Exopolysaccharides, known as bacterial EPS, are complex sugar polymers that bacteria secrete into their environment. EPSs play a crucial role in bacterial survival and proliferation by protecting cells from environmental threats. They also contribute to proper adhesion to numerous surfaces through biofilm production. Bacterial EPS display a wide range of biological activities conferred by their outstanding physical and chemical properties, which make them great candidates for medical and industrial applications. The main biological activities recorded up-to-day include antioxidant, anticancer, antiviral, anti-inflammatory, anticancer, antibacterial, immune-modulatory and chelating properties. They also can be used as thickening agents in the industry or as additives to improve soil quality in agriculture. The current review offers a thorough overview of bacterial EPS, their biosynthesis processes and regulation, and biotechnological strategies to increase their production. The review also unravels the main extraction, purification, and identification techniques and highlights the key functional features of these complex molecules.
2 July 2024 in Journal of microbiology, biotechnology and food sciences
Faced with global environmental challenges, the quest for sustainable food production has gathered momentum. While abiotic stresses adversely affect plant health and productivity, Verticillium wilt causes considerable yield losses worldwide, particularly in crops such as olive. Recently, drought-tolerant bacteria have been used to alleviate both abiotic stress and pathogen pressure in crops. In this context, our work focuses on the isolation of tolerant indigenous rhizobacteria to mitigate these challenges by investigating their role in biocontrol and abiotic stress tolerance. Thus, a total of 94 rhizobacterial strains were isolated from the rhizospheres of olive trees in southeastern Morocco and characterized to identify tolerant plant growth-promoting rhizobacteria that inhibit Verticillium dahliae. 24 strains demonstrated in vitro suppression of Verticillium dahliae Klebahn, and exhibited tolerance to different abiotic stresses (drought, salinity, and high temperature). In addition, they proved xerotolerant (Aw ≤ 0.91), halotolerant (≥10% NaCl), and thermotolerant (≥ 55°C) capabilities. Beyond, these isolates showcased multifaceted plant growth-promoting traits, such as phosphate solubilization and significant synthesis of essential bioactive compounds like siderophores, indole-3-acetic acid and hydrolytic enzymes. Evaluating outcomes, three standout rhizobacterial isolates emerged due to their exceptional stress tolerance, unique plant growth-promoting qualities, and potent antagonistic potential. Molecular analysis identified them as Bacillus paranthracis (OZ-60) and Bacillus licheniformis (OZ-48 and OZ-77) through 16S rRNA sequencing. Besides enhancing plant abiotic stress resistance, these isolates hold promise in bolstering the sustainability of olive cultivation and fortifying plant defenses against pathogens.
Tomatoes are globally significant crops worldwide. Understanding the molecular mechanisms underlying their growth, development, and stress responses is crucial to enhance crop productivity and resilience. The WUSCHEL-related homeobox (WOX) gene family is implicated in developmental processes and stress responses, yet its regulatory complexity in tomato remains underexplored. This study presents an integrative genome-wide analysis approach to characterize the WOX family in tomato. Ten SlWOX genes were identified and phylogenetically classified into three clades, WUS, intermediate and ancient, underscoring their evolutionary relationships. Structural analysis revealed significant variability in gene structure even within the same clade, indicating potential diversity in functional roles. Conserved domains’ screening enables the detection of conserved motifs, including the homeodomain and WUS box. Cis-element analysis showed diverse regulatory elements across the SlWOXs, with a strong emphasis on elements involved in growth and development and stress response. Expression profiling across different organs and growth conditions including abiotic and biotic stresses revealed variability in SlWOXs’ expression patterns. Furthermore, several miRNAs were predicted to target the SlWOXs, emphasizing the existence of post-transcriptional regulation. Functional annotation and interactome analysis further revealed the key role of some SlWOXs, mainly SlWUS, SlWOX4 and SlWOX13, as central regulatory hubs. Collectively, these findings uncover the structural diversity, regulatory mechanisms and functional flexibility of the SlWOX gene family. It also highlights potential targets for improving tomato crop resilience and productivity, making it a significant contribution to plant biology and agriculture.