The potential and capability of the methylotrophic yeast Ogataea methanolica in a "methanol bioeconomy".

Efficient bioconversion of methanol, which can be generated from greenhouse gases, into valuable resources contributes to achieving climate goals and developing a sustainable economy. The methylotrophic yeast Ogataea methanolica is considered to be a suitable host for efficient methanol bioconversion because it has outstanding characteristics for the better adaptive potential to a high methanol environment (i.e., greater than 5%). This capacity represents a huge potential to construct an innovative carbon-neutral production system that converts methanol into value-added chemicals under the control of strong methanol-induced promoters. In this review, we discuss what is known about the regulation of methanol metabolism and adaptation mechanisms for 5% methanol conditions in O. methanolica in detail. We also discuss about the potential to breed "super methylotrophic yeast," which has potent growth characteristics under high methanol conditions.

Effect of TEAS combined with general anesthesia on early postoperative cognitive function in elderly patients undergoing single-port thoracoscopic lobectomy.

Objective: To investigate the effect of transcutaneous electrical acupoint stimulation (TEAS) on early cognitive function in elderly patients after single port thoracoscopic lobectomy. Methods: One hundred and nine patients who underwent single whole thoracoscopic lobectomy in Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine from January 2020 to October 2021 were included in this single-center, retrospective observational study. According to the treatment records, before anesthesia, 56 patients received TEAS (TEAS-group), and 53 patients applied electrodes at the same acupoint without electrical stimulation (control-group). Preoperative and postoperative cognitive function (Mini mental state examination, MMSE score), serum neuron specific enolase (NSE), S100ß protein and p-tau protein levels and postoperative complications were compared between the two groups. Results: After operation, the MMSE of the TEAS-group was significantly better than that of the Control-group, with the MMSE of the TEAS-group returned to the preoperative level 72 hours after operation. Serum NSE, S100ß and p-tau concentrations 24 hours and 72 hours after operation in the TEAS-group returned to their preoperative level and were significantly lower than those in the control-group. Hospitalization time of the TEAS-group was significantly shorter and hospitalization expenses were significantly lower comparing to the control-group. Conclusion: TEAS treatment could promote improved early postoperative cognitive function of elderly patients undergoing single port thoracoscopic lobectomy and could accelerate the recovery.

Fatty acid composition of the methylotrophic yeast Komagataella phaffii grown under low- and high-methanol conditions.

In this study, we analysed the intracellular fatty acid profiles of Komagataella phaffii during methylotrophic growth. K. phaffii grown on methanol had significantly lower total fatty acid contents in the cells compared with glucose-grown cells. C18 and C16 fatty acids were the predominant fatty acids in K. phaffii, although the contents of odd-chain fatty acids such as C17 fatty acids were also relatively high. Moreover, the intracellular fatty acid composition of K. phaffii changed in response to not only carbon sources but also methanol concentrations: C17 fatty acids and C18:2 content increased significantly as methanol concentration increased, whereas C18:1 and C18:3 contents were significantly lower in methanol-grown cells. The intracellular content of unidentified compounds (Cn H2n O4 ), on the other hand, was significantly greater in cells grown on methanol. As the intracellular contents of these Cn H2n O4 compounds were significantly higher in a gene-disrupted strain for glutathione peroxidase (gpx1Δ) than in the wild-type strain, we presume that the Cn H2n O4 compounds are fatty acid peroxides. These results indicate that K. phaffii can coordinate intracellular fatty acid composition during methylotrophic growth in order to adapt to high-methanol conditions and that certain fatty acid species such as C17:0, C17:1, C17:2 and C18:2 may be related to the physiological functions by which K. phaffii adapts to high-methanol conditions.

Endothelial Hypoxia-Inducible Factor-2α Is Required for the Maintenance of Airway Microvasculature.

BACKGROUND: Hypoxia-inducible factors (HIFs), especially HIF-1α and HIF-2α, are key mediators of the adaptive response to hypoxic stress and play essential roles in maintaining lung homeostasis. Human and animal genetics studies confirm that abnormal HIF correlates with pulmonary vascular pathology and chronic lung diseases, but it remains unclear whether endothelial cell HIF production is essential for microvascular health. The large airway has an ideal circulatory bed for evaluating histological changes and physiology in genetically modified rodents. METHODS: The tracheal microvasculature of mice, with conditionally deleted or overexpressed HIF-1α or HIF-2α, was evaluated for anatomy, perfusion, and permeability. Angiogenic signaling studies assessed vascular changes attributable to dysregulated HIF expression. An orthotopic tracheal transplantation model further evaluated the contribution of individual HIF isoforms in airway endothelial cells. RESULTS: The genetic deletion of Hif-2α but not Hif-1α caused tracheal endothelial cell apoptosis, diminished pericyte coverage, reduced vascular perfusion, defective barrier function, overlying epithelial abnormalities, and subepithelial fibrotic remodeling. HIF-2α promoted microvascular integrity in airways through endothelial angiopoietin-1/TIE2 signaling and Notch activity. In functional tracheal transplants, HIF-2α deficiency in airway donors accelerated graft microvascular loss, whereas HIF-2α or angiopoietin-1 overexpression prolonged transplant microvascular perfusion. Augmented endothelial HIF-2α in transplant donors promoted airway microvascular integrity and diminished alloimmune inflammation. CONCLUSIONS: Our findings reveal that the constitutive expression of endothelial HIF-2α is required for airway microvascular health.

Effects of natural deep eutectic solvents on lactic acid bacteria viability during cryopreservation.

In this study, a new method of cryopreservation of lactic acid bacteria (LAB) using natural deep eutectic solvents (NADESs) was developed. Survival rates of LAB during 24-h short-term and 180-day long-term cryostorage at - 20 °C were investigated. The results revealed that survival of Streptococcus thermophilus (S. thermophilus) in NADESs after 24 h of cryostorage was superior to survival of two other tested LAB. Moreover, survival was higher at a ratio of NADESs to S. thermophilus of 1:1 (v/v) than observed using a 4:1 (v/v) ratio. Representative freezing characteristics of five NADESs were elucidated, including thermodynamic properties and hydrogen bonding interactions after addition of water. In order to identify the protective mechanism of NADESs on cell structure and vital metabolic enzymes of S. thermophilus during cryostorage, transmission electron microscopy (TEM) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were employed and enzyme activities of both lactate dehydrogenase (LDH) and ß-galactosidase were determined. Subsequently, NADES GlyP prepared from glycerol and L-proline was demonstrated to maintain cell membrane structural integrity and significantly (p < 0.05) maintain activities of both intracellular enzymes of S. thermophilus. Moreover, NADESs could efficiently penetrate S. thermophilus cells and intracellular ß-galactosidase activity could be used to demonstrate NADESs effectiveness in maintaining S. thermophilus survival after long-term cryostorage. These results demonstrate that NADESs can be used as green cryoprotective chemical agents (CPAs) that can efficiently increase LAB viability during cryostorage. These results should have great value in the food production and probiotics industries.

The formation of starch-lipid complexes in instant rice noodles incorporated with different fatty acids: Effect on the structure, in vitro enzymatic digestibility and retrogradation properties during storage.

The formation of starch-lipid complexes in instant rice noodles (IRN) free from and incorporated with fatty acids (FAs) and their impacts on textural, in vitro digestive and retrogradation properties were investigated. The gelatinization enthalpy values of IRN samples (1.24-4.93 J/g) were noticeably decreased (P < 0.05) compared to rice starch samples (2.54-6.89 J/g) fortified with FAs. Additionally, long-chain saturated FAs (stearic acid (SA, C18:0)) complexes produced higher ordered structures than the shorter-chain FAs (C12:0-C16:0), for 18-carbon FAs, the unsaturated FAs (linoleic acid (LOA, C18:2)) exhibited the strongest intermolecular interactions with rice starch. The relative crystallinity of IRN (27.01%-38.47%) was lower than the rice starch-FAs complexes (38.36%-56.80%). FAs delayed the retrogradation degree of IRN storaged at 4 °C for 21 days ascribed to the formation of V-type complexes. Higher enzymatic resistance was observed in IRN added FAs with resistant starch content increased from 5.13% to 14.42% (LOA), and the sample fortified with SA exhibited the highest slowly digestible starch content (35.92%). SEM revealed that the IRN compounded with palmitic acid, SA and LOA displayed more compact and regular structures. Overall, the formation of starch-FAs complexes probably is a novel strategy in improving the textural, digestive, and retrogradation properties of IRN.

Comparison of the effects of general, spinal and epidural anesthesia on ureter access and surgical outcomes during flexible ureterorenoscopy for transurethral single stone removal surgeries: a monocentric retrospective study.

BACKGROUND: In ureterorenoscopy, anaesthesiologists are preferring regional anaesthesia to avoid postoperative complications, while surgeons are preferring general anaesthesia to avoid ureteral trauma. China has not published its guidelines and not referring to the European Association of Urology guidelines. The objectives of study were to evaluate the effects of general, spinal, and epidural anaesthesia on ureter access and surgical outcomes of ureterorenoscopy. METHODS: Charts of a total of 392 patients with the American Society of Anaesthesiologists grade I or II, and underwent flexible ureterorenoscopy for removal of the proximal, middle, or distal ureteral single stone under general anaesthesia (GA group; n = 145) or spinal anaesthesia (SA group; n = 131) or epidural anaesthesia (EA group; n = 116) were reviewed retrospectively. RESULTS: The dilatation time for patients of GA group was fewer than those of SA (104.01 ± 12.77 sec/patient vs. 130.55 ± 22.53 sec/patient, p < .0001, q = 17.0350) and EA (104.01 ± 12.77 sec/patient vs. 147.03 ± 18.76 sec/patient, p < .0001, q = 26.7240) groups. The time to reach to stone for patients of GA group was fewer than those of SA (126.68 ± 12.59 sec/patient vs. 137.60 ± 17.84 sec/patient, p < .0001, q = 8.4510) and EA (126.68 ± 12.59 sec/patient vs. 149.44 ± 14.85 sec/patient, p < .0001, q = 17.0350) groups. The lithotripsy time (p = .359), operation time (p = .449), intraoperative complications (p = .058), and length of hospital stays (p = .057) of patients were same among groups. Visual analog scale pain scores of patients of the GA group found higher among groups. General anaesthesia caused nausea and vomiting. CONCLUSIONS: This study suggests general anaesthesia for flexible ureterorenoscopy if there is no contraindication.KEY MESSAGEGeneral anaesthesia facilitates early dilatation of ureters and access to the stone.No strong correlation of the anaesthesia method of choice with lithotripsy time, operation time, intraoperative complications, stone-free conditions, and length of hospital stays.Epidural and spinal anaesthesia have advantages of fewer postoperative pain and better postoperative outcomes for flexible ureterorenoscopy.

Metabolic regulation adapting to high methanol environment in the methylotrophic yeast Ogataea methanolica.

Since methylotrophic yeasts such as Ogataea methanolica can use methanol as a sole carbon feedstock, they could be applied to produce valuable products from methanol, a next-generation energy source synthesized from natural gases, using genetic engineering tools. In this study, metabolite profiling of O. methanolica was conducted under glucose (Glc) and low and high methanol (L- and H-MeOH) conditions to show the adaptation mechanism to a H-MeOH environment. The yeast strain responded not only to the presence of methanol but also to its concentration based on the growth condition. Under H-MeOH conditions, O. methanolica downregulated the methanol utilization, glycolytic pathway and alcohol oxidase (AOD) isozymes and dihydroxyacetone synthase (DAS) expression compared with L-MeOH-grown cells. However, levels of energy carriers, such as ATP, were maintained to support cell survival. In H-MeOH-grown cells, reactive oxygen species (ROS) levels were significantly elevated. Along with increasing ROS levels, ROS scavenging system expression was significantly increased in H-MeOH-grown cells. Thus, we concluded that formaldehyde and H2 O2 , which are products of methanol oxidation by AOD isozymes in the peroxisome, are overproduced in H-MeOH-grown cells, and excessive ROS derived from these cells is generated in the cytosol, resulting in upregulation of the antioxidant system and downregulation of the methanol-utilizing pathway to suppress overproduction of toxic intermediates.