Screening, characterization, and optimization of the fermentation conditions of a novel cellulase-producing microorganism from soil of Qinghai-Tibet Plateau.

Cellulases play an important role in the bioconversion of lignocellulose. Microorganisms found in extreme environments are a potentially rich source of cellulases with unique properties. Due to the uniqueness of the environment, the abundant microbial resources in the Qinghai-Tibet Plateau (QTP) are worth being explored. The aim of this study was to isolate and characterize an acidic, mesophilic cellulase-producing microorganism from QTP. Moreover, the fermentation conditions for cellulase production were optimized for future application of cellulase in the development of lignocellulose biomass. A novel cellulase-producing strain, Penicillium oxalicum XC10, was isolated from the soil of QTP. The cellulase produced by XC10 was a mesophilic cellulase that exhibited good acid resistance and some cold-adaptation properties, with maximum activity at pH 4.0 and 40°C. Cellulase activity was significantly enhanced by Na+ (p < 0.05) and inhibited by Mg2+, Ca2+, Cu2+, and Fe3+ (p < 0.05). After optimization, maximum cellulase activity (8.56 U/mL) was increased nearly 10-fold. Optimal fermentation conditions included an inoculum size of 3% (v/v) in a mixture of corn straw (40 g/L), peptone (5 g/L), and Mg2+ (4 g/L), at pH 4.0, 33°C, and shaking at 200 rpm. The specific properties of the P. oxalicum XC10 cellulase suggest the enzyme may serve as an excellent candidate for the bioconversion and utilization of lignocellulose biomass generated as agricultural and food-processing wastes.

Characterization and Assessment of Native Lactic Acid Bacteria from Broiler Intestines for Potential Probiotic Properties.

Probiotics are the most promising alternative to antibiotics for improving animal production and controlling pathogenic infections, while strains derived from natural hosts are considered highly desirable due to their good adaptation to the gastrointestinal tract. The aim of this study was to screen Lactobacillus with broad-spectrum antibacterial activity from broilers fed an antibiotic-free diet and evaluate their potential as poultry probiotics. A total of 44 lactic acid bacteria (LAB) strains were isolated from the intestines of healthy broilers, among which 3 strains exhibited outstanding antimicrobial activity and were subsequently identified through 16S rRNA sequencing as Enterococcus faecium L8, Lactiplantibacillus plantarum L10, and Limosilactobacillus reuteri H11. These three isolates demonstrated potent bacteriostatic activity against Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella cholerae, with inhibition zones ranging from 15.67 ± 1.53 to 21.33 ± 0.58 mm. The selected LAB strains exhibited high tolerance to acid and bile salts, with L. reuteri H11 displaying the highest survival rate (ranging from 34.68% to 110.28%) after exposure to 0.3% (w/v) bile salts for 6 h or a low pH environment (pH 2, 2.5, and 3) for 3 h. Notably, L. reuteri H11 outperformed other strains in terms of hydrophobicity (84.31%), auto-aggregation (53.12%), and co-aggregation with E. coli ATCC 25922 (36.81%) and S. aureus ATCC 6538 (40.20%). In addition, the three LAB isolates were either fully or moderately susceptible to the tested antibiotics, except for strain L8, which resisted gentamycin and vancomycin. Consequently, these three LAB strains, especially L. reuteri H11, isolated from the intestines of broiler chickens, represent promising probiotic candidates that can be employed as feed additives to enhance production performance and control poultry pathogens.

Injectable Ozone-Rich Nanocomposite Hydrogel Loaded with D-Mannose for Anti-Inflammatory and Cartilage Protection in Osteoarthritis Treatment.

Osteoarthritis (OA) is a dynamic condition characterized by cartilage damage and synovial inflammation. Ozone (O3) shows potential therapeutic effects owing to its anti-inflammatory properties; however, its high reactivity and short half-life substantially limit its effectiveness in OA treatment. In this study, an ozone-rich thermosensitive nanocomposite hydrogel loaded with D-mannose is developed for OA treatment. Briefly, O3 is encapsulated in nanoparticles (NPs) composed of perfluorotributylamine and fluorinated hyaluronic acid to improve its stability. Next, D-mannose is conjugated with α-amino of the hydroxypropyl chitin (HPCH) via Schiff base to prepare MHPCH. These nanoparticles are encapsulated in MHPCH to produce O3 NPs@MHPCH. In vitro cell experiments demonstrate that the O3 NPs@MHPCH treatment significantly reduced VEGF and inflammation levels, accompanied by a decrease in inflammatory factors such as IL-1ß, IL-6, TNF-α, and iNOS. Furthermore, O3 NPs@MHPCH promotes the expression of collagen II and aggrecan and stimulates chondrocyte proliferation. Additionally, in vivo studies show that O3 NPs@MHPCH significantly alleviated OA by reducing synovial inflammation, cartilage destruction, and subchondral bone remodeling. O3 NPs@MHPCH offers a promising option for improving the efficacy of O3 therapy and reducing the risk of synovial inflammation and cartilage degeneration in OA.

Factors affecting the success of fallopian tube recanalization in treatment of tubal obstructive infertility.

OBJECTIVE: To examine potential risk factors associated with the success rate following fallopian tube recanalization (FTR) in infertile women with obstruction of the proximal fallopian tube. METHODS: We retrospectively studied patients who underwent FTR for tubal obstructive infertility between January 2016 and December 2018 at the Third Affiliated Hospital of Guangzhou Medical University. FTR was performed using a catheter and guidewire system to clear tubal obstruction. Predictive factors potentially associated with the success rate were assessed by logistic regression. RESULTS: A total of 762 patients were included. Multivariable analysis showed that age (odds ratio [OR] = 2.38, 95% confidence interval [CI]: 1.24-4.58), infertility type (OR = 2.82, 95% CI: 1.36-6.21), history of ectopic pregnancy (OR = 7.87, 95% CI: 4.05-15.81), history of abdominal surgery (OR = 4.30, 95% CI: 2.22-8.60), history of artificial abortion curettage (OR = 4.08, 95% CI: 2.12-8.03), and duration of infertility (OR = 2.03, 95% CI: 1.06-3.85) were independently associated with postoperative tubal patency. CONCLUSIONS: Our findings suggest that risk factors, such as age ≥35 years, secondary infertility, duration of infertility ≥5 years, and histories of ectopic pregnancy, abdominal surgery, and artificial abortion curettage, affect the success rate of FTR. These factors may also predict surgical success in treating tubal obstructive infertility.

Ascorbic Acid can Reverse the Inhibition of Phytic Acid, Sodium Oxalate and Sodium Silicate on Iron Absorption in Caco-2 cells.

The objective of the present study is to determine the effect of phytic acid (PA), sodium oxalate (SO) and sodium silicate (SS) on non-heme iron bioavailability in both the presence and absence of ascorbic acid (AA) using an in vitro digestion/Caco-2 cell model, and the levels of AA needed to promote Fe absorption from Fe complexed with PA, SO or SS were also determined. The results indicated that adding PA at 1:1, 3:1, 5:1 and 10:1 molar as compared to Fe decreased ferrous iron uptake by 55.80 %(P < 0.05), 72.33 % (P < 0.05), 73.32 % (P < 0.05), and 73.26 % (P < 0.05), respectively. Adding SS at 1:1, 3:1, 5:1 and 10:1 molar as compared to Fe also decreased ferrous iron uptake by 51.40 % (P < 0.05), 66.12 %(P < 0.05), 60.19 % (P < 0.05) and 45.11 % (P < 0.05), respectively. Adding SO at 5:1 and 10:1 molar as compared to Fe decreased ferrous iron uptake by 40.81 % (P < 0.05) and 33.14 % (P < 0.05), respectively. When adding AA to iron plus organic acid medias reached molar ratios of 5:5:1 AA:PA:Fe, 3:5:1 AA:SO:Fe and 5:5:1 AA:SS:Fe, iron absorption from FeSO4 were significantly increased (P < 0.05). However, no significant effect was observed in iron absorption from FeCl3 when adding AA to the media. The results showed that PA, SS or SO decreases iron uptake from ferrous Fe, and AA can counteract their inhibiting effect on ferrous iron absorption and thus increase ferrous iron uptake. The results may be important for elucidating factors affecting iron bioavailability in the small intestine and for the development of foods with improved iron bioavailability.

Iron concentration, bioavailability, and nutritional quality of polished rice affected by different forms of foliar iron fertilizer.

The present study compared the effects of four different forms of foliar iron (Fe) fertilizers on Fe concentration, bioavailability and nutritional quality of polished rice. The results showed that foliar fertilisation at the anthesis stage was an effective way to promote Fe concentration and bioavailability of polished rice, especially in case of DTPA-Fe. Compared to the control, foliar application of DTPA-Fe increased sulphur concentration and the nutrition promoter cysteine content, whereas decreased phosphorus concentration and the antinutrient phytic acid content of polished rice, as a result increased 67.2% ferrtin formation in Caco-2 cell. Moreover, foliar DTPA-Fe application could maintain amylase, protein and minerals quality of polished rice. According to the current study, DTPA-Fe is recommended as an excellent foliar Fe form for Fe biofortification program.

Differential iron-bioavailability with relation to nutrient compositions in polished rice among selected Chinese genotypes using Caco-2 cell culture model.

Genotypic variation of iron bioavailability and the relationship between iron bioavailability and nutrient composition in polished rice among 11 rice genotypes were assessed using an in vitro digestion/Caco-2 cell model. The results indicated that significant differences in iron bioavailability were detected among tested rice genotypes, with a 3-fold range, suggesting a possibility of selecting high bioavailable iron by plant breeding. Although iron bioavailability was not significantly correlated with Fe concentration in polished rice among tested rice genotypes, the results also indicated that most of the iron dense genotypes showed relatively high ferritin formation in Caco-2 cell and transported iron. Additionally, iron bioavailability in polished rice was enhanced by addition of ascorbic acid, with a much wider range of Fe bioavailability variation in polished rice with addition of ascorbic acid than that without addition of ascorbic acid. The positive relationship between iron bioavailability in polished rice and cysteine concentration (R = 0.669) or sulfur (S) concentration (R = 0.744) among tested rice genotypes, suggests that cysteine and sulfur concentration in polished rice could be used as an indicator for high iron bioavailability.

Electrotransformation and expression of cellulase genes in wild-type Lactobacillus reuteri.

Two cellulase genes, Cel15 and Cel73, were amplified from Bacillus subtilis genome DNA in a previous study. Two integrative vectors, pLEM4153 and pLEM4154, containing the genes Cel15 and Cel73, respectively, were constructed and successfully electroporated into the wild-type Lactobacillus reuteri which was isolated from chick guts through an optimized procedure. Two recombinant L. reuteri were selected from a Man, Rogosa, and Sharp (MRS) plate with 10 µg/ml erythromycin, and named L. reuteri XNY-Cel15 and L. reuteri XNY-Cel73, respectively. To verify the transcription and expression of the two cellulase genes in the recombinant L. reuteri strains, the mRNA relative quantity (RQ) and the cellulase activity were determined. The mRNA RQ of Cel15 in L. reuteri XNY-Cel15 is 1,8849.5, and that of Cel73 in L. reuteri XNY-Cel73 is 1,388, and the cellulase activity of the modified MRS broth cultured with L. reuteri XNY-Cel15 was 0.158 U/ml, whereas that with L. reuteri XNY-Cel73 was 0.15 U/ml.

Availability and toxicity of Fe(II) and Fe(III) in Caco-2 cells.

The objective of the present study was to compare the toxicity and availability of Fe(II) and Fe(III) to Caco-2 cells. Cellular damage was studied by measuring cell proliferation and lactate dehydrogenase (LDH) release. The activities of two major antioxidative enzymes [superoxide dismutase (SOD) and glutathione peroxidase (GPx)] and differentiation marker (alkaline phosphatase) were determined after the cells were exposed to different levels of iron salts. The cellular iron concentration was investigated to evaluate iron bioavailability. The results show that iron uptake of the cells treated with Fe(II) is significantly higher than that of the cells treated with Fe(III) (P<0.05). Fe(II) at a concentration >1.5 mmol/L was found to be more effective in reducing cellular viability than Fe(III). LDH release investigation suggests that Fe(II) can reduce stability of the cell membrane. The activities of SOD and GPx of the cells treated with Fe(II) were higher than those of the cells treated with Fe(III), although both of them increased with raising iron supply levels. The results indicate that both Fe(II) and Fe(III) could reduce the cellular antioxidase gene expression at high levels.

Comparison of iron uptake from reduced iron powder and FeSO4 using the Caco-2 cell model: effects of ascorbic acid, phytic acid, and pH.

The reduced iron powder has considerable potential for use as an iron fortificant because it does not change organoleptically during storage or food preparation for cereal flour, and its bioavailability is scarcely influenced by iron absorption inhibitors in foods. The objective of this article is to study the effects of ascorbic acid, phytic acid, and pH on iron uptake from reduced iron powder (43 microm) and FeSO 4, and to compare iron bioavailability of reduced iron powders among four selected granularity levels. The cell ferritin formation is used as a marker of iron uptake. Obviously, iron uptake of reduced iron powder is increased with decreasing of powder granularity and is much lower than FeSO 4 when the size is above 43 microm, but significantly higher at 40-60 nm. In the presence of ascorbic acid or phytic acid, Caco-2 cell iron absorption from reduced iron powder (43 microm) is significantly higher than that from FeSO 4. And iron uptake of Caco-2 cells is decreased with increasing of pH from 5.5 to 7.5. Moreover, the decrease trend is more obvious for reduced iron powder than for FeSO 4. Our results indicated that iron bioavailability of reduced iron powder by intestinal enterocytes is similar to that of iron salts, and reduced iron powder is more excellent than FeSO 4 as food fortificant, especially at ultramicroscopic granularity.