scholarly journals Artificially selecting microbial communities using propagule strategies

2020 ◽  
Author(s):  
Chang-Yu Chang ◽  
Melisa L. Osborne ◽  
Djordje Bajic ◽  
Alvaro Sanchez
Keyword(s):  
Microbial Communities ◽  
Artificial Selection ◽  
Community Level ◽  
Control Treatment ◽  
Strong Response ◽  
Maximum Function ◽  
Selection Experiments ◽  
The Mean ◽  
Feeding Potential ◽  
New Generation

AbstractArtificial selection is a promising approach to manipulate the function of microbial communities. Here, we report the outcome of two artificial selection experiments at the microbial community level. Both experiments used “propagule” strategies, in which a set of the best-performing communities are used as the inocula to form a new generation of communities. In both cases, the selected communities are compared to a control treatment where communities are randomly selected. The first experiment used a defined set of strains as the starting inoculum, and the function under selection was the amylolytic activity of the consortia. The second experiment used a diverse set of natural communities as the inoculum, and the function under selection was the cross-feeding potential of the resulting communities towards a reference bacterial strain. In both experiments, the selected communities reached a higher mean and a higher maximum function than the control. In the first experiment this is caused by a decline in function of the control, rather than an improvement of the selected line. In the second experiment, the strong response of the mean is caused by the large initial variance in function across communities, and is the immediate consequence of the spread of the top-performing community in the starting group, whose function does not increase. Our results are in agreement with basic expectations of artificial selection theory, pointing out some of the limitations of community-level selection experiments which can inform the design of future studies.

scholarly journals Characterization of Maize Genotypes (Zea mays L.) for Resistance to Striga asiatica and S. hermonthica and Compatibility with Fusarium oxysporum f. sp. strigae (FOS) in Tanzania

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1004
Author(s):  
John Lobulu ◽  
Hussein Shimelis ◽  
Mark D. Laing ◽  
Arnold Angelo Mushongi ◽  
Admire Isaac Tichafa Shayanowako
Keyword(s):  
Grain Yield ◽  
Fusarium Oxysporum ◽  
Biocontrol Agent ◽  
Zea Mays L ◽  
Control Treatment ◽  
Yield Reduction ◽  
Maize Genotypes ◽  
Significant Yield ◽  
The Mean

Striga species cause significant yield loss in maize varying from 20 to 100%. The aim of the present study was to screen and identify maize genotypes with partial resistance to S. hermonthica (Sh) and S. asiatica (Sa) and compatible with Fusarium oxysporum f. sp. strigae (FOS), a biocontrol agent. Fifty-six maize genotypes were evaluated for resistance to Sh and Sa, and FOS compatibility. Results showed that FOS treatment significantly (p < 0.001) enhanced Striga management compared to the untreated control under both Sh and Sa infestations. The mean grain yield was reduced by 19.13% in FOS-untreated genotypes compared with a loss of 13.94% in the same genotypes treated with FOS under Sh infestation. Likewise, under Sa infestation, FOS-treated genotypes had a mean grain yield reduction of 18% while untreated genotypes had a mean loss of 21.4% compared to the control treatment. Overall, based on Striga emergence count, Striga host damage rating, grain yield and FOS compatibility, under Sh and Sa infestations, 23 maize genotypes carrying farmer preferred traits were identified. The genotypes are useful genetic materials in the development of Striga-resistant cultivars in Tanzania and related agro-ecologies.

scholarly journals Latitudinal distribution of microbial communities in anaerobic biological stabilization ponds: effect of the mean annual temperature

2016 ◽  
Vol 9 (6) ◽  
pp. 834-845 ◽  
Author(s):  
Mengdong Yuan ◽  
Jing Zhu ◽  
Cheng Wang ◽  
Mengxiong Wu ◽  
Faqian Sun ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Mean Annual Temperature ◽  
Latitudinal Distribution ◽  
Stabilization Ponds ◽  
The Mean

Effects of Community Versus Single Strain Inoculants on the Biocontrol of Salmonella and Microbial Community Dynamics in Alfalfa Sprouts†

2005 ◽  
Vol 68 (1) ◽  
pp. 40-48 ◽  
Author(s):  
ANABELLE MATOS ◽  
JAY L. GARLAND
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Community Dynamics ◽  
Community Level ◽  
Microbial Consortia ◽  
Single Strain ◽  
Acridine Orange Staining ◽  
Physiological Profiles ◽  
Alfalfa Sprouts ◽  
Alfalfa Seeds

Potential biological control inoculants, Pseudomonas fluorescens 2-79 and microbial communities derived from market sprouts or laboratory-grown alfalfa sprouts, were introduced into alfalfa seeds with and without a Salmonella inoculum. We examined their ability to inhibit the growth of this foodborne pathogen and assess the relative effects of the inoculants on the alfalfa microbial community structure and function. Alfalfa seeds contaminated with a Salmonella cocktail were soaked for 2 h in bacterial suspensions from each inoculant tested. Inoculated alfalfa seeds were grown for 7 days and sampled during days 1, 3, and 7. At each sampling, alfalfa sprouts were sonicated for 7 min to recover microflora from the surface, and the resulting suspensions were diluted and plated on selective and nonselective media. Total bacterial counts were obtained using acridine orange staining, and the percentage culturability was calculated. Phenotypic potential of sprout-associated microbial communities inoculated with biocontrol treatments was assessed using community-level physiological profiles based on patterns of use of 95 separate carbon sources in Biolog plates. Community-level physiological profiles were also determined using oxygen-sensitive fluorophore in BD microtiter plates to examine functional patterns in these communities. No significant differences in total and mesophilic aerobe microbial cell density or microbial richness resulting from the introduction of inoculants on alfalfa seeds with and without Salmonella were observed. P. fluorescens 2-79 exhibited the greatest reduction in the growth of Salmonella early during alfalfa growth (4.22 log at day 1), while the market sprout inoculum had the reverse effect, resulting in a maximum log reduction (5.48) of Salmonella on day 7. Community-level physiological profiles analyses revealed that market sprout communities peaked higher and faster compared with the other inoculants tested. These results suggest that different modes of actions of single versus microbial consortia biocontrol treatments may be involved.

Comparison Of Drugs in Patients Using New Generation Anticoagulants

2021 ◽  
Vol 6 (14) ◽  
pp. 56-67
Author(s):  
Arslan Say ◽  
Abdülkadir ÇAKMAK ◽  
Gökhan KESKİN ◽  
Erdinç PELİT ◽  
Yılmaz ÖZBAY
Keyword(s):  
Atrial Fibrillation ◽  
Clinical Practice ◽  
Venous Thromboembolism ◽  
Oral Anticoagulants ◽  
Recurrent Venous Thromboembolism ◽  
Anticoagulant Drugs ◽  
History Of ◽  
The Mean ◽  
N 93 ◽  
New Generation

Aim: New generation anticoagulants rapidly find a wider area of use in the clinic due to the use problems of other oral anticoagulants. Anticoagulants such as Dabigatran, Rivaroxaban, and Apixaban with safer treatment intervals have been accepted in clinical practice guidelines and have taken their place as preferred drugs. In this study, we aimed to retrospectively examine the effects of three new-generation anticoagulant drugs on a group of patients. Material and Methods: In this retrospectively planned study, patients diagnosed with atrial fibrillation (n = 522) were divided into three groups according to the drugs used for treatment (Dabigatran, Rivaroxaban, and Apixaban). Routine blood values of the patients in each group were retrospectively scanned according to age, gender, time of drug initiation and presence of chronic disease. Results: According to the results obtained, it was found that the mean HCT, BUN, AST, ALT, MPV, Iron, and Ferritin were higher in patients using Apixaban than those using Dabigatran and Rivaroxaban drugs, but the age, average values of Hgb1 Hgb2, Hgb1, PLT, CrCl, Gfr and INR of the patients using Apixaban lower than those using Dabigatran and Rivaroxaban. The highest rate (22.5%) was found in the group of patients taking apixaban (n=93) when people taking the drugs were examined in terms of mortality. Conclusion: It has been observed that Rivaroxaban can be used more safely in patients with a history of acute cancer and thrombosis, patients with recurrent venous thromboembolism, and patients with high frailty, three drugs should be preferred instead of oral anticoagulants.

scholarly journals Effects of Insecticides for Controlling Hogplum Beetle Podontia 14-punctata under Laboratory and Field Conditions

2015 ◽  
Vol 8 (1) ◽  
pp. 79-83
Author(s):  
MJ Uddin ◽  
MMH Khan
Keyword(s):  
Natural Resources ◽  
Field Condition ◽  
Field Trial ◽  
Adult Stage ◽  
Control Treatment ◽  
Larval Instars ◽  
Significant Difference ◽  
Laboratory Trial ◽  
The Mean ◽  
Hog Plum

Experiments on hogplum beetle, Podontia 14-punctata were carried out to find out the suitable insecticide(s) with appropriate dose(s) for suppressing both larvae and adults. Results revealed that the highest mortality (100%) was found in 1st instar larvae after 24 hours at each dose of superior 505EC and the lowest mortality was in T4 treated leaves. The highest mortality was also found in 2nd, 3rd, 4th and adult stages of hog-plum beetle by T5 and T6 treatments. No mortality was observed in control treatment in laboratory trial. The mean number of larvae ranged from 1.5 to 7.6 per square meter of quadrate at one week after last spray. No significant difference was observed among treatments regarding percent leaf infestation at one day before 1st spray. The percent leaf infestation ranged from 5.01 to 9.82 at one week after last spray. The lowest percent (5.87%) leaf infestation was found in T6 treated plants while the highest percent (15.76%) leaf infestation was found in untreated control plants. The highest mortality was observed in T5 and T6 treated plants at all larval instars and no significant difference was found between two doses of each insecticide under field condition. The results of field trial also revealed that the minimum dose (0.75 ml L-1 of water) of Superior 505 EC is sufficient to suppress the field population of larvae and adults of Podontia 14-punctata effectively. Finally, it may be concluded that the highest mortality was found in all larval instars and adult stage of hog-plum beetle after 24 hours at each dose of superior 505 EC (T5 and T6 treatments) both in laboratory and field trials.J. Environ. Sci. & Natural Resources, 8(1): 79-83 2015

scholarly journals Intergenerational transmission of symbiotic bacteria in oviparous and viviparous demosponges, with emphasis on intracytoplasmically-compartmented bacterial types

2007 ◽  
Vol 87 (6) ◽  
pp. 1701-1713 ◽  
Author(s):  
Manuel Maldonado
Keyword(s):  
Microbial Communities ◽  
Symbiotic Bacteria ◽  
Free Swimming ◽  
Transmission Electron ◽  
Early Embryos ◽  
Membrane Bound ◽  
Chondrilla Nucula ◽  
New Generation ◽  
Swimming Larva ◽  
Free Swimming Larva

Recent molecular detection of vast microbial communities exclusively associated with sponges has made evident the need for a better understanding of the mechanisms by which these symbiotic microbes are handled and transferred from one sponge generation to another. This transmission electron microscopy (TEM) study investigated the occurrence of symbiotic bacteria in free-swimming larvae of two viviparous species (Haliclona caerulea and Corticium candelabrum) and spawned gametes of two oviparous species (Chondrilla nucula and Petrosia ficiformis). Complex microbial communities were found in these sponges, which in two cases included bacteria characterized by an intra-cytoplasmic membrane (ICM). When ICM-bearing and ICM-lacking bacteria co-existed, they were transferred following identical pathways. Nevertheless, the mechanism for microbial transference varied substantially between species. In C. nucula, a combination of intercellular symbiotic ICM-bearing and ICM-lacking bacteria, along with cyanobacteria and yeasts, were collected from the mesohyl by amoeboid nurse cells, then transported and transferred to the oocytes. In the case of Corticium candelabrum, intercellular bacteria did not enter the gametes, but spread into the division furrows of early embryos and proliferated in the central cavity of the free-swimming larva. Surprisingly, symbiotic bacteria were not vertically transmitted by P. ficiformis gametes or embryos, but apparently acquired from the environment by the juveniles of each new generation. This study failed to unravel the mechanism by which the intercellular endosymbiotic bacterium found in the central mesohyl of the H. caerulea larva got there. Nevertheless, the ultrastructure of this bacterial rod, which was characterized by a star-shaped cross section with nine radial protrusions, an ICM-bound riboplasm, and a putative membrane-bound acidocalcisome, suggested that it may represent a novel organization grade within the prokaryotes. It combines traits occurring in members of Poribacteria, Planctomycetes and Verrucomicrobia, emerging as one of the most complex prokaryotic architectures known to date.

scholarly journals A SIMULATION STUDY OF TRUNCATION SELECTION FOR A QUANTITATIVE TRAIT OPPOSED BY NATURAL SELECTION

Genetics ◽  
1980 ◽  
Vol 94 (4) ◽  
pp. 989-1000
Author(s):  
Francis Minvielle
Keyword(s):  
Natural Selection ◽  
Artificial Selection ◽  
Random Mating ◽  
Selection Response ◽  
Quantitative Character ◽  
Mass Selection ◽  
Frequency Selection ◽  
Selection Experiments ◽  
Selection For ◽  
Selective Process

ABSTRACT A quantitative character controlled at one locus with two alleles was submitted to artificial (mass) selection and to three modes of opposing natural selection (directional selection, overdominance and underdominance) in a large random-mating population. The selection response and the limits of the selective process were studied by deterministic simulation. The lifetime of the process was generally between 20 and 100 generations and did not appear to depend on the mode of natural selection. However, depending on the values of the parameters (initial gene frequency, selection intensity, ratio of the effect of the gene to the environmental standard deviation, fitness values) the following outcomes of selection were observed: fixation of the allele favored by artificial selection, stable nontrivial equilibrium, unstable equilibrium and loss of the allele favored by artificial selection. Finally, the results of the simulation were compared to the results of selection experiments.

scholarly journals How Is Fitness of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) Affected When Different Developmental Stages Are Exposed to Chlorfenapyr?

Insects ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 542
Author(s):  
Anna Skourti ◽  
Nickolas G. Kavallieratos ◽  
Nikos E. Papanikolaou
Keyword(s):  
Life Table ◽  
Tribolium Castaneum ◽  
Developmental Stages ◽  
Survival Curve ◽  
Control Treatment ◽  
Intrinsic Rate Of Increase ◽  
Net Reproductive Rate ◽  
Rate Of Increase ◽  
The Mean ◽  
Coleoptera Tenebrionidae

Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) is an important pest of stored products. Insecticidal treatment is a common practice for the control of this notorious insect pest. Most studies are focused on the immediate and/or delayed mortality effects, while there are no data on the effects of insecticides on the population fitness. This study deals with the effect of chlorfenapyr on T. castaneum, investigating the cost of exposure of different developmental stages on population performance, by using life table statistics and a survival analysis method. For this purpose, eggs, larvae, and parental adult females of T. castaneum were exposed to chlorfenapyr and birth or death rates were calculated daily. The exposure of eggs and larvae to chlorfenapyr was detrimental for T. castaneum and they did not complete development. When parental females were exposed to chlorfenapyr, the progeny survival curve, biological features, as well as the life table parameters did not differ significantly compared to the control treatment. Thus, egg hatching, larval and pupal developmental periods, female and male longevities for the control treatment, and the progeny of the females that were exposed to chlorfenapyr were 4.66 and 4.76 days, 25.85 and 25.71 days, 5.00 and 5.26 days, 87.33 and 104.22 days, and 76.87 and 91.87 days, respectively. In addition, the mean values of the net reproductive rate, the intrinsic rate of increase, the mean generation time and the doubling time for the control treatment and the progeny of the parental females which were exposed to chlorfenapyr were 14.3 and 9.3 females/female, 0.038 and 0.028 females/female/day, 1.039 and 1.029, 70.0 and 76.9 days, and 18.5 and 24.9 days, respectively. We expect these results to have bearing on the management of T. castaneum, since the repeatedly insecticidal applications could be reduced in storage facilities.

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