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Endophytic bacteria serve as a rich source of diverse antimicrobial compounds. Recently, there has been a growing interest in utilizing endophytic Bacillus spp. as biological agents against phytogenic fungi, owing to their potential to produce a wide range of antimicrobial substances. The objective of this research was to investigate the protective abilities of 15 endophytic Bacillus spp. isolated from previous study from wheat plant, against the phytopathogenic fungi, Fusarium graminearum and Macrophomina phaseolina. A dual culture plate assay was conducted as a preliminary analysis, revealing that 7 out of 15 endophytic Bacillus spp. demonstrated inhibition against one or both of the phytopathogenic fungi used in this study. All seven endophytes were further assessed for the presence of diffusible antifungal metabolites. The cultures were grown in potato dextrose broth for 120 h, and the cell-free supernatant was extracted and analyzed using the cup plate method. The methanolic extract yielded similar results to the dual culture plate analysis, except for WL2-15. Additionally, deformities in the mycelial structure were examined under the light microscope upon exposure to methanolic extract. Furthermore, the analysis and identification of metabolites were carried out via gas chromatography-mass spectrometry of methanolic extract from selected seven endophytic Bacillus spp. The chromatogram revealed the presence of some major peaks such as tridecanoic acid, methyl ester, hydroperoxide, 1-methylbutyl, 9-octadecenamide, (z)-, hexane-1,3,4-triol, 3,5-dimethyl- tetradecanoic acid. To the best of our knowledge, this is the first report of these biocontrol agents in endophytic Bacillus spp. Interestingly, volatile organic compound production was also seen in all the isolates against the phytopathogenic fungi., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.) more...

The Cholla cactus is a species of cacti that survives in arid environments and produces a unique mesh-like porous wood. In this article, we present a comprehensive investigation on the hierarchical structure and micromechanical properties of the Cholla cactus wood. Multiple approaches consisting of X-ray tomography, scanning electron microscopy, scanning probe microscopy, nanoindentation, and finite element simulations were used to gain insight into the structure, property, and design principles of the Cholla cactus wood. The microstructure of the Cholla cactus wood consists of different components, including vessels, rays, and fibers. In the present study, we quantitatively describe the structure of each of these wood components and their likely functions, both from the perspective of biological and mechanical behavior. Nanoindentation experiments revealed for the first time that the cell walls of the fibers exhibit stiffness and hardness higher than those of rays. Furthermore, the idea of making porous, thin-walled cylinders was abstracted from the design of vessel elements, and the structures inspired by this principle were studied in tensile and torsional loading conditions using finite element simulations. Finite element simulations revealed that the utilization of a larger volume of material to carry the load leads to an increase in toughness of these structures, and thus suggested that the pores should be architected to maximize the distribution of load. STATEMENT OF SIGNIFICANCE: The Cholla cactus wood possess a unique hierarchical structure that enables it to thrive in arid environments. Our correlative microscopy approach reveals incredible strategies that individual wood components exhibit to enable the survival of Cholla cactus in extreme environments. The present work quantifies the microstructure and mechanical properties of this very interesting natural system. We further investigate a design principle inspired by the vessel elements, one of the wood components of Cholla cactus, using finite element simulations. The study presented here advances our understanding of the structural significance of Cholla cactus and potentially other desert plants and will further help design architected structural materials., Competing Interests: Declaration of Competing Interest The authors do not have any financial interests associated with this manuscript., (Copyright © 2023 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.) more...

The fibers of the deep-sea sponge Euplectella aspergillum exhibit exceptional mechanical properties due to their unique layered structure at a micrometer length scale. In the present study, we utilize a correlative approach comprising of in situ tensile testing inside a scanning electron microscope (SEM) and post-failure fractography to precisely understand mechanisms through which layered architecture of fibers fracture and improves damage tolerance in tensile loading condition. The real-time observation of fibers in the present study confirms for the first time that the failure starts from the surface of fibers and proceeds to the center through successive layers. The concentric layers surrounding the central core sacrifice themselves and protect the central core through various toughening mechanisms like crack deflection, crack arrest, interface debonding, and fiber pullout. STATEMENT OF SIGNIFICANCE: Biological materials often exhibit multiscale hierarchical structures that can be incorporated into the design of next generation of engineering materials. The fibers of deep-sea sponge E. aspergillum possess core-shell like layered architecture. Our in situ study reveals astounding strategies by which this architecture delays the fracture of the fiber. The core-shell architecture of these fibers behaves like fiber-reinforced ceramic matrix composite, where the outer shells act as a matrix and the central core acts as a fiber. The outer shells take the environmental brunt and scarify themselves to protect the central core. The precise understanding of damage evolution presented here will help to design architected materials for load-bearing applications., Competing Interests: Declaration of Competing Interest The authors do not have any financial interests associated with this manuscript., (Copyright © 2023 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.) more...

Biodiversity provides a massive library of ideas for bio-inspired design, but the sheer number of species to consider can be daunting. Current approaches for sifting through biodiversity to identify relevant biological models include searching for champion adapters that are particularly adept at solving a particular design challenge. While the champion adapter approach has benefits, it tends to focus on a narrow set of popular models while neglecting the majority of species. An alternative approach to bio-inspired design is the comparative method, which leverages biodiversity by drawing inspiration across a broad range of species. This approach uses methods in phylogenetics to map traits across evolutionary trees and compare trait variation to infer structure-function relationships. Although comparative methods have not been widely used in bio-inspired design, they have led to breakthroughs in studies on gecko-inspired adhesives and multifunctionality of butterfly wing scales. Here we outline how comparative methods can be used to complement existing approaches to bioinspired design, and we provide an example focused on bio-inspired lattices, including honeycomb and glass sponges. We demonstrate how comparative methods can lead to breakthroughs in bio-inspired applications as well as answer major questions in biology, which can strengthen collaborations with biologists and produce deeper insights into biological function., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology.) more...