Folia microbiologica最新文献

This study examines the bioremoval of multiple heavy metals by five bacterial strains which include Enterobacter cloacae ES38G, Kurthia gibsonii ES43G, Kluyvera cryocrescens ES45G, Aeromonas caviae ES50G, and Comamonas aquatica ES54G. The bioremoval rates by ES38G, ES43G, ES45G, ES50G, and ES54G were significantly influenced by metal concentration, contact time, pH, temperature, and bacterial strains. For example, ES43G removed 100% Ni at 5 and 50 mg/L. ES43G, ES45G, and ES54G completely (100%) removed Cr, while ES43G, ES50G and ES54G achieved 100% Cd removal when exposed to 5 and 50 mg/L. Complete Pb removal (100%) was recorded for ES43G and ES54G at 5, 50, and 100 mg/L. At pH 6, ES43G, ES45G and ES54G achieved 100% Ni removal. ES43G also removed 100% Ni at pH 7. ES43G and ES45G removed 100% Cr at pH 5-7, while 100% Cr was removed by ES50G at pH 6 and ES54G at pH 5 and 7. ES43G, ES45G and ES54G completely removed Pb at pH 7-8, while ES54G and ES50G removed 100% Pb at pH 6 and pH 7, respectively. ES43G and ES54G also removed 100% Cd both at pH 6 and 7, while ES45G and ES50G removed 100% Cd at pH 6 and 7, respectively. However, bioremoval efficiencies of all these strains markedly decreased at 22 °C and 37 °C compared to 28 °C. Fourier transform infrared spectroscopy revealed that functional groups such as C = O, N-H, COO⁻, and P = O were actively involved in metal biosorption. Therefore, these bacterial strains exhibit strong potential for application in the bioremoval of heavy metals from wastewater.

The study presents an optimization process to produce L-arginine deiminase (ADI) from the fungus Penicillium chrysogenum, focusing on the impact of growth parameters and the role of phytohormones and polyamines. ADI, an enzyme that catalyzes the conversion of L-arginine to citrulline and ammonia, holds potential for cancer therapy by depleting L-arginine into auxotrophic tumors. The research identified optimal conditions for ADI production, including an incubation period of 6 days, 150 rpm agitation, and specific nutrient concentrations, with glucose and yeast extract as preferred carbon and nitrogen sources, respectively. L-arginine enhancement was most effective at pH 6 and 35 °C. Phytohormones such as gibberellic acid (GA3) and polyamines including spermidine and spermine were found to significantly boost enzyme production at lower concentrations. The study employed a Plackett-Burman design to determine critical factors, highlighting pH and glucose concentration as key influencers, supported by statistical analysis and 3D surface plots. These results open the door for the therapeutic synthesis of ADIs on a massive scale, necessitating additional study to maximize these enzymes for use in clinical settings.

A total of 65 blue-green pigment-producing bacterial strains were isolated from different environmental sources. The strains were identified as Pseudomonas aeruginosa Z57 and Pseudomonas aeruginosa Z62 using the Vitek2 identification system. Both strains were confirmed to be Gram-negative and exhibited positive reactions for several enzymes, including glutamyl arylamidase, d-glucose, gamma-glutamyl-transferase, d-mannose, beta-alanine arylamidase, and proline arylamidase, while testing negative for others. Optimal growth conditions were established at 35°C and pH 7, utilizing glucose and casein as carbon and nitrogen sources, respectively. The most potent isolate, Pseudomonas aeruginosa WM1, was confirmed by 16S rRNA sequencing and registered in Gene Bank with Accession No. (PV055704). Pyocyanin was extracted, and then purified using column chromatography. It was further characterized by UV-Vis Spectrophotometer, Fourier transformer Infrared spectrometry (FTIR), and nuclear magnetic resonance (NMR). Antimicrobial assays showed that higher concentrations of purified pyocyanin resulted in larger inhibition zones against pathogenic microbes. Interestingly, bacterial strains demonstrated greater resistance to pyocyanin than fungal strains; at a concentration of 2.5 µg/mL, Staphylococcus aureus and Aspergillus niger were identified as the most resistant organisms.

In this work, we use a fungal isolate, Aspergillus sp. SO23, derived from a marine sponge collected from the coast of Hurghada, Egypt, to isolate, identify, and biosynthesis silver nanoparticles (Ag NPs). Following molecular and visual identification of the fungal isolates, the 18S rRNA gene sequence showed a high degree of similarity (more than 99%) to Aspergillus sp. Using the fungal culture supernatant, Ag NPs were biosynthesized, giving rise to the distinctive brown coloration that is indicative of Ag NP generation. When the synthesized Ag NPs were examined with a UV-Vis. spectrophotometer, HRTEM, SEM, DLS, and XRD, they were found to have polydisperse particles with a crystalline structure and an average size of 45.16 ± 2.1 nm. DPPH and ABTS assays were used to assess the antioxidant activity of the biosynthesized Ag NPs, which showed notable free radical scavenging. Furthermore, Ag NPs showed a moderate chelating efficacy in comparison to ascorbic acid in the chelation of ferrous ions. Additionally, the immunomodulatory potential of the biosynthesized Ag NPs in cancer therapy was investigated, and it was discovered that Ag NPs stimulated the production of TNF-α, IL-1β, and IL-1 in Sk-Mel-28 cells. Cell growth was suppressed, and the M30 epitope, a sign of apoptosis induction, was present in conjunction with this stimulation. All things considered, our results demonstrate the potential uses of biogenic Ag NPs in several domains, such as cancer treatment and nanomedicine.

In this study, β-glucan extraction was optimized from the Pichia kudriavzevii M10 strain, which was randomly selected from five yeast candidates (M5, M10, M13, M16, and M57). The goal was not only to maximize extraction yield but also to thoroughly characterize the structural and functional properties of the obtained β-glucan. β-glucan yields from cell walls were evaluated under optimized extraction conditions (inoculation, autolysis, hot water, sonication, and protease). Among the five yeast strains initially screened, P. kudriavzevii M13 exhibited the highest β-glucan content (87.8%) and was therefore selected for the optimization process and further analysis of its prebiotic properties. Fermentability of β-gluM13 by Ligilactobacillus plantarum GD2, Bifidobacterium bifidum A12, and Saccharomyces cerevisiae BD1 was assessed. Viability of these strains increased in media with β-gluM13 as the sole carbon source compared to controls. Lactobacillus Growth-Promoting (LGP), Bifido Growth-Promoting (BGP), and Yeast Growth-Promoting (MGP) activities of β-gluM13 at 0.5-10 mg/mL were compared with inulin. The highest LGP, BGP, and MGP activity were designated in the media containing 10 mg/mL (9.4 ± 0.1 log CFU/mL), 5 mg/mL (9.4 ± 0.1 log CFU/mL), and 10 mg/mL (9.4 ± 0.3 log CFU/mL) β- gluM13, respectively. Antioxidant activity of β-gluM13 (0.2-50 mg/mL) was measured via DPPH (2,2-diphenyl-1-picrylhydrazil) assay, showing lower activity than ascorbic acid. Gastrointestinal stability was tested in simulated gastric and bile fluids; β-gluM13 exhibited minimal hydrolysis (1.14% at 5 mg/mL, pH 2, 180 min; 1.16% at 10 mg/mL, 0.5% bile). β-gluM13's notable LGP, BGP, and MGP activities, moderate antioxidant properties, and gastrointestinal stability suggest its potential for gut health and functional food applications.

Pregnancy induces significant alterations in the maternal microbiome, which are critical for fetal development and maternal health. Gynecological diseases, along with infertility, have increased due to excessive personal care product usage, which contains endocrine-disrupting chemicals (EDCs). Mammalian immune systems develop during pregnancy and after birth owing to crucial inputs from the environment. The growing incidence of autoimmune diseases (AIMDs) emphasizes the need to understand the environmental elements that play a role in their development, with the microbiome emerging as a key player. Exposure to EDCs with oxidative stress (OS) induces microbiome disruptions to promote AIMDs and negatively impacts female reproductive health and fetuses. Because the body changes in a number of ways to provide ideal conditions for fetal growth, pregnancy is a special moment in a woman's life. All microorganisms undergo changes, and their quantity and composition vary over the three trimesters of pregnancy. Recent research suggests a connection between pregnancy issues and the microorganisms present during pregnancy. This review explores the pivotal role of the human microbiome in pregnancy health, emphasizing how microbiome dynamics influence immune development and long-term immunity in offspring. It examines the impact of environmental factors, particularly EDCs, on maternal microbiota and their association with pregnancy complications such as hypertensive disorders and autoimmune diseases. The manuscript highlights current research findings and discusses potential microbiome-targeted interventions to promote maternal and fetal well-being.

Hepatocellular carcinoma (HCC) remains a major clinical challenge due to its late diagnosis and poor prognosis. To address these limitations, we developed a novel gefitinib derivative (DCQ-Me) and integrated it into a multifunctional fluorescent nanosystem, AL-STEROID-CHO@DCQ-ME, designed for both targeted drug delivery and real-time tumor detection. The system exhibits ratiometric fluorescence behavior, enabling sensitive detection of the HCC biomarker GP73 through a new emission signal at 500 nm and a quantifiable intensity ratio (F500/F410), with a detection limit of 0.189 mmol L⁻¹. In vitro assays further demonstrated that AL-STEROID-CHO@DCQ-ME significantly inhibits proliferation and induces apoptosis in HCC cells. These results underline the dual functionality of the platform, offering precise diagnostic readouts alongside therapeutic efficacy. Overall, this study introduces an innovative theranostic strategy with potential to improve early detection and personalized treatment of liver cancer.

Salinity stress is a major constraint on global crop productivity, necessitating sustainable strategies to enhance plant resilience. Plant growth-promoting rhizobacteria (PGPR) with 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity have emerged as promising candidates for mitigating salt stress in crops. The present study evaluated the potential of PGPR isolates in improving salinity tolerance of okra (Abelmoschus esculentus L.). Growth performance, chlorophyll content, and antioxidant enzyme activities-superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT)-were assessed under salinity stress conditions. PGPR inoculation significantly enhanced growth attributes, increased chlorophyll content, and improved antioxidant enzyme activity in stressed okra plants compared to uninoculated controls. Among the tested isolates, Caballeronia sp. AS11 showed the most pronounced improvement in plant growth and oxidative stress mitigation. These findings highlight the potential of ACC deaminase-producing PGPR, particularly Caballeronia sp. AS11, as bioinoculants for enhancing salinity tolerance in okra. The application of such beneficial microbes offers a sustainable approach to improve crop productivity in saline-prone environments.

Multidrug-resistant Klebsiella pneumoniae (MDR-KP) poses a significant clinical challenge due to limited therapeutic options and high mortality. This study investigated the antimicrobial efficacy of gamma-irradiation-synthesized gentamicin-conjugated silver nanoparticles (Gent-Ag NPs), copper oxide nanoparticles (CuO NPs), and bimetallic Ag-CuO NPs against three MDR-KP isolates in comparison with the gamma-irradiated gentamicin alone. Gent-Ag, Gent-CuO, and bimetallic Gent-Ag-CuO NPs were synthesized via gamma-radiation-induced reduction and characterized by different analytical methods to confirm their shape, size, surface morphology, particle size distribution, and crystallinity using HRTEM, SEM, DLS, and XRD, respectively. Comparative analysis demonstrated that Gent-Ag NPs exhibited superior antimicrobial activity, while Gent-CuO NPs showed diminished efficacy. SEM imaging analysis showed that Gent-Ag-CuO NPs effectively damaged and weakened the bacterial surfaces. It should be noted that the complete lys of K. pneumoniae cells is depicted by the white holes seen inside the bacteria. These findings suggest potential therapeutic applications of Ag-based NPs against MDR-KP, warranting further validation with larger sample sizes.