Journal of Basic Microbiology最新文献

Almost all cell types naturally secret extracellular vesicles (EVs) in the extracellular space with variable metabolic cargo facilitating intracellular communication, posing immune-modulation capacity. Thus, “bacterial extracellular vesicles” (BEVs), with their great immunoregulatory, immune response stimulation and disease condition-altering potential, have gained importance in the medical and therapeutic industry. Various subtypes of BEVs were observed and reported in the literature, such as exosomes (30–150 nm), microvesicles (100–1000 nm), apoptotic bodies (1000–5000 nm), and oncosomes (1000–10,000 nm). As biological systems are complex entities, inserting BEVs requires extra high purity. Various techniques for BEV isolation have been employed alone or with other strategies, such as ultracentrifugation, precipitation, size-exclusion chromatography, affinity-based separation, ultrafiltration, and field-flow fractionation. But to date, no BEV isolation method is considered perfect as the lack of standard protocols limits their scale-up. Medical research has focused on BEVs to explore their diverse therapeutic potential. This review particularly focused on the recent advancements in the potential medical application of BEVs, current challenges, and prospects associated with their scale-up.

The current situation involves an increase in interest in nanotechnology, in particular the ways in which it can be applied in the commercial and medical fields. However, traditional methods of synthesizing nanoparticles have some drawbacks, including the generation of harmful byproducts, high energy consumption, and cost. As a result, researchers have shifted their focus to “green” nanoparticle synthesis to circumvent these drawbacks. Because of their exceptional physiochemical properties, silver nanoparticles (Ag Nps) are the noble metal nanoparticles that are used most frequently. The green approach to Ag NP synthesis is environmentally friendly, non-toxic, and cost-effective, and it makes use of a variety of biological entities. Cyanobacteria, in particular, have garnered the most attention because of the abundance of bioactive substances that they contain, which serve both as reducing agents and as stabilizing agents during the process of biosynthesis. This review article discusses the current state of cyanobacteria-mediated Ag NP synthesis, the potential mechanisms that are involved, nanoparticle characterization, the various applications of Ag NP in different fields, and their prospects.

The integrated application of inorganic fertilizers, organic fertilizers, and biofertilizers helps sustain the nutrient pool and benefits the soil quality, thereby boosting plant health. The effect of different combinations of biofertilizers (consortium biofertilizer [CBF]—non-rhizobial PGPR), inorganic fertilizers, and organic fertilizers on soil health, growth, and yield of cowpea was evaluated by conducting a field experiment. The application of N₁₀₀ FYM + CBF resulted in significantly higher populations of bacteria, fungi, PSB, and diazotroph, as well as soil dehydrogenase and alkaline phosphatase enzyme activities. However, the application of N₁₀₀ FYM recorded a significantly higher actinomycetes population. The application of N₁₀₀ FYM + CBF resulted in significantly higher soil OC, available nitrogen, phosphorus, and potassium. The soil pH was recorded to be highest in control, and soil EC was recorded to be lowest in control. The plant uptake of nitrogen, phosphorus, and potassium was significantly higher with N₅₀ FYM + NP₅₀ + CBF. The root–shoot biomass, number of leaves, nodules/plant, number of pods/plants, pod biomass, pod length, and pod width were significantly higher in treatment having N₅₀ FYM + NP₅₀ + CBF. However, the height of the plant, number of branches, and biomass of leaves were highest in treatment with N₂₅ FYM + NP₇₅ + CBF. The pod and stover yield were significantly higher in treatment with N₅₀ FYM + NP₅₀ + CBF. The results showed that the integrated application of non-rhizobial PGPR along with organic and inorganic fertilizer helps to improve overall soil health, quality, and plant growth of forage cowpea contributing to an increase in crop yield.

Antibiotic resistance poses a formidable challenge to global public health, necessitating comprehensive understanding and strategic interventions. This review explores the evolution and transmission dynamics of antibiotic resistance genes, with a focus on Bangladesh. The indiscriminate use of antibiotics, compounded by substandard formulations and clinical misdiagnosis, fuels the emergence and spread of resistance in the country. Studies reveal high resistance rates among common pathogens, emphasizing the urgent need for targeted interventions and rational antibiotic use. Molecular assessments uncover a diverse array of antibiotic resistance genes in environmental reservoirs, highlighting the complex interplay between human activities and resistance dissemination. Horizontal gene transfer mechanisms, particularly plasmid-mediated conjugation, facilitate the exchange of resistance determinants among bacterial populations, driving the evolution of multidrug-resistant strains. The review discusses clinical implications, emphasizing the interconnectedness of environmental and clinical settings in resistance dynamics. Furthermore, bioinformatic and experimental evidence elucidates novel mechanisms of resistance gene transfer, underscoring the dynamic nature of resistance evolution. In conclusion, combating antibiotic resistance requires a multifaceted approach, integrating surveillance, stewardship, and innovative research to preserve the efficacy of antimicrobial agents and safeguard public health.

Ranaviruses, members of the genus Ranavirus within the family Iridoviridae, have become a significant concern for amphibian populations globally, along with other cold-blooded vertebrates, due to their emergence as a significant threat. We employed bioinformatics tools to examine the codon usage patterns in 61 DNA pol genes from Ranavirus, Lymphocystivirus, Megalocytivirus, and two unclassified ranaviruses, as no prior studies had been conducted on this topic. The results showed a slight or low level of codon usage bias (CUB) in the DNA pol genes of Ranavirus. Relative synonymous codon usage (RSCU) analysis indicated that the predominant codons favored in Ranavirus DNA pol genes terminate with C or G. Correlation analysis examining nucleotide content, third codon position, effective number of codons (ENC), correspondence analysis (COA), Aroma values, and GRAVY values indicated that the CUB across DNA pol genes could be influenced by both mutation pressure and natural selection. The neutrality plot indicated that natural selection is the primary factor driving codon usage. Furthermore, the analysis of the codon adaptation index (CAI) illustrated the robust adaptability of Ranavirus DNA pol genes to their hosts. Analysis of the relative codon deoptimization index (RCDI) suggested that Ranavirus DNA pol genes underwent greater selection pressure from their hosts. These findings will aid in comprehending the factors influencing the evolution and adaptation of Ranavirus to its hosts.

Cotton root rot caused by Macrophomina phaseolina pose a significant threat to cotton production, leading to substantial yield and quality losses. Early and accurate diagnosis of this pathogen in soil is crucial for effective disease management. This study presents a pioneering investigation into the utilization of the nit gene encoding nitrilase for the development of a molecular diagnostic assay aimed at the rapid detection of M. phaseolina in field soils. The methodology involved the design and validation of primers targeting the Nit gene sequence, followed by the optimization of PCR conditions for efficient amplification. Leveraging state-of-the-art molecular techniques, the assay offers a novel protocol to accurately identify the presence of M. phaseolina in soil with high sensitivity and specificity. The specificity of the designed primers was confirmed through PCR amplification using DNA from M. phaseolina and other related fungi. Sensitivity tests demonstrated that the PCR assay reliably detected M. phaseolina DNA at concentrations as low as 1 ng. Furthermore, the performance of the diagnostic assay was rigorously evaluated using field soil samples with a known status of M. phaseolina infection, demonstrating its reliability and efficacy in real-world scenarios. This study introduces a novel molecular marker for the detection of M. phaseolina and offers a rapid and efficient means for screening M. phaseolina in large soil samples with minimal time and manpower.

Anthocyanins are high-value natural compounds, but to date, their production still mainly relies on extraction from plants. A five-step metabolic pathway was constructed in probiotic Lactococcus lactis NZ9000 for rapid, stable, and glycosylated anthocyanin biosynthesis using chalcone as a substrate. The genes were cloned from anthocyanin-rich blueberry: chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), anthocyanin synthase (ANS), and UDPG-flavonoid 3-O-glycosyltransferase (3GT). Using HR, the polysaccharide pellicle (PSP) segment of the cell wall polysaccharide synthesis (cwps) gene cluster from L. lactis NZ9000 was cloned into vector p15A-Cm-repDE. Then, CHI and F3H were placed sequentially under the control of NZProm 3 of this gene cluster in the vector, which was transformed into L. lactis NZ9000 to obtain Strain A. Furthermore, Strain B was constructed by placing F3H-DFR-ANS and 3GT under NZProm 2 and 3, respectively. Using LC-MS/MS analysis, several types of anthocyanins, including callistephin chloride, oenin chloride, malvidin O-hexoside, malvidin 3,5-diglucoside, and pelargonidin 3-O-malonyl-malonylhexoside, increased in the supernatant of the co-culture of Strains A and B compared to that of L. lactis NZ9000. This is the first time that a five-step metabolic pathway has been developed for anthocyanin biosynthesis in probiotic L. lactis NZ9000. This work lays the groundwork for novel anthocyanin production by a process involving the placement of several biosynthesis genes under the control of a gene cluster.

This study analyzed arbuscular mycorrhizal fungi (AMF) activity and soil chemical properties in Aspidosperma pyrifolium, Bauhinia ungulata, Caesalpinia pyramidalis, and Caesalpinia ferrea. AMF spores, root colonization, total glomalin-related soil protein (T-GRSP), easily extracted GRSP (EE-GRSP), and soil chemical properties were measured four times (July 2019, 2020 and December 2019, 2020). Significant differences were observed in AMF spores, root colonization, T-GRSP, and EE-GRSP among the plant species and across seasons. For soil chemical properties, we observed differences among plant species. During the dry season, B. ungulata and C. pyramidalis had the highest AMF spores and root colonization (57.3 ± 0.27 spores 50 g soil⁻¹ and 48.8 ± 1.05, respectively), whereas during the rainy season, C. pyramidalis and C. ferrea showed the highest AMF spores and root colonization (36.6 ± 0.13 spores 50 g soil⁻¹ and 62.2 ± 1.17, respectively). A. pyrifolium showed the highest T-GRSP in both seasons. On the basis of the soil chemical properties, we found that (i) A. pyrifolium, B. ungulata, and C. ferrea showed the highest soil organic carbon (1.32 ± 0.03 g kg⁻¹), phosphorus (7.01 ± 0.26 mg kg⁻¹), and soil pH (5.85 ± 0.23) and (ii) C. pyramidalis showed the highest Ca²⁺, Mg²⁺, Na⁺, H⁺ + Al³⁺, K⁺, and soil total nitrogen (1.36 ± 0.04, 0.73 ± 0.01, 3.72 ± 0.85, 4.56 ± 0.12 cmol_c kg⁻¹, 15.43 ± 1.53 mg kg⁻¹, and 0.16 ± 0.01 g kg⁻¹, respectively). Our results highlight the advantage of AMF spores as perennating structures over other AM fungal propagules in seasonal vegetation like Caatinga.