Impact of Different Rates of Nitrogen Supplementation on Soil PhysicochemicalProperties and Microbial Diversity in Goji Berry

Goji berry(Lycium barbarum L.)is substantially dependent on nitrogen fertilizer application,which can signifi-cantly enhance fruit yield and Goji berry industrial development in Ningxia,China.This study aimed to analyze the functions of differential nitrogen application rates including low(N1),medium(N2),and high(N3)levels in soil microbial community structure(bacterial and fungal)at 2 diverse soil depths(0-20,20-40 cm)through high-throughput sequencing technology by targeting 16S RNA gene and ITS1&ITS2 regions.All the observed physicochemical parameters exhibited significant improvement(p<0.05)with increased levels of nitrogen and the highest values for most parameters were observed at N2.However,pH decreased(p<0.05)gradually.The alpha and beta diversity analyses for bacterial and fungal communities’metagenome displayed more similarities than differences among all groups.The top bacterial and fungal phyla and genera suggested no obvious(p>0.05)differences among three group treatments(N1,N2,and N3).Furthermore,the functional enrichment analysis demonstrated significant(p<0.05)enrichment of quorum sensing,cysteine and methionine metabolism,and transcriptional machinery for bacterial communities,while various saprotrophic functional roles for fungal communities.Conclusively,moderately reducing the use of N-supplemented fertilizers is conducive to increasing soil nitrogen utilization rate,which can contribute to sustainable agriculture practices through improved soil quality,and microbial community structure and functions.

Small nucleolar RNA host gene 3 functions as a novel biomarker in liver cancer and other tumour progression

Cancer has become the most life-threatening disease in the world.Mutations in and aberrant expression of genes encoding proteins and mutations in noncoding RNAs,especially long noncoding RNAs(lncRNAs),have significant effects in human cancers.LncRNAs have no protein-coding ability but function extensively in numerous physiological and pathological processes.Small nucleolar RNA host gene 3(SNHG3)is a novel lncRNA and has been reported to be differentially expressed in various tumors,such as liver cancer,gastric cancer,and glioma.However,the interaction mechanisms for the regulation between SNHG3 and tumor progression are poorly understood.In this review,we summarize the results of SNHG3 studies in humans,animal models,and cells to underline the expression and role of SNHG3 in cancer.SNHG3 expression is upregulated in most tumors and is detrimental to patient prognosis.SNHG3 expression in lung adenocarcinoma remains controversial.Concurrently,SNHG3 affects oncogenes and tumor suppressor genes through various mechanisms,including competing endogenous RNA effects.A deeper understanding of the contribution of SNHG3 in clinical applications and tumor development may provide a new target for cancer diagnosis and treatment.

Mechanism of lncRNA SNHG19 miR-299-5p MAPK6 signaling axis promoting metastasis of non-small cell lung cancer cells

Objective The aim of this study was to explore the mechanism behind lncRNA small nucleolar RNA host gene 19(lncRNA SNHG19)/microrNA-299-5P(miR-299-5p)/mitogen-activated protein kinase 6(MAPK6)signaling axis promoting metastasis of non-small cell lung cancer(NSCLC).Methods To analyze the abnormal expression of lncRNAs in NSCLC,50 surgically resected NSCLC and adjacent tissue samples were collected from August 2021 to August 2022.The mRNA expression levels of lncRNA SNHG19,Mir-299-5p,and MAPK6 were detected by qRT-PCR.The functions of lncRNA SNHG19,Mir-299-5p and MAPK6 were investigated by CCK-8,clone formation,EdU,scratch,Transwell western blotting(WB)and in vivo xenograft assay.RNA fluorescence in-situ hybridization(FISH),RNA pull-down,dual luciferase reporter,and RNA co-immunoprecipitation assays were used to explore the mechanism of action between lncRNA SNHG19,miR-299-5p,and MAPK6.Results High expression of lncRNA SNHG19 was correlated with poor prognosis,tumor size,lymph node metastasis,and TNM stage in NSCLC patients(P<0.05).Cell function experiments showed that lncRNA SNHG19 could improve the proliferation,clone formation,migration,and invasion ability of A549 cells both in vitro and in vivo(all P<0.05)and increased the relative expression levels of vimentin and MAPK6(P<0.05).The relative expression level of E-cadherin was decreased(P<0.05).lncRNA SNHG19 can interact with Mir-299-5p and regulate the expression level of MAPK6.Conclusion lncRNA SNHG19 is upregulated in NSCLC tissues and cells,and its high expression is associated with tumor progression and poor survival.Moreover,it can act as a molecular sponge for Mir-299-5p to regulate MAPK6 expression and promote the proliferation and metastasis of A549 cells.

Microbiome changes in the gastric mucosa and gastric juice in different histological stages of Helicobacter pylori-negative gastric cancers

BACKGROUND The gastric microbiota in patients with gastric cancer(GC)has received increasing attention,but the profiling of the gastric microbiome through the histological stages of gastric tumorigenesis remains poorly understood,especially for patients with Helicobacter pylori-negative GC(HPNGC).AIM To characterize microbial profiles of gastric mucosa and juice for HPNGC carcinogenesis and identify distinct taxa in precancerous lesions.METHODS The 16S rRNA gene analysis was performed on gastric mucosa from 134 Helicobacter pylori-negative cases,including 56 superficial gastritis(SG),9 atrophic gastritis(AG),27 intestinal metaplasia(IM),29 dysplasia(Dys),and 13 GC cases,to investigate differences in gastric microbial diversity and composition across the disease stages.In addition,paired gastric mucosa and juice samples from 18 SG,18 IM,and 18 Dys samples were analyzed.α-Diversity was measured by Shannon and Chao1 indexes,andβ-diversity was calculated using partial least squares discrimination analysis(PLS-DA).Differences in the microbial composition across disease stages in different sample types were assessed using the linear discriminant analysis effect size.RESULTS The diversity and composition of the bacterial microbiota in the gastric mucosa changed progressively across stages of gastric carcinogenesis.The diversity of the gastric mucosa microbiota was found to be significantly lower in the IM and Dys groups than in the SG group,and the patients with GC had the lowest bacterial community richness(P<0.05).Patients with IM and those with Dys had similar gastric mucosa microbiota profiles with Ralstonia and Rhodococcus as the predominant genera.Microbial network analysis showed that there was increasing correlation strength between IM and Dys(|correlation threshold|≥0.5,P<0.05).GC and its precancerous lesions have distinguishable bacterial taxa;our results identified HPNGC-associated bacteria Streptococcaceae and Lactobacillaceae(P<0.05).Additionally,across precancerous lesion stages from AG to Dys in Helicobacter pylori-negative patients,Burkholderiaceae abundance continuously increased,while Streptococcaceae and Prevotellaceae abundance presented a continuous downward trend.Furthermore,the microbial diversity was higher in gastric juice(P<0.001)than in the mucosa,while PLS-DA revealed a statistically significant difference between the two groups(ANOSIM,P=0.001).A significant difference in the microbial structure was identified,with Proteobacteria being more prevalent in the gastric mucosa and Firmicutes being more abundant in gastric juice.CONCLUSION Our results provide insights into potential taxonomic biomarkers for HPNGC and its precancerous stages and assist in predicting the prognosis of IM and Dys based on the mucosal microbiota profile.

Phylogenetic Diversity of Microorganisms from Chemocline of the Meromictic Soda Lake Doroninskoe(Zabaikalie,Russia)

1 Introduction Many soda and salt lakes are characterized by the formation of the meromictic conditions under which a part of the water column is not involved in the annual process of mixing(Mac Intyre,Melack,1982).This creates an

Amplification and function analysis of N6-adenine-specific DNA methyltransferase gene in Nilaparvata lugens

Methylation of the N6 position of adenine, termed N6-methyladenine, protects DNA from restriction endonucleases via the host-specific restriction-modification system. N6-methyladenine was discovered and has been well studied in bacteria. N6-adenine-specific DNA methyltransferase（N6AMT） is the main enzyme catalyzing the methylation of the adenine base and knowledge of this enzyme was mainly derived from work in prokaryotic models. However, large-scale gene discovery at the genome level in many model organisms indicated that the N6AMT gene also exists in eukaryotes, such as humans, mice, fruit flies and plants. Here, we cloned a N6AMT gene from Nilaparvata lugens（Nlu-N6AMT） and amplified its fulllength transcript. Then, we carried out a systematic investigation of N6AMT in 33 publically available insect genomes, indicating that all studied insects had N6AMT. Genomic structure analysis showed that insect N6AMT has short introns compared with the mammalian homologs. Domain and phylogenetic analysis indicated that insect N6AMT had a conserved N6-adenine Mlase domain that is specific to catalyze the adenine methylation. Nlu-N6AMT was highly expressed in the adult female. We knocked down Nlu-N6AMT by feeding ds RNA from the second instar nymph to adult female, inducing retard development of adult female. In all, we provide the first genome-wide analysis of N6AMT in insects and presented the experimental evidence that N6AMT might have important functions in reproductive development and ovary maturation.

Molecular identifi cation and population diff erentiation of Aurelia spp.ephyrae in sea cucumber aquaculture ponds of northern China

Aurelia spp.ephyrae have been reported to form blooms in sea cucumber aquaculture ponds in the Bohai and Yellow Seas.To identify the species,we carried out a genetic analysis of Aurelia spp.ephyrae and medusae based on mitochondrial 16 S rRNA gene.Samples offour Aurelia sp.ephyrae populations were collected in sea cucumber aquaculture ponds and samples offour Aurelia sp.medusae populations were collected in coastal waters.Using a BLASTn search,we found that both the ephyrae collected in the aquaculture ponds and medusae collected in coastal waters belong to Aurelia coerulea.Seventeen haplotypes were recovered from the 16 S rRNA gene.The overall haplotype diversity and nucleotide diversity of the 166 A.coerulea individuals were 0.686%and 0.329%,respectively,indicating high haplotype diversity and low nucleotide diversity.Moreover,the haplotype diversity of ephyrae populations were generally lower than that of medusae populations with close sampling points.The genetic differentiation between ephyrae populations collected in the sea cucumber aquaculture ponds and A.coerulea medusae collected in coastal waters was not significant,suggesting the ephyrae populations in the sea cucumber culture ponds were part of the same genetic group as the medusae populations in the coastal waters.Phylogeographic analysis of the 16 S rRNA region revealed that there was no significant correlation between the haplotypes and the geographic distribution of populations.Pairwise fixation index values showed significant genetic differentiation and limited gene flow between A.coerulea population of Weifang and other locations.

Molecular Identification of a Species in Genus Nannochloropsis

Nannochloropsis is a genus of marine eukaryotic unicellular algae,which belongs to class Eustigmatophyceae.The spe-cies of Nannochloropsis which are fine rotifer feed and rich in eicosapentaenoic acid(EPA)are economically important.Species in this genus are usually 2-5μm in size and are morphologically similar,which makes their identification difficult.We obtained a monoclone of Nannochloropsis with plating method in this study.DNA was extracted and the quality was determined by restriction enzyme digestion and spectrophotometer analysis.The DNA extracted was used to amplify the sequences of 18S ribosomal RNA gene,ITS region of ribosomal RNA transcription unit and rbcL gene.The phylogenetic analysis was carried out by constructing the neighbor-joining trees with Tamura-Nei distances.The phylogenetic analysis showed that the monoclone is N.oceanica.

Powerful quantifiers for cancer transcriptomics

Every day,investigators find a new link between a form of cancer and a particular alteration in the sequence or/and expression level of a key gene,awarding this gene the title of“biomarker”.The clinician may choose from numerous available panels to assess the type of cancer based on the mutation or expression regulation(“transcriptomic signature”)of“driver”genes.However,cancer is not a“onegene show”and,together with the alleged biomarker,hundreds other genes are found as mutated or/and regulated in cancer samples.Regardless of the platform,a well-designed transcriptomic study produces three independent features for each gene:Average expression level,expression variability and coordination with expression of each other gene.While the average expression level is used in all studies to identify what genes were up-/down-regulated or turn on/off,the other two features are unfairly ignored.We use all three features to quantify the transcriptomic change during the progression of the disease and recovery in response to a treatment.Data from our published microarray experiments on cancer nodules and surrounding normal tissue from surgically removed tumors prove that the transcriptomic topologies are not only different in histopathologically distinct regions of a tumor but also dynamic and unique for each human being.We show also that the most influential genes in cancer nodules[the Gene Master Regulators(GMRs)]are significantly less influential in the normal tissue.As such,“smart”manipulation of the cancer GMRs expression may selectively kill cancer cells with little consequences on the normal ones.Therefore,we strongly recommend a really personalized approach of cancer medicine and present the experimental procedure and the mathematical algorithm to identify the most legitimate targets(GMRs)for gene therapy.

A single degenerated primer significantly improves COX1 barcoding performance in soil nematode community profiling

A new COX1 primer for soil nematode metabarcoding was designed,and this primer outperforms other commonly used COX1 primer pairs in species recovery and quantity of PCR products.•The lack of reference database is the main reason that led to the low species recovery in COX1 metabarcoding.•We expanded current NCBI database by adding 51 newly generated COX1 reference sequences.Microscopic nematodes play important roles in soil ecosystems and often serve as bioindicators of soil health.The identification of soil nematodes is often difficult due to their limited diagnostic characters and high phenotypic plasticity.DNA barcoding and metabarcoding techniques are promising but lack universal primers,especially for mitochondrial COX1 gene.In this study a degenerated COX1 forward primer COIFGED was developed.The primer pair(COIFGED/JB5GED)outperforms other four commonly used COX1 primer pairs in species recovery and quantity of polymerase chain reaction(PCR)products.In metabarcoding analysis,the reads obtained from the new primer pair had the highest sequencing saturation threshold and amplicon sequence variant(ASV)diversity in comparison to other COX1 as well as 18S rRNA primers.The annotation of ASVs suggested the new primer pair initially recovered 9 and 6 out of 25 genera from mock communities,respectively,outperformed other COX1 primers,but underperformed the widely used 18S NF1/18Sr2b primers(16 out of 25 genera).By supplementing the COX1 database with our reference sequences,we recovered an additional 6 mock community species bringing the tally closer to that obtained with 18S primers.In summary,our newly designed COX1 primers significantly improved species recovery and thus can be supplementary or alternative to the conventional 18S metabarcoding.

Gain of human telomerase RNA gene is associated with progression of cervical intraepithelial neoplasia grade Ⅰ or Ⅱ

Background The 3q26 chromosome region, where the human telomerase RNA gene （hTERC） is located, is a biomarker for cervical cancer and precancerous lesions. The aim of this study was to confirm the value of measuring hTERC gene gain in predicting the progression of cervical intraepithelial neoplasia grade Ⅰ or Ⅱ （CIN-Ⅰ and -Ⅱ, respectively） to CIN-Ⅲ and cervical cancer. Methods Liquid-based cytological samples from 54 patients with CIN-Ⅰ or CIN-Ⅱ lesions were enrolled in this study. Follow-up was performed with colposcopy and biopsy within 24 months after the diagnosis of CIN-Ⅰ or CIN-Ⅱ. Copy numbers of the hTERC gene were measured by fluorescence in situ hybridization with a dual-color probe mix containing the hTERC gene probe （labeled red） and the control, the chromosome 3 centromere-specific probe （labeled green）.Results All patients whose lesions progressed from CIN-Ⅰ or CIN-Ⅱ to CIN-Ⅲ displayed a gain of the hTERC gene, whereas patients where the hTERC gene was not amplified did not subsequently progress to CIN-Ⅲ or cervical cancer. The signal ratio pattern per cell was recorded as N：N （green： red）. The numbers of cells with the signal ratio pattern of 4：4 or N：≥5 in patients whose lesions progressed to CIN-Ⅲ were significantly higher than those whose lesions did not progress. Significantly, none of the patients with a 4：4 signal ratio pattern regressed spontaneously.Conclusions In conclusion, measurement of hTERC gene gain in CIN-Ⅰ or CIN-Ⅱ patients using liquid-based cytological samples could be a useful biomarker to predict the progression of such cervical lesions. In addition, a 4：4 or N：≥5 signal ratio pattern may indicate the unlikeness of spontaneous regression of CIN-Ⅰ or CIN-Ⅱ lesions.

Expression and Regulatory Network Analysis of Function of Small Nucleolar RNA Host Gene 4 in Hepatocellular Carcinoma

Background and Aims:Long non-coding RNA small nucleolar RNA host genes(SNHGs)play a critical role in the occurrence and development of tumors.In this study,we aimed to investigate the role of SNHG4 in hepatocellular carcinoma(HCC)and its underlining mechanism.Methods:Datasets were acquired from The Cancer Genome Atlas(TCGA)database.lncLocator 2.0 was used to identify the distribution of SNHG4 in HCC cells.Gene expression,Kaplan-Meier survival,microRNA and transcription factor target analyses were performed with the University of Alabama Cancer(UALCAN)Database,Kaplan-Meier Plotter,LinkedOmics,WebGestalt and gene set enrichment analysis,respectively.Gene Ontology and pathway enrichment analyses and assessment of RNA binding proteins were performed by R software,circlncRNAnet and Encyclopedia of RNA Interactomes(EN-CORI).In addition,CirclncRNAnet and ENCORI were used to find the correlation between SNHG4 and important proteins,while the prognostic value was assessed with the Human Protein Atlas database and Kaplan-Meier Plotter.Results:Expression of SNHG4 in HCC is higher in HCC tissue than in normal healthy liver tissues and is mainly distributed in the nucleus.SNHG4 positively correlated with poor prognosis(p<0.01 for overall survival and recurrence-free survival).Functional enrichment analysis revealed SNHG4 involve-ment with regulation of ribosomal RNA synthesis and the RNA processing and surveillance pathway.SNHG4 is closely associated with miR-154 and miR-206,transcription factor target E2F family and the signaling pathway for MAPK/ERK and mTOR.U2 auxiliary factor 2(U2AF2)showed strong correlation with SNHG4,while low-expression of U2AF2 showed good prognosis.Conclusions:Based on our find-ings,we infer SNHG4 may play a role in the formation of HCC via regulation of tumor-related pathways.

RNA silencing movement in plants

Multicellular organisms, like higher plants, need to coordinate their growth and development and to cope with environmental cues. To achieve this, various signal molecules are transported between neighboring cells and distant organs to control the fate of the recipient cells and organs. RNA silencing produces cell non-autonomous signal molecules that can move over short or long distances leading to the sequence specific silencing of a target gene in a well defined area of cells or throughout the entire plant,respectively. The nature of these signal molecules, the route of silencing spread, and the genes involved in their production, movement and reception are discussed in this review. Additionally, a short section on features of silencing spread in animal models is presented at the end of this review.

Specific anti-viral effects of RNA interference on replication and expression of hepatitis B virus in mice

Background RNA interference （RNAi） is a powerful tool to silence gene expression post-transcriptionally. Our previous study has demonstrated that small interfering RNAs （siRNAs） have sufficiently inhibited hepatitis B virus （HBV） replication and expression in vitro. In this study we observed the RNAi-mediated inhibitory effects on HBV replication in mice models and accessed the specificity of these effects. Methods A mutant RNAi vector （pSI-C mut） with two base pairs different from the original target gene sequence at the RNAi vector （pSI-C） was constructed according to the method described in this study, A mouse model of acute hepatitis B virus infection was established by injecting naked plasmid pHBV1.3 via the tail vein with acute circulatory overload, pSI-C, pSI-C mut and the irrelevant RNAi control plasmid for green fluorescent protein （GFP） gene, pSIGFP were respectively delivered with pHBV1.3 by tail vein injection method. Six days post injection, enzyme-linked immunosorbent assay （ELISA） assay was used to measure the concentration of HBV surface antigen （HBsAg） in mouse serum, immunohistochemical straining method was used to visualize the expressin of HBV core protein （HBcAg） in liver tissues, and the transcriptional level of HBV C mRNA in liver tissues was detectedd by reverse transcriptase PCR （RT-PCR） analysis. Results Injection of pSI-C exerted magnificent and specific inhibitory effects on the replication and expression of HBV in the murine model. After 6-day post-injection （ p. i. ）, the OD values were shown to be 5.07 ± 1.07 in infecting group and 0.62 ± 0. 59 in pSI-C group. The concentration of HBsAg in pSI-C group was significantly lower than that in infecting group （ P 〈 0. 01 ）. Liver intracellular synthesis of viral core protein was sharply reduced to 0. 9% ±0. 1%, compared with 5.4% ± 1.2% of positive hepatocytes in infecting group （P 〈0. 01 ）, and the transcriptional level of HBV C mRNA was greatly reduced by 84. 7%. However, the irrelevant RNAi control plasmid （pSIGFP）, and the pSI-C mut did not show the same robust inhibitory effects as pSI-C. Conclusion pSI-C exert efficient and specific inhibitory effects on HBV replication and expression in mice models.

Advances in quantum dot-mediated siRNA delivery

Nano-sized quantum dots（QDs） exhibit uniquely optical properties that are tunable with different sizes and shapes.QDs can emit narrow symmetric bands under a wide excitation range,possess antiphotobleaching stability,and be bio-functionalized on the large surface area.Therefore,QDs are attractive vectors for imaging-guided therapy.Small-interfering RNA（siRNAs）-based therapeutics hold great potential to target a large part of the currently undruggable genes,but overcoming the lipid bilayer to deliver siRNA into cells has remained a major challenge to solve for widespread development of siRNA therapeutics.In this mini-review,we focus on theranostic QD/siRNA assembles for enhancing delivery of siRNA and facilitating evaluation of therapeutic efficacy via imaging of QDs,with special attention to carbonaceous QDs for delivery of siRNA.

Taxonomy and phylogeny of the section Chaetoceros(Chaetocerotaceae,Bacillariophyta),with description of two new species

Chaetoceros Ehrenberg is one of the most diverse genera of planktonic diatoms.The species in section Chaetoceros are characterized by cells and setae having numerous chloroplasts and being widely distributed.However,the delimitations of some species are problematic because of limited morphological information in the classical descriptions.Monoclonal strains of the section Chaetoceros were established,morphological features were studied using light and electron microscopy,and the hypervariable D 1-D 3 region of the nuclear ribosomal large subunit gene was sequenced to address phylogenetic relationships.Fifteen species belonging to the section Chaetoceros were recorded,including two new species,C.hainanensis sp.nov.and C.tridiscus sp.nov.Chaetoceros hainanensis was characterized by straight chains,narrowly lanceolate to hexagonal apertures,sibling setae diverging in nearly right angles,stipule-shaped spines on terminal setae and arrowhead-shaped spines on intercalary setae.C.tridiscus had short straight chains,narrowly lanceolate apertures,arrowhead-shaped spines and circular poroids arranged in a grid pattern on terminal and intercalary setae.The phylogenetic analyses revealed six groups formed by 19 species within the section Chaetoceros,which was found to be monophyletic.The subdivision of the section is still not well understood.The morphological characters within each group varied considerably and molecular information on more species are needed to enrich the phylogenetic profiling.

Potent and specific inhibition of SARS-CoV antigen expression by RNA interference

Background Severe acute respiratory syndrome (SARS) is an infectious disease caused by SARS-CoV. There are no effective antiviral drugs for SARS although the epidemic of SARS was controlled. The aim of this study was to develop an RNAi (RNA interference) approach that specifically targeted the N gene sequence of severe acute respiratory syndrome associated coronavirus (SARS-CoV) by synthesizing short hairpin RNA (shRNA) in vivo , and to assess the inhibitory effect of this shRNA on SARS-CoV N antigen expression. Methods The eukaryotic expression plasmid pEGFP-C1-N, containing SARS-CoV N gene, was co-transfected into 293 cells with either the RNAi plasmid pshRNA-N or unrelated control plasmid pshRNA-HBV-C4. At 24, 48 and 72 hours post transfection, the green fluorescence was observed through a fluorescence microscope. The RNA levels of SARS-CoV N were determined by reverse transcription polymerase chain reaction (RT-PCR). The expression of Green Fluorescent Protein (GFP) and protein N were detected using Western blot.Results The vector, pshRNA-N expressing shRNA which targeted the N gene of SARS-CoV, was successfully constructed. The introduction of RNAi plasmid efficiently and specifically inhibited the synthesis of protein N. RT-PCR showed that RNAs of N gene were clearly reduced when the pEGFP-C1-N was cotransfected with pshRNA-N, whereas the control vector did not exhibit inhibitory effect on N gene transcription.Conclusions Our results demonstrate that RNAi mediated silencing of SARS-CoV gene could effectively inhibit expression of SARS-CoV antigen, hence RNAi based strategy should be further explored as a more efficacious antiviral therapy of SARS-CoV infection.

Identification of Anamorph Yeast of Tremella aurantialba and Optimization of Medium Composition for Production of Exopolysaccharides

A yeast-like fungus strain B1 isolated from wild fungus Tremella aurantialba was identified and initially characterized. Two phylogenetic trees were generated based on the sequences of large subunit ribosomal RNA gene D1/D2 regions and internal transcribed spacer (ITS) regions of related fungi, respectively. The analysis of D1/D2 regions and ITS sequences showed that fungus B1 was clustered together with T. aurantialba, T. aurantia and T. microspore in the phylogenetic trees. Both the morphological characteristic and phylogenetic analysis established that fungus B1 was one of the anamorph strains of T. aurantialba and belongs to Tremella genus. A fermentation medium for exopolysaccharides (EPS) production by T. aurantialba B1 . Plackett-Burmen design was used to evaluate the effects of different components in the culture medium. Glucose and yeast extract have significant influence on the EPS production. The concentrations of two factors were optimized subsequently using central composite design and response surface analysis. The results showed that 49.2 g/L glucose and 10.4 g/L yeast extract could lead to the maximum production of EPS (4.99 g/L). The optimized medium led to a 1.5-fold enhancement of the production of EPS by T. aurantialba B1 , as compared with that without optimization.