scholarly journals Capture of Essential Trace Elements and Phosphate Accumulation as a Basis for the Antimicrobial Activity of a New Ultramicrobacterium—Microbacterium lacticum Str. F2E

2022 ◽  
Vol 10 (1) ◽  
pp. 128
Author(s):  
Nataliya E. Suzina ◽  
Andrey V. Machulin ◽  
Vladimir V. Sorokin ◽  
Valentina N. Polivtseva ◽  
Tatiana Z. Esikova ◽  
...  

Microbial interactions play an important role in natural habitat. The long-term coevolution of various species leads to the adaptation of certain types of microorganisms as well as to the formation of a wide variety of interactions such as competitive, antagonistic, pathogenic and parasitic relationships. The aim of this work is a comprehensive study of a new ultramicrobacterium Microbacterium lacticum str. F2E, isolated from perennial oil sludge, which is characterized by high antimicrobial activity and a unique ultrastructural organization of the cell envelope, which includes globular surface ultrastructures with a high negative charge. A previously undescribed mechanism for the antagonistic action of the F2E strain against the prey bacterium is proposed. This mechanism is based on the ability to preferentially capture essential microelements, in which charge interactions and the property of phosphate accumulation may play a significant role. The revealed type of intermicrobial interaction can probably be attributed to the non-contact type antagonistic action in the absence of any diffuse factor secreted by the antagonistic bacteria.

1995 ◽  
Vol 46 (5) ◽  
pp. 853 ◽  
Author(s):  
NS Barrett

Movement patterns were studied on a 1-ha isolated reef surrounding Arch Rock in southern Tasmania. Short-term movements were identified from diver observations, and interpretation of long-term movements involved multiple recaptures of tagged individuals. Visual observations indicated that the sex-changing labrids Notolabrus tetricus, Pictilabrus laticlavius and Pseudolabrus psittaculus were all site-attached, with females having overlapping home ranges and males being territorial. In the non-sex-changing labrid Notolabrus fucicola and in the monacanthids Penicipelta vittiger and Meuschenia australis, there was no evidence of territorial behaviour and 1-h movements were in excess of the scale of the study. The long-term results indicated that all species were permanent reef residents, with most individuals of all species except M. australis always being recaptured within a home range of 100 m × 25 m or less. Only 15% of individuals of M. australis were always recaptured within this range category. The natural habitat boundary of open sand between the Arch Rock reef and adjacent reefs appeared to be an effective deterrent to emigration. The use of natural boundaries should be an important consideration in the design of marine reserves where the aim is to minimize the loss of protected species to adjacent fished areas.


1993 ◽  
Vol 12 (6) ◽  
pp. 365-368 ◽  
Author(s):  
D.A. Johnston ◽  
G. Phillips ◽  
M. Perry ◽  
H. McAlpine ◽  
J. Richards ◽  
...  

PLoS ONE ◽  
2017 ◽  
Vol 12 (7) ◽  
pp. e0180925 ◽  
Author(s):  
Albert B. Jeon ◽  
Andrés Obregón-Henao ◽  
David F. Ackart ◽  
Brendan K. Podell ◽  
Juan M. Belardinelli ◽  
...  

2021 ◽  
Author(s):  
Yuan Tian ◽  
Jianyu Xiao ◽  
Xinjie Zha ◽  
Chengqun Yu

Abstract Although previous studies have been reported between the Kashin–Beck Disease (KBD) epidemic and the hydrochemical characteristics of surface waters, the etiology of the disease remains unclear. In the present study, we investigated the relationship between the KBD and the environment by comprehensively examining the hydrochemical characteristics of surface waters in Longzi County, Tibet, and the spatial incidence of the disease. Results show that, the pH (mean = 7.27±0.30), TH (mean = 57.08±45.74 mg L–1), and TDS (mean = 67.56±44.00 mg L–1) of surface waters in KBD endemic areas are lower than for those in the non-KBD endemic areas (means of pH = 7.49±0.30; TH = 262.06±123.29 mg L–1; TDS = 253.25±100.39 mg L–1). These results suggest that long-term consumption of low TDS, essential trace elements (e.g., nickel, cobalt, iron, selenium, zinc, molybdenum, and iodine) deficient, and potential toxic elements (such as arsenic) enriched waters by humans likely causes the KBD. Environmental factors such as the geology and geomorphology may produce biogeochemical imbalance, geomorphic, vegetation types and local climatic conditions may have significant impact on food fungi toxin poisoning and water organic compound poisoning, and these are also important in the KBD occurrence.


Author(s):  
Z. K. Klimenko ◽  
S. A. Plugatar ◽  
V. K. Zykova ◽  
I. N. Kravchenko

The article presents the results of a long-term research on the introduction study and evaluation of cultivars of tea-hybrid roses introduced and selected by the Nikitsky Botanical Gardens to determine the possibilities of their use in floriculture of the Southern Coast of the Crimea. The research was conducted in the period from 1955 to 2014. The material for the study was 679 cultivars of garden roses from the tea-hybrid garden group of the collection of the Nikitsky Botanical Gardens. As a result of a comprehensive study, 400 cultivars are recommended for use in the floriculture of the Crimea. The main options for this use becomes the growing of tea-hybrid roses in the open ground for gardening purposes in bush and tree-shaped forms, as well as the growing cultivars for cutting in both open and protected ground. The biological features of the cultivars, which determine the possibility of different types of the use and the cultivars, that have these features were identified: 400 cultivars were recommended for use in landscaping in bush form, 45 cultivars - also in tree-shaped form, 226 cultivars are promising for cutting in the open ground and 107 cultivars - for forcing and cutting in greenhouses. The main methods of propagation of cultivars of tea-hybrid roses under the conditions of the Southern Coast of the Crimea are budding and rooting of green and hardwood cuttings. The optimal timing for propagation by each of these methods is indicated. The best rootstocks for budding were identified, depending on the type of their use in floriculture. 


2021 ◽  
Vol 10 (1) ◽  
pp. 167-172
Author(s):  
Natalya Vladimirovna Tsybulya ◽  
Tatyana Dmitrievna Fershalova

The paper continues multi-year integrated studies of the numerous taxons of tropical Begonia genus, which allowed us to evaluate the adaptive capacity of the representatives of this genus relying on the revealed morphological, rhythmological and biochemical features. The investigation of antimicrobial activity of intact plants and different fractions of plant extracts allowed us to distinguish several promising representatives of this genus exhibiting activity against a broad range of test microorganisms. The involvement of these plants within phytomodules in child care centers caused a substantial decrease in total microbial contamination of the air. The paper contains results of the experimental investigation of seasonal antimicrobial activity of 13 species, 8 hybrids. The phytoncide activity was measured by exposing the streak cultures of microbial test species bacteria Staphylococcus epidermidis, Esсherichia coli and yeast-like fungi Candida albicans to the volatile emissions of plants. It has been established that 95% of begonias are distinguished by the pronounced activity against S. epidermidis bacteria, 48% against E. coli bacteria and 43% against fungi Candida albicans. The seasonal specificity of the antimicrobial action of begonias was detected: the growth of the colonies of S. epidermidis bacteria is inhibited to the highest extent during spring and summer, at the phase of intense growth, while the activity against E. coli is the highest during autumn and winter at the phase of moderate growth. The taxons with clearly pronounced, long-term and universal antimicrobial action to the studied test objects were revealed and recommended for practical planting in various types of indoor environments. The data obtained in the study may serve as the basis for further investigation of the chemical composition of volatile exometabolites by the example of the representatives of Gireoudia and Coelocentrum sections that have exhibited high antimicrobial activity against S. epidermidis and E. coli.


2015 ◽  
Vol 37 (2) ◽  
pp. 170 ◽  
Author(s):  
Emily J. Miller ◽  
Mark D. B. Eldridge ◽  
Keith Morris ◽  
Neil Thomas ◽  
Catherine A. Herbert

The endemic Australian greater bilby (Macrotis lagotis) is a vulnerable and iconic species. It has declined significantly due to habitat loss, as well as competition and predation from introduced species. Conservation measures include a National Recovery Plan that incorporates several captive breeding programs. Two of these programs were established within 12 months of one another (1997/98), with the same number and sex ratio of founding individuals, but executed different breeding strategies: (1) unmanipulated mating in semi–free range natural habitat versus (2) minimising mean kinship in large enclosures, with the supplementation of new individuals into both populations. This study evaluates the long-term genetic impact of these programs and examines the congruency between the pedigree studbook estimates of diversity and molecular data. Our data demonstrate that genetic diversity was maintained in both populations, with the supplementation of new individuals contributing to the gene pool. The studbook estimates of diversity and inbreeding are not consistent with the microsatellite data and should not solely be relied upon to evaluate the genetic health of captive populations. Our analyses suggest that captive breeding programs may not require costly and intensive management to effectively maintain long-term genetic diversity in a promiscuous species.


Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1309 ◽  
Author(s):  
Karla Čech Barabaszová ◽  
Sylva Holešová ◽  
Kateřina Šulcová ◽  
Marianna Hundáková ◽  
Barbora Thomasová

Microbial infection and biofilm formation are both problems associated with medical implants and devices. In recent years, hybrid organic-inorganic nanocomposites based on clay minerals have attracted significant attention due to their application potential in the field of antimicrobial materials. Organic drug/metal oxide hybrids exhibit improved antimicrobial activity, and intercalating the above materials into the interlayer of clay endows a long-term and controlled-release behavior. Since antimicrobial activity is strongly related to the structure of the material, ultrasonic treatment appears to be a suitable method for the synthesis of these materials as it can well control particle size distribution and morphology. This study aims to prepare novel, structurally stable, and highly antimicrobial nanocomposites based on zinc oxide/vermiculite/chlorhexidine. The influence of ultrasonic treatment at different time intervals and under different intercalation conditions (ultrasonic action in a breaker or in a Roset’s vessel) on the structure, morphology, and particle size of prepared hybrid nanocomposite materials was evaluated by the following methods: scanning electron microscopy, X-ray diffraction, energy dispersive X-ray fluorescence spectroscopy, carbon phase analysis, Fourier transforms infrared spectroscopy, specific surface area measurement, particle size analysis, and Zeta potential analysis. Particle size analyses confirmed that the ultrasonic method contributes to the reduction of particle size, and to their homogenization/arrangement. Further, X-ray diffraction analysis confirmed that ultrasound intercalation in a beaker helps to more efficiently intercalate chlorhexidine dihydrochloride (CH) into the vermiculite interlayer space, while a Roset’s vessel contributed to the attachment of the CH molecules to the vermiculite surface. The antibacterial activity of hybrid nanocomposite materials was investigated on Gram negative (Escherichia coli, Pseudomonas aeruginosa) and Gram positive (Staphylococcus aureus, Enterococcus faecalis) bacterial strains by finding the minimum inhibitory concentration. All hybrid nanocomposite materials prepared by ultrasound methods showed high antimicrobial activity after 30 min, with a long-lasting effect and without being affected by the concentration of the antibacterial components zinc oxide (ZnO) and CH. The benefits of the samples prepared by ultrasonic methods are the rapid onset of an antimicrobial effect and its long-term duration.


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