Enzymatic conversion is very important to produce functional rare sugars, but the conversion rate of single enzymes is generally low. To increase the conversion rate, a dual-enzyme coupled reaction system was developed. Dual-enzyme coupled reaction system was constructed using D-psicose-3-epimerase (DPE) and L-rhamnose isomerase (L-RhI), and used to convert D-fructose to D-psicose and D-allose. The ratio of DPE and L-RhI was 1:10 (W/W), and the concentration of DPE was 0.05 mg/mL. The optimum temperature was 60 degrees C and pH was 9.0. When the concentration of D-fructose was 2%, the reaction reached its equilibrium after 10 h, and the yield of D-psicose and D-allose was 5.12 and 2.04 g/L, respectively. Using the dual-enzymes coupled system developed in the current study, we could obtain sugar syrup containing functional rare sugar from fructose-rich raw material, such as high fructose corn syrup.
Aldose-Ketose Isomerases ; metabolism ; Carbohydrate Epimerases ; metabolism ; Fructose ; chemistry ; Glucose ; chemistry ; Hydrogen-Ion Concentration ; Temperature

Rare sugar is a kind of important low-energy monosaccharide that is rarely found in nature and difficult to synthesize chemically. D-allose, a six-carbon aldose, is an important rare sugar with unique physiological functions. It is radical scavenging active and can inhibit cancer cell proliferation. To obtain D-allose, the microorganisms deriving D-psicose 3-epimerase (DPE) and L-rhamnose isomerase (L-RhI) have drawn intense attention. In this paper, DPE from Clostridium cellulolyticum H10 was cloned and expressed in Bacillus subtilis, and L-RhI from Bacillus subtilis 168 was cloned and expressed in Escherichia coli BL21 (DE3). The obtained crude DPE and L-RhI were then purified through a HisTrap HP affinity chromatography column and an anion-exchange chromatography column. The purified DPE and L-RhI were employed for the production of rare sugars at last, in which DPE catalyzed D-fructose into D-psicose while L-RhI converted D-psicose into D-allose. The conversion of D-fructose into D-psicose by DPE was 27.34%, and the conversion of D-psicose into D-allose was 34.64%.
Aldose-Ketose Isomerases ; metabolism ; Bacillus subtilis ; enzymology ; Carbohydrate Epimerases ; metabolism ; Clostridium cellulolyticum ; enzymology ; Escherichia coli ; metabolism ; Fructose ; metabolism ; Glucose ; metabolism

Objective To investigate the relationship between microRNA-149 (rs2292832),microRNA-499 (rs2292832) polymorphism and hepatocellular carcinoma susceptibility by meta-analysis.Methods We used "hepatocellular carcinoma/HCC","miRNA-149/miR-149/microRNA-149",and "miRNA-499/miR-499/microRNA-499" as key words to search papers in databases including China National Knowledge Internet (CNKI),Chinese BioMedical Literature (CBM),Vip Citation Databases (VIP),Wanfang,PubMed and Web of Science databases,and collected the case-control studies on the association of rs2292832 or rs3746444 and the susceptibility to hepatocellular carcinoma from updated to May 31st 2015.Data were extracted by two independent reviewers and pooled OR with 95％ CI was calculated.A bioinformatics analysis was further conducted.Results A total of 13 research papers were collected,and 5 studies for rs2292832 and 12 studies for rs3746444.1 096 cases and 1 701 controls were included for rs2292832 and 3 117 cases and 4 126 controls were included for rs3746444.Meta-analysis failed to detect associations between rs2292832,rs3746444 and susceptibility to hepatocellular carcinoma under each genetic model tested and alleles of OR(95％ CI) were 0.99(0.78-1.28) and 1.11(0.88-1.40).However,subgroup analysis showed that rs3746444 C allele seem to be associated with an increased hepatocellular carcinoma risk in both researches which had more than 400 samples and which used more accurate genotyping methods,and OR(95％C1) were 1.32(1.02-1.70) and 1.34(1.09-1.66),respectively.Furthermore,bioinformatics analysis also showed that the expression of both SNPs were down-regulated in HepG2 cells and indicated possible functional effects on gene transcription.Cochran's Q test indicated that there was the heterogeneity among the studies included.Conclusions No significant association was found between rs2292832,rs3746444 and susceptibility to hepatocellular carcinoma,but subgroup study indicated C allele might be associated with increased hepatocellular carcinoma risk for rs3746444.Bioinformatics analysis indicated that the two SNPs might have possible influence on gene transcription.

Objective To investigate the relationship between microRNA-149 (rs2292832),microRNA-499 (rs2292832) polymorphism and hepatocellular carcinoma susceptibility by meta-analysis.Methods We used "hepatocellular carcinoma/HCC","miRNA-149/miR-149/microRNA-149",and "miRNA-499/miR-499/microRNA-499" as key words to search papers in databases including China National Knowledge Internet (CNKI),Chinese BioMedical Literature (CBM),Vip Citation Databases (VIP),Wanfang,PubMed and Web of Science databases,and collected the case-control studies on the association of rs2292832 or rs3746444 and the susceptibility to hepatocellular carcinoma from updated to May 31st 2015.Data were extracted by two independent reviewers and pooled OR with 95％ CI was calculated.A bioinformatics analysis was further conducted.Results A total of 13 research papers were collected,and 5 studies for rs2292832 and 12 studies for rs3746444.1 096 cases and 1 701 controls were included for rs2292832 and 3 117 cases and 4 126 controls were included for rs3746444.Meta-analysis failed to detect associations between rs2292832,rs3746444 and susceptibility to hepatocellular carcinoma under each genetic model tested and alleles of OR(95％ CI) were 0.99(0.78-1.28) and 1.11(0.88-1.40).However,subgroup analysis showed that rs3746444 C allele seem to be associated with an increased hepatocellular carcinoma risk in both researches which had more than 400 samples and which used more accurate genotyping methods,and OR(95％C1) were 1.32(1.02-1.70) and 1.34(1.09-1.66),respectively.Furthermore,bioinformatics analysis also showed that the expression of both SNPs were down-regulated in HepG2 cells and indicated possible functional effects on gene transcription.Cochran's Q test indicated that there was the heterogeneity among the studies included.Conclusions No significant association was found between rs2292832,rs3746444 and susceptibility to hepatocellular carcinoma,but subgroup study indicated C allele might be associated with increased hepatocellular carcinoma risk for rs3746444.Bioinformatics analysis indicated that the two SNPs might have possible influence on gene transcription.

Objective To monitor the antifungal resistance of clinical isolates of Candida spp.in the East China region.Methods MALDI-TOF MS or molecular methods were used to re-identify the strains collected from January 2018 to December 2022.Antifungal susceptibility testing was performed using the broth microdilution method.The susceptibility test results were interpreted according to the breakpoints of 2022 Clinical and Laboratory Standards Institute(CLSI)documents M27 M44s-Ed3 and M57s-Ed4.Results A total of 3 026 strains of Candida were collected,65.33％of which were isolated from sterile body sites,mainly from blood(38.86％)and pleural effusion/ascites(10.21％).The predominant species of Candida were Candida albicans(44.51％),followed by Candida parapsilosis complex(19.46％),Candida tropicalis(13.98％),Candida glabrata(10.34％),and other Candida species(0.79％).Candida albicans showed overall high susceptibility rates to the 10 antifungal drugs tested(the lowest rate being 93.62％).Only 2.97％of the strains showed dose-dependent susceptibility(SDD)to fluconazole.Candida parapsilosis complex had a SDD rate of 2.61％and a resistance rate of 9.42％to fluconazole,and susceptibility rates above 90％to other drugs.Candida glabrata had a SDD rate of 92.01％and a resistance rate of 7.99％to fluconazole,resistance rates of 32.27％and 48.24％to posaconazole and voriconazole non-wild-type strains(NWT),respectively,and susceptibility rates above 90％to other drugs.Candida tropicalis had resistance rates of 29.55％and 26.24％to fluconazole and voriconazole,respectively,resistance rates of 76.60％and 21.99％to posaconazole and echinocandins non-wild-type strains(NWT),and a resistance rate of 2.36％to echinocandins.Conclusions The prevalence and species distribution of Candida spp.in the East China region are consistent with previous domestic and international reports.Candida glabrata exhibits certain degree of resistance to fluconazole,while Candida tropicalis demonstrates higher resistance to triazole drugs.Additionally,echinocandins resistance has emerged in Candida albicans,Candida glabrata,Candida tropicalis,and Candida parapsilosis.