World journal of microbiology & biotechnology最新文献

Citrus Greening Disease (CGD), caused by Candidatus Liberibacter asiaticus (CLas), severely impairs citrus growth and productivity. Among five Bacillus isolates from acid lime leaves, Bacillus subtilis LBS5 exhibited superior plant growth-promoting traits, including a glucanolytic index of 5.85, siderophore production of 9.85 µmol/ml, IAA synthesis of 28.67 µg/ml, and phosphate solubilization of 249.34 µg/ml. LBS5 inhibited the surrogates, Xanthomonas citri and Agrobacterium tumefaciens with inhibition zones of 1.15 cm and 1.06 cm, respectively, and significantly reduced CLas titres from 6.33 ± 0.04 × 10⁸ to 9.15 ± 0.05 × 10³ copies within five days, comparable to tetracycline ((2.75 ± 0.91) × 10⁴). Gene expression analysis revealed marked upregulation of defense-related genes, PAL (5.87-17.05-fold) and PR2 (3.87-16.05-fold), indicating activation of phenylpropanoid and glucanase-mediated defense pathways. Integrated metabolomic and pathway analyses, including PLS-DA, demonstrated coordinated upregulation of PAL (2.08 log₂FC) and PR2 (2.65 log₂FC), accumulation of phenylpropanoid metabolites such as quinic acid (6.17 log₂FC), coumaric acid (2.62 log₂FC), and phenylalanine (1.36 log₂FC), and modulation of carbohydrate and antioxidant metabolism. FTIR and ¹H NMR analyses confirmed reduced lipid oxidation and lignin deposition, along with enhanced defense-related metabolites. Collectively, LBS5 effectively suppresses CLas, activates key defense pathways, and enhances metabolite-mediated resistance, highlighting its potential as a biocontrol and plant growth-promoting agent for sustainable management of CGD.

The fruit surface microbiome influences quality formation and disease occurrence, yet carposphere microbial diversity and functions remain poorly studied. This study employed 16S rRNA and ITS high-throughput sequencing technology to investigate the spatiotemporal variation patterns of the olive carposphere microbiome in Longnan City, Gansu Province, China, with respect to cultivars, maturity stages, and geographical locations. The results showed that the olive carposphere bacterial communities were dominated by Proteobacteria, and their abundance increased with fruit ripening. Methylobacterium-Methylorubrum showed significant enrichment at the mature stage, while Streptococcus served as a dominant genus across all geographical regions. For fungal communities, Ascomycota was the predominant phylum, while Nothophoma and Aureobasidium identified as the major genera. Diversity analyses revealed that both bacterial and fungal communities in the olive carposphere varied with cultivar, maturation stage, and geographical location. Among these factors, geographical location emerged as the most dominant driver, which implies that the environment and human activities play an important role in determining the carposphere microbiome. These findings enhance our understanding of the microbial diversity in olive carposphere, also provide valuable species information for the future use of microbial technology to modulate the fruit quality and prevent and control biological diseases.

Drought stress is one of the major environmental constraints affecting plant growth, development, and economic yield, particularly in vulnerable regions. Conventional plant responses to water scarcity often involve trade-offs that limit yield, posing an urgent need for sustainable strategies to enhance crop resilience. Moreover, decreased crop production, rising inflation, abrupt disease cycling, frequent insect and pest pressures, and other socio-economic issues cumulatively affected global food production and are a concern for nutritional security for expanding populations. Addressing these challenges demands urgent climate adaptation, improved water management, and policy innovation for future resilience. The present review explains the fundamentals of beneficial plant-microbe interactions in mitigating drought stress and utilizing these beneficial microbes, especially microbial consortia, as an integrated approach for gaining agro-ecological sustainability. It brings together current approaches on how plants recruit these stress-tolerant microbes purposefully through changed root exudates and rhizosphere chemistry, and how this changed environment favors the recruited players to work synergistically. Microbial consortia boost the plant performance even under the stressed environment through several key mechanisms, including the synthesis of osmoprotectants, the production of exopolysaccharides for improved water retention and biofilm formation, hormonal changes, antioxidative defense mechanisms, and improved nutrient mobilization under drought conditions. Field applications in several crops demonstrated better performances in growth, yield, and physiological health. However, consortia developed using multiple microbes that have plant growth-promoting properties are more effective than single microbes in alleviating the impacts of drought stress. The application of customized microbial consortia is a potent and environmentally friendly approach for mitigating drought-induced losses, reducing the use of chemicals, and striving toward climate-resilient agriculture. Advanced biotechnological interventions are required in order to address formulation and delivery challenges. Development of SynComs, use of CRISPR/Cas9 technology to enhance microbes, and application of AI and multi-omics technologies for developing efficient and crop-specific microbial inoculants will be the future of efficient agricultural systems.

Riboflavin (RF) or vitamin B₂ is an essential micronutrient for redox balance, energy metabolism, and cellular homeostasis. Although RF production titers of lactic acid bacteria (LAB) are lower than those achieved by established industrial microorganisms such as Ashbya gossypii and Bacillus subtilis, LAB are a promising and attractive platform for the development of functional foods and nutraceuticals enriched with RF because they have a generally regarded as safe/qualified presumption of safety status, probiotic potential, natural association with numerous consumed fermented foods, and compatibility with food-grade commercial processes. It has been demonstrated that several RF-producing LAB possess stable phenotypes, survive gastrointestinal conditions, exhibit antimicrobial activity against human pathogens, and display favorable adhesion to intestinal epithelial cells and antibiotic susceptibility profiles. Their industrial feasibility is further strengthened by advances in strategies to enhance their RF biosynthetic capacity, fermentation optimization, and microencapsulation technologies, which improve LAB strain performance, product safety and stability, and RF delivery. Collectively, LAB represent a sustainable, consumer-friendly, and regulatory-compliant solution for enhancing the RF content in foods and beverages and meeting the growing demand for clean-label functional products. This review summarizes the regulatory mechanisms underlying RF biosynthesis, recent advances in RF production, and progress in the development of LAB-based RF-enriched foods.