Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
Cell Death Discov ; 10(1): 285, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38877005

RESUMO

DUSP22, an atypical dual-specificity phosphatase enzyme, plays a significant role in regulating multiple kinase signaling pathways by dephosphorylation. Our study demonstrated that decreased DUSP22 expression is associated with shorter disease-free survival, advanced TNM (tumor, lymph nodes, and metastasis), cancer stage, and higher tumor grade in lung adenocarcinoma (LUAD) patients. Exogenous DUSP22 expression reduces the colony-forming capacity of lung cancer cells and inhibits xenograft tumor growth primarily by targeting EGFR and suppressing its activity through dephosphorylation. Knockdown of DUSP22 using shRNA enhances EGFR dependency in HCC827 lung cancer cells and increases sensitivity to gefitinib, an EGFR inhibitor. Consistently, genetic deletion of DUSP22 enhances EGFRdel (exon 19 deletion)-driven lung tumorigenesis and elevates EGFR activity. Pharmacological inhibition of DUSP22 activates EGFR, ERK1/2, and upregulates downstream PD-L1 expression. Additionally, lentiviral deletion of DUSP22 by shRNA enhances lung cancer cell migration through EGFR/c-Met and PD-L1-dependent pathways. Gefitinib, an EGFR inhibitor, mechanistically suppresses migration induced by DUSP22 deletion and inhibits c-Met activity. Furthermore, cabozantinib, a c-Met inhibitor, reduces migration and attenuates EGFR activation caused by DUSP22 deletion. Collectively, our findings support the hypothesis that loss of DUSP22 function in lung cancer cells confers a survival advantage by augmenting EGFR signaling, leading to increased activation of downstream c-Met, ERK1/2, and PD-L1 axis, ultimately contributing to the progression of advanced lung cancer.

2.
Biochimie ; 214(Pt B): 134-144, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37442534

RESUMO

Oral dysbiosis contributes to periodontitis and has implications for systemic diseases. Diabetes mellitus is a common metabolic disorder characterized by impaired glucose regulation. AMP-activated protein kinase (AMPK) plays a vital role in regulating glucose uptake and glycogenesis in the liver. This study aimed to investigate the association between periodontal bacteria and diabetes mellitus. A clinical trial was conducted to explore the association between oral bacteria and hyperglycemia. Additionally, we elucidated the molecular mechanisms by which periodontal bacteria cause insulin resistance. In the clinical trial, we discovered significant alterations in the expression levels of Fusobacterium nucleatum (Fn) and Tannerella forsythia (Tf) in patients with diabetes compared with healthy controls. Furthermore, Fn and Tf levels positively correlated with fasting blood glucose and glycated hemoglobin (HbA1C) levels. Moreover, we explored and elucidated the molecular mechanism by which Fusobacterium nucleatum culture filtrate (FNCF) induces cytokine release via the Toll-like receptor 2 (TLR2) signaling pathway in human gingival epithelial Smulow-Glickman (S-G) cells. This study investigated the effects of cytokines on insulin resistance pathways in liver cells. The use of an extracellular signal-regulated kinase (ERK) inhibitor (U0126) demonstrated that FNCF regulates the insulin receptor substrate 1 and protein kinase B (IRS1/AKT) signaling pathway, which affects key proteins involved in hepatic glycogen synthesis, including glycogen synthase kinase-3 beta (GSK3ß) and glycogen synthase (GS), ultimately leading to insulin resistance. These findings suggest that ERK plays a crucial role in hepatocyte insulin resistance.


Assuntos
Diabetes Mellitus Tipo 2 , Diabetes Mellitus , Resistência à Insulina , Microbiota , Humanos , Sistema de Sinalização das MAP Quinases , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Glucose/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Insulina/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Glicogênio Sintase Quinase 3 beta/farmacologia , Diabetes Mellitus Tipo 2/metabolismo
3.
FASEB J ; 33(12): 14653-14667, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31693867

RESUMO

Dual-specificity phosphatases (DUSPs) regulate the activity of various downstream kinases through serine or threonine or tyrosine dephosphorylation. Loss of function and aberrant expression of DUSPs has been implicated in cancer progression and poor survival, yet the function of DUSP22 in prostate cancer (PCa) cells is not clear. Gene Expression Omnibus and cBioPortal microarray database analyses showed that DUSP22 expression was lower in PCa tissues than normal prostate tissues, and altered DUSP22 expression was associated with shorter progression-free and disease-free survival of patients with PCa. Exogenous DUSP22 expression in LNCaP, PC3, and C4-2B PCa cells inhibited cellular proliferation and colony formation, supporting a growth inhibitory role for DUSP22 in PCa cells. DUSP22 expression significantly attenuated epidermal growth factor (EGF) receptor (EGFR) and its downstream ERK1/2 signaling by dephosphorylation. However, DUSP22 failed to suppress the growth of CWR22Rv1 and DU145 cells with elevated phosphorylated (p-)ERK1/2 levels. A serine-to-alanine mutation at position 58, a potential ERK1/2-targeted phosphorylation site in DUSP22, was sufficient to suppress growth of CWR22Rv1 cells with elevated p-ERK1/2 levels, suggesting a mutually antagonistic relationship between DUSP22 and ERK1/2 dependent on phosphorylation status. We showed that DUSP22 can suppress prostate-specific antigen gene expression through phosphatase-dependent pathways, suggesting that DUSP22 is an important regulator of the androgen receptor (AR) in PCa cells. Mechanistically, DUSP22 can interact with AR as a regulatory partner and interfere with EGF-induced AR phosphorylation at Tyr534, suggesting that DUSP22 serves as a crucial suppressor of both EGFR and AR-dependent signaling in PCa cells via dephosphorylation. Our findings indicate that loss of function of DUSP22 in PCa cells leads to aberrant activation of both EGFR-ERKs and AR signaling and ultimately progression of PCa, supporting the potential for novel therapeutic design of harnessing DUSP22 in the treatment of PCa.-Lin, H.-P., Ho, H.-M., Chang, C.-W., Yeh, S.-D., Su, Y.-W., Tan, T.-H., Lin, W.-J. DUSP22 suppresses prostate cancer proliferation by targeting the EGFR-AR axis.


Assuntos
Fosfatases de Especificidade Dupla/metabolismo , Receptores ErbB/metabolismo , Fosfatases da Proteína Quinase Ativada por Mitógeno/metabolismo , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/metabolismo , Transdução de Sinais , Animais , Linhagem Celular Tumoral , Proliferação de Células , Fosfatases de Especificidade Dupla/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosfatases da Proteína Quinase Ativada por Mitógeno/genética , Fosforilação , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Ligação Proteica
4.
Cancers (Basel) ; 11(2)2019 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-30823599

RESUMO

Epithelial ovarian cancer patients usually relapse after primary management. We utilized the support vector machine algorithm to develop a model for the chemo-response using the Cancer Cell Line Encyclopedia (CCLE) and validated the model in The Cancer Genome Atlas (TCGA) and the GSE9891 dataset. Finally, we evaluated the feasibility of the model using ovarian cancer patients from our institute. The 10-gene predictive model demonstrated that the high response group had a longer recurrence-free survival (RFS) (log-rank test, p = 0.015 for TCGA, p = 0.013 for GSE9891 and p = 0.039 for NTUH) and overall survival (OS) (log-rank test, p = 0.002 for TCGA and p = 0.016 for NTUH). In a multivariate Cox hazard regression model, the predictive model (HR: 0.644, 95% CI: 0.436⁻0.952, p = 0.027) and residual tumor size < 1 cm (HR: 0.312, 95% CI: 0.170⁻0.573, p < 0.001) were significant factors for recurrence. The predictive model (HR: 0.511, 95% CI: 0.334⁻0.783, p = 0.002) and residual tumor size < 1 cm (HR: 0.252, 95% CI: 0.128⁻0.496, p < 0.001) were still significant factors for death. In conclusion, the patients of high response group stratified by the model had good response and favourable prognosis, whereas for the patients of medium to low response groups, introduction of other drugs or clinical trials might be beneficial.

5.
Epigenomics ; 10(11): 1397-1413, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30324802

RESUMO

AIM: To investigate the CDH1, DLEC1 and SFRP5 gene methylation panel for advanced epithelial ovarian carcinoma (EOC). MATERIALS & METHODS: One hundred and seventy-seven advanced EOC specimens were evaluated by methylation-specific PCR. We also used The Cancer Genome Atlas dataset to evaluate the panel. RESULTS: The presence of two or more methylated genes was significant in recurrence (hazard ratio [HR]: 1.91 [1.33-2.76]; p = 0.002) and death (HR: 1.96 [1.26-3.06]; p = 0.006) in our cohort. In The Cancer Genome Atlas dataset, the presence of two or three methylated genes was significant in death (HR: 1.59 [1.15-2.18]; p = 0.0047) and close to the significance level in recurrence (HR: 1.37 [0.99-1.88]; p = 0.058). CONCLUSION: The CDH1, DLEC1 and SFRP5 methylation panel is a potential prognostic biomarker for advanced EOC.


Assuntos
Antígenos CD/genética , Biomarcadores Tumorais/genética , Caderinas/genética , Carcinoma Epitelial do Ovário/genética , Metilação de DNA , Proteínas do Olho/genética , Proteínas de Membrana/genética , Neoplasias Ovarianas/genética , Proteínas Supressoras de Tumor/genética , Proteínas Adaptadoras de Transdução de Sinal , Adulto , Idoso , Carcinoma Epitelial do Ovário/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/patologia , Análise de Sobrevida
6.
Oncotarget ; 7(7): 8389-98, 2016 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-26701731

RESUMO

Prostate-specific antigen (PSA) is regarded as the most sensitive biomarker for prostate cancer. Although androgen/androgen receptor (AR) signaling promotes prostate cancer progression, suppression of AR signaling induces chemokine (CC motif) ligand 2 (CCL2), which enables prostate cancer cells to gain metastatic potential. AR-controlled PSA alone may be an unreliable biomarker for patients receiving androgen deprivation therapy. Therefore, we investigated the validity of CCL2 as a complementary biomarker to PSA for prostate cancer. Our in vitro approach of enriching for prostate cancer cells with higher migration potential showed that CCL2 activated cellular migration. Importantly, we found that CCL2 levels were significantly different between men (n = 379) with and without prostate cancer. Patients with CCL2 ≥ 320 pg/mL had worse overall survival and prostate cancer -specific survival than those with CCL2 < 320 pg/mL. A novel risk classification was developed according to the risk factors CCL2 ≥ 320 pg/mL and PSA ≥ 100 ng/mL, and scores of 2, 1, and 0 were defined as poor, intermediate, and good risk, respectively, and clearly distinguished patient outcomes. CCL2 may serve as a novel biomarker for prostate cancer. The novel risk classification based on combining CCL2 and PSA is more reliable than using either alone.


Assuntos
Biomarcadores Tumorais/sangue , Quimiocina CCL2/sangue , Neoplasias da Próstata/patologia , Idoso , Idoso de 80 Anos ou mais , Apoptose , Biomarcadores Tumorais/genética , Movimento Celular , Proliferação de Células , Quimiocina CCL2/genética , Terapia Combinada , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , Neoplasias da Próstata/sangue , Neoplasias da Próstata/terapia , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de Sobrevida , Células Tumorais Cultivadas
7.
BMC Infect Dis ; 15: 241, 2015 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-26104109

RESUMO

BACKGROUND: Outbreaks of low and high pathogenic avian influenza (LPAI, HPAI) H5N2 in chickens have occurred in Taiwan since 2003 and 2012, respectively. Fully understanding the different awareness, attitudes and protective behaviors adopted by workers in live-poultry markets (LPMWs) and local community residents (CRs) to face the challenges of LPAI and HPAI is very important to minimize viral adaptations to human populations. METHODS: A structural questionnaire containing information on respondents' occupation, personal risk awareness, attitudes toward different policies, and preventative measures was administered. The two-stage survey (before and after HPAI H5N2 outbreaks) was conducted from 2007 to 2012, including: (1) 430 LPMWs and 418 CRs at LPMs from different geographical areas of Taiwan after the government announced outbreaks of LPAI H5N2 during 2007-2009, and (2) 73 LPMWs and 152 CRs at two LPMs in central Taiwan after the HPAI H5N2 outbreaks in 2012. The chi-squared test and logistic regression were applied for univariate and multivariate analyses, respectively. RESULTS: Before HPAI-H5N2 outbreaks, higher educated respondents demonstrated greater risk awareness and concerns regarding AI. However, LPM-workers protected themselves less from AI viruses (AIVs) and had lower acceptance of human or avian influenza vaccines. Most importantly, the participants who opposed (versus agreed with) the policy on banning live-poultry slaughtering at LPMs reported lower awareness of government prevention and control policies [Odds Ratio (OR): 0.76, 95 % Confidence Interval (CI): 0.56-1.01] or practiced preventive measures (OR: 0.42, 95 % CI: 0.25-0.70). After HPAI-H5N2 outbreaks, the risk awareness about AI in central Taiwan significantly increased [LPAI to HPAI LPMWs: 34.6 to 65.6 %, p < 0.05; CRs: 44.0 to 76.5 %, p < 0.05] and LPMWs' belief in the effectiveness of vaccination to prevent human or avian influenza virus infection strikingly decreased (92.3 to 68.5 %, p < 0.05). CONCLUSIONS: Risk awareness depends on high or low pathogenicity of AIVs, working in LPMs, levels of education, age, and proximity to the sites of severe AI outbreaks. Regardless of novel LPAI or HPAI virus reassortants that pose public health risks, prompt and clear risk communication focusing on both correct information about AIVs and the most appropriate preventive measures are important for effective prevention of human infection.


Assuntos
Atitude Frente a Saúde , Conscientização , Influenza Aviária/epidemiologia , Adolescente , Adulto , Idoso , Animais , Galinhas , Surtos de Doenças/veterinária , Feminino , Regulamentação Governamental , Humanos , Vírus da Influenza A Subtipo H5N2/isolamento & purificação , Vacinas contra Influenza/imunologia , Influenza Aviária/virologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Risco , Inquéritos e Questionários , Taiwan/epidemiologia , Adulto Jovem
8.
Reprod Sci ; 22(6): 725-34, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25394645

RESUMO

A new cell line, CA5171, derived from a chemotherapy-naive, high-grade undifferentiated ovarian carcinoma was established and characterized. The CA5171 cells presented with cobblestone morphology and a doubling time of 24 hours. Gene mutation analysis showed that the cells belonged to the type II ovarian cancer pathway with mutations of PIK3CA, PTEN, and TP53. Single-nucleotide polymorphism array analysis showed no homozygous gene deletion; however, several loci of gene copy number gains were noted in chromosome 1, 2, 5, 9, 10, 12, 15, 16, 20, and X. The in vitro and in vivo experiments showed that the cells were sensitive to paclitaxel and doxorubicin, but resistant to cisplatin. The cells also presented epithelial-mesenchymal transition properties that may have been related to their invasion and migration potential. The CA5171 cells show the potential as a new cell line for studies on epithelial ovarian carcinoma.


Assuntos
Neoplasias Epiteliais e Glandulares , Neoplasias Ovarianas , Antineoplásicos/farmacologia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma Epitelial do Ovário , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Forma Celular , Cisplatino/farmacologia , Classe I de Fosfatidilinositol 3-Quinases , Variações do Número de Cópias de DNA , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Transição Epitelial-Mesenquimal , Feminino , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Humanos , Pessoa de Meia-Idade , Mutação , Invasividade Neoplásica , Neoplasias Epiteliais e Glandulares/tratamento farmacológico , Neoplasias Epiteliais e Glandulares/genética , Neoplasias Epiteliais e Glandulares/metabolismo , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Paclitaxel/farmacologia , Fenótipo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Polimorfismo de Nucleotídeo Único , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
9.
Int J Cancer ; 135(4): 809-19, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-24477565

RESUMO

SOX2 is a transcription factor essential for self-renewal and pluripotency of embryonic stem cells. Recently, SOX2 was found overexpressed in the majority of the lung squamous cell carcinoma (SQC), in which it acts as a lineage-survival oncogene. However, downstream targets/pathways of SOX2 in lung SQC cells remain to be identified. Here, we show that BMP4 is a downstream target of SOX2 in lung SQC. We found that SOX2-silencing-mediated inhibition of cell growth was accompanied by upregulation of BMP4 mRNA and its protein expression. Meta-analysis with 293 samples and qRT-PCR validation with 73 clinical samples revealed an inversely correlated relationship between levels of SOX2 and BMP4 mRNA, and significantly lower mRNA levels in tumor than in adjacent normal tissues. This was corroborated by immunohistochemistry analysis of 35 lung SQC samples showing lower BMP4 protein expression in tumor tissues. Cell-based experiments including siRNA transfection, growth assay and flow cytometry assay, further combined with a xenograft tumor model in mice, revealed that reactivation of BMP4 signaling could partially account for growth inhibition and cell cycle arrest in lung SQC cells upon silencing SOX2. Finally, chromatin immunoprecipitation analysis and luciferase reporter assay revealed that SOX2 could negatively regulate BMP4 promoter activity, possibly through binding to the promoter located in the first intron region of BMP4. Collectively, our findings suggest that BMP4 could act as a tumor suppressor and its downregulation by elevated SOX2 resulting in enhanced growth of lung SQC cells.


Assuntos
Proteína Morfogenética Óssea 4/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma de Células Escamosas/metabolismo , Neoplasias Pulmonares/metabolismo , Fatores de Transcrição SOXB1/metabolismo , Animais , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma de Células Escamosas/genética , Bases de Dados Genéticas , Regulação para Baixo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Humanos , Pulmão/metabolismo , Neoplasias Pulmonares/genética , Camundongos , Transplante de Neoplasias , Análise de Sequência com Séries de Oligonucleotídeos , Regiões Promotoras Genéticas , Transdução de Sinais
10.
J Natl Cancer Inst ; 98(12): 825-38, 2006 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-16788156

RESUMO

BACKGROUND: We previously identified DnaJ-like heat shock protein (HLJ1) as a gene associated with tumor invasion. Here, we investigated the clinical significance of HLJ1 expression in non-small-cell lung cancer (NSCLC) patients and its role in cancer progression. METHODS: We induced HLJ1 overexpression or knockdown in human lung adenocarcinoma CL1-5 cells and analyzed cell proliferation, anchorage-independent growth, in vivo tumorigenesis, cell motility, invasion, and cell cycle progression. Expression of genes that act downstream of HLJ1 was examined by DNA microarray analysis, pathway analysis, and western blotting. We measured HLJ1 expression in tumors and adjacent normal tissues of 71 NSCLC patients by quantitative reverse transcription-polymerase chain reaction. Associations between HLJ1 expression and disease-free and overall survival were determined using the log-rank test and multivariable Cox proportional hazards regression analysis. Validation was performed in an independent cohort of 56 NSCLC patients. Loss of heterozygosity (LOH) mapping of the HLJ1 locus was analyzed in 48 paired microdissected NSCLC tumors. All statistical tests were two-sided. RESULTS: HLJ1 expression inhibited lung cancer cell proliferation, anchorage-independent growth, tumorigenesis, cell motility, and invasion, and slowed cell cycle progression through a novel STAT1/P21(WAF1) pathway that is independent of P53 and interferon. HLJ1 expression was lower in tumors than in adjacent normal tissue in 55 of 71 patients studied. NSCLC patients with high HLJI expressing tumors had reduced cancer recurrence (hazard ratio [HR] = 0.47; 95% confidence interval [CI] = 0.23 to 0.93; P = .03) and longer overall survival (HR = 0.38; 95% CI = 0.16 to 0.89; P = .03) than those with low-expressing tumors. Validation in the independent patient cohort confirmed the association between HLJ1 expression and patient outcome. LOH mapping revealed high frequencies (66.7% and 70.8%) of allelic loss and microsatellite instability (87.5% and 95.2%) of the HLJ1 locus at chromosome 1p31.1. CONCLUSIONS: HLJ1 is a novel tumor suppressor in NSCLC, and high HLJ1 expression is associated with reduced cancer recurrence and prolonged survival of NSCLC patients.


Assuntos
Biomarcadores Tumorais/análise , Carcinoma Pulmonar de Células não Pequenas/química , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Proteínas de Choque Térmico HSP40/análise , Neoplasias Pulmonares/química , Neoplasias Pulmonares/mortalidade , Biomarcadores Tumorais/genética , Northern Blotting , Western Blotting , Ciclo Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Ciclina D1/análise , Inibidor de Quinase Dependente de Ciclina p21/análise , Progressão da Doença , Intervalo Livre de Doença , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica , Proteínas de Choque Térmico HSP40/genética , Humanos , Perda de Heterozigosidade , Repetições de Microssatélites , Recidiva Local de Neoplasia/epidemiologia , Razão de Chances , Análise de Sequência com Séries de Oligonucleotídeos , RNA Interferente Pequeno , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT1/análise , Análise de Sobrevida , Transfecção
11.
Extremophiles ; 8(5): 345-9, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15480864

RESUMO

A novel, cellulolytic, bacterial thermophilic strain, T4, was isolated from sugar refinery wastewater in southern Taiwan. This isolate, a Gram-negative, motile, aerobically growing sporulating rod, can secrete thermostable endocellulase (endo-1,4-beta-D-glucanase, EC 3.2.1.4) and hydrolyze carboxymethylcellulose (CMC), phosphoric acid-swollen cellulose, Avicel, filter paper, and salicin. When strain T4 was grown in CMC medium, the cellulolytic enzyme activity in culture supernatants was stable up to 70 degrees C. More than 10% of the original activity was still detectable after heating to 100 degrees C with a pH 7.0 for 1 h. Based on 16S rDNA sequence analysis, DNA base composition, phenotypic and physiological characteristics, as well as DNA-DNA hybridization, strain T4 was classified as Geobacillus thermoleovorans T4 (DSM 14791 = CCRC 17200). We also demonstrated that the type species G. stearothermophilus (DSM 22 = ATCC 12980) could hydrolyze amorphous and crystalline (filter paper) celluloses at a rate of 13 and 14%, respectively, in comparison with strain T4.


Assuntos
Bacillaceae/fisiologia , Bacillaceae/classificação , Álcoois Benzílicos/química , Carboximetilcelulose Sódica/química , Celulose/química , DNA/química , DNA Ribossômico/química , Glucosídeos , Temperatura Alta , Concentração de Íons de Hidrogênio , Hidrólise , Hibridização de Ácido Nucleico , Fenótipo , Filogenia , Análise de Sequência de DNA , Temperatura , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...