Information on co-adherence of different oral bacterial species is important for understanding interspecies interactions within oral microbial community. Current knowledge on this topic is heavily based on pariwise co...Information on co-adherence of different oral bacterial species is important for understanding interspecies interactions within oral microbial community. Current knowledge on this topic is heavily based on pariwise coaggregation of known, cultivable species. In this study, we employed a membrane binding assay coupled with polymerase chain reaction-denaturing gradient gel electrophoresis （PCR-DGGE） to systematically analyze the co-adherence profiles of oral bacterial species, and achieved a more profound knowledge beyond pairwise coaggregation. Two oral bacterial species were selected to serve as ＂bait＂： Fusobacterium nucleatum （F. nucleatum） whose ability to adhere to a multitude of oral bacterial species has been extensively studied for pairwise interactions and Streptococcus mutans （S. mutans） whose interacting partners are largely unknown. To enable screening of interacting partner species within bacterial mixtures, cells of the ＂bait＂ oral bacterium were immobilized on nitrocellulose membranes which were washed and blocked to prevent unspecific binding. The ＂prey＂ bacterial mixtures （including known species or natural saliva samples） were added, unbound ceils were washed off after the incubation period and the remaining cells were eluted using 0.2 mol.L1 glycine. Genomic DNA was extraeted, subjeeted to 16S rRNA PCR amplification and separation of the resulting PCR produets by DGGE. Selected bands were recovered from the gel, sequenced and identified via Nucleotide BLAST searches against different databases. While few bacterial species bound to S. mutans, consistent with previous findings F.. nucleatum adhered to a variety of bacterial species including uncultivable and uneharacterized onesl This new approach can more effectively analyze the co-adherence profiles of oral bacteria, and could facilitate the systematic study of interbacterial binding of oral microbial species.展开更多
Soil microbial biomass and community structures are commonly used as indicators for soil quality and fertility. A investigation was performed to study the effects of long-term natural restoration, cropping, and bare f...Soil microbial biomass and community structures are commonly used as indicators for soil quality and fertility. A investigation was performed to study the effects of long-term natural restoration, cropping, and bare fallow managements on the soil microbial biomass and bacterial community structures in depths of 0-10, 20 30, and 40-50 cm in a black soil （Mollisol）. Microbial biomass was estimated from chloroform fumigation-extraction, and bacterial community structures were determined by analysis of 16S rDNA using polymerase chain reaction-denaturing gradient gel electrophoresis （PCR- DGGE）. Experimental results showed that microbial biomass significantly declined with soil depth in the managements of restoration and cropping, but not in the bare fallow. DGGE profiles indicated that the band number in top 0-10 cm soils was less than that in depth of 20-30 or 40-50 cm. These suggested that the microbial population was high but the bacterial community structure was simple in the topsoil. Cluster and principle component analysis based on DGGE banding patterns showed that the bacterial community structure was affected by soil depth more primarily than by managements, and the succession of bacterial community as increase of soil depth has a similar tendency in the three managements. Fourteen predominating DGGE bands were excised and sequenced, in which 6 bands were identified as the taxa of Verrueomicrobia, 2 bands as Actinobacteria, 2 bands as α-Proteobacteria, and the other 4 bands as 8-Proteobacteria, Aeidobacteria, Nitrospira, and unclassified bacteria. In addition, the sequences of 11 DGGE bands were closely related to uncultured bacteria. Thus, the bacterial community structure in black soil was stable, and the predominating bacterial groups were uncultured.展开更多
AIM: To explore the virulence and the potential pathogenicity of coccoid Helicobacter pylori (H. pylori) transformed from spiral form by exposure to antibiotic. METHODS: Three strains of H. pylori, isolated from gastr...AIM: To explore the virulence and the potential pathogenicity of coccoid Helicobacter pylori (H. pylori) transformed from spiral form by exposure to antibiotic. METHODS: Three strains of H. pylori, isolated from gastric biopsy specimens of confirmed peptic ulcer, were converted from spiral into coccoid from by exposure to metronidazole. Both spiral and coccoid form of H. pylori were tested for the urease activity, the adherence to Hep-2 cells and the vacuolating cytotoxicity to Hela cells, and the differences of the protein were analysed by SDS-PAGE and Western blot. The mutation of the genes including ureA, ureB,hpaA, vacA and cagA, related with virulence, was detected by means of PCR and PCR-SSCP. RESULTS: In the coccoid H. pylori,the urease activity, the adherence to Hep-2 cells and the vacuolating cytotoxicity to Hela cells all decreased. In strain F44, the rate and index of adherence reduced from 70.0% +/- 5.3% to 33% +/- 5.1% and from 2.6 +/- 0.4 to 0.96 +/- 0.3 (P 【 0.01), respectively. The invasion of coccoid H. pylori into Hep-2 cell could be seen under electronmicroscope. SDS-PAGE showed that the content of the protein with the molecular weight over Mr 74000 decreased, and the hybriditional signal in band M(r) 125000 weakened, while the band M(r)110000 and M(r)63000 strengthened in coccoid H.pylori as shown in Western blot. The results of PCR were all positive, and PCR-SSCP indicated that there may exist the point mutation in gene hpaA or vacA. CONCLUSION: The virulence and the proteins with molecular weight over M(r)74000 in coccoid H.pylori decrease, but no deletion exists in amplification fragments from ureA, ureB, hpaA, vacA and cagA genes, suggesting that coccoid H.pylori may have potential pathogenicity.展开更多
Enzymatic activities of beta-gincosidase （ β-GLC ）, （ LAP）, and alkaline phosphatase （ APA）, corresponding to nutrient eliminations, and the microbial community structures were analyzed in an anaerobic-anoxic-a...Enzymatic activities of beta-gincosidase （ β-GLC ）, （ LAP）, and alkaline phosphatase （ APA）, corresponding to nutrient eliminations, and the microbial community structures were analyzed in an anaerobic-anoxic-aerobic reactor system. Results showed that most activity of β-GLC （64.2 μmoi/（ L · h ）） associated with the largest fraction of small- molecular-weight carbohydrates was found in the aerobic reactor, indicating the existence of coupled hydrolysis-uptake mechanism in the aerobic bacteria. Similar activities of LAP presented in the anoxic and aerobic environments, whose increases accompanied by increments in nitrogen uptake rates greatly accelerated the processes of aerobic nitrification and anoxic denitrification. The highest APA activity displayed in the anaerobic reactor, however, dephosphorization performance was mainly achieved under aerobic condition. Microbial community fingerprints generated by polymerase chain reaction amplification and denaturing gradient gel dectrophoresls （ PCR-DGGE ） revealed that Proteobacterium, Actinobacterium, and Nitrosplra were the predominant classes in the activated sindge and there was no evidence of community variations among each function reactor in the system with biomass recycling.展开更多
A new method for screening gene mutations by using a Coupled In Vitro Transcription and Translation System is reported in this paper. It includes the following steps: (1) The target DNA fragments with T7T1 sequence a...A new method for screening gene mutations by using a Coupled In Vitro Transcription and Translation System is reported in this paper. It includes the following steps: (1) The target DNA fragments with T7T1 sequence at its 5 prime end are amplified (T7T1: GGATCCTAATACGACTCTATAGGGAG ACCACCATG); (2) The RNA and peptide are synthesized and labeled from the PCR product in the coupled In Vitro Transcription-Translation System; (3) The produced peptides are analyzed by using SDS-PAGE and pH Gradient gel focusing electrophoresis. Four peptide products from 4 HB patients with nonsense mutation in Exon H of F IX gene show truncated protein bands with speeded migration in the autoradiography of the SDS-PAGE. Ten out of 11 HB patients with different missense mutations show abnormal patterns in the autoradiography of a pH 4-7 gradient gel focusing electrophoresis. Conclusion: The PCR and the Coupled In Vitro Transcription-Translation System/SDS-PAGE is a good method for proteins truncation test. The PCR and the Transcription-Translation System combined with pH gradient gel focusing electrophoresis is an efficient method for screening the abnormal protein products from DNA fragments with missense mutations.展开更多
This study aimed to characterize the morphological changes in the ovary of the female crab Neptunus pelagicus and to identify specific fractions of vitelloginin and vitelline molecules during primary and secondary vit...This study aimed to characterize the morphological changes in the ovary of the female crab Neptunus pelagicus and to identify specific fractions of vitelloginin and vitelline molecules during primary and secondary vitellogenesis.Samples of the blue crab were collected from the Mediterranean Sea of Alexandria monthly during 2017.Ovaries and oocytes in primary and secondary vitellogenesis were detached and treated for histological test.Native polyacrylamide gel electrophoresis(PAGE)Bis-Tris Gels was applied to identify vitelloginin(VN)and vitelline(VL)molecules.Protein Analyses were done by PAGE-SDS.The initial degenerate primers were built regarding the conserved amino acid domains of the yolk proteins.Primary and secondary vitellogeneses consisted of 8 phases.Lipoprotein fraction with molecular weight 550 kDa was identified in the hemolymph in secondary vitellogenesis.Two protein fractions(VLI&VLII)were identified in secondary vitellogenic oocytes.The electrophoresis performed with extract of stage I oocyte showed two protein fractions with molecular weights 550 kDa and 460 kDa.In stage II and III oocyte,4 subunits were presented of 180,195,140 and 120 kDa in VLI and 2 subunits with molecular weight of 110 kDa and 95 kDa in VLII.Another two fractions in stage V oocyte presented with molecular weights of 380 kDa and 360 kDa.Western blot analysis proved that both fractions were of four major polypeptide subunits with molecular weight of 180,125,90 and 85 kDa in each of the two VLs.The hybridization signal obtained by the Northern blot was detected in the hepatopancreas during ovarian cycle and in the ovary during secondary vitellogenesis.The result of the reverse transcription-polymerase chain reaction(RT-PCR)analysis showed that the mRNA that encodes the C-terminal region of the VN cDNA was found in the ovary in secondary vitellogenesis and in the hepatopancreas.展开更多
Objective To ascertain the relationship between paraoxonase gene (PON) and the morbidity of coronary arterial disease (CAD) in Chinese non-insulin-dependent diabetes mellitus (NIDDM) patients. Methods The exons of PON...Objective To ascertain the relationship between paraoxonase gene (PON) and the morbidity of coronary arterial disease (CAD) in Chinese non-insulin-dependent diabetes mellitus (NIDDM) patients. Methods The exons of PON gene were screened by polymerase chain reaction-denaturing gradient gel elec-trophoresis in 49 NIDDM patients complicated with CAD, 49 NIDDM and 101 healthy control cases of Chinese population. Results Gln-Arg191 polymorphism of the PON gene was detected in Chinese with the AIR allele frequency 0.39 and 0. 61 respectively. The genotype distribution (AA, AR and RB) of the PON gene polymor-phism was significantly different between NIDDM patients complicated with CAD and controls (NIDDM and healthy subjects). The former had a significantly higher B allele frequency (0. 79 vs 0. 62 and 0. 61, P < 0. 01). Conclusion Gln-Arg191 polymorphism of the PON gene is associated with CAD morbidity in Chinese NJDDM patients and B allele might be a risk factor.展开更多
核酸适配体是人工合成的短链核酸,作为分子识别元件,能够与各类靶标物质高特异性、高亲和力的结合,分为单链DNA和RNA两种类型。其中单链DNA适配体由于其稳定性比RNA适配体更好而更受欢迎,因此得到广泛应用。核酸适配体筛选通常是通过配...核酸适配体是人工合成的短链核酸,作为分子识别元件,能够与各类靶标物质高特异性、高亲和力的结合,分为单链DNA和RNA两种类型。其中单链DNA适配体由于其稳定性比RNA适配体更好而更受欢迎,因此得到广泛应用。核酸适配体筛选通常是通过配体指数富集系统进化技术(systematic evolution of ligands by exponential enrichment,SELEX)实现的,筛选能否成功在很大程度上取决于其最关键的单链制备步骤,即将双链DNA转化为相应的单链DNA。目前,存在许多方法可以制备单链DNA,包括热变性法、生物素-链霉亲和素亲和分离法、变性胶电泳分离法、核酸外切酶消化法、不对称聚合酶链式反应(polymerase chain reaction,PCR)法等。本文在总结文献报道的基础上,具体阐述了各种单链DNA制备方法的原理、优缺点及近5年的应用情况,并对这些单链DNA制备方法进行了比较和展望,以期能为成功筛选各类靶标的核酸适配体提供参考。展开更多
采用聚合酶链式反应-变性梯度凝胶电泳(polymerase chain reaction-denaturing gradient gel electrophoresis,PCR-DGGE)技术对盐质量浓度5 g/100 m L和19 g/100 m L腌制麻竹笋的微生物区系进行研究。结果表明,经DNA提取、巢式PCR、DGG...采用聚合酶链式反应-变性梯度凝胶电泳(polymerase chain reaction-denaturing gradient gel electrophoresis,PCR-DGGE)技术对盐质量浓度5 g/100 m L和19 g/100 m L腌制麻竹笋的微生物区系进行研究。结果表明,经DNA提取、巢式PCR、DGGE电泳和克隆测序后,从低盐质量浓度(5 g/100 m L)腌制笋中分离出4条明显的亮带,经鉴定分别为食窦魏斯氏菌(Weissella cibaria)、乳球菌属(Lactococcus sp.)、魏斯氏菌属(Weissella sp.)和乳酸乳球菌(Lactococcus lactis);从高盐质量浓度(19 g/100 m L)腌制笋中分离出5条明显的亮带,经鉴定分别为绿色气球菌(Aerococcus viridans)、赖氨酸芽孢杆菌属(Lysinibacillus sp.)、未得到培养的细菌(uncultured bacterium)、厌氧芽孢杆菌属(Anoxybacillus sp.)和芽孢杆菌属(Bacillus sp.);低盐腌制笋的优势菌多为益生菌,而高盐腌制笋的优势菌则多为抗性较强的菌。基于16S r DNA的PCR-DGGE技术为分析腌制麻竹笋中微生物多样性提供了一条可靠、快速的有效途径。展开更多
基金supported by Chinese State Scholarship Fund to R. WangUS National Institutes of Health (NIH) Grants DE020102 and GM95373 to W. Shi
文摘Information on co-adherence of different oral bacterial species is important for understanding interspecies interactions within oral microbial community. Current knowledge on this topic is heavily based on pariwise coaggregation of known, cultivable species. In this study, we employed a membrane binding assay coupled with polymerase chain reaction-denaturing gradient gel electrophoresis （PCR-DGGE） to systematically analyze the co-adherence profiles of oral bacterial species, and achieved a more profound knowledge beyond pairwise coaggregation. Two oral bacterial species were selected to serve as ＂bait＂： Fusobacterium nucleatum （F. nucleatum） whose ability to adhere to a multitude of oral bacterial species has been extensively studied for pairwise interactions and Streptococcus mutans （S. mutans） whose interacting partners are largely unknown. To enable screening of interacting partner species within bacterial mixtures, cells of the ＂bait＂ oral bacterium were immobilized on nitrocellulose membranes which were washed and blocked to prevent unspecific binding. The ＂prey＂ bacterial mixtures （including known species or natural saliva samples） were added, unbound ceils were washed off after the incubation period and the remaining cells were eluted using 0.2 mol.L1 glycine. Genomic DNA was extraeted, subjeeted to 16S rRNA PCR amplification and separation of the resulting PCR produets by DGGE. Selected bands were recovered from the gel, sequenced and identified via Nucleotide BLAST searches against different databases. While few bacterial species bound to S. mutans, consistent with previous findings F.. nucleatum adhered to a variety of bacterial species including uncultivable and uneharacterized onesl This new approach can more effectively analyze the co-adherence profiles of oral bacteria, and could facilitate the systematic study of interbacterial binding of oral microbial species.
基金Project supported by the National Natural Science Foundation of China (No.40671099)
文摘Soil microbial biomass and community structures are commonly used as indicators for soil quality and fertility. A investigation was performed to study the effects of long-term natural restoration, cropping, and bare fallow managements on the soil microbial biomass and bacterial community structures in depths of 0-10, 20 30, and 40-50 cm in a black soil （Mollisol）. Microbial biomass was estimated from chloroform fumigation-extraction, and bacterial community structures were determined by analysis of 16S rDNA using polymerase chain reaction-denaturing gradient gel electrophoresis （PCR- DGGE）. Experimental results showed that microbial biomass significantly declined with soil depth in the managements of restoration and cropping, but not in the bare fallow. DGGE profiles indicated that the band number in top 0-10 cm soils was less than that in depth of 20-30 or 40-50 cm. These suggested that the microbial population was high but the bacterial community structure was simple in the topsoil. Cluster and principle component analysis based on DGGE banding patterns showed that the bacterial community structure was affected by soil depth more primarily than by managements, and the succession of bacterial community as increase of soil depth has a similar tendency in the three managements. Fourteen predominating DGGE bands were excised and sequenced, in which 6 bands were identified as the taxa of Verrueomicrobia, 2 bands as Actinobacteria, 2 bands as α-Proteobacteria, and the other 4 bands as 8-Proteobacteria, Aeidobacteria, Nitrospira, and unclassified bacteria. In addition, the sequences of 11 DGGE bands were closely related to uncultured bacteria. Thus, the bacterial community structure in black soil was stable, and the predominating bacterial groups were uncultured.
基金Supported by the Natural Science Foundation of Fujian Province,China,No.95A003
文摘AIM: To explore the virulence and the potential pathogenicity of coccoid Helicobacter pylori (H. pylori) transformed from spiral form by exposure to antibiotic. METHODS: Three strains of H. pylori, isolated from gastric biopsy specimens of confirmed peptic ulcer, were converted from spiral into coccoid from by exposure to metronidazole. Both spiral and coccoid form of H. pylori were tested for the urease activity, the adherence to Hep-2 cells and the vacuolating cytotoxicity to Hela cells, and the differences of the protein were analysed by SDS-PAGE and Western blot. The mutation of the genes including ureA, ureB,hpaA, vacA and cagA, related with virulence, was detected by means of PCR and PCR-SSCP. RESULTS: In the coccoid H. pylori,the urease activity, the adherence to Hep-2 cells and the vacuolating cytotoxicity to Hela cells all decreased. In strain F44, the rate and index of adherence reduced from 70.0% +/- 5.3% to 33% +/- 5.1% and from 2.6 +/- 0.4 to 0.96 +/- 0.3 (P 【 0.01), respectively. The invasion of coccoid H. pylori into Hep-2 cell could be seen under electronmicroscope. SDS-PAGE showed that the content of the protein with the molecular weight over Mr 74000 decreased, and the hybriditional signal in band M(r) 125000 weakened, while the band M(r)110000 and M(r)63000 strengthened in coccoid H.pylori as shown in Western blot. The results of PCR were all positive, and PCR-SSCP indicated that there may exist the point mutation in gene hpaA or vacA. CONCLUSION: The virulence and the proteins with molecular weight over M(r)74000 in coccoid H.pylori decrease, but no deletion exists in amplification fragments from ureA, ureB, hpaA, vacA and cagA genes, suggesting that coccoid H.pylori may have potential pathogenicity.
文摘Enzymatic activities of beta-gincosidase （ β-GLC ）, （ LAP）, and alkaline phosphatase （ APA）, corresponding to nutrient eliminations, and the microbial community structures were analyzed in an anaerobic-anoxic-aerobic reactor system. Results showed that most activity of β-GLC （64.2 μmoi/（ L · h ）） associated with the largest fraction of small- molecular-weight carbohydrates was found in the aerobic reactor, indicating the existence of coupled hydrolysis-uptake mechanism in the aerobic bacteria. Similar activities of LAP presented in the anoxic and aerobic environments, whose increases accompanied by increments in nitrogen uptake rates greatly accelerated the processes of aerobic nitrification and anoxic denitrification. The highest APA activity displayed in the anaerobic reactor, however, dephosphorization performance was mainly achieved under aerobic condition. Microbial community fingerprints generated by polymerase chain reaction amplification and denaturing gradient gel dectrophoresls （ PCR-DGGE ） revealed that Proteobacterium, Actinobacterium, and Nitrosplra were the predominant classes in the activated sindge and there was no evidence of community variations among each function reactor in the system with biomass recycling.
文摘A new method for screening gene mutations by using a Coupled In Vitro Transcription and Translation System is reported in this paper. It includes the following steps: (1) The target DNA fragments with T7T1 sequence at its 5 prime end are amplified (T7T1: GGATCCTAATACGACTCTATAGGGAG ACCACCATG); (2) The RNA and peptide are synthesized and labeled from the PCR product in the coupled In Vitro Transcription-Translation System; (3) The produced peptides are analyzed by using SDS-PAGE and pH Gradient gel focusing electrophoresis. Four peptide products from 4 HB patients with nonsense mutation in Exon H of F IX gene show truncated protein bands with speeded migration in the autoradiography of the SDS-PAGE. Ten out of 11 HB patients with different missense mutations show abnormal patterns in the autoradiography of a pH 4-7 gradient gel focusing electrophoresis. Conclusion: The PCR and the Coupled In Vitro Transcription-Translation System/SDS-PAGE is a good method for proteins truncation test. The PCR and the Transcription-Translation System combined with pH gradient gel focusing electrophoresis is an efficient method for screening the abnormal protein products from DNA fragments with missense mutations.
文摘This study aimed to characterize the morphological changes in the ovary of the female crab Neptunus pelagicus and to identify specific fractions of vitelloginin and vitelline molecules during primary and secondary vitellogenesis.Samples of the blue crab were collected from the Mediterranean Sea of Alexandria monthly during 2017.Ovaries and oocytes in primary and secondary vitellogenesis were detached and treated for histological test.Native polyacrylamide gel electrophoresis(PAGE)Bis-Tris Gels was applied to identify vitelloginin(VN)and vitelline(VL)molecules.Protein Analyses were done by PAGE-SDS.The initial degenerate primers were built regarding the conserved amino acid domains of the yolk proteins.Primary and secondary vitellogeneses consisted of 8 phases.Lipoprotein fraction with molecular weight 550 kDa was identified in the hemolymph in secondary vitellogenesis.Two protein fractions(VLI&VLII)were identified in secondary vitellogenic oocytes.The electrophoresis performed with extract of stage I oocyte showed two protein fractions with molecular weights 550 kDa and 460 kDa.In stage II and III oocyte,4 subunits were presented of 180,195,140 and 120 kDa in VLI and 2 subunits with molecular weight of 110 kDa and 95 kDa in VLII.Another two fractions in stage V oocyte presented with molecular weights of 380 kDa and 360 kDa.Western blot analysis proved that both fractions were of four major polypeptide subunits with molecular weight of 180,125,90 and 85 kDa in each of the two VLs.The hybridization signal obtained by the Northern blot was detected in the hepatopancreas during ovarian cycle and in the ovary during secondary vitellogenesis.The result of the reverse transcription-polymerase chain reaction(RT-PCR)analysis showed that the mRNA that encodes the C-terminal region of the VN cDNA was found in the ovary in secondary vitellogenesis and in the hepatopancreas.
基金grant from Shanghai Science and Technology Com-mission (974119003)
文摘Objective To ascertain the relationship between paraoxonase gene (PON) and the morbidity of coronary arterial disease (CAD) in Chinese non-insulin-dependent diabetes mellitus (NIDDM) patients. Methods The exons of PON gene were screened by polymerase chain reaction-denaturing gradient gel elec-trophoresis in 49 NIDDM patients complicated with CAD, 49 NIDDM and 101 healthy control cases of Chinese population. Results Gln-Arg191 polymorphism of the PON gene was detected in Chinese with the AIR allele frequency 0.39 and 0. 61 respectively. The genotype distribution (AA, AR and RB) of the PON gene polymor-phism was significantly different between NIDDM patients complicated with CAD and controls (NIDDM and healthy subjects). The former had a significantly higher B allele frequency (0. 79 vs 0. 62 and 0. 61, P < 0. 01). Conclusion Gln-Arg191 polymorphism of the PON gene is associated with CAD morbidity in Chinese NJDDM patients and B allele might be a risk factor.
文摘核酸适配体是人工合成的短链核酸,作为分子识别元件,能够与各类靶标物质高特异性、高亲和力的结合,分为单链DNA和RNA两种类型。其中单链DNA适配体由于其稳定性比RNA适配体更好而更受欢迎,因此得到广泛应用。核酸适配体筛选通常是通过配体指数富集系统进化技术(systematic evolution of ligands by exponential enrichment,SELEX)实现的,筛选能否成功在很大程度上取决于其最关键的单链制备步骤,即将双链DNA转化为相应的单链DNA。目前,存在许多方法可以制备单链DNA,包括热变性法、生物素-链霉亲和素亲和分离法、变性胶电泳分离法、核酸外切酶消化法、不对称聚合酶链式反应(polymerase chain reaction,PCR)法等。本文在总结文献报道的基础上,具体阐述了各种单链DNA制备方法的原理、优缺点及近5年的应用情况,并对这些单链DNA制备方法进行了比较和展望,以期能为成功筛选各类靶标的核酸适配体提供参考。
文摘采用聚合酶链式反应-变性梯度凝胶电泳(polymerase chain reaction-denaturing gradient gel electrophoresis,PCR-DGGE)技术对盐质量浓度5 g/100 m L和19 g/100 m L腌制麻竹笋的微生物区系进行研究。结果表明,经DNA提取、巢式PCR、DGGE电泳和克隆测序后,从低盐质量浓度(5 g/100 m L)腌制笋中分离出4条明显的亮带,经鉴定分别为食窦魏斯氏菌(Weissella cibaria)、乳球菌属(Lactococcus sp.)、魏斯氏菌属(Weissella sp.)和乳酸乳球菌(Lactococcus lactis);从高盐质量浓度(19 g/100 m L)腌制笋中分离出5条明显的亮带,经鉴定分别为绿色气球菌(Aerococcus viridans)、赖氨酸芽孢杆菌属(Lysinibacillus sp.)、未得到培养的细菌(uncultured bacterium)、厌氧芽孢杆菌属(Anoxybacillus sp.)和芽孢杆菌属(Bacillus sp.);低盐腌制笋的优势菌多为益生菌,而高盐腌制笋的优势菌则多为抗性较强的菌。基于16S r DNA的PCR-DGGE技术为分析腌制麻竹笋中微生物多样性提供了一条可靠、快速的有效途径。
