The fermentation optimization for alkaline protease production by Bacillus subtilis BS-QR-052

IntroductionProteases exhibit a wide range of applications, and among them, alkaline proteases have become a prominent area of research due to their stability in highly alkaline environments. To optimize the production yield and activity of alkaline proteases, researchers are continuously exploring different fermentation conditions and culture medium components.MethodsIn this paper, the fermentation conditions of the alkaline protease (EC 3.4.21.14) production by Bacillus subtilis BS-QR-052 were optimized, and the effect of different nutrition and fermentation conditions was investigated. Based on the single-variable experiments, the Plackett–Burman design was used to explore the significant factors, and then the optimized fermentation conditions, as well as the interaction between these factors, were evaluated by response surface methodology through the Box–Behnken design.Results and discussionThe results showed that 1.03% corn syrup powder, 0.05% MgSO4, 8.02% inoculation volume, 1:1.22 vvm airflow rate, as well as 0.5% corn starch, 0.05% MnSO4, 180 rpm agitation speed, 36°C fermentation temperature, 8.0 initial pH and 96 h incubation time were predicted to be the optimal fermentation conditions. The alkaline protease enzyme activity was estimated to be approximately 1787.91 U/mL, whereas subsequent experimental validation confirmed it reached 1780.03 U/mL, while that of 500 L scale-up fermentation reached 1798.33 U/mL. This study optimized the fermentation conditions for alkaline protease production by B. subtilis through systematic experimental design and data analysis, and the activity of the alkaline protease increased to 300.72% of its original level. The established model for predicting alkaline protease activity was validated, achieving significantly higher levels of enzymatic activity. The findings provide valuable references for further enhancing the yield and activity of alkaline protease, thereby holding substantial practical significance and economic benefits for industrial applications

High Quality-Factor and Spectrum-Clean AlN Lamb-Wave Resonators with Optimized Lateral Reflection Boundary Conditions and Transducer Design

This paper presents a high quality-factor (Q) and spectrum-clean AlN Lamb-wave resonator (LWR). The width of its lateral reflection boundary was optimized to weaken the transverse modes’ coupling and wave guiding, and then to improve the LWR’s Q value and spectral purity, which was verified by finite element analysis and experimental characterization. In addition, the series resonance quality factor (Qs) value of the interdigitated (IDT)-Ground LWR is similar to that of the IDT-Floating LWR, but its parallel resonance quality factor (Qp) is nearly doubled, due to the reduction of the electrical loss induced by its static capacitance (C0). The measured results show that the designed LWR with optimized boundary reflection conditions and IDT-Ground structure exhibit Qs and Qp values as high as 4019.8 and 839.5 at 401.2 MHz and 402.9 MHz, respectively, meanwhile, it has good spectral purity. Moreover, the influence of the metal ratio and material of the LWR’s IDT electrodes on the device’s performance was also studied by theoretical analysis and experimental verification

Diagnostic Potential of microRNAs in Extracellular Vesicles Derived from Bronchoalveolar Lavage Fluid for Pneumonia—A Preliminary Report

Current clinical needs require the development and use of rapid and effective diagnostic indicators to accelerate the identification of pneumonia and the process of microbiological diagnosis. MicroRNAs (miRNAs) in extracellular vesicles (EVs) have become attractive candidates for novel biomarkers to evaluate the presence and progress of many diseases. We assessed their performance as biomarkers of pneumonia. Patients were divided into the pneumonia group (with pneumonia) and the control group (without pneumonia). We identified and compared two upregulated miRNAs in EVs derived from bronchoalveolar lavage fluid (BALF-EVs) between the two groups (PmiR–17–5p = 0.009; PmiR–193a–5p = 0.031). Interestingly, in cell-debris pellets and EVs-free supernatants derived from bronchoalveolar lavage fluid (BALF-cell-debris pellets and BALF-EVs-free supernatants), total plasma, and EVs derived from plasma (plasma-EVs), the expression of miR–17–5p and miR–193a–5p showed no difference between pneumonia group and control group. In vitro experiments revealed that miR–17–5p and miR–193a–5p were strikingly upregulated in EVs derived from macrophages stimulated by lipopolysaccharide. MiR–17–5p (area under the curve, AUC: 0.753) and miR–193a–5p (AUC: 0.692) in BALF-EVs are not inferior to procalcitonin (AUC: 0.685) in the diagnosis of pneumonia. Furthermore, miR–17–5p and miR–193a–5p in BALF-EVs had a significantly higher specificity compared to procalcitonin and could be served as a potential diagnostic marker. MiR–17–5p and miR–193a–5p in EVs may be involved in lung inflammation by influencing the forkhead box O (FoxO) signaling pathway and protein processing in endoplasmic reticulum. This study is one of the few studies which focused on the potential diagnostic role of miRNAs in BALF-EVs for pneumonia and the possibility to use them as new biomarkers for a rapid and early diagnosis

Uric Acid is independently associated with diabetic kidney disease: a cross-sectional study in a Chinese population.

Association between hyperuricaemia and chronic kidney disease has been studied widely, but the influence of uric acid on the kidneys remains controversial. We aimed to summarize the association between uric acid and diabetic kidney disease (DKD), and to evaluate the role of uric acid in DKD.We enrolled 3,212 type 2 diabetic patients in a cross-sectional study. The patients' basic characteristics (sex, age, BMI, duration of disease, and blood pressure) and chemical parameters (triglycerides, total cholesterol, low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), microalbuminuria, creatinine, and uric acid) were recorded, and the association between uric acid and DKD was evaluated.In the 3,212 diabetic patients, the prevalence of diabetic kidney disease was higher in hyperuricaemic patients than in patients with normouricaemia (68.3% vs 41.5%). The prevalence of DKD increased with increasing uric acid (p < 0.0001). Logistic analysis identified uric acid as an independent predictor of DKD (p < 0.0001; adjusted OR (95%CI) = 1.005 (1.004-1.007), p < 0.0001). Uric acid was positively correlated with albuminuria and creatinine levels (p < 0.0001) but negatively correlated with eGFR (p < 0.0001) after adjusting for confounding factors.Hyperuricaemia is a risk factor for DKD. Serum uric acid levels within the high-normal range are independently associated with DKD

Clinical characteristics of the study subjects.

<p>Data are shown as mean±SD or the median (interquartile range). BMI: Body mass index. SP: Systolic blood pressure. DP: Diastolic blood pressure. MDRD: Modification of diet in renal disease. LDL: Low-density lipoprotein cholesterol. HDL: High-density lipoprotein cholesterol. TC: Total cholesterol. FPG: fasting plasma glucose. 2h PG: 2 hour postprandial glucose.</p><p>Clinical characteristics of the study subjects.</p

Index trends according to the uric acid category.

<p>Data are shown as the median (interquartile range). SP: Systolic blood pressure. DP: Diastolic blood pressure. MDRD: Modification of diet in renal disease. LDL: Low-density lipoprotein cholesterol. HDL: High-density lipoprotein cholesterol. TC: Total cholesterol.</p><p>Index trends according to the uric acid category.</p

Association between uric acid and HbA1c levels and the prevalence of DKD.

<p>The uric acid was categorized into 6 levels and the HbA1c levels, the prevalence of DKD were calculated separately. HbA1c levels were shown by box plots, and the prevalence of DKD was shown by simple straight line & scatter. Increased serum uric acid was correlated with decreased HbA1c and an elevated prevalence of DKD (<i>p</i><0.0001).</p

The Scap-SREBP1-S1P/S2P lipogenesis signal orchestrates the homeostasis and spatiotemporal activation of NF-κB

Summary: The nuclear factor κB (NF-κB) pathway plays essential roles in innate and adaptive immunity, but little is known how NF-κB signaling is compartmentalized and spatiotemporally activated in the cytoplasm. Here, we show that the lipogenesis signal cascade Scap-SREBP1-S1P/S2P orchestrates the homeostasis and spatiotemporal activation of NF-κB. SREBP cleavage-activating protein (Scap) and sterol regulatory element-binding protein 1 (SREBP1) form a super complex with inhibitors of NF-κB α (IκBα) to associate NF-κB close to the endoplasmic reticulum (ER). Upon lipopolysaccharide (LPS) stimulation, Scap transports the complex to the Golgi apparatus, where SREBP1 is cleaved by site-1 protease (S1P)/S2P, liberating IκBα for IκB kinase (Ikk)-mediated phosphorylation and subsequent activation of NF-κB. Loss of Scap or inhibition of S1P or S2P diminishes, while SREBP1 deficiency augments, LPS-induced NF-κB activation and subsequent inflammatory responses. Our results reveal the Scap-SREBP1 complex as an additional cytoplasmic checkpoint for NF-κB homeostasis and unveil the Golgi apparatus as the optimal cellular platform for NF-κB activation, providing insights into the crosstalk between lipogenesis signaling and immunity