Efficacy and safety of intrapleural perfusion with hyperthermic chemotherapy for malignant pleural effusion: a meta-analysis.

OBJECTIVE: To evaluate the efficacy and safety of intrapleural perfusion with hyperthermic chemotherapy (IPHC) in treating malignant pleural effusion (MPE). METHODS: PubMed, Embase, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM), VIP Chinese Science and Technology Journal Full-text Database (VP-CSJFD), and Wanfang database were searched by computer from database establishment to January 17, 2024. Relevant randomized controlled articles with IPHC as the observational group and intrapleural perfusion chemotherapy (IPC) as the control group for MPE were included. Then, the methodological quality of the included articles was evaluated and statistically analyzed using Stata 16.0. RESULTS: Sixteen trials with 647 patients receiving IPHC and 661 patients receiving IPC were included. The meta-analysis found that MPE patients in the IPHC group had a more significant objective response rate [RR = 1.31, 95%CI (1.23, 1.38), P < 0.05] and life quality improvement rate [RR = 2.88, 95%CI (1.95, 4.24), P < 0.05] than those in the IPC group. IPHC and IPC for MPE patients had similar incidence rates of asthenia, thrombocytopenia, hepatic impairment, and leukopenia. CONCLUSION: Compared with IPC, IPHC has a higher objective response rate without significantly increasing adverse reactions. Therefore, IPHC is effective and safe. However, this study is limited by the quality of the literature. Therefore, more high-quality, multi-center, large-sample, rigorously designed randomized controlled clinical studies are still needed for verification and evaluation.

Case report: EGFR fusion mutation combined with EGFR amplification responds to EGFR-TKI therapy.

Given their good antitumor effects, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are standard first-line therapy for EGFR-sensitive mutations, including exon 19 deletions and exon 21 L858R mutations. EGFR fusion mutations and EGFR amplification are very rare in non-small cell lung cancer (NSCLC). We describe 2 patients with NSCLC harboring EGFR fusion mutations (EGFR-MACF1 and EGFR-GNAT3) combined with EGFR amplification. Both patients received EGFR-TKI treatment, and 1 of them showed an antitumor response.

Genome-wide analysis of the switchgrass YABBY family and functional characterization of PvYABBY14 in response to ABA and GA stress in Arabidopsis.

BACKGROUND: The small YABBY plant-specific transcription factor has a prominent role in regulating plant growth progress and responding to abiotic stress. RESULTS: Here, a total of 16 PvYABBYs from switchgrass (Panicum virgatum L.) were identified and classified into four distinct subgroups. Proteins within the same subgroup exhibited similar conserved motifs and gene structures. Synteny analyses indicated that segmental duplication contributed to the expansion of the YABBY gene family in switchgrass and that complex duplication events occurred in rice, maize, soybean, and sorghum. Promoter regions of PvYABBY genes contained numerous cis-elements related to stress responsiveness and plant hormones. Expression profile analysis indicated higher expression levels of many PvYABBY genes during inflorescence development and seed maturation, with lower expression levels during root growth. Real-time quantitative PCR analysis demonstrated the sensitivity of multiple YABBY genes to PEG, NaCl, ABA, and GA treatments. The overexpression of PvYABBY14 in Arabidopsis resulted in increased root length after treatment with GA and ABA compared to wild-type plants. CONCLUSIONS: Taken together, our study provides the first genome-wide overview of the YABBY transcription factor family, laying the groundwork for understanding the molecular basis and regulatory mechanisms of PvYABBY14 in response to ABA and GA responses in switchgrass.

Management of esophageal cancer in patients with a right aortic arch or double aortic arch: a case series of 34 cases.

BACKGROUND: Few cases describing patients with a right aortic arch (RAA) or double aortic arch (DAA) and esophageal cancer (EC) have been reported. METHODS: We analyzed RAA and DAA cases treated with esophagectomy in our center's database and reported in English-language studies until April 1, 2023. Our study assessed the malformation characteristics and surgical details of EC patients with RAA and DAA. RESULTS: We extracted data of 24 EC patients with RAAs and 10 EC patients with DAAs. In both groups, the patients were more likely to be Japanese and male, to have squamous cell carcinoma and to have tumors located in the upper thoracic esophagus or middle thoracic esophagus. Left thoracotomy was commonly applied for RAA patients. For DAA patients, the proportions of left-sided and right-sided approaches were similar. Esophagectomy under video-assisted thoracoscopic surgery (VATS) in RAA or DAA patients had been performed on a routine basis in recent years. There were two anastomotic leakages in each group. Specifically, Kommerell diverticulum rupture occurred in 1 RAA patient; gastric tube dilation occurred in 1 DAA patient; and recurrent laryngeal nerve (RLN) injury occurred in 2 RAA patients. The postoperative course was uneventful for most patients in both cohorts. CONCLUSIONS: Esophageal carcinoma is rarely seen in patients with an RAA or DAA. To adequately dissect superior mediastinal LNs, an auxiliary incision (such as sternotomy), the left door open method or a preceding cervical procedure should be used appropriately. Esophagectomy, whether via thoracotomy or thoracoscopic surgery, can be performed safely for both RAA and DAA.

Different gastric tubes in esophageal reconstruction during esophagectomy.

Esophagectomy is currently the mainstay of treatment for resectable esophageal carcinoma. Gastric grafts are the first substitutes in esophageal reconstruction. According to the different tailoring methods applied to the stomach, gastric grafts can be classified as whole stomach, subtotal stomach and gastric tube. Gastric-tube placement has been proven to be the preferred method, with advantages in terms of postoperative complications and long-term survival. In recent years, several novel methods involving special-shaped gastric tubes have been proposed, which have further decreased the incidence of perioperative complications. This article will review the progress and clinical application status of different types of gastric grafts from the perspectives of preparation methods, studies of anatomy and perioperative outcomes, existing problems and future outlook.

Cold-adapted enzymes: mechanisms, engineering and biotechnological application.

Most cold-adapted enzymes display high catalytic activity at low temperatures (20-25 °C) and can still maintain more than 40-50% of their maximum activity at lower temperatures (0-10 °C) but are inactivated after a moderate increase in temperature. The activity of some cold-adapted enzymes increases significantly in the presence of high salt concentrations and metal ions. Interestingly, we also observed that some cold-adapted enzymes have a wide range of optimum temperatures, exhibiting not only maximum activity under low-temperature conditions but also the ability to maintain high enzyme activity under high-temperature conditions, which is a novel feature of cold-adapted enzymes. This unique property of cold-adapted enzymes is generally attractive for biotechnological and industrial applications because these enzymes can reduce energy consumption and the chance of microbial contamination, thereby lowering the production costs and maintaining the flavor, taste and quality of foods. How high catalytic activity is maintained at low temperatures remains unknown. The relationship between the structure of cold-adapted enzymes and their activity, flexibility and stability is complex, and thus far, a unified explanation has not been provided. Herein, we systematically review the sources, catalytic characteristics and cold adaptation of enzymes from four enzymes categories systematically and discuss how these properties may be exploited in biotechnology. A thorough understanding of the properties, catalytic mechanisms, and engineering of cold-adapted enzymes is critical for future biotechnological applications in the detergent industry and food and beverage industries.

Analysis of morphological traits and regulatory mechanism of a semi-dwarf, albino, and blue grain wheat line.

The plant height and leaf color are important traits in crops since they contribute to the production of grains and biomass. Progress has been made in mapping the genes that regulate plant height and leaf color in wheat (Triticum aestivum L.) and other crops. Wheat line DW-B (dwarfing, white leaves, and blue grains) with semi-dwarfing and albinism at the tillering stage and re-greening at the jointing stage was created using Lango and Indian Blue Grain. Transcriptomic analyses of the three wheat lines at the early jointing stages indicated that the genes of gibberellin (GA) signaling pathway and chlorophyll (Chl) biosynthesis were expressed differently in DW-B and its parents. Furthermore, the response to GA and Chl contents differed between DW-B and its parents. The dwarfing and albinism in DW-B were owing to defects in the GA signaling pathway and abnormal chloroplast development. This study can improve understanding of the regulation of plant height and leaf color. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-023-01379-z.

Delta-radiomics based on CT predicts pathologic complete response in ESCC treated with neoadjuvant immunochemotherapy and surgery.

Background and purpose: Unnecessary surgery can be avoided, and more appropriate treatment plans can be developed for patients if the efficacy of neoadjuvant immunochemotherapy for esophageal cancer (EC) can be predicted before surgery. The purpose of this study was to evaluate the ability of machine learning models based on delta features of immunochemotherapy CT images to predict the efficacy of neoadjuvant immunochemotherapy in patients with esophageal squamous cell carcinoma (ESCC) compared with machine learning models based solely on postimmunochemotherapy CT images. Materials and methods: A total of 95 patients were enrolled in our study and randomly divided into a training group (n = 66) and test group (n = 29). We extracted preimmunochemotherapy radiomics features from preimmunochemotherapy enhanced CT images in the preimmunochemotherapy group (pregroup) and postimmunochemotherapy radiomics features from postimmunochemotherapy enhanced CT images in the postimmunochemotherapy group (postgroup). We then subtracted the preimmunochemotherapy features from the postimmunochemotherapy features and obtained a series of new radiomics features that were included in the delta group. The reduction and screening of radiomics features were carried out by using the Mann-Whitney U test and LASSO regression. Five pairwise machine learning models were established, the performance of which was evaluated by receiver operating characteristic (ROC) curve and decision curve analyses. Results: The radiomics signature of the postgroup was composed of 6 radiomics features; that of the delta-group was composed of 8 radiomics features. The area under the ROC curve (AUC) of the machine learning model with the best efficacy was 0.824 (0.706-0.917) in the postgroup and 0.848 (0.765-0.917) in the delta group. The decision curve showed that our machine learning models had good predictive performance. The delta group performed better than the postgroup for each corresponding machine learning model. Conclusion: We established machine learning models that have good predictive efficacy and can provide certain reference values for clinical treatment decision-making. Our machine learning models based on delta imaging features performed better than those based on single time-stage postimmunochemotherapy imaging features.

Comprehensive Transcriptomic and Metabolic Profiling of Agrobacterium-tumefaciens-Infected Immature Wheat Embryos.

The transformation efficiency (TE) was improved by a series of special chemical and physical methods using immature embryos from the cultivar Fielder, with the PureWheat technique. To analyze the reaction of immature embryos infected, which seemed to provide the necessary by Agrobacterium tumefaciens in PureWheat, a combination of scanning electron microscopy (SEM), complete transcriptome analysis, and metabolome analysis was conducted to understand the progress. The results of the SEM analysis revealed that Agrobacterium tumefaciens were deposited under the damaged cortex of immature embryos as a result of pretreatment and contacted the receptor cells to improve the TE. Transcriptome analysis indicated that the differentially expressed genes were mainly enriched in phenylpropanoid biosynthesis, starch and sucrose metabolism, plant-pathogen interaction, plant hormone signal transduction, and the MAPK (Mitogen-activated protein kinase) signaling pathway. By analyzing the correlation between differentially expressed genes and metabolites, the expression of many genes and the accumulation of metabolites were changed in glucose metabolism and the TCA cycle (Citrate cycle), as well as the amino acid metabolism; this suggests that the infection of wheat embryos with Agrobacterium is an energy-demanding process. The shikimate pathway may act as a hub between glucose metabolism and phenylpropanoid metabolism during Agrobacterium infection. The downregulation of the F5H gene and upregulation of the CCR gene led to the accumulation of lignin precursors through phenylpropanoid metabolism. In addition, several metabolic pathways and oxidases were found to be involved in the infection treatment, including melatonin biosynthesis, benzoxazinoid biosynthesis, betaine biosynthesis, superoxide dismutase, and peroxidase, suggesting that wheat embryos may be under the stress of Agrobacterium and, thus, undergo an oxidative stress response. These findings explore the physiological and molecular changes of immature embryos during the co-culture stage of the PureWheat technique and provide insights for Agrobacterium-mediated transgenic wheat experiments.

Green biosynthesis of rare DHA-phospholipids by lipase-catalyzed transesterification with edible algal oil in solvent-free system and catalytic mechanism study.

Docosahexaenoic acid (DHA)-enriched phosphatidylcholine (PC) has received significant scientific attention due to the health benefits in food and pharmaceutical products. In this work, the edible algal oil rich in DHA-triacylglycerol (DHA-TAG) without pretreatment was first used as the DHA donor for the transesterification of phospholipids (PLs) to prepare three kinds of rare PLs, including DHA-PC, DHA-phosphatidylethanolamine (DHA-PE), and DHA-phosphatidylserine (DHA-PS). Here, 153 protein structures of triacylglycerol lipase (EC 3.1.1.3) were virtually screened and evaluated by transesterification. PLA1 was the best candidate due to a higher DHA incorporation. Results showed that the transesterification of PC with DHA-TAG at 45°C and 0.7% water content (without additional water addition) could produce DHA-PC with 39.1% DHA incorporation at 30 min. The different DHA donors, including forms of fatty acid, methyl ester, and triglycerides, were compared. Molecular dynamics (MD) was used to illustrate the catalytic mechanism at the molecular level containing the diffusions of substrates, the structure-activity relationship of PLA1, and the effect of water content.

Feasibility analysis of combined surgery for esophageal cancer.

BACKGROUND: As the preoperative examination of esophageal cancer has improved, the likelihood of finding diseases in other organs that require surgical treatment has also increased. The purpose of this study was to explore the feasibility of combined surgery for esophageal cancer by analyzing the occurrence of postoperative complications in patients with esophageal cancer. METHODS: The clinical characteristics of 1566 patients with esophageal cancer who underwent thoracic surgery in our hospital between January 2017 and September 2022 were analyzed retrospectively. The feasibility of combined surgery for esophageal cancer was analyzed by comparing postoperative complications in patients who underwent simple esophageal cancer surgery (SEC) with those in patients who underwent combined surgery for esophageal cancer (COEC). The tendency scores of patients in the COEC and SEC groups (1:2) were matched to balance the confounding clinical factors, and the difference in postoperative complications was further analyzed. Moreover, we performed a subgroup analysis of esophagectomy combined with lung resection (ECL). In addition, the independent risk factors for postoperative Clavien-Dindo ≥ grade III complications of esophageal cancer were analyzed by multivariate logistic regression. RESULTS: A total of 1566 patients (1147 (73.2%) males and 419 (26.8%) females), with an average age of 64.2 years, were analyzed. There was no significant difference in postoperative complications between the SEC and COEC groups according to the Clavien-Dindo classification (P=0.713). An analysis of the complications revealed that those in the COEC group had a higher incidence of lung consolidation than those in the SEC group (P=0.007). However, when we performed propensity score matching (PSM) on the SEC and COEC groups, there was still no significant difference in complications according to the Clavien-Dindo classification (P=0.346); furthermore, when a detailed analysis of complications was performed, there was no significant difference between the two. In subgroup analysis, after we performed PSM in ECL patients and SEC patients, we also found no significant difference in postoperative complications between patients with ECL and patients with SEC. In addition, we found that a history of diabetes (OR=1.604, P=0.029, 95% CI=1.049-2.454), a history of coronary heart disease (OR=1.592, P=0.046, 95% CI=1.008-2.515), diffusing capacity of the lungs for carbon monoxide (DLCO) (OR=0.916, P=0.024, 95% CI=0.849-0.988), and ALB level (OR=0.955, P=0.007, 95% CI=0.924-0.987) were independent factors that influenced postoperative complications in esophageal cancer patients with grade III or higher complications. CONCLUSION: Combined surgery for esophageal cancer does not increase the incidence of postoperative complications. In addition, a history of diabetes mellitus or coronary heart disease, carbon monoxide dispersion, and preoperative ALB level are independent risk factors for grade III or higher postoperative complications of esophageal cancer.

Selenium-Enriched Black Soybean Protein Prevents Benzo(a)pyrene-Induced Pyroptotic Colon Damage and Gut Dysbacteriosis.

Selenium-enriched black soybean protein (SeBSP) is a kind of high-quality selenium resource with many physiological functions. Benzo(a)pyrene (BaP) is a well-known injurant that widely exists in high-temperature processed food and has been previously found to cause colon injury. In this study, the effects of SeBSP on colonic damage induced by BaP in BALB/C mice were investigated by comparing it with normal black soybean protein (BSP). SeBSP inhibited the BaP-induced reductions on body weight, food intake, and water intake. Moreover, metabolic enzymes, including AhR, CYP1A1, CYP1B1, and GST-P1, that were promoted by BaP were downregulated by SeBSP, reducing oxidative damage caused by BaP in the metabolic process. The classical pyroptosis indexes (i.e., NLRP3, ASC, Caspase-1, GSDMD) and inflammatory factors (i.e., TNF-α, IL-1ß, IL-18, iNOS, COX-2) were downregulated by SeBSP in BaP-treated mice, suggesting the benefits of SeBSP in reducing colonic toxicity. Notably, SeBSP enhanced microbial diversity of gut microbiota and increased relative abundances of prebiotic bacteria, for example, Lactobacillus reuteri, Bacteroides thetaiotaomicron, and genera Bifidobacterium, and Blautia, along with the promotion of short-chain fatty acids. Integrative analysis showed strong links between the antioxidant and anti-inflammatory effects of SeBSP and its altered gut microbiota. Collectively, our study demonstrates the pronounced benefits of Se-enriched black soybean in preventing the colonic toxicity of BaP, and such effects could be mediated by gut microbiota.

Predictive value of modified systemic inflammation score for postoperative unplanned ICU admission in patients with NSCLC.

Background: The purpose of this study was to investigate the predictive value of the modified systemic inflammation score (mSIS) in postoperative unplanned admission to the intensive care unit (ICU) in patients with non-small-cell lung cancer (NSCLC). Methods: The clinical data of 1,321 patients with NSCLC treated with thoracic surgery in our hospital from August 2019 to June 2021 were analyzed retrospectively. The preoperative mSIS, which takes into account the serum albumin (ALB) level and lymphocyte-to-monocyte ratio (LMR), was recorded as 0, 1 or 2 and then was used to identify high-risk patients with unplanned admission to the ICU. The independent risk factors for unplanned admission to the ICU in patients with NSCLC after surgery were identified by multivariate logistic regression analysis. Results: A total of 1,321 patients, including 549 (41.6%) males and 772 (58.4%) females, were included. The median age was 57 years (range 16-95 years). The incidence of unplanned admission to the ICU in patients with mSIS = 2 was significantly higher than that in those with mSIS = 0 and mSIS = 1. The multivariate analysis showed that an mSIS of 2 (OR = 3.728; P = 0.004; 95% CI, 1.520-9.143), an alcohol consumption history (OR = 2.791, P = 0.011; 95% CI, 1.262-6.171), intraoperative infusion volume (OR = 1.001, P = 0.021; 95% CI, 1.000-1.001) and preoperative underlying diseases (OR = 3. 57, P = 0.004; 95% CI, 1.497-8.552) were independent risk factors for unplanned admission to the ICU after lung cancer surgery. In addition, the multivariate logistic regression model showed that the C-statistic value was 0.799 (95% CI: 0.726∼0.872, P < 0.001). Conclusions: The mSIS scoring system can be used as a simplified and effective predictive tool for unplanned ICU admission in patients with NSCLC.

Comparison of Global and Regional Compliance-Guided Positive End-Expiratory Pressure Titration on Regional Lung Ventilation in Moderate-to-Severe Pediatric Acute Respiratory Distress Syndrome.

Purpose: To investigate the difference in the positive end-expiratory pressure (PEEP) selected with chest electrical impedance tomography (EIT) and with global dynamic respiratory system compliance (Crs) in moderate-to-severe pediatric acute respiratory distress syndrome (pARDS). Methods: Patients with moderate-to-severe pARDS (PaO2/FiO2 < 200 mmHg) were retrospectively included. On the day of pARDS diagnosis, two PEEP levels were determined during the decremental PEEP titration for each individual using the best compliance (PEEPC) and EIT-based regional compliance (PEEPEIT) methods. The differences of global and regional compliance (for both gravity-dependent and non-dependent regions) under the two PEEP conditions were compared. In addition, the EIT-based global inhomogeneity index (GI), the center of ventilation (CoV), and standard deviation of regional delayed ventilation (RVDSD) were also calculated and compared. Results: A total of 12 children with pARDS (5 with severe and 7 with moderate pARDS) were included. PEEPC and PEEPEIT were identical in 6 patients. In others, the differences were only ± 2 cm H2O (one PEEP step). There were no statistical differences in global compliance at PEEPC and PEEPEIT [28.7 (2.84-33.15) vs. 29.74 (2.84-33.47) ml/cm H2O median (IQR), p = 0.028 (the significant level after adjusted for multiple comparison was 0.017)]. Furthermore, no differences were found in regional compliances and other EIT-based parameters measuring spatial and temporal ventilation distributions. Conclusion: Although EIT provided information on ventilation distribution, PEEP selected with the best Crs might be non-inferior to EIT-guided regional ventilation in moderate-to-severe pARDS. Further study with a large sample size is required to confirm the finding.

CD4+FoxP3+CD73+ regulatory T cell promotes cardiac healing post-myocardial infarction.

Rationale: Despite recent studies indicating a crucial role of ecto-5'-nucleotidase (CD73) on T cells in cardiac injury after ischemia/reperfusion, the involvement of CD73+ regulatory T cells (Tregs) in cardiac repair post-myocardial infarction (MI) remains unclear. We sought to investigate the contribution of CD73 on Tregs to the resolution of cardiac inflammation and remodeling after MI. Methods: Cardiac function, tissue injury, Tregs percentage in injured hearts, and purinergic signaling changes in cardiac FoxP3+ Tregs were analyzed after permanent descending coronary artery ligation. CD73 knockout Tregs were used to determine the function of CD73 on Tregs. Peripheral blood mononuclear cells (PBMCs) from acute myocardial infarction (AMI) patients and matched non-MI subjects were assessed via flow cytometry. Results: Cardiac Tregs exhibited distinction of purinergic signaling post MI with dramatically high level of CD73 compared to the sham Tregs. CD73 deficiency decreased the tissue tropism, and impaired the immunosuppressive and protective function of Tregs in cardiac healing. Administration of low-dose of IL-2/anti-IL-2 complex resulted in FoxP3+CD73+Tregs expansion in the heart and contributed to the recovery of cardiac function. CD73 derived from FoxP3+Tregs could bind to FoxP3- effector T-cells and inhibit the production of multiple inflammatory cytokines. In AMI patients, CD73 expressions on both CD4+ cells and FoxP3+Tregs decreased in PBMCs. Moreover, CD73 expressions on CD4+ T cells were negatively correlated with the levels of NT pro-BNP and myocardial zymogram in serum. Conclusions: Our findings indicated the importance of FoxP3+CD73+Tregs in inflammation resolution and cardiac healing post-MI.

RNA Sequencing Reveals Dynamic Carbohydrate Metabolism and Phytohormone Signaling Accompanying Post-mowing Regeneration of Forage Winter Wheat (Triticum aestivum L.).

Winter wheat (Triticum aestivum L.) is used as fresh green winter forage worldwide, and its ability to regenerate after mowing determines whether it can be used for forage production; however, the molecular mechanism of regeneration is poorly understood. This study identified long-chain coding and non-coding RNAs in the wheat cultivar "XN9106," which is cultivated for forage and grain production separately in winter and summer, and analyzed their function during post-mowing regeneration. The results showed that the degradation of carbohydrate plays an important role in regeneration, as demonstrated by decreased carbohydrate content. The increased gene expression of enzymes including ß-amylase, ß-fructofuranosidase, sucrose synthase, sucrose-6-phosphate synthase, trehalose-6-phosphate synthase, and trehalose-6-phosphate phosphatase in mowed seedlings suggests regeneration is fueled by degraded carbohydrates that provide energy and carbon skeletons for the Krebs cycle and amino acid synthesis. The decreased auxin content relieved the inhibition of cytokinin synthesis, that controls the transition from cell division to cell expansion and stimulates cell expansion and differentiation during the cell expansion phase, and eventually accelerate post-mowing regeneration of seedlings. Additionally, differentially expressed long-chain non-coding RNAs (lncRNAs) might participate in the regulation of gene expression related to carbohydrate metabolism and hormone signal transduction. This study demonstrated the responses of key mRNAs and lncRNAs during post-mowing regeneration of winter wheat and revealed the importance of carbohydrate and hormone during regeneration, providing valuable information for genetic improvement of forage wheat.

Changes in Phenols, Polysaccharides and Volatile Profiles of Noni (Morinda citrifolia L.) Juice during Fermentation.

The change in phenols, polysaccharides and volatile profiles of noni juice from laboratory- and factory-scale fermentation was analyzed during a 63-day fermentation process. The phenol and polysaccharide contents and aroma characteristics clearly changed according to fermentation scale and time conditions. The flavonoid content in noni juice gradually increased with fermentation. Seventy-three volatile compounds were identified by solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS). Methyl hexanoate, 3-methyl-3-buten-1-ol, octanoic acid, hexanoic acid and 2-heptanone were found to be the main aroma components of fresh and fermented noni juice. A decrease in octanoic acid and hexanoic acid contents resulted in the less pungent aroma in noni juice from factory-scale fermentation. The results of principal component analysis of the electronic nose suggested that the difference in nitrogen oxide, alkanes, alcohols, and aromatic and sulfur compounds, contributed to the discrimination of noni juice from different fermentation times and scales.

YALI0C22088g from Yarrowia lipolytica catalyses the conversion of l-methionine into volatile organic sulfur-containing compounds.

The enzymatic conversion of l-methionine (l-Met) into volatile organic sulfur-containing compounds (VOSCs) plays an important role in developing the characteristic aroma of foods. However, the mechanism for the direct conversion of l-Met into VOSCs is still unclear in yeast cells used to make food products. Here, we show that the transcription profile of YALI0C22088g from Yarrowia lipolytica correlates positively with l-Met addition. YALI0C22088g catalyses the γ-elimination of l-Met, directly converting l-Met into VOSCs. YALI0C22088g also exhibits strong C-S lysis activities towards l-cystathionine and the other sulfur-containing compounds and forms a distinct cystathionine-γ-lyase subgroup. We identified eight key amino acid residues in YALI0C22088g, and we inferred that the size of the tunnel and the charges carried by the entrance amino acid residue are the determinants for the enzymatic conversion of l-Met into VOSCs. These findings reveal the formation mechanism of VOSCs produced directly from l-Met via the demethiolation pathway in Yarrowia lipolytica, which provides a rationale for engineering the enzymatic conversion of l-Met into VOSCs and thus stimulates the enzymatic production of aroma compounds.