Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
28,254
result(s) for
"Biological Control Agents"
Sort by:
Pathogens for War : Biological Weapons, Canadian Life Scientists, and North American Biodefence
\"Pathogens for War explores how Canada and its allies have attempted to deal with the threat of germ warfare, one of the most fearful weapons of mass destruction, since the Second World War. In addressing this subject, distinguished historian Donald Avery investigates the relationship between bioweapons, poison gas, and nuclear devices, as well as the connection between bioattacks and natural disease pandemics. Avery emphasizes the crucially important activities of Canadian biodefence scientists - beginning with Nobel Laureate Frederick Banting - at both the national level and through cooperative projects within the framework of an elaborate alliance system\"--Preliminary page.
Book
Antimicrobial secondary metabolites from agriculturally important fungi as next biocontrol agents
Synthetic chemical pesticides have been used for many years to increase the yield of agricultural crops. However, in the future, this approach is likely to be limited due to negative impacts on human health and the environment. Therefore, studies of the secondary metabolites produced by agriculturally important microorganisms have an important role in improving the quality of the crops entering the human food chain. In this review, we have compiled information about the most important secondary metabolites of fungal species currently used in agriculture pest and disease management.
Journal Article
Bacillus velezensis: a versatile ally in the battle against phytopathogens—insights and prospects
The escalating interest in
Bacillus velezensis
as a biocontrol agent arises from its demonstrated efficacy in inhibiting both phytopathogenic fungi and bacteria, positioning it as a promising candidate for biotechnological applications. This mini review aims to offer a comprehensive exploration of the multifaceted properties of
B. velezensis
, with particular focus on its beneficial interactions with plants and its potential for controlling phytopathogenic fungi. The molecular dialogues involving
B. velezensis
, plants, and phytopathogens are scrutinized to underscore the intricate mechanisms orchestrating these interactions. Additionally, the review elucidates the mode of action of
B. velezensis
, particularly through cyclic lipopeptides, highlighting their importance in biocontrol and promoting plant growth. The agricultural applications of
B. velezensis
are detailed, showcasing its role in enhancing crop health and productivity while reducing reliance on chemical pesticides. Furthermore, the review extends its purview in the industrial and environmental arenas, highlighting its versatility across various sectors. By addressing challenges such as formulation optimization and regulatory frameworks, the review aims to chart a course for the effective utilization of
B. velezensis
.
Key points
•
B. velezensis fights phytopathogens, boosting biotech potential
•
B. velezensis shapes agri-biotech future, offers sustainable solutions
•
Explores plant-B. velezensis dialogue, lipopeptide potential showcased
Journal Article
Chaetomium globosum CDW7, a potential biological control strain and its antifungal metabolites
Abstract
Screening for endophytic fungi with antifungal activity is an effective strategy for the discovery of novel biopesticides. Our previous work indicated that Chaetomium globosum CDW7, an endophyte from Ginkgo biloba, exhibited strong inhibitory activity against plant pathogenic fungi in vitro. In this study, we evaluated the CDW7 strain for its antifungal activities against nine phytopathogenic fungi and its biocontrol potential against rape sclerotinia rot caused by Sclerotinia sclerotiorum. The fermentation broth of CDW7 could successfully inhibit disease development in S. sclerotiorum-infected rape in vivo with 57.8% protective efficiency, which is comparable to that of carbendazim (59.8%) at 250 μg mL−1. The fermentation broth also expressed significant activity stability when exposed to 60°C and UV illumination, or when stored at 4°C. Furthermore, we found that 10% fermentation broth can promote the germination and growth of rape seedlings. Followed by the bioassay-guided approach, seven known metabolites were isolated and identified by spectroscopic analyses. Among them, chaetoglobosin A and D exhibited inhibitory activity against S. sclerotiorum with IC50 values of 0.35 and 0.62 μg mL−1, respectively, compared with carbendazim (0.17 μg mL−1). Therefore, our study demonstrated that CDW7 is a promising biocontrol fungus against S. sclerotiorum in agriculture.
Chaetomium globosum CDW7, an endophyte from Ginkgo biloba, is a promising biocontrol fungus against Sclerotinia sclerotiorum in agriculture.
Journal Article
Biological control of potato common scab by Bacillus amyloliquefaciens Ba01
Potato common scab, which is caused by soil-borne Streptomyces species, is a severe plant disease that results in a significant reduction in the economic value of potatoes worldwide. Due to the lack of efficacious pesticides, crop rotations, and resistant potato cultivars against the disease, we investigated whether biological control can serve as an alternative approach. In this study, multiple Bacillus species were isolated from healthy potato tubers, and Bacillus amyloliquefaciens Ba01 was chosen for further analyses based on its potency against the potato common scab pathogen Streptomyces scabies. Ba01 inhibited the growth and sporulation of S. scabies and secreted secondary metabolites such as surfactin, iturin A, and fengycin with potential activity against S. scabies as determined by imaging mass spectrometry. In pot assays, the disease severity of potato common scab decreased from 55.6 ± 11.1% (inoculated with S. scabies only) to 4.2 ± 1.4% (inoculated with S. scabies and Ba01). In the field trial, the disease severity of potato common scab was reduced from 14.4 ± 2.9% (naturally occurring) to 5.6 ± 1.1% after Ba01 treatment, representing evidence that Bacillus species control potato common scab in nature.
Journal Article
Structure of ribosome-bound azole-modified peptide phazolicin rationalizes its species-specific mode of bacterial translation inhibition
Ribosome-synthesized post-translationally modified peptides (RiPPs) represent a rapidly expanding class of natural products with various biological activities. Linear azol(in)e-containing peptides (LAPs) comprise a subclass of RiPPs that display outstanding diversity of mechanisms of action while sharing common structural features. Here, we report the discovery of a new LAP biosynthetic gene cluster in the genome of
Rhizobium
Pop5, which encodes the precursor peptide and modification machinery of phazolicin (PHZ) – an extensively modified peptide exhibiting narrow-spectrum antibacterial activity against some symbiotic bacteria of leguminous plants. The cryo-EM structure of the
Escherichia coli
70S-PHZ complex reveals that the drug interacts with the 23S rRNA and uL4/uL22 proteins and obstructs ribosomal exit tunnel in a way that is distinct from other compounds. We show that the uL4 loop sequence determines the species-specificity of antibiotic action. PHZ expands the known diversity of LAPs and may be used in the future as biocontrol agent for agricultural needs.
The authors report the identification of phazolicin (PHZ) - a prokaryotic translation inhibitory peptide - and its structure in complex with the
E. coli
ribosome, delineating PHZ’s mode of action and suggesting a basis for its bacterial species-specific activity.
Journal Article
Optimal Extraction of Ocimum basilicum Essential Oil by Association of Ultrasound and Hydrodistillation and Its Potential as a Biopesticide Against a Major Stored Grains Pest
The essential oil of basil (Ocimum basilicum) has significant biological activity against insect pests and can be extracted through various techniques. This work aimed to optimize and validate the extraction process of the essential oil of O. basilicum submitted to different drying temperatures of the leaves and extracted by the combination of a Clevenger method and ultrasound. The biological activity of the extracted oil under different conditions was evaluated for potential control of Sitophilus zeamais. The extraction method was optimized according to the sonication time by ultrasound (0, 8, 19, 31 and 38 min) and hydrodistillation (20, 30, 45, 60 and 70 min) and drying temperature (20, 30, 45, 60 and 70 °C). The bioactivity of the essential oil was assessed against adults of S. zeamais and the effects of each variable and its interactions on the mortality of the insects were evaluated. The best yield of essential oil was obtained with the longest sonication and hydrodistillation times and the lowest drying temperature of leaves. Higher toxicity of the essential oil against S. zeamais was obtained by the use of ultrasound for its extraction. The identification and the relative percentage of the compounds of the essential oil were performed with a gas chromatograph coupled to a mass selective detector. The performance of the method was assessed by studying selectivity, linearity, limits of detection (LOD) and quantification (LOQ), precision and accuracy. The LOD and LOQ values for linalool were 2.19 and 6.62 µg mL−1 and for estragole 2.001 and 6.063 µg mL−1, respectively. The coefficients of determination (R2) were >0.99. The average recoveries ranged between 71 and 106%, with coefficient of variation ≤6.4%.
Journal Article
Biopesticide Compounds from an Endolichenic Fungus Xylaria sp. Isolated from the Lichen Hypogymnia tubulosa
Endolichenic fungi represent an important ecological group of microorganisms that form associations with photobionts in the lichen thallus. These endofungi that live in and coevolve with lichens are known for synthesizing secondary metabolites with novel structures and diverse chemical skeletons making them an unexplored microbial community of great interest. As part of our search for new phytoprotectants, in this work, we studied the endolichenic fungus Xylaria sp. isolated from the lichen Hypogymnia tubulosa, which grows as an epiphyte on the bark of the endemic Canarian tree Pinus canariensis. From the extract of the liquid fermentation, we isolated two unreported piliformic derivatives, (+)-9-hydroxypiliformic acid (1) and (+)-8-hydroxypiliformic acid (2), along with four previously reported compounds, (+)-piliformic acid (3), hexylaconitic acid A anhydride (4), 2-hydroxyphenylacetic acid (5), and 4-hydroxyphenylacetic acid (6). Their structures were elucidated based on NMR and HRESIMS data. The extract and the isolated compounds were tested for their insect antifeedant (Myzus persicae, Rhopalosiphum padi, and Spodoptera littoralis), antifungal (Alternaria alternata, Botrytis cinerea, and Fusarium oxysporum), nematicidal (Meloidogyne javanica), and phytotoxic effects on mono- and dicotyledonous plant models (Lolium perenne and Lactuca sativa). Compounds 4, 5, and 6 were effective antifeedants against M. persicae and 4 was also active against R. padi. Moreover, 3 and 4 showed antifungal activity against B. cinerea and 4 was the only nematicidal. The extract had a strong phytotoxic effect on L. sativa and L. perenne growth, with compounds 3, 4, and 5 identified as the phytotoxic agents, while at low concentrations compounds 3 and 4 stimulated L. sativa root growth.
Journal Article
The spread of Wolbachia through mosquito populations
In many regions of the world, mosquito-borne viruses pose a growing threat to human health. As an alternative to traditional control measures, the bacterial symbiont Wolbachia has been transferred from Drosophila into the mosquito Aedes aegypti, where it can block the transmission of dengue and Zika viruses. A recent paper has reported large-scale releases of Wolbachia-infected Ae. aegypti in the city of Cairns, Australia. Wolbachia, which is maternally transmitted, invaded and spread through the populations due to a sperm-egg incompatibility called cytoplasmic incompatibility. Over a period of 2 years, a wave of Wolbachia infection slowly spread out from 2 release sites, demonstrating that it will be possible to deploy this strategy in large urban areas. In line with theoretical predictions, Wolbachia infection at a third, smaller release site collapsed due to the immigration of Wolbachia-free mosquitoes from surrounding areas. This remarkable field experiment has both validated theoretical models of Wolbachia population dynamics and demonstrated that this is a viable strategy to modify mosquito populations.
Journal Article
New Sorbicillinoids with Tea Pathogenic Fungus Inhibitory Effect from Marine-Derived Fungus Hypocrea jecorina H8
Four new dimeric sorbicillinoids (1–3 and 5) and a new monomeric sorbicillinoid (4) as well as six known analogs (6–11) were purified from the fungal strain Hypocrea jecorina H8, which was obtained from mangrove sediment, and showed potent inhibitory activity against the tea pathogenic fungus Pestalotiopsis theae (P. theae). The planar structures of 1–5 were assigned by analyses of their UV, IR, HR-ESI-MS, and NMR spectroscopic data. All the compounds were evaluated for growth inhibition of tea pathogenic fungus P. theae. Compounds 5, 6, 8, 9, and 10 exhibited more potent inhibitory activities compared with the positive control hexaconazole with an ED50 of 24.25 ± 1.57 µg/mL. The ED50 values of compounds 5, 6, 8, 9, and 10 were 9.13 ± 1.25, 2.04 ± 1.24, 18.22 ± 1.29, 1.83 ± 1.37, and 4.68 ± 1.44 µg/mL, respectively. Additionally, the effects of these compounds on zebrafish embryo development were also evaluated. Except for compounds 5 and 8, which imparted toxic effects on zebrafish even at 0.625 μM, the other isolated compounds did not exhibit significant toxicity to zebrafish eggs, embryos, or larvae. Taken together, sorbicillinoid derivatives (6, 9, and 10) from H. jecorina H8 displayed low toxicity and high anti-tea pathogenic fungus potential.
Journal Article