AMB Express最新文献

Amikacin (AMK), a potent aminoglycoside antibiotic, is clinically valuable for severe Gram-negative infections but is limited by its nephrotoxic and hepatotoxic effects, primarily mediated through oxidative stress and inflammation. This study investigated the protective role of pentoxifylline (PTX), a methylxanthine derivative with antioxidant and anti-inflammatory properties, against AMK-induced organ damage in male BALB/c mice. Thirty mice were divided into six groups: control, AMK (100 mg/kg/day), PTX monotherapy (50 or 100 mg/kg/day), and AMK combined with PTX (50 or 100 mg/kg/day). After 28 days, biochemical, oxidative stress, inflammatory, and histopathological analyses were conducted. AMK administration significantly elevated renal (BUN and creatinine) and hepatic (ALT, AST and ALP) markers, increased oxidative stress (MDA), and upregulated inflammatory cytokines (IL-17), alongside histopathological damage in kidney and liver tissues. Co-treatment with PTX, particularly at 100 mg/kg, normalized these parameters, restored antioxidant defenses, reduced inflammation, and preserved tissue architecture. PTX demonstrated dose-dependent efficacy, with the higher dose offering complete protection against AMK-induced toxicity. These findings highlighted PTX's potential as an adjunctive therapy to mitigate AMK-associated nephrotoxicity and hepatotoxicity, suggesting its clinical utility in optimizing aminoglycoside safety without compromising efficacy.

This study investigated the early salivary microbiome response to a sucrose challenge in caries-free and caries-active individuals. Eighteen healthy adults aged 24-40 years were recruited, including eight caries-free and ten caries-active participants. Saliva samples were collected at baseline and at 30 min and 2 h after a 20% sucrose rinse. Microbial diversity and composition were assessed using 16 S rRNA gene sequencing to compare dynamic changes between the two groups. The salivary microbiome of caries-active individuals showed a greater and more rapid increase in amplicon sequence variants (ASVs) and more complex microbial interaction networks following sucrose exposure. After 2 h, Actinomyces graevenitzii increased considerably in both groups, while Schaalia odontolytica was enriched only in caries-active individuals, suggesting a microbial signature associated with caries susceptibility. Although global diversity metrics (Shannon and Chao1 indices) did not change significantly after rinsing, caries-active individuals exhibited more pronounced ecological shifts, indicating heightened responsiveness to sucrose. These findings highlight the potential of the salivary microbiome as an early indicator of caries risk and underscore the importance of microbial dynamics in caries pathogenesis. The study provides new ecological insights into how dietary sugars influence oral microbiota and may inform microbiome-based strategies for caries prevention and early diagnosis.

Chitosan oligosaccharides (COSs) are short-length oligomers produced by the action of chitosanase enzymes. These oligomers are characterized by high water solubility and bioavailability. COSs have demonstrated several biological activities in the medical field, including antitumor, antimicrobial, antioxidant, and immunomodulatory. This study aimed to assess and purify bio-produced COSs obtained from a culture containing a locally isolated Bacillus cereus strain from an Egyptian soil sample and investigate their biological activities, such as immunostimulatory and anti-inflammatory activities. The COSs were bio-produced by fermentation of a native B. cereus strain in media containing colloidal chitosan hydrolyzed by the action of chitosanase enzyme. COSs were then purified on a column packed with a Sephadex LH-20 column. The purified form of COSs were quantified and detected according to their molecular weights and degree of polymerization by UPLC-Mass spectroscopy. The purified COSs were detected as polymers of GlcN at different degrees of polymerization (DP1-DP6) and different molecular weight ranges (m z^-1). The purified COSs were administered orally to groups of mice to evaluate their immunostimulatory effects on cyclophosphamide-induced immunosuppression by measuring cytokine levels in their thymus glands and spleens. Cytokine analysis revealed that COSs enhanced the release of IL-6, TNF-α, and IFN-γ in both the thymus and spleen (p < 0.05). The activity of COSs as an anti-inflammatory was assessed by inducing edema in the paws using carrageenan. COSs' dose of 500 mg kg^-1 exhibited a potential anti-inflammatory effect when compared to dexamethasone (p < 0.05). This study concluded that the bio-produced COSs have considerable potential and are promising as a drug with immunostimulant activities. These observed activities resulted from the ability of COSs to stimulate the production of different cytokine markers in safe doses. Also, these COSs showed significant anti-inflammatory activity when administered orally.

Isolation of Pythium and Globisporangium (Chromista, Oomycota) from their natural sources is very difficult due to the heavy contamination with other microbes, which hinders obtaining them in pure form. This study aims to develop a new, cheap and safe selective medium to isolate Pythium and Globisporangium species from their natural sources, despite the previous presence of more than 3 types of selective media including: VP₃ (Vancomycin + PCNB + Penicillin + Pimaricin), NARM (Nystatin + Ampicillin + Rifampicin + Miconazole), and NARF (Nystatin + Ampicillin + Rifampicin + Fluazinam) used to isolate Oomycota. The elevated expense of antibiotics, along with alerts regarding potential contamination, toxicity, and tumor proliferation, renders them undesirable. Safe and inexpensive antibiotics from pharmaceutical sources were used with fixed formulations and concentrations. A selective medium was developed, called FANS (Fluconazole + Ampicillin + Nystatin + Sulbactam) with the following concentrations (1200 mg + 500 mg + 100,000 IU + 250 mg) respectively/L Corn Meal Agar promotes only the growth and formation of reproductive structures of Pythium and Globisporangium. On the other hand, these antibiotics completely inhibited the growth of other contaminated fungi and bacteria. Mycelial growth, zoospore formation, and oospore production for (Pythium aphanidermatum, Pythium oligandrum, and Globisporangium ultimum var. ultimum) were highest in FANS, followed by NARM, then NARF, while VP₃ gave the lowest results compared to the control sample. It can be concluded that the use of FANS selective medium made the process of Pythium isolation easier, safer, and less expensive for worldwide researchers especially in developing and low-income countries.

Zanthoxylum bungeanum meal (ZBM), a byproduct of oil extraction, contains toxic alkaloids and alkylamides limiting its use as animal feed. This study investigated the degradation of these compounds using lactic acid bacteria (LAB) strains Lactobacillus acidipiscis and Lactobacillus paracasei isolated from ZBM via solid-state fermentation (SSF). LAB were identified using hyperspectral imaging, morphology, and plate counting. Fermentation conditions were optimized (e.g., 37 °C, pH 6.0, 48 h), with data analyzed via t-test, one-way ANOVA, and linear regression. Results showed degradation rates of 39.01% for alkaloids (to 3.01 mg/g) and 50.41% for alkylamides (to 2.87 mg/g). pH decreased over time due to organic acid production, while LAB growth peaked at 9 × 10^7 CFU/g before declining. This approach offers an economical, environmentally friendly method to convert ZBM into safe feed, though limitations include strain-specific efficacy and scale-up challenges.

Since its foundation in 2011, AMB Express has grown from a journal focused on classical applied microbiology and industrial biotechnology into a multidisciplinary platform covering microbiome research, antimicrobials, biocatalysis, and synthetic biology. In this Editorial, an overview of our journal's evolution is provided, along with an outline of the directions in which it should develop to maintain its status as a reference journal of applied microbiology and biotechnology.

The fermentation of sorghum wort is one of the fundamental steps that determine the quality of this beer. It is influenced by several parameters, among others: temperature, pH, sugar content, amino acid profile, phenolic compound content, and redox potential. Controlling these parameters will therefore make it possible to optimize the production of alcohol and the growth of the yeast during fermentation. The aim of this work is to show that the extraction of polyphenols, the main inhibitors of sorghum enzyme activity, prior to malting increases enzyme activity in the malt, thereby producing high levels of reducing sugars. This is reflected in the high alcohol content at the end of the fermentation process. Three parameters were considered in this work, namely: The polyphenol content in the grain (Discolored and non-discolored sorghum), temperature (12 and 25 °C) and fermentation time (in hours). The choice of fermentation temperature was made depending on the specific characteristics of the yeast used and taking into account the range used by artisan breweries producing sorghum beer in DR Congo. These breweries ferment their beers at room temperature. The results obtained give a better alcohol content of 7.53% for the E1T1 sample (Discolored sorghum, fermentation at 12 °C). The comparison of the results confirms that the extraction of the phenolic compounds before malting as well as the fermentation temperature had a significant effect on the production of alcohol and the growth of the yeast. The results of this work open the door to many other studies to provide to the industrial and artisanal brewers with scientific data that will allow them to better integrate red sorghum malt as raw material into brewing.

Bacillus coagulans is a spore-producing lactic acid bacterium with strong stress resistance. It has been widely used in food preservation, food fermentation, livestock diarrhea prevention, medication-assisted treatment, pollutant removal et al. In the study, a Bacillus coagulans strain with superior inhibition on Staphylococcus aureus, Escherichia coli, Vibrio parahaemolyticus and Aeromonas hydrophila was screened. Its medium composition and culture conditions were optimized in flasks using single factor experiment, Plackett Burman experiment, minimum addition experiment and response surface analysis experiment. The optimal medium composition was determined to be 14.64 g/L molasses, 0.4848 g/L MgSO₄, 0.0833 g/L MnSO₄, 1.5 g/L K₂HPO₄, 0.5 g/L KCl, 8 g/L peptone, and 10 g/L corn syrup dry powder. The optimal culture conditions were 40 °C, initial pH 6.0, inoculation ratio 4%, loading ratio 30%, and rotational speed 140 rpm, and cultivate for 44 h. After feed strategy optimization in 10 L fermenting tank, the concentrations of live bacteria and spores reached 4.63 × 10⁹ CFU/mL and 4.03 × 10⁹ CFU/mL, corresponding to a 14.5-fold and 16.4-fold increase, respectively. This study reduced the production cost of Bacillus coagulans greatly and supply technical support for Bacillus coagulans production.

The considerable contribution of ruminant livestock to methane emissions has become a major global concern in recent years. Although dietary approaches for reducing ruminant methane emissions have been explored, the sustainable potential of probiotics to influence rumen function and lower methane production has increasingly attracted research attention. While previous studies have focused on single or dual-strain probiotics, this study is among the first to evaluate the synergistic effects of quadric-strain formulations. Hence, this study aimed to evaluate the impact of multi-strain probiotic blends, each at two distinct concentrations on rumen fermentation, nutrient degradability, and methane emission in sheep using an in vitro gas production technique following a completely randomized design. The basal diet with no probiotic supplements served as a control, while the supplemented bacterial combinations were Bacillus licheniformis, Lactobacillus acidophilus, L. bulgaricus, and Bifidobacterium bifidum (ABLB; at a ratio of 1:1:1:1) at levels of 2 × 10⁹ (ABLB2) and 4 × 10⁹ (ABLB4) CFU/g of feed, and Lactobacillus casei, Lactobacillus plantarum, Bacillus subtilis plus Bifidobacterium bifidum (CPSB; at a ratio of 1:1:1:1) at levels of 2 × 10⁹ (CPSB2) and 4 × 10⁹ (CPSB4) CFU/g of feed. Probiotic supplementation significantly improved in vitro dry matter and fiber degradability (IVDMD and IVCFD), with the most effective results observed in ABLB treatments. These blends also reduced methane production and ammonia-N concentrations, while increasing total volatile fatty acids (TVFA), indicating more efficient fermentation. Protozoa counts were notably lower in treated groups, supporting the role of probiotics in mitigating methane via microbial modulation (P < 0.01). Probiotic supplementation did not affect the values of pH (P > 0.05). Predictive values for metabolizable energy (ME), net energy for lactation (NEL), and organic matter digestibility (OMD) were improved across treatments. These findings highlight the potential of targeted probiotic formulations to enhance rumen efficiency and reduce environmental emissions in ruminant systems.