The physicochemistry, metabolic properties, and microbial community structure of a tropical estuary persistently inundated with anthropogenic pollutants were elucidated using diverse analytical tools and a shotgun metagenomics approach. The physicochemistry of the Awoye estuary surface water (AEW) and sediment (AES) revealed higher values in the sediment for most of the parameters analyzed, while aside from copper and zinc, the concentrations of the detected heavy metals (Cd, Cr, Pb, Fe, As, Ni, Hg, Mn, Se) in the water and sediment were higher than the acceptable thresholds. Hydrocarbon content analysis revealed increasingly high concentrations of high molecular weight polycyclic aromatic hydrocarbons (HMW PAHs) in the sediment. Structurally, the predominant taxa in the AEW metagenome are Proteobacteria (50.35%), Alphaproteobacteria (43.31%), Brevundimonas (49.96%), and Leptolyngbya boryana (14.93%), while in the sediment (AES) metagenome, Proteobacteria (53.03%), Gammaproteobacteria (28.66%), Azospirillum (6.51%), and Acidihalobacter prosperus (7.56%) were preponderant. Statistical analysis of the two microbiomes (AEW, AES) revealed significant statistical differences (P < 0.05) at all the hierarchical levels. Functional characterization of the two metagenomes revealed extensive adaptations of the sediment microbiome to various environmental stressors as evident in the high numbers of putative genes involved in the degradation of diverse classes of aromatic hydrocarbons, efflux, detoxification, and transport of heavy metals, and metabolism of organic/inorganic nutrients. Findings from this study revealed that the estuary sediment is the sink for most of the anthropogenic pollutants and harbors the more adapted microbiome that could serve as a potential bioresource for the bioremediation of the perturbed estuary.

Previous studies have predominantly focused on the pathogenic mechanisms and epidemiological investigations of pathogenic Escherichia coli (E. coli), but much remains unknown about the non-virulent and non-drug-resistant E. coli (NVNR E. coli) residing in the pig gut. In this study, 215 E. coli strains were identified from fecal samples collected from 26 healthy pigs in Guangdong Province, China. Among them, 12 NVNR E. coli strains were identified through PCR, antibiotic susceptibility tests, and genomic virulence analysis. Phylogenetic analysis revealed that 8 of these NVNR E. coli strains were located in the upstream cluster of the phylogenetic tree, which we consider as the ancestral phylogroup of porcine native E. coli. Notably, strain 2-9 showed a close evolutionary relationship with the probiotics Nissle1917 and EcAZ-1, suggesting it may also be a probiotic strain. These 9 strains (i.e., the 8 ancestral phylogroup strains and the suspected probiotic strain) were designated as evolutionarily superior strains. The 12 NVNR E. coli strains were non-hemolytic and exhibited growth rates comparable to typical E. coli strains, but they varied significantly in their tolerance to gastrointestinal conditions and adherence to IPEC-J2 cells. Most of them lacked the ability to inhibit pathogenic E. coli. Interestingly, the majority of strains exhibiting strong gastrointestinal tolerance, most of those with high adhesion capacity, and all strains possessing antibacterial ability, were found within the range of 9 evolutionarily superior strains. These findings suggest that 9 strains have shown great potential as superior porcine native E. coli strains and warrant further study.

Worldwide prevalence of multi-antibiotic resistant bacteria is rapidly increasing, and the education of undergraduates and graduates about antibiotic resistance and its associated horizontal gene transfer is critical in the general effort to confront the spread of antibiotic resistance. In this study, a deeper understanding of antibiotic resistance and horizontal gene transfer was achieved by biomedical undergraduate students through a scientific research programme. The enthusiasm of students to participate in the training programme was very high, and results revealed that each student could identify the antibiotic resistance integrative and conjugative element from the Stenotrophomonas maltophilia MER1 genome. Each student could also draw the phylogenetic relationship of the antibiotic resistance integrative and conjugative element. In addition, students proved the horizontal transfer of antibiotic resistance genes from S. maltophilia MER1 to Escherichia coli strain 25DN through conjugation and PCR assays. Each group of students was able to obtain the expected results, indicating that the outcome of the scientific research programme was highly reproducible. This programme improved the theoretical knowledge about antibiotic resistance and horizontal gene transfer and the research skills of biomedical sciences students. Through this programme, students learned that antibiotic resistance genes can be horizontally transferred among different bacteria, laying a solid foundation for students to value the importance of the appropriate use of antibiotics in their future work and life.

Elevated levels of cholesterol or triglycerides in the blood are one of the major risk factors for coronary heart disease, which is the foremost leading cause of death across the world. The aims of this study were to isolate and verify the potential probiotic strain and cholesterol-lowering capability from goat milk. The C03B-STR isolate had a broad-spectrum antibacterial property and exhibited remarkable bacteriostatic activity against Klebsiella pneumoniae ATCC 13883 (27.00 ± 1.73 mm), Pseudomonas aeruginosa ATCC 27853 (19.33 ± 0.57 mm) and Staphylococcus aureus ATCC 10832 (19.00 ± 1.00 mm) by agar well diffusion assay. This isolate is closely related to the 16S rDNA sequence of Acidipropionibacterium acidipropionici. Acidipropionibacterium acidipropionici C03B-STR can survive under acidic conditions (60.51 ± 0.02% of survival rate at pH 3.0 for 3 h) and was as bile-tolerant strain (> 80% of survival rate at 0.30% bile salts after 3 h of incubation). Furthermore, it showed significantly high cell surface hydrophobicity (74.36 ± 0.23%) and aggregation capability (> 83%) (p ≤ 0.05) but displayed low to moderate co-aggregation ability (44-61%). This strain can also be regarded as strongly adhesive (73.69 ± 0.74%) and inhibit pathogen attachment to the Caco-2 cell lines (39.20 ± 0.59-69.01 ± 0.29%). A. acidipropionici C03B-STR appeared to be safe (non-haemolytic) and controllable (sensitive to various antibiotics). Notably, it had the potential to suppress cholesterol uptake in Caco-2 cells (approximately 45%) and also reduced cholesterol level above 84% during the exponential phase under acidic conditions. Thus, A. acidipropionici C03B-STR from goat milk may be a promising novel potential cholesterol-lowering probiotic strain for application in functional foods and biotherapeutics.

Bacterial resistance has become a global concern for public health agencies. Various resistance mechanisms found in Staphylococcus aureus strains grant this bacterium resistance to a wide range of antibiotics, contributing to the rise in human mortality worldwide. Resistance mediated by efflux pumps is one of the most prevalent mechanisms in multi-resistant bacteria, which has aroused the interest of several researchers in the search for possible efflux pump inhibitors. In view of the aforementioned considerations, it is important that new strategies, such as the synthesis of chalcones, be made available as a viable strategy in antimicrobial therapy. In this study, the synthesized chalcone (2E)-1-(3'-aminophenyl)-3-(4-dimethylaminophenyl)-prop-2-en-1-one was tested for its antibacterial activity, focusing on antibiotic modification and the inhibition of the MepA efflux pump present in S. aureus strain K2068. The broth microdilution method, using microdilution plates, was employed in microbiological tests to determine the minimum inhibitory concentration of the chalcone, antibiotics, and ethidium bromide. The results show that while the chalcone did not exhibit direct antibacterial activity, it synergistically enhanced the effects of ciprofloxacin and ethidium bromide, as evidenced by the reduction in MICs. In addition, computer simulations of molecular docking demonstrate that the tested chalcone acts on the same binding site as the efflux pump inhibitor chlorpromazine, interacting with essentially the same residues. These data suggest that the chalcone may act as a MepA inhibitor.

In screening biocontrol strains with broad-spectrum and high-efficiency herbicidal activities, a strain with strong pathogenicity, HY-021, was isolated from the leaves of Rumex acetosa, which was identified as Botrytis fabiopsis based on morphology and molecular biology. The herbicidal activities of the fermentation filtrate of strain HY-021 against nine weeds, including Chenopodium album L., Elsholtzia densa Benth., Malva verticillata L. var. Crispa, Polygonum lapathifolium L., Amaranthus retroflexus L., Avena fatua L., Thlaspi arvense L., Polygonum aviculare L., and Galium spurium L., were determined in vitro and in vivo. The results showed that the pathogenicity of strain HY-021 to the different weeds in vitro was as follows: E. densa > A. retroflexus > P. aviculare > P. lapathifolium > M. verticillata > T. arvense > G. spurium > A. fatua > C. album. Seven days after inoculation with the HY-021 strain, the incidences in nine weeds were in the range of 32.9-87.23%, and the disease index values of the nine weeds were 41.73-94.57%. The pathogenic effects from high to low were A. retroflexus > E. densa > A. fatua > G. spurium > C. album > M. verticillata > T. arvense > P. aviculare > P. lapathifolium. The crop safety test showed that the biocontrol strain HY-021 was safe to V. faba, P. sativum, H. vulgare, and T. aestivum, but had a slight effect on B. napus. Scanning electron microscopy showed that the mycelium of strain HY-021 invaded the tissue through the stomata of C. album leaves, parasitized and reproduced in the tissue, and gradually destroyed the tissue. The results of this study provide a basis for the development and utilization of new and efficient microbial source herbicides.

Fructobacillus, a Gram-positive, non-spore-forming, facultative anaerobic bacterium, belongs to the fructophilic lactic acid bacteria (FLAB) group. The group's name originates from fructose, the favored carbon source for its members. Fructobacillus spp. are noteworthy for their distinctive traits, captivating the interest of scientists. However, there have been relatively few publications regarding the isolation and potential utilization of these microorganisms in the industry. In recent years, F. tropaeoli has garnered interest for its promising role in the food and pharmaceutical sectors, although the availability of isolates is rather limited. A more comprehensive understanding of Fructobacillus is imperative to evaluate their functionality in the industry, given their unique and exceptional properties. Our in vitro study on Fructobacillus tropaeoli KKP 3032 confirmed its fructophilic nature and high osmotolerance. This strain thrives in a 30% sugar concentration, shows resistance to low pH and bile salts, and exhibits robust autoaggregation. Additionally, it displays significant antimicrobial activity against foodborne pathogens. Evaluating its probiotic potential, it aligns with EFSA recommendations in antibiotic resistance, except for kanamycin, to which it is resistant. Further research is necessary, but preliminary analyses confirm the high probiotic potential of F. tropaeoli KKP 3032 and its ability to thrive in the presence of high concentrations of fructose. The results indicate that the isolate F. tropaeoli KKP 3032 could potentially be used in the future as a fructophilic probiotic, protective culture, and/or active ingredient in fructose-rich food.

Necrotizing enterocolitis (NEC) is one of the most devastating intestinal diseases observed in preterm in the first days of life. Researchers have recently focused on potential predictive biomarkers for early and concomitant diagnoses. Thus, we inquired about the linkage of intestinal dysbiosis, one of the most important factors in NEC development to the gut microbiota. In this study, the systematic differences in the bacterial composition between neonates affected by NEC and healthy newborns were highlighted by metagenomic analysis. The next-generation sequencing of the V3-V4 variable region of the 16S rRNA gene and gene-specific qPCR analyzed the untargeted gut microbiota. Total bacteria, total and fecal coliform loads in stool samples with NEC were higher than control. OTU-level relative abundances of NEC infant was characterized by Firmicutes and Bacteroidetes at phylum levels. At the genus level, NEC stool was identified by the lack of Klebsiella and the presence of Roseburia, Blautia, and Parasutterella. Finally, Clostridium fessum was the predominant species of Clostridium genus in disease and healthy specimens at the species level, whereas Clostridium jeddahitimonense was at NEC diagnosis. Despite a strong relationship between pathophysiology and characterization of gut microbiota at a clinical diagnosis of NEC, our results emphasize the broad difficulty in identifying potential biomarkers.

The diversity of cultivable endophytic fungi in native subshrubs of the Brazilian Cerrado is largely unknown. This study investigated the cultivable endophytic mycobiome of stems, leaves, and flowers of Peltaea polymorpha (Malvaceae). In total, 208 endophytic fungi were isolated, 95 from stems, 65 from leaves, and 48 from flowers. The isolates were classified as ascomycetes belonging to three classes, eight orders, ten families, 12 genera, and 31 species. Diaporthe, Nigrospora, and Colletotrichum were the dominant genera in the three analyzed organs. The richness estimators suggested that the number of species might be slightly higher than observed. The highest values for the Shannon and Simpson diversity indices were observed in stems. Beta diversity showed overlapping of fungal communities in different organs, with a high rate of sharing of taxa. Furthermore, the dominant primary fungal lifestyles were plant pathogens and saprobes. Our findings show that the cultivable endophytic fungal community of P. polymorpha is species-rich and that communities in different organs share genera and species.

Microbial transglutaminase (MTG) is an enzyme widely used in the food industry because it creates cross-links between proteins, enhancing the texture and stability of food products. Its unique properties make it a valuable tool for modifying the functional characteristics of proteins, significantly impacting the quality and innovation of food products. In this study, response surface methodology was employed to optimize the fermentation conditions for microbial transglutaminase production by the strain Streptoverticillium cinnamoneum KKP 1658. The effects of nitrogen dose, cultivation time, and initial pH on the activity of the produced transglutaminase were investigated. The significance of the examined factors was determined as follows: cultivation time > nitrogen dose > pH. The interaction between nitrogen dose and cultivation time was found to be crucial, having the second most significant impact on transglutaminase activity. Optimal conditions were identified as 48 h of cultivation with a 2% nitrogen source dose and an initial medium pH of approximately 6.0. Under these conditions, transglutaminase activity ranged from 4.5 to 5.5 U/mL. The results of this study demonstrated that response surface methodology is a promising approach for optimizing microbial transglutaminase production. Future applications of transglutaminase include the development of modern food products with improved texture and nutritional value, as well as its potential use in regenerative medicine for creating biomaterials and tissue scaffolds. This topic is particularly important and timely as it addresses the growing demand for innovative and sustainable solutions in the food and biomedical industries, contributing to an improved quality of life.

Nitrogen, phosphorus, and potassium are the three most essential micronutrients which play major roles in plant survivability by being a structural or non-structural component of the cell. Plants acquire these nutrients from soil in the fixed (NO, NH) and solubilized forms (K, HPO and HPO). In soil, the fixed and solubilized forms of nutrients are unavailable or available in bare minimum amounts; therefore, agrochemicals were introduced. Agrochemicals, mined from the deposits or chemically prepared, have been widely used in the agricultural farms over the decades for the sake of higher production of the crops. The excessive use of agrochemicals has been found to be deleterious for humans, as well as the environment. In the environment, agrochemical usage resulted in soil acidification, disturbance of microbial ecology, and eutrophication of aquatic and terrestrial ecosystems. A solution to such devastating agro-input was found to be substituted by macronutrients-availing microbiomes. Macronutrients-availing microbiomes solubilize and fix the insoluble form of nutrients and convert them into soluble forms without causing any significant harm to the environment. Microbes convert the insoluble form to the soluble form of macronutrients (nitrogen, phosphorus, and potassium) through different mechanisms such as fixation, solubilization, and chelation. The microbiomes having capability of fixing and solubilizing nutrients contain some specific genes which have been reported in diverse microbial species surviving in different niches. In the present review, the biodiversity, mechanism of action, and genomics of different macronutrients-availing microbiomes are presented.

Endophytes are symbionts that live in healthy plants and potentially improve the health of plant holobionts. Here, we investigated the bacterial endophyte community of Citrus reticulata grown in the northern Persian Gulf. Bacteria were isolated seasonally from healthy trees (root, stem, bark, trunk, leaf, and crown tissues) in four regions of Hormozgan province (i.e., Ahmadi, Siyahoo, Sikhoran, Roudan), a subtropical hot region in Iran. A total of 742 strains from 17 taxa, 3 phyla, and 5 orders were found, most of which belonged to Actinobacteria (Actinobacteriales) as the dominant group, followed by Firmicutes (Bacillales), Proteobacteria (Sphingomonadales, Rhizobiales), and Cyanobacteria (Synechoccales). The genera included Altererythrobacter, Arthrobacter, Bacillus, Cellulosimicrobium, Curtobacterium, Kocuria, Kytococcus, Methylopila, Mycobacterium, Nocardioides, Okiabacterium, Paracraurococcus, and Psychrobacillus. The most frequently occurring species included Psychrobacillus psychrodurans, Kytococcus schroetri, and Bacillus cereus. In addition, the overall colonization frequency and variability of endophytes were higher on the trunks. The leaves showed the lowest species variability in all sampling periods. The frequency of endophyte colonization was also higher in summer. The Shannon-Wiener (H') and Simpson indices varied with all factors, i.e., region, season, and tissue type, with the maximum in Roudan. Furthermore, 52.9% of the strains were capable of nitrogen fixation, and 70% produced antagonistic hydrogen cyanide (HCN). Thus, C. reticulata harbors a variety of bioactive bacterial endophytes that could be beneficial for host fitness in such harsh environments.

Cyanobacteria are prokaryotic organisms characterised by their complex structures and a wide range of pigments. With their ability to fix CO, cyanobacteria are interesting for white biotechnology as cell factories to produce various high-value metabolites such as polyhydroxyalkanoates, pigments, or proteins. White biotechnology is the industrial production and processing of chemicals, materials, and energy using microorganisms. It is known that exposing cyanobacteria to low levels of stressors can induce the production of secondary metabolites. Understanding of this phenomenon, known as hormesis, can involve the strategic application of controlled stressors to enhance the production of specific metabolites. Consequently, precise measurement of cyanobacterial viability becomes crucial for process control. However, there is no established reliable and quick viability assay protocol for cyanobacteria since the task is challenging due to strong interferences of autofluorescence signals of intercellular pigments and fluorescent viability probes when flow cytometry is used. We performed the screening of selected fluorescent viability probes used frequently in bacteria viability assays. The results of our investigation demonstrated the efficacy and reliability of three widely utilised types of viability probes for the assessment of the viability of Synechocystis strains. The developed technique can be possibly utilised for the evaluation of the importance of polyhydroxyalkanoates for cyanobacterial cultures with respect to selected stressor-repeated freezing and thawing. The results indicated that the presence of polyhydroxyalkanoate granules in cyanobacterial cells could hypothetically contribute to the survival of repeated freezing and thawing.

β-Glucans comprise a group of β-D-glucose polysaccharides (glucans) that occur naturally in the cell walls of bacteria, fungi, and cereals. Its degradation is catalyzed by β-glucanases, enzymes that catalyze the breakdown of β-glucan into cello-oligosaccharides and glucose. These enzymes are classified as endo-glucanases, exo-glucanases, and glucosidases according to their mechanism of action, being the lichenases (β-1,3;1,4-glucanases, EC 3.2.1.73) one of them. Hence, we aimed to enhance lichenase production by Thermothelomyces thermophilus through the application of response surface methodology, using tamarind (Tamarindus indica) and jatoba (Hymenaea courbaril) seeds as carbon sources. The crude extract was immobilized, with a focus on improving lichenase activity, using various ionic supports, including MANAE (monoamine-N-aminoethyl), DEAE (diethylaminoethyl)-cellulose, CM (carboxymethyl)-cellulose, and PEI (polyethyleneimine)-agarose. Regarding lichenase, the optimal conditions yielding the highest activity were determined as 1.5% tamarind seeds, cultivation at 50 °C under static conditions for 72 h. Moreover, transitioning from Erlenmeyer flasks to a bioreactor proved pivotal, resulting in a 2.21-fold increase in activity. Biochemical characterization revealed an optimum temperature of 50 °C and pH of 6.5. However, sustained stability at varying pH and temperature levels was challenging, underscoring the necessity of immobilizing lichenase on ionic supports. Notably, CM-cellulose emerged as the most effective immobilization medium, exhibiting an activity of 1.01 U/g of the derivative (enzyme plus support), marking a substantial enhancement. This study marks the first lichenase immobilization on these chemical supports in existing literature.

Yeasts are unicellular fungi that occur in a wide range of ecological niches, where they perform numerous functions. Furthermore, these microorganisms are used in industrial processes, food production, and bioremediation. Understanding the physiological and adaptive characteristics of yeasts is of great importance from ecological, biotechnological, and industrial perspectives. In this context, we evaluated the abilities to assimilate and ferment different carbon sources, to produce extracellular hydrolytic enzymes, and to tolerate salt stress, heavy metal stress, and UV-C radiation of two isolates of Eremothecium coryli, isolated from Momordica indica fruits. The two isolates were molecularly identified based on sequencing of the 18S-ITS1-5.8S-ITS2 region. Our isolates were able to assimilate nine carbon sources (dextrose, galactose, mannose, cellobiose, lactose, maltose, sucrose, melezitose, and pectin) and ferment three (glucose, maltose, and sucrose). The highest values of cellular dry weight were observed in the sugars maltose, sucrose, and melezitose. We observed the presence of hyphae and pseudohyphae in all assimilated carbon sources. The two isolates were also capable of producing amylase, catalase, pectinase, and proteases, with the highest values of enzymatic activity found in amylase. Furthermore, the two isolates were able to grow in media supplemented with copper, iron, manganese, nickel, and zinc and to tolerate saline stress in media supplemented with 5% NaCl. However, we observed a decrease in CFU at higher concentrations of these metals and NaCl. We also observed morphological changes in the presence of metals, which include changes in cell shape and cellular dimorphisms. The isolates were sensitive to UV-C radiation in the shortest exposure time (1 min). Our findings reinforce the importance of endophytic yeasts for biotechnological and industrial applications and also help to understand how these microorganisms respond to environmental variations caused by human activities.

The marine environment is considered one of the most important ecosystems with high biodiversity. Microorganisms in this environment are variable and coexist with other marine organisms. The microbes associated with other marine organisms produce compounds with biological activity that may help the host's defense against invading organisms. The symbiotic association of bacteria with marine invertebrates is of ecological and biotechnological importance. Biologically active metabolites isolated from bacteria associated with marine invertebrates are considered potential sources of natural antimicrobial molecules for treating infectious diseases. Many studies have been conducted to screen the antimicrobial activity of metabolites produced by bacteria associated with marine invertebrates. This work provides an overview of the advancements in antimicrobial compound research on bacteria associated with marine invertebrates.

The present study has undertaken the isolation of marine yeasts from mangrove sediment samples and their ability to produce alkaline protease enzymes. A total of 14 yeast isolates were recovered on yeast-malt agar (YMA) and yeast extract peptone dextrose (YEPD) agar medium. After screening for proteolytic activity on skim milk agar, marine yeast isolate, AKB-1 exhibited a hydrolysis zone of 18 mm. Optimal conditions for the enzyme production from yeast isolate AKB-1 were at 30 °C, pH 8, fructose as carbon source, potassium nitrate as nitrogen source, and 25% saline concentration. Under the optimal conditions, the protease enzyme activity of the isolate AKB-1 was observed to be 978 IU/mL. The structural and functional analysis was carried out through FTIR and HPLC analysis for the extracted protease enzyme. Furthermore, the enzyme produced was partially purified by solvent extraction using ethyl acetate and ammonium sulfate precipitation (3.4-fold) followed by dialysis (56.8-fold). The molecular weight of the purified enzyme was observed to be around 60 kDa using SDS-PAGE. The extracted protein showed good antibacterial activity against six different clinical bacterial pathogens and the highest against Bacillus cereus (16 ± 0.5 mm). The extracted protease enzyme was revealed to remove blood stains from cloth within 20 min of application similar to the commercial detergent. The marine yeast isolate was further identified as Candida orthopsilosis AKB-1 (Accession number KY348766) through 18S rRNA sequencing, and a phylogenetic tree was generated.

The spread of multidrug-resistant Escherichia coli in healthcare facilities is a global challenge. Hospital-acquired infections produced by Escherichia coli include gastrointestinal, blood-borne, urinary tract, surgical sites, and neonatal infections. Therefore, novel approaches are needed to deal with this pathogen and its rising resistance. The concept of attenuating virulence factors is an alternative strategy that might lead to low levels of resistance and combat this pathogen. A sub-inhibitory concentration (¼ MIC) of sitagliptin and nitazoxanide was used for phenotypic assessments of Escherichia coli virulence factors such as biofilm production, swimming motility, serum resistance, and protease production. Moreover, qRT-PCR was used to determine the impact of sub-MIC of the tested drugs on the relative expression levels of papC, fimH, fliC, kpsMTII, ompT_m, and stcE genes encoding virulence factors in Escherichia coli. Also, an in vivo model was conducted as a confirmatory test. Phenotypically, our findings demonstrated that the tested strains showed a significant decrease in all the tested virulence factors. Moreover, the genotypic results showed a significant downregulation in the relative expression levels of all the tested genes. Besides, the examined drugs were found to be effective in protecting mice against Escherichia coli pathogenesis. Sitagliptin and nitazoxanide exhibited strong anti-virulence activities against Escherichia coli. In addition, it is recommended that they might function as adjuvant in the management of Escherichia coli infections with either conventional antimicrobial agents or alone as alternative treatment measures.

The growth and accumulation of active ingredients of Angelica sinensis were affected by rhizosphere soil microbial communities and soil environmental factors. However, the correlationship between growth and active ingredients and soil biotic and abiotic factors is still unclear. This study explored rhizosphere soil microbial community structures, soil physicochemical properties, enzyme activities, and their effects on the growth and active ingredient contents of A. sinensis in three principal cropping areas. Results indicated that the growth indices, ligustilide, ferulic acid contents, and soil environmental factors varied in cropping areas. Pearson correlation analysis revealed that the growth of A. sinensis was affected by organic matter, total nitrogen, total phosphorus, and available phosphorus; ferulic acid and ligustilide accumulation were related to soil catalase and alkaline phosphatase activities, respectively. Illumina MiSeq sequencing showed that the genera Mortierella and Conocybe were the dominant fungal communities, and Sphingomonas, Pseudomonas, Bryobacter, and Lysobacter were the main bacterial communities associated with the rhizosphere soil. Kruskal-Wallis one-way ANOVA and Spearman correlation conjoint analysis demonstrated a significant positive correlation (p < 0.001) among the composition of the rhizosphere microbial communities at all three sampling sites. The growth and active ingredient accumulation of A. sinensis not only was significantly susceptible to the bacterial communities of Sphingomonas, Epicoccum, Marivita, Muribaculum, and Gemmatimonas but also were significantly influenced by the fungal communities of Inocybe, Septoria, Tetracladium, and Mortierella (p < 0.05). Our findings provide a scientific basis for understanding the relationship between the growth and active ingredients in A. sinensis and their corresponding rhizosphere soil microbial communities, soil physicochemical properties, and enzyme activities.

Bacillus is well known for producing a wide range of compounds that inhibit microbial phytopathogens. From this perspective, we were interested in evaluating the biocontrol potential of 5 plant growth-promoting rhizobacteria Bacillus species (PGPR-Bacillus) on 21 microbial pectinolytic plant pathogens isolated from previous studies. Phytopathogenicity and in vivo biocontrol potential of PGPR curative and preventive treatments were investigated from this angle. Overall, the pathogenicity test on healthy tomato, zucchini, and mandarin showed low rot to no symptoms for all PGPR strain culture treatments. Conversely, zucchini pre-treated with PGPR strains B. circulans and B. cereus for 72 h showed no signs of soft rot and remained healthy when in vitro contaminated with phytopathogens (Neisseria cinerea and Pichia anomala). Additionally, the PGPR-Bacillus strains were shown to be effective in mitigating the symptoms of soft rot in tomatoes, zucchini, and oranges using in vivo curative treatment. It is true that the majority of pectinolytic phytopathogenic strains exhibited antibiotic resistance. In vivo tests revealed that PGPR-Bacillus cell culture was effective against plant pathogens. Thus, PGPR-Bacillus can be considered a potential biocontrol agent for pectinolytic plant pathogens.

Acinetobacter baumannii thrives within eukaryotic cells, influencing persistence, treatment approaches, and progression of disease. We probed epithelial cell invasion by A. baumannii and the influence of antibodies raised to outer membrane protein 34 (Omp34) on epithelial interactions. We expressed and purified recombinant Omp34 and induced anti-Omp34 antibodies in Bagg albino or BALB/c mice. Omp34 was evaluated for acute toxicity in mice through histological analysis of six organs. The host cell line, A549, was exposed to both A. baumannii 19606 and a clinical isolate. The study also investigated serum resistance, adherence, internalization, and proliferation of A. baumannii in A549 cells, with and without anti-Omp34 sera, utilizing cell culture techniques and light microscopy. A549 cell viability was evaluated by A. baumannii challenge and exposure to anti-Omp34 sera. Actin disruption experiments using cytochalasin D probed microfilament and microtubule roles in A. baumannii invasion. Omp34 prompted antibody production without toxicity in mice. The serum showed bactericidal effects on both strains. Additionally, both A. baumannii strains were found to form biofilms. Omp34 serum was observed to decrease biofilm formation, bacterial adherence, internalization, and proliferation in A549 cells. Furthermore, the use of anti-Omp34 serum enhanced the post-infection survival of the host cell. Pre-exposure of A549 cells to cytochalasin D reduced bacterial internalization, highlighting the role of actin polymerization in the invasion process. Microscopic analysis revealed various interactions, such as adherence, membrane alterations, vacuolization, apoptosis, and cellular damage. Anti-Omp34 serum-exposed A549 cells were protected and showed reduced damage. The findings reveal that A. baumannii can significantly multiply intracellularly within host cells. This suggests the bacterium's ability to establish an environment conducive to its replication by preventing fusion with degradative lysosomes and inhibiting acidification. This finding contributes to the understanding of A. baumannii's intracellular persistence and highlights the role of Omp34 in influencing apoptosis, autophagy, and bacterial adherence, which may impact the development of effective treatments against A. baumannii infections.