World journal of microbiology & biotechnology最新文献

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.

Bacterial ghosts (BGs) are an emerging vaccine platform produced by completely removing the cytoplasmic contents of bacterial cells while preserving their native surface architecture. This unique structural integrity enables BGs to function simultaneously as safe, non-living vaccines and efficient delivery vehicles. Recent advances in both genetic (phage lysis gene E) and chemical "sponge-like" protocols have expanded the range of microorganisms from which BGs can be produced, improving safety, scalability, and antigenic stability. This review summarizes current progress in BG technology with a focus on their innovative applications as antibacterial, antifungal, and anticancer vaccines; adjuvants; and carriers for DNA, proteins, and bioactive molecules. Particular emphasis is placed on emerging directions such as yeast and fungal ghosts, novel characterization methods, and the development of BG-based nano-vaccines. Future prospects highlight the need for standardized production, improved clinical translation, and comparative evaluation with related platforms such as membrane vesicles. Together, these advancements position BGs as a promising next-generation vaccine and drug-delivery strategy with significant potential for translational impact.

Melanin is a pigmentated polymer with antioxidant capacity, and it also plays a role as a quality factor in those fungi that can synthetize it. However, this pigment is soluble only in alkaline solutions, limiting its application. This work used ultrasonication of fungal melanin, extracted from nonviable Cordyceps javanica CHE-CNRCB 307 conidia, and obtained hydrophilic melanin. Suspensions of freshly harvested conidia from Beauveria bassiana CHE-CNRCB 614 or Metarhizium acridum CHE-CNRCB 213 were prepared with a hydrophilic melanin solution at 0.1 mg/mL. These conidia formulations were more resistant to UV-B radiation, up to 34.9%, 26.2%, and 23.3% higher than those without hydrophilic melanin at doses of 10, 14, and 18 kJ/m², respectively, without affecting the virulence or thermotolerance parameters. Based on these results, hydrophilic melanin served as a compatible photoprotector in conidia suspensions from two widely entomopathogenic fungi used in biological control. In addition, the hydrophilic melanin source can be Cordyceps javanica conidia, which keeps melanin beyond the loss of viability, with high added value.

Rare earth elements (REE) are metals in great demand by the overall industry, they are present in most electronic equipment, ceramics and green energy generation. The REE are currently at high risk of supply and have become critical to world development. The increasing demand for REE brings out the necessity to obtain these metals from multiple sources. Chemically centered processes like leaching and resin adsorption have been the predominant techniques to extract REE from primary and secondary sources. These processes are harsh and damaging to the environment due to the use of strong inorganic acids, high temperatures and low regeneration potential. It has become necessary to find ways to obtain these metals without causing environmental harm. Bioprocesses may prove to be a potential solution to the extraction and recovery of REE in a less harmful way. Bioprocesses involve the use of microorganisms to produce acids, chelating substances or to serve as sorbates, allowing for the solubilization and adsorption of metals, respectively. Since these processes utilize microorganisms, they can be seen as renewable and clean, though selectivity and process time may impact effectiveness. In this review the two main bioprocesses: bioleaching and biosorption will be analyzed regarding their mechanisms, process parameters and challenges, a comparison discussing the two is also expressed.

This study investigates the biocalcification potential of Bacillus subtilis ATCC 6633, a ureolytic bacterium, for the biohealing of marble surfaces through calcium carbonate (CaCO₃) precipitation. Comparative experiments were conducted using live and dead bacterial cells on CO₂-pre-treated and untreated marble samples, with calcium chloride and calcium acetate employed as calcium sources, to evaluate their effects on crystal polymorphism and surface modification. The results show that bacterial viability and calcium source jointly influence mineral phase formation, with live cells predominantly promoting the formation of stable calcite and aragonite, whereas dead cells and calcium acetate favor the formation of metastable vaterite. Microstructural and mineralogical analyses using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and atomic force microscopy (AFM) confirmed substantial CaCO₃ deposition on marble surfaces. AFM measurements indicated a reduction in maximum pore depth, defined as the vertical height difference between pore bottoms and the surrounding marble surface, from 35.00 ± 7.07 μm in control samples to 22.50 ± 8.20 μm in biocalcified samples, reflecting partial filling of pores and cracks. In addition, micropores (0.02-0.03 mm) were fully filled, while macropores (3-5 mm) were partially occluded by crystalline deposits. CO₂ pre-treatment enhanced surface carbon availability and promoted more uniform CaCO₃ nucleation, as supported by SEM-EDX and XRD analyses. Overall, these findings indicate that microbially induced carbonate precipitation (MICP), combined with appropriate surface preconditioning and calcium source selection, represents a potential and sustainable strategy for marble conservation and related bio-construction applications.

Press mud is an acidic by-product of sugarcane processing that is commonly discarded, despite containing components with potential agricultural value. This study assessed sugarcane mill press mud through physicochemical, microbiological and enzymatic analyses to evaluate its environmental implications and suitability as a soil amendment. The material was slightly acidic (pH 6.4) and rich in essential nutrients, including potassium (1061.06 ppm), magnesium (624.96 ppm), calcium (461.06 ppm) and phosphorus (513.11 ppm). However, elevated metals such as aluminium (2083.22 ppm), iron (2342.57 ppm), manganese (85.90 ppm), zinc (60.84 ppm), copper (17.70 ppm), lead (3.10 ppm) and chromium (4.18 ppm), together with the detection of the pollutant 2,4-di-tert-butylphenol (2,4-DTBP), suggest the need for proper regulated application to mitigate environmental risks. Microbial profiling across acidic (6.4), neutral (7.0) and alkaline (9.5) conditions revealed diverse bacterial taxa. Acidic conditions yielded Escherichia coli (PQ001953), Bacillus licheniformis (PQ001957) and Moraxella catarrhalis (PQ047632); neutral conditions favored Herbaspirillum seropedicae (PQ008927), Enterococcus faecium (PQ012564) and Micrococcus luteus (PQ012569); while alkaline conditions supported Bacillus subtilis (PQ012572), Listeria ivanovii (PQ060442) and Paracoccus pantotrophus (PQ012574). Notably, E. coli, H. seropedicae and M. luteus exhibited pronounced ligninolytic enzyme activity, indicating a capacity to degrade complex organic substrates. Plant growth trials using mustard (Brassica campestris) demonstrated that a 5:1 soil-to-press-mud ratio significantly enhanced plant growth relative to untreated soil. Collectively, these findings indicate that when applied in controlled quantities, press mud, represents a promising bioresource with valuable ligninolytic and plant growth-promoting microbial communities, while warranting careful oversight due to its contaminant load.