scholarly journals Plant thionins: structure, biological functions and potential use in biotechnology

2018 ◽  
Vol 22 (6) ◽  
pp. 667-675 ◽  
Author(s):  
T. I. Odintsova ◽  
M. P. Slezina ◽  
E. A. Istomina
Keyword(s):  
Pathogenic Bacteria ◽  
Plant Pathogens ◽  
Biological Activities ◽  
Three Dimensional ◽  
Amino Acid Sequences ◽  
Lipid Transfer ◽  
Human Pathogens ◽  
Candida Spp ◽  
Wide Range ◽  
Bacteria And Fungi

Antimicrobial peptides (AMPs) are important components of defense system in both plants and animals. They represent an ancient mechanism of innate immunity providing rapid first line of defense against pathogens. Plant AMPs are classified into several families: thionins, defensins, nonspecific lipid-transfer proteins, hevein- and knottin-type peptides, hairpinins and macrocyclic peptides (cyclotides). The review focuses on the thionin family. Thionins comprise a plant-specific AMP family that consists of short (~5 kDA) cysteine-rich peptides containing 6 or 8 cysteine residues with antimicrobial and toxic properties. Based on similarity in amino acid sequences and the arrangement of disulphide bonds, five structural classes of thionins are discriminated. The three-dimensional structures of a number of thionins were determined. The amphipathic thionin molecule resembles the Greek letter Г, in which the long arm is formed by two antiparallel α-helices, while the short one, by two parallel β-strands. The residues responsible for the antimicrobial activity of thionins were identified. Thionins are synthesized as precursor proteins consisting of a signal peptide, the mature peptide region and the C-terminal prodomain. Thionins protect plants from pathogenic bacteria and fungi acting directly on the membranes of microorganisms at micromolar concentrations, although their precise mode of action remains unclear. In addition to plant pathogens, thionins inhibit growth of a number of human pathogens and opportunistic microorganisms, such as Candida spp., Saccharomyces cerevisiae, Fusarium solani, Staphylococcus aureus and Escherichia coli. Thionins are toxic to different types of cells including mammalian cancer cell lines. Transgenic plants expressing thionin genes display enhanced resistance to pathogens. A wide range of biological activities makes thionins promising candidates for practical application in agriculture and medicine.

scholarly journals In Search of the Antimicrobial Potential of Benzimidazole Derivatives

2016 ◽  
Vol 65 (3) ◽  
pp. 359-364 ◽  
Author(s):  
Monika Janeczko ◽  
Zygmunt Kazimierczuk ◽  
Andrzej Orzeszko ◽  
Andrzej Niewiadomy ◽  
Ewa Król ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Benzimidazole Derivatives ◽  
Human Pathogens ◽  
Bacterial Strains ◽  
Growth Reduction ◽  
Candida Spp ◽  
Fusarium Sp ◽  
Bacteria And Fungi ◽  
Klebsiella Spp ◽  
High Inhibition

A broad series of 4,5,6,7-tetrahalogenated benzimidazoles and 4-(1H-benzimidazol-2-yl)-benzene-1,3-diol derivatives was tested against selected bacteria and fungi. For this study three plant pathogens Colletotrichum sp., Fusarium sp., and Sclerotinia sp., as well as Staphylococcus sp., Enterococcus sp., Escherichia sp., Enterobacter sp., Klebsiella spp. , and Candida spp. as human pathogens were used. MIC values and/or area of growth reduction method were applied in order to compare the activity of the synthesized compounds. From the presented set of 22 compounds, only 8, 16, 18 and 19 showed moderate to good inhibition against bacterial strains. Against Candida strains only compound 19 with three hydroxyl substituted benzene moiety presented high inhibition at nystatin level or lower.

scholarly journals Thermoflavimicrobium dichotomicum as a novel thermoalkaliphile for production of environmental and industrial enzymes

2019 ◽  
Vol 10 (1) ◽  
pp. 4811-4820
Keyword(s):  
Pathogenic Bacteria ◽  
Biological Activities ◽  
Environmental Aspects ◽  
E Coli ◽  
Wide Range ◽  
Actinomycete Strain ◽  
Inhibition Zones ◽  
Bacteria And Fungi ◽  
Physiological And Biochemical Characters ◽  
Physiological And Biochemical

Thermoalkaliphilic actinomycetes enzymes have many important applications in many industrial, biotechnological and environmental aspects. So, the current study aimed to obtain the thermoalkali-enzymes producing actinomycetes. A novel thermoalkaliphilic actinomycete strain was isolated from Egyptian Siwa oasis and identified according to its morphological, physiological and biochemical characters as Thermoflavimicrobium dichotomicum. And then confirmed by phylogenetic analysis and the partial sequence was deposited in GenBank under accession number of KR011193 and name of Thermoflavimicrobium dichotomicum HwSw11. It could produce amylase, cellulase, lipase, pectinase and proteinase enzymes. Also, this strain exhibited anti-bacterial activities against P. aeruginosa and E. coli with inhibition zones of 14 and 20 mm, respectively. Consequently, it has antifungal activity against A. niger, A. flavus and Penicillium notatum with inhibition zones of 17, 14 and 14 mm, respectively. For that, it may be concluded that Thermoflavimicrobium dichotomicum HwSw11 as a novel thermoalkaliphile has a wide range of biological activities against a broad spectrum of pathogenic bacteria and fungi, in addition to produce many enzymes (amylase, cellulase, lipase, pectinase and proteinase). So, this isolate could be applied as manufactory for many industrial, biotechnological and environmental sectors.

Associated microflora of medicinal ferns: biotechnological potentials and possible applications

2016 ◽  
Vol 5 (03) ◽  
pp. 4927 ◽  
Author(s):  
Shubhi Srivastava ◽  
Paul A. K.
Keyword(s):  
Secondary Metabolites ◽  
Growth Promotion ◽  
Biological Activities ◽  
Hydrolytic Enzymes ◽  
In Vitro Production ◽  
Wide Range ◽  
Negative Effect ◽  
Bacteria And Fungi

Plant associated microorganisms that colonize the upper and internal tissues of roots, stems, leaves and flowers of healthy plants without causing any visible harmful or negative effect on their host. Diversity of microbes have been extensively studied in a wide variety of vascular plants and shown to promote plant establishment, growth and development and impart resistance against pathogenic infections. Ferns and their associated microbes have also attracted the attention of the scientific communities as sources of novel bioactive secondary metabolites. The ferns and fern alleles, which are well adapted to diverse environmental conditions, produce various secondary metabolites such as flavonoids, steroids, alkaloids, phenols, triterpenoid compounds, variety of amino acids and fatty acids along with some unique metabolites as adaptive features and are traditionally used for human health and medicine. In this review attention has been focused to prepare a comprehensive account of ethnomedicinal properties of some common ferns and fern alleles. Association of bacteria and fungi in the rhizosphere, phyllosphere and endosphere of these medicinally important ferns and their interaction with the host plant has been emphasized keeping in view their possible biotechnological potentials and applications. The processes of host-microbe interaction leading to establishment and colonization of endophytes are less-well characterized in comparison to rhizospheric and phyllospheric microflora. However, the endophytes are possessing same characteristics as rhizospheric and phyllospheric to stimulate the in vivo synthesis as well as in vitro production of secondary metabolites with a wide range of biological activities such as plant growth promotion by production of phytohormones, siderophores, fixation of nitrogen, and phosphate solubilization. Synthesis of pharmaceutically important products such as anticancer compounds, antioxidants, antimicrobials, antiviral substances and hydrolytic enzymes could be some of the promising areas of research and commercial exploitation.

scholarly journals Antimicrobial Activities of Marine Sponge-Associated Bacteria

2021 ◽  
Vol 9 (1) ◽  
pp. 171
Author(s):  
Yitayal S. Anteneh ◽  
Qi Yang ◽  
Melissa H. Brown ◽  
Christopher M. M. Franco
Keyword(s):  
Pathogenic Bacteria ◽  
South Australia ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Marine Sponges ◽  
Bioactive Metabolites ◽  
Human Pathogens ◽  
Sponge Associated Bacteria ◽  
Microbial Symbionts ◽  
Bacteria And Fungi

The misuse and overuse of antibiotics have led to the emergence of multidrug-resistant microorganisms, which decreases the chance of treating those infected with existing antibiotics. This resistance calls for the search of new antimicrobials from prolific producers of novel natural products including marine sponges. Many of the novel active compounds reported from sponges have originated from their microbial symbionts. Therefore, this study aims to screen for bioactive metabolites from bacteria isolated from sponges. Twelve sponge samples were collected from South Australian marine environments and grown on seven isolation media under four incubation conditions; a total of 1234 bacterial isolates were obtained. Of these, 169 bacteria were tested in media optimized for production of antimicrobial metabolites and screened against eleven human pathogens. Seventy bacteria were found to be active against at least one test bacterial or fungal pathogen, while 37% of the tested bacteria showed activity against Staphylococcus aureus including methicillin-resistant strains and antifungal activity was produced by 21% the isolates. A potential novel active compound was purified possessing inhibitory activity against S. aureus. Using 16S rRNA, the strain was identified as Streptomyces sp. Our study highlights that the marine sponges of South Australia are a rich source of abundant and diverse bacteria producing metabolites with antimicrobial activities against human pathogenic bacteria and fungi.

scholarly journals Granulins: the structure and function of an emerging family of growth factors

1998 ◽  
Vol 158 (2) ◽  
pp. 145-151 ◽  
Author(s):  
A Bateman ◽  
HP Bennett
Keyword(s):  
Cell Growth ◽  
Biological Activities ◽  
Three Dimensional ◽  
Mesenchymal Cells ◽  
Amino Acid Sequences ◽  
The Body ◽  
Egf Receptors ◽  
Haematopoietic Cells ◽  
And Function ◽  
Related Proteins

The granulin/epithelin motif defines a family of structurally unique proteins, of great evolutionary antiquity, which have been implicated as regulators of cell growth. Recurrent in granulin research are the surprising parallels between the granulin and EGF systems. Both are cysteinerich peptides of approximately 6 kDa that can modify cell growth. They show similar, but not identical, biological activities, although granulin/epithelin peptides do not bind EGF receptors; the three-dimensional folds of granulin and EGF are partially superimposible; and the precursors for mammalian granulin/epithelins and EGF are both organized as multiple repeats of conserved cysteine modules. Given the dissimilarity between amino acid sequences of members of the granulin/epithelin family and EGF-related peptides, the parallelism between the two systems probably represents convergent evolution towards related solutions to common biological problems. The granulin/epithelin precursor gene is expressed throughout the body, but its expression is predominantly in epithelial and haematopoietic cells. There is a great deal of versatility in the means by which cells process and handle the granulin/epithelin precursor. In some instances, the precursor is secreted intact (Zhou et al. 1993), and in others it is stored in a vesicular organelle, such as the sperm acrosome (Baba et al. 1993a). It may be processed into small 6-kDa peptides, which, in the neutrophil, can also be stored in vesicles (Bateman et al. 1990, Couto et al. 1992). The 6-kDa peptide forms, the intact precursor, and related proteins such as TGFe, regulate the growth of epithelial and mesenchymal cells. Epithelial cells express putative receptors for granulin/epithelin peptides and TGFe (Culouscou et al. 1993, Parnell et al. 1995). Thus, although much remains to be clarified, granulin/epithelin polypeptides and related proteins are emerging as widely distributed potential autocrine and paracrine growth modulating factors for epithelial and mesenchymal cells.

scholarly journals Isolation and Identification of Antibiotic-Producing Halophilic Bacteria from Dagh Biarjmand and Haj Aligholi Salt Deserts, Iran

2019 ◽  
Vol 25 (1) ◽  
pp. 70-77 ◽  
Author(s):  
Babak Elyasifar ◽  
Sevda Jafari ◽  
Somayeh Hallaj-Nezhadi ◽  
Florence Chapeland-leclerc ◽  
Gwenaël Ruprich-Robert ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Plant Pathogens ◽  
Halophilic Bacteria ◽  
Pathogenic Fungi ◽  
Antibacterial Activities ◽  
Biochemical Properties ◽  
Diffusion Method ◽  
Human Pathogens ◽  
Isolation And Identification ◽  
Phylogenic Tree

Background: Halophilic bacteria are potent organisms in production of novel bioactive antimicrobial compounds which might be considered in drug innovation and control of plant pathogens. Salt deserts in Semnan province are of the most permanent hypersaline areas in the North of Iran. Despite the importance of these areas, there is no scientific report regarding the biodiversity and potency of their halophilic bacteria. Thus, aforementioned areas were selected to detect the halophilic bacteria. Methods: Here, seven strains were isolated and cultured on their molecular and biochemical properties were characterized. To determine the antibiotic potency of the isolates, agar well diffusion method was conducted. Phylogenetic analysis was done to reveal the isolates relationship with previously known strains. Results: As a result, growth of the strains in the medium containing 5 to 20% (w/v) NaCl determined that the majority of the isolates were moderately halophile. Catalase activity of all strains was positive. The results represented that D6A, Dar and D8B have antimicrobial effects against different plant and human pathogens. Phylogenic tree analysis also showed that two strains of D6A and Dar are belonged to Bacillus subtilis and D8B is belonged to Virgibacillus olivae. The bacteria extracts were evaluated for their antifungal and antibacterial activities on human and Plant pathogenic strains. The MIC of the extract B. subtilis against was found active against human pathogenic fungi and Plant pathogenic bacteria and fungi, ranging from 12.5 to 25 µg/mL. Conclusion: This study highlights the therapeutic and prophylactic potential of B. subtilis extracts as antibacterial and antifungal agents.

scholarly journals Essential Oils as Potential Alternative Biocontrol Products against Plant Pathogens and Weeds: A Review

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 365 ◽  
Author(s):  
Robin Raveau ◽  
Joël Fontaine ◽  
Anissa Lounès-Hadj Sahraoui
Keyword(s):  
Essential Oils ◽  
Plant Pathogens ◽  
Crop Yields ◽  
Biological Activities ◽  
Pathogenic Fungi ◽  
Phytopathogenic Fungi ◽  
Plant Diseases ◽  
Present Review ◽  
Traditional Medicines ◽  
Wide Range

Naturally produced by aromatic plants, essential oils (EO) contain a wide range of volatile molecules, including mostly secondary metabolites, which possess several biological activities. Essential oils properties such as antioxidant, antimicrobial and anti-inflammatory activities are known for a long time and hence widely used in traditional medicines, cosmetics and food industries. However, despite their effects against many phytopathogenic fungi, oomycetes and bacteria as well as weeds, their use in agriculture remains surprisingly scarce. The purpose of the present review is to gather and discuss up-to-date biological activities of EO against weeds, plant pathogenic fungi, oomycetes and bacteria, reported in the scientific literature. Innovative methods, potentially valuable to improve the efficiency and reliability of EO, have been investigated. In particular, their use towards a more sustainable agriculture has been discussed, aiming at encouraging the use of alternative products to substitute synthetic pesticides to control weeds and plant diseases, without significantly affecting crop yields. An overview of the market and the recent advances on the regulation of these products as well as future challenges to promote their development and wider use in disease management programs is described. Because of several recent reviews on EO insecticidal properties, this topic is not covered in the present review.

scholarly journals ChoK-ing the Pathogenic Bacteria: Potential of Human Choline Kinase Inhibitors as Antimicrobial Agents

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Moad Khalifa ◽  
Ling Ling Few ◽  
Wei Cun See Too
Keyword(s):  
Cell Wall ◽  
Targeted Delivery ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Kinase Inhibitors ◽  
Amino Acid Sequences ◽  
Choline Kinase ◽  
Anticancer Properties ◽  
Wide Range ◽  
Catalytic Sites

Novel antimicrobial agents are crucial to combat antibiotic resistance in pathogenic bacteria. Choline kinase (ChoK) in bacteria catalyzes the synthesis of phosphorylcholine, which is subsequently incorporated into the cell wall or outer membrane. In certain species of bacteria, phosphorylcholine is also used to synthesize membrane phosphatidylcholine. Numerous human ChoK inhibitors (ChoKIs) have been synthesized and tested for anticancer properties. Inhibition of S. pneumoniae ChoK by human ChoKIs showed a promising effect by distorting the cell wall and retarded the growth of this pathogen. Comparison of amino acid sequences at the catalytic sites of putative choline kinases from pathogenic bacteria and human enzymes revealed striking sequence conservation that supports the potential application of currently available ChoKIs for inhibiting bacterial enzymes. We also propose the combined use of ChoKIs and nanoparticles for targeted delivery to the pathogen while shielding the human host from any possible side effects of the inhibitors. More research should focus on the verification of putative bacterial ChoK activities and the characterization of ChoKIs with active enzymes. In conclusion, the presence of ChoK in a wide range of pathogenic bacteria and the distinct function of this enzyme has made it an attractive drug target. This review highlighted the possibility of “choking” bacterial ChoKs by using human ChoKIs.

scholarly journals Transition Metal Complexes of Mixed Bioligands: Synthesis, Characterization, DFT Modeling, and Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Mohamed S. A. Abdel-Mottaleb ◽  
Eman H. Ismail
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Corrosion Inhibition ◽  
Transition Metal Complexes ◽  
Pathogenic Bacteria ◽  
Chemical Potential ◽  
Biological Activities ◽  
Aluminum Surface ◽  
Bacteria And Fungi

Divalent transition metal complexes [MGlu-Arg (H2O)]H2O and [MGlu-Arg (H2O)]H2O, where M = Co, Ni, Cu, and Zn, Glu = glutamic acid, and Arg = L-arginine, are prepared and characterized using different techniques. DFT and TD-DFT modelling validated and interpreted some experimental results. Weight loss technique reveals efficient corrosion inhibition action of these complexes towards aluminum metal at different temperatures. Our results point to corrosion inhibition through chemical adsorption on the aluminum surface. Additionally, a facile calcination of Co and Cu complexes at 550°C yields nanosized oxides of Co3O4, CoO, and CuO crystalline phases. The complexes show remarkable biological activities towards pathogenic bacteria and fungi. Moreover, in vitro anticancer activity evaluation of these complexes is achieved against hepatocellular carcinoma (HepG-2). The results are correlated with molecular descriptors such as chemical potential and hardness obtained from the frontier orbitals.

scholarly journals The Secretion of Toxins and Other Exoproteins of Cronobacter: Role in Virulence, Adaption, and Persistence

2020 ◽  
Vol 8 (2) ◽  
pp. 229 ◽  
Author(s):  
Hyein Jang ◽  
Gopal R. Gopinath ◽  
Athmanya Eshwar ◽  
Shabarinath Srikumar ◽  
Scott Nguyen ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Human Disease ◽  
Pathogenic Bacteria ◽  
Eukaryotic Cell ◽  
Human Pathogens ◽  
Wide Range ◽  
Cell Processes ◽  
Cronobacter Species ◽  
Foodborne Pathogenic Bacteria ◽  
Species Specific

Cronobacter species are considered an opportunistic group of foodborne pathogenic bacteria capable of causing both intestinal and systemic human disease. This review describes common virulence themes shared among the seven Cronobacter species and describes multiple exoproteins secreted by Cronobacter, many of which are bacterial toxins that may play a role in human disease. The review will particularly concentrate on the virulence factors secreted by C. sakazakii, C. malonaticus, and C. turicensis, which are the primary human pathogens of interest. It has been discovered that various species-specific virulence factors adversely affect a wide range of eukaryotic cell processes including protein synthesis, cell division, and ion secretion. Many of these factors are toxins which have been shown to also modulate the host immune response. These factors are encoded on a variety of mobile genetic elements such as plasmids and transposons; this genomic plasticity implies ongoing re-assortment of virulence factor genes which has complicated our efforts to categorize Cronobacter into sharply defined genomic pathotypes.

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