Role of 5-hydroxytryptamine type 3 receptors in the regulation of anxiety reactions / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

5-Hydroxytryptamine (5-HT) type 3 receptor (5-HT3R) is the only type of ligand-gated ion channel in the 5-HT receptor family. Through the high permeability of Na+, K+, and Ca2+ and activation of subsequent voltage-gated calcium channels (VGCCs), 5-HT3R induces a rapid increase of neuronal excitability or the release of neurotransmitters from axon terminals in the central nervous system (CNS). 5-HT3Rs are widely expressed in the medial prefrontal cortex (mPFC), amygdala (AMYG), hippocampus (HIP), periaqueductal gray (PAG), and other brain regions closely associated with anxiety reactions. They have a bidirectional regulatory effect on anxiety reactions by acting on different types of cells in different brain regions. 5-HT3Rs mediate the activation of the cholecystokinin (CCK) system in the AMYG, and the γ‍-aminobutyric acid (GABA) "disinhibition" mechanism in the prelimbic area of the mPFC promotes anxiety by the activation of GABAergic intermediate inhibitory neurons (IINs). In contrast, a 5-HT3R-induced GABA "disinhibition" mechanism in the infralimbic area of the mPFC and the ventral HIP produces anxiolytic effects. 5-HT2R-mediated regulation of anxiety reactions are also activated by 5-HT3R-activated 5-HT release in the HIP and PAG. This provides a theoretical basis for the treatment of anxiety disorders or the production of anxiolytic drugs by targeting 5-HT3Rs. However, given the circuit specific modulation of 5-HT3Rs on emotion, systemic use of 5-HT3R agonism or antagonism alone seems unlikely to remedy anxiety, which deeply hinders the current clinical application of 5-HT3R drugs. Therefore, the exploitation of circuit targeting methods or a combined drug strategy might be a useful developmental approach in the future.

Adaptive evolution of microorganisms based on industrial environmental perturbations / 生物工程学报

The development of synthetic biology has greatly promoted the construction of microbial cell factories, providing an important strategy for green and efficient chemical production. However, the bottleneck of poor tolerance to harsh industrial environments has become the key factor hampering the productivity of microbial cells. Adaptive evolution is an important method to domesticate microorganisms for a certain period by applying targeted selection pressure to obtain desired phenotypic or physiological properties that are adapted to a specific environment. Recently, with the development of technologies such as microfluidics, biosensors, and omics analysis, adaptive evolution has laid the foundation for efficient productivity of microbial cell factories. Herein, we discuss the key technologies of adaptive evolution and their important applications in improvement of environmental tolerance and production efficiency of microbial cell factories. Moreover, we looked forward to the prospects of adaptive evolution to realize industrial production by microbial cell factories.

Efficient synthesis of L-methionine by engineering the one carbon module of Escherichia coli / 生物工程学报

L-methionine, also known as L-aminomethane, is one of the eight essential amino acids required by the human body and has important applications in the fields of feed, medicine, and food. In this study, an L-methionine high-yielding strain was constructed using a modular metabolic engineering strategy based on the M2 strain (Escherichia coli W3110 ΔIJAHFEBC/PAM) previously constructed in our laboratory. Firstly, the production of one-carbon module methyl donors was enhanced by overexpression of methylenetetrahydrofolate reductase (methylenetetrahydrofolate reductase, MetF) and screening of hydroxymethyltransferase (GlyA) from different sources, optimizing the one-carbon module. Subsequently, cysteamine lyase (hydroxymethyltransferase, MalY) and cysteine internal transporter gene (fliY) were overexpressed to improve the supply of L-homocysteine and L-cysteine, two precursors of the one-carbon module. The production of L-methionine in shake flask fermentation was increased from 2.8 g/L to 4.05 g/L, and up to 18.26 g/L in a 5 L fermenter. The results indicate that the one carbon module has a significant impact on the biosynthesis of L-methionine, and efficient biosynthesis of L-methionine can be achieved through optimizing the one carbon module. This study may facilitate further improvement of microbial fermentation production of L-methionine.

Biosynthesis of immunosuppressant tacrolimus: a review / 生物工程学报

Tacrolimus (FK506) is a 23-membered macrolide with immunosuppressant activity that is widely used clinically for treating the rejection after organ transplantation. The research on tacrolimus production was mainly focused on biosynthesis methods, within which there are still some bottlenecks. This review summarizes the progress made in tacrolimus biosynthesis via modification of metabolic pathways and control of fermentation process, with the hope to address the technical bottlenecks for tacrolimus biosynthesis and improve tacrolimus production by fermentation engineering and metabolic engineering.

Evaluation of Qi-deficiency Model Based on Urine Non-targeted Metabonomics / 中国实验方剂学杂志

ObjectiveTo evaluate the success of Qi-deficiency model of Balb/C-nu mice established by swimming exhaustion test from the view of biomarkers and metabolic pathways by metabonomics. MethodBalb/C-nu mice were randomly divided into the normal group and Qi-deficiency group， Qi-deficiency model was established by swimming with 5% body weight metal fixed at the tail for 15 consecutive days until exhaustion （nose tip immersion time>5 s）. The urine metabonomics was analyzed by ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry （UPLC-Q-TOF/MS）， and the mobile phase was acetonitrile （A）-0.1% formic acid aqueous solution （B） for gradient elution （0-1 min， 5%-8%A； 1-4 min， 8%-8.5%A； 4-5 min， 8.5%-12%A； 5-10 min， 12%-40%A； 10-12 min， 40%-100%A； 12-15 min， 100%A）， the flow rate was 0.3 mL·min-1， the injection volume was 10 μL， electrospray ionization （ESI） in positive and negative ion modes was used in MS analysis， the MS data were acquired in full-scan mode from m/z 50-1 000. Principal component analysis （PCA）， orthogonal partial least squares-discriminant analysis （OPLS-DA）， human metabolome database （HMDB）， high collision energy ion fragments collected by MSE and tandem MS （MS/MS） ion information were used to identify potential biomarkers. Kyoto Encyclopedia of Genes and Genomes （KEGG） database and MetaboAnalyst 5.0 were used to analyze the corresponding metabolic pathways and pathway enrichment of biomarkers. ResultEndogenous substances in urine of mice in normal group and Qi-deficiency group were obviously separated， and there were 24 biomarkers with significant difference. The metabolic pathways involved in these biomarkers were tricarboxylic acid cycle， glycolysis metabolism， amino acid metabolism， fatty acid metabolism， pyrimidine metabolism， steroid hormone biosynthesis and tryptophan metabolism. Among them， the metabolic pathways related to energy were tricarboxylic acid cycle， glycolysis metabolism， amino acid metabolism， fatty acid metabolism， pyrimidine metabolism and steroid hormone biosynthesis. ConclusionThrough the investigation of urine metabonomics， combined with the physical signs， the Qi-deficiency model established by swimming exhaustion test in Balb/C-nu mice is successfully evaluated， and it is also verified that there is a close correlation between Qi-deficiency and energy metabolism.

Evaluation of Qi-deficiency Model Based on Urine Non-targeted Metabonomics / 中国实验方剂学杂志

ObjectiveTo evaluate the success of Qi-deficiency model of Balb/C-nu mice established by swimming exhaustion test from the view of biomarkers and metabolic pathways by metabonomics. MethodBalb/C-nu mice were randomly divided into the normal group and Qi-deficiency group， Qi-deficiency model was established by swimming with 5% body weight metal fixed at the tail for 15 consecutive days until exhaustion （nose tip immersion time>5 s）. The urine metabonomics was analyzed by ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry （UPLC-Q-TOF/MS）， and the mobile phase was acetonitrile （A）-0.1% formic acid aqueous solution （B） for gradient elution （0-1 min， 5%-8%A； 1-4 min， 8%-8.5%A； 4-5 min， 8.5%-12%A； 5-10 min， 12%-40%A； 10-12 min， 40%-100%A； 12-15 min， 100%A）， the flow rate was 0.3 mL·min-1， the injection volume was 10 μL， electrospray ionization （ESI） in positive and negative ion modes was used in MS analysis， the MS data were acquired in full-scan mode from m/z 50-1 000. Principal component analysis （PCA）， orthogonal partial least squares-discriminant analysis （OPLS-DA）， human metabolome database （HMDB）， high collision energy ion fragments collected by MSE and tandem MS （MS/MS） ion information were used to identify potential biomarkers. Kyoto Encyclopedia of Genes and Genomes （KEGG） database and MetaboAnalyst 5.0 were used to analyze the corresponding metabolic pathways and pathway enrichment of biomarkers. ResultEndogenous substances in urine of mice in normal group and Qi-deficiency group were obviously separated， and there were 24 biomarkers with significant difference. The metabolic pathways involved in these biomarkers were tricarboxylic acid cycle， glycolysis metabolism， amino acid metabolism， fatty acid metabolism， pyrimidine metabolism， steroid hormone biosynthesis and tryptophan metabolism. Among them， the metabolic pathways related to energy were tricarboxylic acid cycle， glycolysis metabolism， amino acid metabolism， fatty acid metabolism， pyrimidine metabolism and steroid hormone biosynthesis. ConclusionThrough the investigation of urine metabonomics， combined with the physical signs， the Qi-deficiency model established by swimming exhaustion test in Balb/C-nu mice is successfully evaluated， and it is also verified that there is a close correlation between Qi-deficiency and energy metabolism.

Short-term clinical observation on the treatment of single-segment lumbar disc herniation and lumbar spinal stenosis by improved transforaminal endoscopic spine system technique with full visual endoscopic foraminoplasty / 中国综合临床

Objective:To investigate the safety and efficacy of the modified transcutaneous endoscopic spine system (TESSYS) with full visual foramen plasty and percutaneous endoscopic discectomy (PTED) in the treatment of lumbar disc herniation and lumbar spinal stenosis.Methods:A case-control study was conducted to analyze the clinical data of 68 patients with single segment lumbar disc herniation and lumbar spinal stenosis treated with visual endoscopic foraminal plasty and modified TESSYS technique and intervertebral foraminal fusion from April 2020 to March 2021. According to the operation method, 38 cases were divided into two groups: pted group (38 cases) and TLIF group (30 cases). Independent sample t-test was used to compare the incision length, bleeding volume, operation time, time to go down and hospital stay between the two groups. Visual analog scale (VAS) scores and Oswestry disability index (ODI) scores were measured repeatedly. The differences between preoperative and postoperative 7 days and 1, 3, 6 months were analyzed and compared by generalized estimation equation. Rank sum test was performed in combination with the modified MacNab standard in the last follow-up. The excellent and good rate was compared between groups χ 2. Test and evaluate the curative effect. Results:The postoperative follow-up was 8.5-14.0 months. The incision length (1.25±0.33) cm, operation time (119.45±14.95), blood loss (24.03±8.62) mL, downtime time (1.42±0.50) d, and hospital stay (3.39±0.55) d in the PTED group were all higher than those in the TLIF group ((14.37±2.91) cm, (140.53±16.16) min, (158.00±51.35) mL, (3.20±0.96) d, (7.33±0.55) d) had obvious advantages ( t values were 24.56, 5.57, 14.13, 9.20, and 29.48, respectively; all P<0.001). The VAS scores and ODI scores of the two groups after operation were significantly improved compared with those before operation (all P<0.001), and with the passage of time, the VAS scores and ODI scores of the two groups of patients from 7 days to 6 months after operation by month were significantly decreased ( P<0.001). However, there was no significant difference between the two groups in VAS score from 1 week to 6 months after operation: P7d=0.997, P1 month=0.139, P3 month=0.057, P6 month=0.539, all P>0.05. There was no significant difference in ODI scores between time points (ODI: P7d=0.278, P1 month=0.442, P3 month=0.963, P6 month=0.278, all P>0.05). There was no significant difference between the two groups in terms of clinical efficacy and excellent and good rate evaluated by modified MacNab criteria at the last follow-up ( Z=0.09, P=0.927; χ 2=0.92, P=0.761). Conclusion:The short-term curative effect of full visual endoscopic foraminal plasty and modified TESSYS technique in the treatment of single level lumbar disc herniation and lumbar spinal stenosis is close to that of classical foraminal interbody fusion, and has certain advantages.

Construction of an l-cysteine hyper-producing strain of Escherichia coli based on a balanced carbon and sulfur module strategy / 生物工程学报

l-cysteine is an important sulfur-containing α-amino acid. It exhibits multiple physiological functions with diverse applications in pharmaceutical cosmetics and food industry. Here, a strategy of coordinated gene expression between carbon and sulfur modules in Escherichia coli was proposed and conducted for the production of l-cysteine. Initially, the titer of l-cysteine was improved to (0.38±0.02) g/L from zero by enhancing the biosynthesis of l-serine module (serAf, serB and serCCg) and overexpression of CysB. Then, promotion of l-cysteine transporter, increased assimilation of sulfur, reduction or deletion of l-cysteine and l-serine degradation pathway and enhanced expression of cysEf (encoding serine acetyltransferase) and cysBSt (encoding transcriptional dual regulator CysB) were achieved, resulting in an improved l-cysteine titer (3.82±0.01) g/L. Subsequently, expressions of cysM, nrdH, cysK and cysIJ genes that were involved in sulfur module were regulated synergistically with carbon module combined with utilization of sulfate and thiosulfate, resulting in a strain producing (4.17±0.07) g/L l-cysteine in flask shake and (11.94±0.1) g/L l-cysteine in 2 L bioreactor. Our results indicated that efficient biosynthesis of l-cysteine could be achieved by a proportional supply of sulfur and carbon in vivo. This study would facilitate the commercial bioproduction of l-cysteine.

Advances in the biosynthesis of L-homoserine and its derivatives by metabolic engineering of Escherichia coli / 生物工程学报

L-homoserine and its derivatives (O-succinyl-L-homoserine and O-acetyl-L-homoserine) are precursors for the biosynthesis of L-methionine, and various C4 compounds (isobutanol, γ-butyrolactone, 1, 4-butanediol, 2, 4-dihydroxybutyric acid) and L-phosphinothricin. Therefore, the fermentative production of L-homoserine and its derivatives became the research hotspot in recent years. However, the low fermentation yield and conversion rate, and the unclear regulation mechanism for the biosynthesis of L-homoserine and its derivatives, hamper the development of an efficient production process for L-homoserine and its derivatives. This review summarized the advances in the biosynthesis of L-homoserine and its derivatives by metabolic engineering of Escherichia coli from the aspects of substrate uptake, redirection of carbon flow at the key nodes, recycle of NADPH and export of target products. This review may facilitate subsequent metabolic engineering and biotechnological production of L-homoserine and its derivatives.

Construction and application of microbial cell factories for unnatural amino acids / 生物工程学报

Unnatural amino acids are widely used in medicine, pesticide, material, and other industries and the green and efficient synthesis has attracted a lot of attention. In recent years, with the rapid development of synthetic biology, microbial cell factories have become a promising means for biosynthesis of unnatural amino acids. This study reviewed the construction and application of microbial cell factories for unnatural amino acid, including the synthetic pathway reconstruction, design/modification of key enzymes and their coordinated regulation with precursors, blocking of competitive alternative pathways, and construction of cofactor circulation systems. Meanwhile, on the basis of the new principles for designing the microbial cell factories, new biosynthetic pathways adapted to cells and the production environment, as well as new biomanufacturing system established based on cell adaptive evolution and intelligent fermentation regulation, we looked forward to the further construction and application of microbial cell factories for industrial bio-production.

A deep learning-based dual-omics prediction model for radiation pneumonitis.

PURPOSE: Radiation pneumonitis (RP) is the main source of toxicity in thoracic radiotherapy. This study proposed a deep learning-based dual-omics model, which aims to improve the RP prediction performance by integrating more data points and exploring the data in greater depth. MATERIALS AND METHODS: The bimodality data were the original dose (OD) distribution and the ventilation image (VI) derived from four-dimensional computed tomography (4DCT). The functional dose (FD) distribution was obtained by weighting OD with VI. A pre-trained three-dimensional convolution (C3D) network was used to extract the features from FD, VI, and OD. The extracted features were then filtered and selected using entropy-based methods. The prediction models were constructed with four most commonly used binary classifiers. Cross-validation, bootstrap, and nested sampling methods were adopted in the process of training and hyper-tuning. RESULTS: Data from 217 thoracic cancer patients treated with radiotherapy were used to train and validate the prediction model. The 4DCT-based VI showed the inhomogeneous pulmonary function of the lungs. More than half of the extracted features were singular (of none-zero value for few patients), which were eliminated to improve the stability of the model. The area under curve (AUC) of the dual-omics model was 0.874 (95% confidence interval: 0.871-0.877), and the AUC of the single-omics model was 0.780 (0.775-0.785, VI) and 0.810 (0.804-0.811, OD), respectively. CONCLUSIONS: The dual-omics outperformed single-omics for RP prediction, which can be contributed to: (1) using more data points; (2) exploring the data in greater depth; and (3) incorporating of the bimodality data.

Efficacy and Safety of Endovascular Treatment for Acute Large-Vessel Ischemic Stroke Beyond 6 h After Symptom Onset: A Meta-Analysis.

Background: There is considerable evidence on the benefits of endovascular thrombectomy (EVT) for acute ischemic stroke (AIS) within 6 h after symptom onset. However, uncertainties remain regarding EVT efficacy beyond 6 h after symptom onset. We undertook a meta-analysis to assess the efficacy and safety of EVT in patients with AIS >6 h after symptom onset. Methods: We searched PubMed, EMBASE, and Chinese Biomedical through July 2019. We included studies involving early (≤6 h) vs. delayed (>6 h) EVT in selected patients with AIS, based on radiological evaluation criteria. Functional independence, successful recanalization, mortality, and symptomatic intracranial hemorrhage (sICH) rates were assessed. Results: Eight articles, with 3,265 patients who had undergone early EVT and 1,078 patients who had received delayed EVT, were included in the meta-analysis. Patients treated with early EVT showed a similar proportion of functional independence at 90 days [odds ratio (OR) = 1.14, 95% confidence interval (CI) = 0.926-1.397, P = 0.219; I 2 = 36.2%, P = 0.128] as those treated with delayed EVT. Delayed EVT was also associated with no significant difference in mortality (OR = 1.015, 95% CI = 0.852-1.209; P = 0.871; I 2 = 0.0%, P = 0.527), successful recanalization (OR = 1.255, 95% CI = 0.923-1.705; P = 0.147; I 2 = 60.5%, P = 0.009), and sICH (OR = 0.976, 95% CI = 0.737-1.293; P = 0.871; I 2 = 0.0%, P = 0.742) rates compared with early EVT. Conclusions: Among selected patients with AIS, delayed EVT showed comparable outcomes in functional independence, recanalization, mortality, and sICH rates compared with early EVT.

Genetic Diversity of Hard Ticks (Acari: Ixodidae) in the South and East Regions of Kazakhstan and Northwestern China

To date, there is no report on the genetic diversity of ticks in these regions. A total of 370 representative ticks from the south and east regions of Kazakhstan (SERK) and Xinjiang Uygur Autonomous Region (XUAR) were selected for molecular comparison. A fragment of the mitochondrial cytochrome c oxidase subunit I (cox1) gene, ranging from 631 bp to 889 bp, was used to analyze genetic diversity among these ticks. Phylogenetic analyses indicated 7 tick species including Hyalomma asiaticum, Hyalomma detritum, Hyalomma anatolicum, Dermacentor marginatus, Rhipicephalus sanguineus, Rhipicephalus turanicus and Haemaphysalis erinacei from the SERK clustered together with conspecific ticks from the XUAR. The network diagram of haplotypes showed that i) Hy. asiaticum from Almaty and Kyzylorda Oblasts together with that from Yuli County of XUAR constituted haplogroup H-2, and the lineage from Chimkent City of South Kazakhstan was newly evolved; and ii) the R. turanicus ticks sampled in Israel, Almaty, South Kazakhstan, Usu City, Ulugqat and Baicheng Counties of XUAR were derivated from an old lineage in Alataw City of XUAR. These findings indicate that: i) Hy. asiaticum, R. turanicus and Ha. erinacei shared genetic similarities between the SERK and XUAR; and ii) Hy. marginatum and D. reticulatus show differences in their evolution.

Lhermitte-Duclos disease: A case report and literature review / 中南大学学报(医学版)

Lhermitte-Duclos disease (LDD) is a type of rare brain tumor located in posterior fossa. A patient with LDD located in the left cerebellum and vermis was admitted by the Department of Neurosurgery, Xiangya Hospital, Central South University. MRI scan showed slightly heterogeneous enhancement at the region close to vermis. The patient underwent partial resection on August 11, 2016 without postoperative chemoradiotherapy. The progress free survival was 11 months and the overall survival was 17 months. What the case reveals is that the partial resection is not beneficial to these patients with LDD as the residual lesion probably recurs in a short term after operation. The pathogenesis, diagnosis and treatment of LDD are explored and summarized in combination with relevant literature.

Research on Application of Intelligent Tracing System for IVD Reagents Based on Blockchain Technology / 中国医疗器械杂志

In recent years, the IVD industry has developed rapidly based on the increasing market demand, and plays an important role in disease prevention, clinical diagnosis, health monitoring and guiding treatment. Therefore, followed quality and safety issues are highly concerned. The unique advantages of blockchain technology, decentralization, distrust and non-tampering, can write into trusted node data in every link covering production, circulation and usage of IVD reagents, and establish a distributed ledger with full backup, which makes the anti-conterfeiting and traceability for IVD reagents possible. We discuss whole process intelligent tracing system for IVD reagents based on blockchain technology. Through the strong mechanism of pre-supervision and post-punishment, the source of reagents can be traced, quality and responsibility can be investigated, and the medical inspection quality and diagnostic safety can be guarded.

Metabolic engineering of Escherichia coli for L-homoserine production / 生物工程学报

L-Homoserine is a non-essential amino acid that is often used as an important platform compound and additive in industrial production. To improve the production efficiency, a previously constructed L-homoserine producing strain E. coli H0-0 was used as a chassis for further metabolic modification. Firstly, the ppc and pyccgP458S genes were overexpressed to optimize the Kreb's cycle. Subsequently, thrAC1034T and lysCcgC932T were overexpressed to improve the product synthesis, followed by inactivation of iclR gene to reduce the accumulation of by-products. The introduction of three sucrose metabolism genes, scrA, scrB and scrK, enabled E. coli to ferment sucrose. The titer of L-homoserine increased from 3.2 g/L to 11.1 g/L.

Research progress in spore-based in-situ restoration technology of concrete with microorganisms / 生物工程学报

Concrete is the most widely used modern building material. It is easy to crack under the action of stress, which makes the concrete structure permeable, affecting the durability and integrity of the structure, and thus shortening its service life. Microbial in-situ remediation technology is a low cost, effective and green way for concrete crack repairing. Due to its excellent biocompatibility, service life elongation, economic losses and environmental pollution reduction, microbial in-situ remediation technology has been intensively investigated. Bacillus has attracted much attention because of its excellent biomineralization ability, extremely strong environmental tolerance and long-term survival ability of its spores. In order to promote the research, development and large-scale application of microbial in-situ healing of concrete, the paper reviews the mechanism of spore-based in-situ healing of concrete, the survival of spores exposed in concrete, the influence of spores and external additives on the mechanical properties of concrete, progress in research and development of healing agent as well as healing effects. Moreover, future research focuses such as improving the survival ability of spores in the harsh environment of concrete, reducing the influence of external additives on the mechanical properties of concrete, and strengthening the healing effect of actual field applications are also summarized.

Design of new gradient scaffolds based on triply periodic minimal surfaces and study on its mechanical, permeability and tissue differentiation characteristics / 生物医学工程学杂志

In order to establish a bone scaffold with good biological properties, two kinds of new gradient triply periodic minimal surfaces (TPMS) scaffolds, i.e., two-way linear gradient G scaffolds (L-G) and D, G fusion scaffold (N-G) were designed based on the gyroid (G) and diamond (D)-type TPMS in this study. The structural mechanical parameters of the two kinds of scaffolds were obtained through the compressive simulation. The flow property parameters were also obtained through the computational fluid dynamics (CFD) simulation in this study, and the permeability of the two kinds of scaffolds were calculated by Darcy's law. The tissue differentiation areas of the two kinds of scaffolds were calculated based on the tissue differentiation theory. The results show that L-G scaffold has a better mechanical property than the N-G scaffold. However, N-G scaffold is better than the L-G scaffold in biological properties such as permeability and cartilage differentiation areas. The modeling processes of L-G and N-G scaffolds provide a new insight for the design of bone scaffold. The simulation in this study can also give reference for the prediction of osseointegration after the implantation of scaffold in the human body.

Reinforcement of sterols production through directed storage and transportation in yeast: a review / 生物工程学报

Sterols, a class of cyclopentane poly-hydrophenanthrene derivatives, are the predominant membrane constituent of eukaryotes. These substances have a variety of biological activities and have been widely used in food and pharmaceutical industries. The presence of endogenous ergosterol biosynthetic pathway in Saccharomyces cerevisiae cells make it an ideal chassis for the de novo synthesis of sterol and its derivatives. Most recently, the rational modification of organelles provides a novel strategy for the directed transportation and storage of target products and the ultimate enhanced product synthesis. This review summarizes the phenotypic responses of S. cerevisiae cells upon different physiological stimulations and the underlying molecular mechanisms. Reinforcement of sterol production through directed storage, transportation, and excretion of sterols offers a novel strategy for breaking the limitation of de novo biosynthesis of sterols in yeast.

Antifungal Activity of an Endophytic Fungus Aspergillus versicolor DYSJ3from Aphanamixis grandifolia Blume against Colletotrichum musae

An endophytic fungus strain DYSJ3 was isolated from a stem of Aphanamixis grandifolia Blume, which was identified as Aspergillus versicolor based on the morphological characteristics, internal transcribed spacer (ITS) and calmodulin gene sequences analyses. A. versicolor DYSJ3 exhibited strong antagonistic activity against Colletotrichum musae, C. gloeosporioides and Fusarium oxysporum f. sp. cubense with the inhibition rates of 61.9, 51.2 and 55.3% respectively. The antifungal metabolites mainly existed in the mycelium of A. versicolor DYSJ3, and its mycelial crude extract (CE) had broad-spectrum antifungal activities against plant pathogenic fungi. The CE had a good thermal stability, and the inhibition rate of 100 mg/mL CE against C. musae was above 70.0% after disposing at 120°C for 1 h. Five secondary metabolites were isolated from the CE and identified as averufanin, ergosterol peroxide, versicolorin B, averythrin and sterigmatocystin. Activity evaluation showed versicolorin B exhibited inhibitory effects on the mycelial growth and conidial germination of C. musae, and sterigmatocystin had a weak inhibitory effect on the mycelial growth of C. musae