Polish journal of microbiology最新文献

The entomopathogenic fungus Beauveria majiangensis strain MJ1015, recently isolated from white grubs on a blueberry farm in Guizhou, China, could be used as a biocontrol agent. As a first step toward determining the effect of different solid culture media, temperature, and pH on colony growth rate and sporulation, we evaluated the optimum solid medium for mycelial growth and conidia production on a commercial scale. Subsequently, we also used single-factor analysis and response surface optimization to optimize the composition of the solid culture medium. On potato dextrose agar (PDA) medium, MJ1015 grew fastest and produced the highest spore yield at 29°C and pH 5. The best solid medium for the growth and sporulation of strain MJ1015 comprised 64.70 g/l of rice, 13.00 g/l of wheat, 0.30 g/l of NaNO₃, 0.36 g/l of K₂HPO₄ · 3H₂O, and 1.00 g/l of CaCO₃. Rice, NaNO₃, and K₂HPO₄ · 3H₂O were the main influencing factors. The predicted value of cultured spores using the optimal medium was 4.56 x 10¹⁰ conidia/l. The validation test results showed that the average growth rate of strain MJ1015 on the optimal medium was 85% and 96% faster than that on Sabouraud dextrose agar with yeast extracts medium (SDAY) and PDA, respectively. Sporulation was 43.90 times and 9.65 times of that produced on SDAY and PDA, respectively. Our findings provide a theoretical basis for the commercial production of B. majiangensis to control white grubs.

Graves' disease (GD) is an autoimmune disorder disease, and its prevalence continues to increase worldwide. Pyrroloquinoline quinone (PQQ) is a naturally antioxidant compound in milk, vegetables, and meat. We aim to identify the treatment efficacy of PQQ on GD and its regulatory effect on intestinal microbiota. The GD mice model was built by an adenovirus expressing autoantigen thyroid-stimulating hormone receptor (Ad-TSHR289). Fecal samples were collected for 16S rDNA sequencing after PQQ pretreatments (20, 40, or 60 mg/kg BW/day) for 4 weeks. Thyroid and intestine functions were measured. The levels of serum TSHR and T4 were significantly raised, and the thyroid gland size was typically enlarged in the GD group than in controls, reversed by PQQ therapy. After PQQ replenishment, IL6 and TNFα levels in small intestine tissues were lower than those in the GD group, with Nrf2 and HO1 levels improved. Also, the PQQ supplement could maintain the mucosal epithelial barrier impaired by GD. In microbial analyses, PQQ treatment could prompt the diversity recovery of gut microbiota and reconstruct the microbiota composition injured by GD. Lactobacillus served as the most abundant genus in all groups, and the abundance of Lactobacillus was increased in the GD group than in control and PQQ groups. Besides, Lactobacillus was highly correlative with all samples and the top 50 genera. PQQ supplementation regulates thyroid function and relieves intestine injury. PQQ changes the primary composition and abundance of GD's intestine microbiota by moderating Lactobacillus, which may exert in the pathogenesis and progression of GD.

We aimed to compare the clinical efficacy of fecal microbiota transplantation (FMT) from the same sex on ulcerative colitis (UC) patients. A total of 272 UC patients were selected in the prospective clinical study, which incorporated four distinct groups, each comprising male and female patients, who were either receiving FMT or placebo, respectively. FMT was performed by sending the gut microbiota of healthy female or male adolescents to the same gender patients via gastroscope three times (one time/three weeks), and a placebo was used with an equal volume of saline. Abdominal pain, diarrhea, thick bloody stool, intestinal mucosal lesion, and Mayo scores were measured. Self-rating anxiety scale (SAS) and self-rating depression scale (SDS) were evaluated. The changes of intestinal flora were detected by the 16S rRNA sequencing. FMT reduced the scores of diarrhea, abdominal pain, mucosal lesion, and Mayo, SAS, and SDS in UC patients compared to the placebo group (p < 0.05). Clostridiales and Desulfovibrionaceae were dominant in gut microbiota from male patients and were reduced after FMT. Meanwhile, the abundance of Prevotella, Lactobacillus, and Bifidobacterium was increased in the male group. Female patients had a higher abundance of Escherichia-Shigella, Desulfovibrionaceae, and Staphylococcaceae before FMT, and it was reduced after FMT. Meanwhile, the abundance of Porphyromonadaceae, Prevotella, Lactobacillus, and Bifidobacterium was increased in the female group. There were no significant changes for the species in the corresponding placebo groups. FMT improved the UC symptoms of male and female patients, which may be associated with different gut microbiota changes.

Fusarium oxysporum is the primary pathogen of blueberry root rot; furthermore, we found that Fusarium commune can also cause root rot in blueberries. Trichoderma spp. is widely used to control plant diseases. We isolated Trichoderma asperellum (TM11) from blueberry rhizosphere soil to explore its control effect and mechanism on F. oxysporum and F. commune. We found that the inhibitory effects of TM11 volatiles and broth metabolites on F. oxysporum were significant, but only F. commune volatile metabolites had a significant inhibitory effect on its growth. Twelve known antimicrobial metabolites were detected from the methanol extract of TM11 fermentation broth by HPLC-MS. TM11 lysed and coiled around the hyphae of F. oxysporum and F. commune. The pot experiment showed that TM11 had significant control effects against F. oxysporum and F. commune, and inoculation of TM11 prior to that of F. oxysporum and F. commune was more effective. The TM11, TM11 and F. oxysporum, or F. commune and distilled water treatments had different effects on the activities of superoxide dismutase, peroxidase and catalase, and the enzyme activity levels exhibited the following order: TM11 > TM11 and F. oxysporum or F. commune > distilled water. The results showed that TM11 provided effective control of blueberry root rot.

Tuberculosis (TB) caused by Mycobacterium tuberculosis is one of the leading causes of morbidity and death in humans worldwide. Some autophagy genes associated with TB and some miRNAs regulating TB have been found, but the identification of autophagy-related genes in M. tuberculosis remains to be explored. Forty-seven autophagy-related genes differentially expressed in TB were identified in this study by analysis of TB-related datasets in the Gene Expression Omnibus (GEO) and autophagy-related genes in the Human Autophagy Database. The potential crucial genes affecting TB were found through the protein-protein interaction (PPI) network, and the possible pathways affected by these genes were verified. Analysis of the PPI network of miRNAs associated with M. tuberculosis infection and their target genes revealed that hsa-let-7, hsa-mir-155, hsa-mir-206, hsa-mir-26a, hsa-mir-30a, and hsa-mir-32 may regulate the expression of multiple autophagy-related genes (MAPK8, UVRAG, UKL2, and GABARAPL1) alone or in combination. Subsequently, Cytoscape was utilized to screen the differentially expressed genes related to autophagy. The hub genes (GABARAPL1 and ULK2) affecting TB were identified. Combined with Gene Set Enrichment Analysis (GSEA), the signaling pathways affected by the hub genes were verified. Finally, we divided TB patients into two subgroups based on autophagy-related genes, and the immune microenvironment of patients in different subgroups was significantly different. Our study found two autophagy-related hub genes that could affect TB and divide TB samples into two subgroups. This finding is of great significance for TB treatment and provides new ideas for exploring the pathogenesis of M. tuberculosis.

This work investigated the genetic relationship among Stenotrophomonas maltophilia strains in fecal samples from dairy cows in northeast China and identified the dominant β-lactamase genotype. One hundred and six samples were collected from two randomly selected cow farms in northeast China, and the isolates were identified with MALDI-TOF/MS. Whole-genome sequencing was conducted using Illumina HiSeq 4000-PE150 platform (Illumina, Inc., USA). The antimicrobial resistance genes were detected using CGE services. The phylogenetic analysis of S. maltophilia strains was performed by Roary and MEGA X. In total, 24 S. maltophilia isolates were isolated. The results of resistome analysis showed all S. maltophilia strains carrying bla _L1 gene, which was the only β-lactamase genotype. In addition, the aminoglycoside resistance genes aac(6')-Iz and aph(3')-IIc were found. The phylogenetic tree indicated the clonal diversity of S. maltophilia in these two regions and the clonal relatedness of the strains from these regions. This study first investigated the dissemination and characterization of S. maltophilia isolates from dairy cows in northeast China and provided evidence of the potential transmission between two provinces. Furthermore, it indicated bla _L1 was the most prevalent genotype of β-lactamase in these regions.

Chlamydia felis is an important zoonotic agent for humans and various animals. A recombinase-aided amplification (RAA) assay was developed for detecting C. felis. RAA can be performed in a closed tube at 39°C within 30 min. The detection limit was 10.6 copies of the C. felis plasmid DNA per reaction. No positive signals for other pathogens were detected. The coincidence rate of RAA and conventional PCR was 95.24% (20/21) and 100% (96/96) for positive and negative samples, respectively. The established RAA assay is a simple, rapid, highly sensitive, and specific method for detecting C. felis.

The prokaryotic microalga Limnothrix redekei KNUA012 isolated from a freshwater bloom sample from Lake Hapcheon, Hapcheon-gun, South Korea, was investigated for its potential as a biofuel feedstock. Microalgae produce straight-chain alkanes/alkenes from acyl carrier protein-linked fatty acyls via aldehyde decarbonylase (AD; EC 1.2.1.3), which can convert aldehyde intermediates into various biofuel precursors, such as alkanes and free fatty acids. In L. redekei KNUA012, long-chain ADs can convert fatty aldehyde intermediates into alkanes. After heterologous AD expression in Escherichia coli (pET28-AD), we identified an AD in L. redekei KNUA012 that can synthesize various alkanes, such as pentadecane (C₁₅H₃₂), 8-heptadecene (C₁₇H₃₄), and heptadecane (C₁₇H₃₆). These alkanes can be directly used as fuels without transesterification. Biodiesel constituents including dodecanoic acid (C₁₃H₂₆O₂), tetradecanoic acid (C₁₅H₃₀O₂), 9-hexa decenoic acid (C₁₇H₃₂O₂), palmitoleic acid (C₁₇H₃₂O₂), hexadecanoic acid (C₁₇H₃₄O₂), 9-octadecenoic acid (C₁₉H₃₆O₂), and octadecanoic acid (C₁₉H₃₈O₂) are produced by L. redekei KNUA012 as the major fatty acids. Our findings suggest that Korean domestic L. redekei KNUA012 is a promising resource for microalgae-based biofuels and biofuel feedstock.

Uricase (or Urate oxidase), a key enzyme involved in purine metabolism, is commonly used in treating conditions such as gout, hyperuricemia, and tumor lysis syndrome. In this study, a uricase-producing strain (named CSAJ-16) was isolated from the soil sample of Cangshan Mountain, Yunnan Province, China. This strain was identified as Arthrobacter sp. CSAJ-16. Based on the gene sequence alignment, the uricase gene (named aruox) of Arthrobacter sp. CSAJ-16 was amplified and heterologously expressed. The recombinant uricase (ArUOX) was about 32 kDa. The optimal pH and temperature of ArUOX were pH 7 and 20°C, respectively. The ArUOX remained above 50% relative activity after incubation at 37°C for 100 min or at pH 6.0-8.6 for 24 h. Moreover, metal ions such as K⁺, Mg²⁺, Ca²⁺, Ba²⁺ and Pb²⁺ can significantly enhance the activity of ArUOX (> 200%). These enzymatic properties indicate that ArUOX has potential applications in pharmaceutical enzymes and uric acid detection kits.

The study aimed to isolate Lactobacillaceae strains with in vitro hypoglycemic activity and probiotic properties and to determine their antidiabetic abilities in vivo. Lactiplantibacillus plantarum 22, L. plantarum 25, Limosilactobacillus fermentum 11, and L. fermentum 305 with high in vitro hypoglycemic activity were screened from 23 strains of Lactobacillaceae isolated from human feces and identified by 16S rDNA sequencing. The fasting blood glucose (FBG) of the mice was recorded weekly. After 12 weeks, liver, kidney, and pancreas tissues were stained with hematoxylin and eosin (H&E) to observe histomorphology; the inflammatory factors were assayed by Quantitative Real-time PCR; PI3K and AKT were measured by Western blot; the short-chain fatty acids (SCFAs) were determined by LC-MS/MS. Inhibitory activities of L. plantarum 22, L. plantarum 25, L. fermentum 11, and L. fermentum 305 against α-amylase were 62.29 ± 0.44%, 51.81 ± 3.65%, 58.40 ± 1.68%, and 57.48 ± 5.04%, respectively. Their inhibitory activities to α-glucosidase were 14.89 ± 0.38%, 15.32 ± 0.89%, 52.63 ± 3.07%, and 51.79 ± 1.13%, respectively. Their survival rate after simulated gastrointestinal test were 12.42 ± 2.84%, 9.10 ± 1.12%, 5.86 ± 0.52%, and 8.82 ± 2.50% and their adhesion rates to Caco-2 cell were 6.09 ± 0.39%, 6.37 ± 0.28%, 6.94 ± 0.27%, and 6.91 ± 0.11%, respectively. The orthogonal tests of bacterial powders of the four strains showed that the maximum inhibitory activities to α-amylase and α-glucosidase were 93.18 ± 1.19% and 75.33 ± 2.89%, respectively. The results showed that the mixture of Lactobacillaceae could lower FBG, reduce inflammation, and liver, kidney, and pancreas damage, promote PI3K/AKT signaling pathway, and increase the content of SCFAs. The combination of L. plantarum 22, L. plantarum 25, L. fermentum 11, and L. fermentum 305 can potentially improve type 2 diabetes mellitus (T2DM).