scholarly journals Antimicrobial Activities and Molecular Signature of Endophytic Fungi of Opuntia ficus-Indica Cacti and the Cactus-Like Plant Aloe vera

2021 ◽  
Vol 14 (4) ◽  
pp. 2025-2031
Author(s):  
Afaf S. Alghamdi

Endophytes are fungi that colonize the internal tissues of plants without causing immediate adverse effects. Saudi Arabia (SA) is rich in Opuntia ficus-indica cacti and the cactus-like plant Aloe vera, which grow in the southern and western areas of SA. This study aimed to isolate and identify endophytic fungi from cacti and cactus-like plants in the Jeddah, Taif, and Al Baha regions KSA and then determine their effects on pathogenic fungal and bacterial growth. The isolates were groupedAloe Vera; Opuntia Ficus-Indica; Endophytic Fungi; Antimicrobial Activities; Pathogenic Bacteria. into 16 distinct operational taxonomic units based on the sequence of the internal transcribed spacer in the rDNA gene with the primers ITS1 and ITS4. Mucor circinelloides was the endophytic fungus found most frequently, with a relative frequency of 20.43%, followed by Talaromyces funiculosus, with a relative frequency of 16.12% when isolated from Opuntia ficus-indica and Aloe vera. Nine out of sixteen endophytic fungi exhibited strong antifungal activity against all the tested pathogens. P. funiculosum, Aspergillus versicolor, Penicillium janthinellum, and Fusarium oxysporum showed vigorous antimicrobial activities against the human pathogenic bacteria Escherichia coli, Shigella sp., and Salmonella typhimurium.

Author(s):  
Taher, M. A. ◽  
Yenn, T. W. ◽  
Ring, L. C. ◽  
Wahidin, S. ◽  
Noor, M. A. M. ◽  
...  

2009 ◽  
Vol 1 (2) ◽  
Author(s):  
Risa Nofiani ◽  
Siti Nurbetty ◽  
Ajuk Sapar

<p>The increase of issues on the antibiotics resistant pathogenic bacteria has triggered high exploration for new antimicrobial compounds. One of the potential sources is sponge-associated bacteria. The aim of this study was to get sponge-associated bacteria extract containing antimicrobial activities. On the basis screening of antimicrobial activity using by streaking on agar medium, there were two potential isolates with antimicrobial activities namely LCS1 and LCS2. The two isolates were cultivated,then secondary metabolite product were extracted using methanol as a solvent. Minimum inhibitory concentrations (MICs) of extract LCS 1 were 1,000 μg/well for S. aureus, 950 μg/well for Salmonella sp.and 800 μg/well for Bacillus subtilis. Minimum inhibitory concentrations of extract LCS 2 were 500 μg/well for S. aureus, 1,050 μg/well for Salmonella sp., 750 μg/well for Bacillus subtilis, 350 μg/well for P. aeruginosa, 750 μg/sumur terhadap B. subtilis. Based on the MIC values, the two assay extracts have a relatively low antimicrobial activity.</p> <p>Keywords:Antimicrobial,Sponges associated bacteria,MICs</p>


2021 ◽  
Vol 22 (5) ◽  
pp. 2643
Author(s):  
Mohamed F. Hassan ◽  
Abdelrahman M. Qutb ◽  
Wubei Dong

Antimicrobial peptides (AMPs) are small molecules consisting of less than fifty residues of amino acids. Plant AMPs establish the first barrier of defense in the innate immune system in response to invading pathogens. The purpose of this study was to isolate new AMPs from the Zea mays L. inbred line B73 and investigate their antimicrobial activities and mechanisms against certain essential plant pathogenic bacteria. In silico, the Collection of Anti-Microbial Peptides (CAMPR3), a computational AMP prediction server, was used to screen a cDNA library for AMPs. A ZM-804 peptide, isolated from the Z. mays L. inbred line B73 cDNA library, was predicted as a new cationic AMP with high prediction values. ZM-804 was tested against eleven pathogens of Gram-negative and Gram-positive bacteria and exhibited high antimicrobial activities as determined by the minimal inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs). A confocal laser scanning microscope observation showed that the ZM-804 AMP targets bacterial cell membranes. SEM and TEM images revealed the disruption and damage of the cell membrane morphology of Clavibacter michiganensis subsp. michiganensis and Pseudomonas syringae pv. tomato (Pst) DC3000 caused by ZM-804. In planta, ZM-804 demonstrated antimicrobial activity and prevented the infection of tomato plants by Pst DC3000. Moreover, four virulent phytopathogenic bacteria were prevented from inducing hypersensitive response (HR) in tobacco leaves in response to low ZM-804 concentrations. ZM-804 exhibits low hemolytic activity against mouse red blood cells (RBCs) and is relatively safe for mammalian cells. In conclusion, the ZM-804 peptide has a strong antibacterial activity and provides an alternative tool for plant disease control. Additionally, the ZM-804 peptide is considered a promising candidate for human and animal drug development.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1066
Author(s):  
Fahima Abdellatif ◽  
Muhammad Akram ◽  
Samir Begaa ◽  
Mohammed Messaoudi ◽  
Adel Benarfa ◽  
...  

This study describes the minerals elements, chemical composition, antioxidant and antimicrobial activities of Algerian Melissa officinalis plant. The essential oil (EO) was extracted by hydrodistillation (HD) using a Clevenger-type apparatus of dry leaves of M. officinalis and was analyzed by two techniques, gas chromatography coupled with flame ionization (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). Eighteen minerals comprising both macro- and microelements (As, Br, K, La, Na, Sb, Sm, Ba, Ca, Ce, Co, Cr, Cs, Fe, Rb, Sc, Th, and Zn) were determined using neutron activation analysis technique for the first time from Algerian Melissa officinalis plant. Seventy-eight compounds were identified in the essential oil, representing 94.090% of the total oil and the yields were 0.470%. The major component was geranial (45.060%). Other predominant components were neral (31.720%) and citronellal (6.420%). The essential oil presented high antimicrobial activity against microorganisms, mainly five human pathogenic bacteria, one yeast, Candida albicans, and two phytopathogenic fungi. The results can be used as a source of information for the pharmaceutical industry and medical research.


2021 ◽  
Vol 9 (1) ◽  
pp. 171
Author(s):  
Yitayal S. Anteneh ◽  
Qi Yang ◽  
Melissa H. Brown ◽  
Christopher M. M. Franco

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.


Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 787
Author(s):  
Tshikala Eddie Lulamba ◽  
Ezekiel Green ◽  
Mahloro Hope Serepa-Dlamini

Entomopathogenic nematodes (EPNs) are known to be highly pathogenic to insect pests, due to their associated symbiotic bacteria, which produce virulence factors, exo-enzymes and other harmful secondary metabolites to conquer, kill, and degrade their insect hosts. However, these properties are not fully characterized. This study reports on the antimicrobial activities of Photorhabdus sp. strain ETL, symbiotically associated to an insect pathogenic nematode, Heterorhabditis zealandica, against human pathogenic bacteria and toxigenic fungi, as well as the non-targeted profiling of its secondary metabolites (SMs) using gas chromatography coupled to high-resolution time-of-flight mass spectrometry. Fatty acids including 3-eicosene, (E)-; 5-eicosene, (E)-; eicosene; 9-octadecenamide; undecanoic acid with shown antimicrobial activities were detected. This provided more insight on the composition and bioactivities of SMs produced by the Photorhabdus sp.


Author(s):  
Prabhurajeshwar C. ◽  
Kelmani Chandrakanth R.

<p><strong>Objective: </strong>Probiotic products consist of specific strains of live bacteria that have potentially favorable health effects. A number of studies provide evidence that milk products with probiotics may be beneficial for digestive health and may improve various digestive problems. The purpose of the present study was to investigate <em>Lactobacillus</em> species with potential activities isolated from different cheese samples of local market.</p><p><strong>Methods: </strong>A total 42 lactic acid bacteria strains were isolated, fourteen (14/42) best <em>Lactobacillus</em> isolates were selected by preliminary screening as potential probiotics with antimicrobial activity against pathogenic bacteria. All the fourteen <em>Lactobacillus</em> isolates were then characterized <em>in vitro</em> for their probiotic features and antimicrobial activities against pathogens.</p><p><strong>Results: </strong>The results noticed that all selected <em>Lactobacillus</em> isolates (CH3, CH4 and CH6) were screened and confirmed as <em>Lactobacillus. </em>The isolates were able to grow at different pH, NaCl and bile salts, also exhibited the best antimicrobial activities against pathogens. All the isolates were susceptible to antibiotics used and isolates were also revealed the noticeable aggregation and hydrophobicity studies.<strong></strong></p><p><strong>Conclusion: </strong>Selected <em>Lactobacillus </em>isolates were considered as ideal, effective probiotic bacteria. Thus, they could be examined further and contribute to preventing and controlling several infections associated with intestine and for human health benefits.</p>


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