of Probiotics for Antagonising Cariogenic Bacterium Streptococcus mutans and Preventing Biofilm Formation

2016 ◽  
Author(s):  
Pei-Pei Lin ◽  
You-Miin Hsieh ◽  
Cheng-Chih Tsai
Keyword(s):  
Antimicrobial Activity ◽  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Antimicrobial Properties ◽  
Antagonistic Activity ◽  
Lactobacillus Pentosus ◽  
Chewing Gums ◽  
Dependent Cell ◽  
Cariogenic Bacterium

Consumption of refined foods and beverages high in sugar make the teeth susceptible to the formation of biofilm, and lead to dental caries and diseases of the oral cavity such as periodontitis and periodontal disease. The aim of the present study was to determine the ability of selected probiotics to inhibit growth and biofilm formation by the cariogenic bacterium Streptococcus mutans in vitro. We screened strains of latic acid bacteria (LAB) (n=120) from the Bioresources Collection and Research Center (BCRC), saliva of healthy adults and infant stool. The antimicrobial activity of LAB in vitro was evaluated by agar spot culture and co-culture of the S. mutans strains. We determined the effect of heating and dilution factors (2- and 4-fold) on the antagonistic activity of LAB. Antagonistic substances in the spent culture suspensions (SCS) of LAB were precipitated by extraction with ammonium sulphate and chloroform to characterise the protein and lipophilic fractions. Results of co-culturing show that the SCS of the three LAB strains (Lactobacillus pentosus 13-1, 13-4 and Lactobacillus crispatus BCRC 14618) subjected to heat treatment showed significantly high antimicrobial activity. We found that substances produced by L. pentosus 13-4 which have the potential to exhibit antimicrobial properties might be lipophilic proteins. Additionally, we infer that the mechanism of reducing biofilm formation by Lactobacillus strains is associated with sucrose-dependent cell&ndash;cell adhesion and the gtfC level of glucosyltransferases (Gtfs) in the biofilm. Native LAB strains screened in our study may be used in chewing gums and other processed foods for preventing tooth decay.

The role of silicon in forages: A quantitative X-Ray study

1987 ◽  
Vol 45 ◽  
pp. 416-417
Author(s):  
Janet H. Woodward ◽  
D. E. Akin
Keyword(s):  
Sodium Acetate ◽  
Dry Matter ◽  
Acetate Buffer ◽  
Plant Tissues ◽  
Sodium Acetate Buffer ◽  
X Ray ◽  
Dry Matter Digestibility ◽  
Percent Composition

Silicon (Si) is distributed throughout plant tissues, but its role in forages has not been clarified. Although Si has been suggested as an antiquality factor which limits the digestibility of structural carbohydrates, other research indicates that its presence in plants does not affect digestibility. We employed x-ray microanalysis to evaluate Si as an antiquality factor at specific sites of two cultivars of bermuda grass (Cynodon dactvlon (L.) Pers.). “Coastal” and “Tifton-78” were chosen for this study because previous work in our lab has shown that, although these two grasses are similar ultrastructurally, they differ in in vitro dry matter digestibility and in percent composition of Si.Two millimeter leaf sections of Tifton-7 8 (Tift-7 8) and Coastal (CBG) were incubated for 72 hr in 2.5% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0. For controls, sections were incubated in the sodium acetate buffer or were not treated.

An integrated screening method for evaluating the pulmonary toxicity of inhaled particulates: Role of microscopic techniques in assessing pulmonary macrophage clearance functions

1990 ◽  
Vol 48 (3) ◽  
pp. 826-827
Author(s):  
David B. Warheit ◽  
Lena Achinko ◽  
Mark A. Hartsky
Keyword(s):  
Bronchoalveolar Lavage ◽  
Pulmonary Toxicity ◽  
Screening Method ◽  
Pulmonary Response ◽  
Inhaled Particles ◽  
Cytochemical Analysis ◽  
Pulmonary Macrophages ◽  
Integrated Screening

There is a great need for the development of a rapid and reliable bioassay to evaluate the pulmonary toxicity of inhaled particles. A number of methods have been proposed, including lung clearance studies, bronchoalveolar lavage analysis, and in vitro cytotoxicity tests. These methods are often limited in scope inasmuch as they measure only one dimension of the pulmonary response to inhaled, instilled or incubated dusts. Accordingly, a comprehensive approach to lung toxicity studies has been developed.To validate the method, rats were exposed for 6 hours or 3 days to various concentrations of either aerosolized alpha quartz silica (Si) or carbonyl iron (CI) particles. Cells and fluids from groups of sham and dust-exposed animals were recovered by bronchoalveolar lavage (BAL). Alkaline phosphatase, LDH and protein values were measured in BAL fluids at several time points postexposure. Cells were counted and evaluated for viability, as well as differential and cytochemical analysis. In addition, pulmonary macrophages (PM) were cultured and studied for morphology, chemotaxis, and phagocytosis by scanning electron microscopy.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

Anti-obesity role of Aster glehni extract: in vivo and in vitro effects

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
HM Lee ◽  
TG Ahn ◽  
CW Kim ◽  
HJ An
Keyword(s):  
In Vitro Effects
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