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1.
Allergol Immunopathol (Madr) ; 50(4): 137-142, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35789413

RESUMEN

OBJECTIVE: To investigate the potential correlation of transforming growth factor-ß (TGF-ß), matrix metalloprotein 9 (MMP-9), tissue inhibitor of metalloproteinases 1 (TIMP-1), Interleukin 1 (IL-1), IL-4, IL-6, IL-17, and tumor necrosis factor alpha (TNF-α) in refractory chronic rhinosinusitis. METHODS: A total of 150 participants were retrospectively included in this study from August 2018 to February 2020. The people enrolled were equally allocated into refractory group (patients with refractory chronic rhinosinusitis), chronic group (patients with chronic rhinosinusitis), and control group (normal people). The level of TGF-ß1, MMP-9, TIMP-1, IL-1, IL-4, IL-6, IL-17, and TNF-α were recorded. The unconditional multivariate binary logistic regression was used to analyze the factors affecting refractory chronic rhinosinusitis. RESULTS: The Davos score, T&T olfactometer threshold test, and Lund-Mackay CT scores in refractory group were significantly higher than the chronic group (P<0.05). The level of TGF-ß1, MMP-9, TIMP-1, IL-1, IL-4, IL-6, IL-17, and TNF-α in the refractory group were significantly higher than the chronic group and the control group (all P<0.05). Similarly, the level of the above mentioned indexes in the chronic group were significantly higher than the control group (P<0.05). The Davos score, T&T olfactometer threshold test score, Lund-Mackay CT score, and the level of TGF-ß1, MMP-9, TIMP-1, IL-1, IL-4, IL-6, IL-17, and TNF-α positively correlated with refractory chronic rhinosinusitis. Moreover, the unconditional multivariate binary logistic regression showed that the influencing factors of refractory chronic rhinosinusitis included TGF-ß1, MMP-9, TIMP-1, IL-1, IL-4, IL-6, IL-17, and TNF-α. CONCLUSION: The findings of the present study provide evidence for TGF-ß1, MMP-9, TIMP-1, IL-4, IL-6, IL-17, and TNF-α as the influencing factors of refractory chronic rhinosinusitis.


Asunto(s)
Metaloproteínas , Sinusitis , Humanos , Interleucina-1 , Interleucina-17 , Interleucina-4 , Interleucina-6 , Metaloproteinasa 1 de la Matriz , Metaloproteinasa 9 de la Matriz , Estudios Retrospectivos , Inhibidor Tisular de Metaloproteinasa-1 , Factor de Crecimiento Transformador beta1 , Factor de Necrosis Tumoral alfa
2.
Immunol Invest ; 49(6): 622-631, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31913054

RESUMEN

Objective This study aimed to investigate the role of zinc sulphate in immune regulation in Artemisia annua pollen-challenged P815 mastocytoma cells. Methods P815 mastocytoma cells were treated with various concentrations of zinc sulphate and Artemisia annua pollen. Cell proliferation was measured using the Cell Counting Kit-8. The amount of ST2 and p38 in the cells were measured using Western blotting. The level of interleukins (IL)-33 in the supernatant was determined using the enzyme-linked immunosorbent assay. The levels of IL-2, IL-4, IL-5, interferon-γ, and tumor necrosis factor were measured using the cytometric bead array. Results Artemisia annua pollen at a concentration >0.001 µg/mL induced allergic response in the P815 mastocytoma cells. Expressions of IL-33, IL-4, ST2, and p38 increased along with higher concentrations of Artemisia annua pollen. Zinc sulphate of 50-200 µmol/L promoted the proliferation of P815 mastocytoma cells. Zinc sulphate attenuated the upregulation of IL-33, IL-4, ST2, and p38 caused by Artemisia annua pollen. Conclusion Zinc sulphate can promote the proliferation of P815 mastocytoma cells. It can also attenuate allergic response in the P815 mastocytoma cells induced by Artemisia annua pollen, which might provide a new treatment method for allergic diseases.


Asunto(s)
Artemisia annua/efectos adversos , Inmunización , Inmunomodulación/efectos de los fármacos , Polen/inmunología , Sulfato de Zinc/farmacología , Biomarcadores , Línea Celular Tumoral , Citocinas/metabolismo , Humanos , Mastocitoma/inmunología , Mastocitoma/metabolismo
3.
J Trace Elem Med Biol ; 75: 127094, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36265320

RESUMEN

BACKGROUND: Allergic rhinitis (AR) is a chronic inflammatory disease of the nasal mucosa mediated by a variety of inflammatory mediators. Zinc (Zn) is one of the main essential trace elements in the human body and plays a variety of biological functions including the inhibition of inflammatory responses. This study aimed to investigate the effects and mechanism of Zn on the ovalbumin (OVA)-induced AR mouse model. METHOD: In this study, we established a model of AR by treating mice with OVA after feeding them with different doses of Zn. ELISA, real-time quantitative PCR, western blot and immunohistochemistry were used to detect the protein expression and mRNA transcription level of IgE, inflammatory cytokines and p38, respectively. RESULTS: The authors identified that immunoglobulin E concentrations were significantly higher in the Zn-deficient mice than in the Zn-normal group; Zn supplementation significantly reversed the increase in IgE concentrations caused by Zn deficiency. The increased concentrations of interleukin-6 and tumor necrosis factor-α in serum caused by Zn deficiency were reduced by Zn supplementation. The study further found that Zn deficiency could significantly increase the expression and activity of the p38 MAPK protein, while its levels were significantly decreased after Zn supplementation. The role of Zn supplement in the inflammatory response induced by Zn deficiency was verified by Zn-deficient mice with a p38 pathway inhibitor (SB203580), and it was observed that the elevated concentrations of IgE and inflammatory cytokines induced by Zn deficiency could be significantly reversed. CONCLUSION: Our data indicated that Zn exerted anti-allergic and anti-inflammatory effects by regulating the p38 MAPK activation in the AR mouse model. The findings provided evidence that Zn might be beneficial in regulating AR.


Asunto(s)
Rinitis Alérgica , Zinc , Proteínas Quinasas p38 Activadas por Mitógenos , Animales , Ratones , Rinitis Alérgica/tratamiento farmacológico , Factor de Necrosis Tumoral alfa , Zinc/farmacología
4.
Artículo en Zh | MEDLINE | ID: mdl-37828886

RESUMEN

Objective:For tympanosclerosis patients with ossicular chain fixation, we use ossicular chain bypass technique and evaluate its long-term effects. Methods:From June 2017 to June 2019, 147 patients with tympanosclerosis who underwent middle ear surgery with otoscopy in Yinchuan First People's Hospital were reviewed. The subjects were divided into three groups according to the implemented operation plan, 51 cases in the ossicular chain mobilization group(OCM), 56 cases in the ossicular chain bypass reconstruction group(OCB), and 40 cases in the malleus-incus complex resection reconstruction group(MICR). Through a three-year follow-up, the medium and long-term effects of different operation plans were compared and analyzed. Results:There was no significant difference among the three groups in the incidence of tympanic membrane perforation, delayed facial nerve palsy, and the dispatch and displacement of PORP. The incidence of tympanic membrane retraction pocket or cholesteatoma after operation in OCB group(0) was significantly lower than that in OCM group(11.76%) and MICR group(7.5%)(P<0.05). At 12 months after operation, ΔABG of OCB group and MICR group were better than that in the OCM group(P<0.05). At 36 months after operation, ΔABG of OCB group was better than that in the OCM group(P<0.05), and there was no significant difference between OCB group and MICR group. The audiological performance of patients with epitympanic sclerosis(ETS) at 12, 24 and 36 months after operation was better than that of patients with posterior tympanosclerosis(PTS) and total tympanosclerosis(TTS)(P<0.05). Conclusion:Compared with patients undergoing ossicular chain mobilization and malleus-incus complex resection for ossicular chain reconstruction, patients with tympanosclerosis undergoing bypass technique have better and stable hearing prognosis in medium and long term. This technique can effectively prevent the formation of retracted pocket and cholesteatoma in patients with tympanosclerosis after operation.


Asunto(s)
Colesteatoma , Prótesis Osicular , Timpanoesclerosis , Humanos , Osículos del Oído/cirugía , Oído Medio , Martillo/cirugía , Estudios Retrospectivos , Resultado del Tratamiento
5.
Artículo en Zh | MEDLINE | ID: mdl-37549949

RESUMEN

Objective:To investigate the distribution of allergens in patients with allergic rhinitis (AR) in Ningxia, and provide theoretical data for the prevention and treatment of AR in this region. Methods:A total of 1664 patients diagnosed with AR in the Otorhinolaryngology Head and Neck Surgery Department of Yinchuan First People's Hospital Outpatient Clinic from January 2018 to December 2021 were retrospectively collected. Use the allergen sIgE antibody detection kit (immunoblotting method) to detect inhalation and ingestion allergens in patients.Results: ①Among all AR patients, 1 158 cases were detected positive, resulting in the detection rate was 69.59%; ②The detection rate of inhalation allergen was 65.87%, and the detection rate of ingestion allergen was 19.83%; ③Mugwort was the most sensitive allergen, and 76.32% of the patients having a positive grade ≥3; ④Out of the patients, 294 cases (25.39%) were allergic to only one allergen, 244 cases (21.07%) were allergic to two allergens, and 620 cases (53.54%) were allergic to three or more allergens; ⑤During different seasons, the highest number of positive allergens detected was in the summer, with 968 cases (83.59%). Mugwort was the main allergen during this season (69.01%). After the COVID-19 epidemic, the total positive rate of sIgE tests in AR patients decreased compared to before, and the difference was statistically significant (P<0.001); ⑥Mugwort, dog epithelium, mold combination, egg, peanut, soybean, Marine fish combination and fruit combination all showed statistically significant differences between different gender groups (P<0.05); ⑦Common ragweed, mugwort, dust mite combination, cockroach, egg, milk, Marine fish combination, shrimp, fruit combination and nut combination all showed statistically significant differences among different age groups (P<0.05); ⑧There were statistically significant differences in hay dust among different ethnic groups (P<0.05). Conclusion:Artemisia argyi is the main allergen in Ningxia, and the distribution characteristics of different allergens are influenced by treatment season, the COVID-19 epidemic, gender, age, ethnicity, and other factors, showing certain distribution patterns and rules.


Asunto(s)
Artemisia , COVID-19 , Rinitis Alérgica , Alérgenos , Estudios Retrospectivos , Pruebas Cutáneas , Humanos , Masculino , Femenino
6.
J Healthc Eng ; 2022: 3718317, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35035826

RESUMEN

OBJECTIVE: We aimed to investigate the expression of serum zinc and cytokines interleukin- (IL-) 13 and IL-33 in patients with allergic rhinitis (AR) and observe the effects of zinc on cytokines and pathway proteins in P815 mast cells stimulated by Artemisia annua allergen (Art.) in the IL-33/suppression of the tumorigenicity 2 (ST2) pathway. We also aimed to explore the possible regulatory role of zinc in AR and provide new ideas to determine the etiology and treatment of AR. METHODS: AR patients treated from March to September in 2018 were selected as the research participants, and 50 healthy people in the same period were selected as the control group. Serum samples of all patients were collected, and those of AR patients were tested for the presence of allergens. The expression of IL-13 and IL-33 was detected by performing an enzyme-linked immunosorbent assay, while the serum zinc level was detected by conducting an inductively coupled plasma mass spectrometry. The cell counting kit (CCK-8) was used to detect the proliferation of P815 mast cells, and western blot was used to detect the expression of ST2, p38, and p65 proteins. RESULTS: A total of 92 AR patients were included in the study; of them, 52 had mild AR, while 40 had moderate AR. The primary allergen found in AR patients was Artemisia, and the positivity rate was 53.26%. The serum zinc ion level of AR patients decreased, and the expression of IL-13 and IL-33 increased. After Art. was used to treat P815 mast cells, the expression of IL-33 in the cell supernatant increased in a concentration-dependent manner, the expression of receptor ST2 increased, and the expression of downstream p38 and p65 proteins increased. However, after treatment with ZnSO4, the expression of IL-33 in the cell supernatant decreased, and the expression of ST2, p38, and p65 protein decreased. CONCLUSION: The serum zinc level of AR patients decreased. In the IL-33/ST2 pathway, ZnSO4 can reduce the hypersensitivity of mast cells induced by Art.


Asunto(s)
Interleucina-33 , Rinitis Alérgica , Alérgenos , Citocinas/metabolismo , Humanos , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Interleucina-13 , Interleucina-33/metabolismo , Rinitis Alérgica/metabolismo , Zinc
7.
Contrast Media Mol Imaging ; 2022: 8990629, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36043146

RESUMEN

Allergic rhinitis is one of the common chronic inflammatory diseases of the nasal mucosa. In order to investigate the effect of zinc on ovalbumin induced allergic rhinitis in BALB/C male mice based on NF-KB signaling pathway, thirty BALB/C male mice are randomly divided into three groups: control group, ovalbumin induced allergic rhinitis asthma group and zinc intervention group. The experimental results show that Zinc supplementation in allergic asthma mice with allergic rhinitis correct the immune response of TH2 cells by inhibiting THE NF-KB signaling pathway, reduce the infiltration of inflammatory cells into lung nasal tissue, and reduce airway co-hyperreactivity to improve the clinical symptoms of asthma and play an immune protective role.


Asunto(s)
Asma , Rinitis Alérgica , Animales , Asma/inducido químicamente , Asma/tratamiento farmacológico , Citocinas/metabolismo , Modelos Animales de Enfermedad , Masculino , Ratones , Ratones Endogámicos BALB C , FN-kappa B/metabolismo , Ovalbúmina , Rinitis Alérgica/metabolismo , Transducción de Señal , Zinc
8.
Ear Nose Throat J ; : 1455613221112355, 2022 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-35786023

RESUMEN

OBJECTIVE: The current study was conducted to explore the association between laryngopharyngeal reflux disease (LPRD) and refractory chronic rhinosinusitis (RCRS), and to reveal the potential role of LPRD in the development of RCRS. METHODS: A total of 104 patients diagnosed as chronic rhinosinusitis (CRS) and hospitalized, as well as 50 healthy participants were enrolled into this study. Among patients enrolled, 53 were RCRS and 51 were CRS. All participants were assessed with reflux symptom index (RSI) and reflux finding score (RFS). Patients with RSI >13 and/or RFS >7 were diagnosed as LPRD. In addition, pepsin in the nasal secretions from the middle meatus tract complex at fasting in the morning was analyzed using ELISA. Patients with pepsin concentration of >75 ng/ml was considered as positive, and confirmed as LPRD. RESULTS: There was no significant difference in age, sex, height, and weight among RCRS, CRS, and control groups. The positive rates of RSI and RFS scores were 39.6% in the RCRS and 52.9% in the CRS, respectively, which were significantly higher than that of the control group (14.0%, P < 0.05), respectively. Significantly higher positive rate of pepsin assay was also observed for RCRS(43.4%) and CRS(64.7%) when compared with the control group (18.0%, P < 0.05). The positive rate of pepsin assay was strongly associated with the positive rate of RSI or RFS (P < 0.001). CONCLUSION: The present findings have important implications that RSI and RFS score was highly associated with pepsin assay result in the patients with RCRS or CRS. We confirmed the importance of RSI and RFS scoring system as well as pepsin test, which may offer insight for clinical screening for LPRD among CRS patients.

9.
Sci Total Environ ; 764: 144508, 2021 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-33387767

RESUMEN

Rice cultivation is the primary source of anthropogenic methane (CH4), which dramatically impacts global climate change. A growing body of evidence shows that optimizing photosynthate distribution is important for increasing rice yields and mitigating CH4 emissions. Therefore, the molecular rice breeding with a barley HvSUSIBA2 gene that confers elevated photosynthate flux to grains, is predicted to enhance rice yield and mitigate CH4 emissions in paddies. Here, in a series of field experiments with differences in growing season and rice variety, we show that SUSIBA2 rice reduced CH4 emissions from paddies. SUSIBA2 rice grown in the early rice season and late rice season showed similar mitigation effects, with reduction rates of 50.98% for early rice and 50.97% for late rice. The reduction rate of SUSIBA2 rice during the winter rice season was significantly lower (22.26%) than those of other rice seasons. The reduction rates also varied between rice varieties, and SUSIBA2 japonica rice showed a more significant CH4 mitigation effect than SUSIBA2 indica rice. Further yield-scaled CH4 emission analyses indicated that the SUSIBA2 effect did not mitigate CH4 emissions at the expense of yield. Compared with the wild type, SUSIBA2 rice significantly reduced soil organic carbon properties and the abundance of CH4-related microbes, and altered methanogenic and methanotrophic communities, indicating that SUSIBA2 rice released less carbon to the soil, which reduced CH4 production. Furthermore, a comparison of microbial communities between SUSIBA2 japonica and indica rice revealed different responses of methanogenic and methanotrophic communities, which may partly explain their differences in growth performance and CH4 mitigation effect. Thus, our results show that SUSIBA2 rice substantially reduces CH4 emissions and that SUSIBA2 can potentially mitigate the CH4 emissions of japonica and indica rice under distinct cultivation conditions.


Asunto(s)
Microbiota , Oryza , Agricultura , Carbono , Metano , Óxido Nitroso , Suelo
11.
Appl Biochem Biotechnol ; 133(3): 251-62, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16720905

RESUMEN

The hydrolysis process on corncob residue was catalyzed synergetically by the cellulase from Trichoderma reesei and the immobilized cellobiase. The feedback inhibition to cellulase reaction caused by the accumulation of cellobiose was eliminated efficiently. The hydrolysis yield of corncob residue was 82.5%, and the percentage of glucose in the reducing sugar reached 88.2%. The glucose in the cellulosic hydrolysate could be converted into lactic acid effectively by the immobilized cells of Lactobacillus delbrueckii. When the enzymatic hydrolysis of cellulose and the fermentation of lactic acid were coupled together, no glucose was accumulated in the reaction system, and the feedback inhibition caused by glucose was also eliminated. Under the batch process of synergetic hydrolysis and lactic acid fermentation with 100 g/L of cellulosic substrate, the conversion efficiency of lactic acid from cellulose and the productivity of lactic acid reached 92.4% and 0.938 g/ (L.h), respectively. By using a fed-batch technique, the total concentration of cellulosic substrate and lactic acid in the synergetic process increased to 200 and 107.5 g/L, respectively, whereas the dosage of cellulase reduced from 20 to 15 IU/g of substrate in the batch process. The results of the bioconversion of renewable cellulosic resources were significant.


Asunto(s)
Biotecnología/métodos , Celulosa/metabolismo , Fermentación , Ácido Láctico/biosíntesis , Trichoderma/enzimología , Reactores Biológicos , Células Inmovilizadas , Celulasa/metabolismo , Glucosa/química , Glucosa/metabolismo , Hidrólisis , Lactobacillus delbrueckii/citología , Lactobacillus delbrueckii/metabolismo , Factores de Tiempo
12.
Artículo en Zh | MEDLINE | ID: mdl-26685395

RESUMEN

OBJECTIVE: To investigate the epidemic features of childhood allergic rhinitis (AR) and correlative risk factors in Yinchuan. METHOD: A questionnaire survey on AR was conducted among 800 children in eight communities, aged from 5 to 14 years old, by random cluster sampling, from March 2012 to March 2013 in Yinchuan. Suspects of AR, as identified by the survey, were recommended to specialist examinations for accurate diagnosis. The results were statistically analyzed. RESULT: Seven hundred and sixteen questionnaires were returned and 662 questionnaires were available. The prevalence rate of AR in children aged from 5 to 14 is 14.65% in Yinchuan. Seventy-nine point thirty-eight percent children suffered from intermittent AR, while 20.61% children suffered from persistent AR. The difference of prevalence between female (13.57%) and male (15.44%) was insignificant statistically (Χ2=0.454, P>0.05). The difference of prevalence between the Han (15.72%) and the Hui (11.35%) insignificant statistically (Χ2=2.055, P>0.05). The prevalence of AR children aged five to nine years was 13.80%, as aged ten to fourteen years was 19.72%. There was a significante differece between two groups (Χ2=4.056, P<0.05). The most explosive outbreak month in children with allergic rhinitis was July to September. The most common allergens found in patients were seasonal plants: mugwort, weed, dandelion, cereal, locust, ragweed, and willow. Fifteen point forty-six percent patients with AR also had rhinitic, 14.43% patients had asthma and 14.43% patients had allergic conjunctivitis. The history of drug allergy accounted for 12.37% in patients with AR, and food allergy accounted for 26.80%. In allergic rhinitis risk factors, family history accounted for 30.92%, non-breastfeeding representing accounted for 34.02%, animal feeding history accounted for 19.59%; exposure to passive smoking accounted for 42.26%; domestic decoration accounted for 12.37%. There were significante difference between AR children and normal in family history and non-breastfeeding (P<0.05). CONCLUSION: The prevalence rate of AR in children aged from 5 to 14 in Yinchuan is 14.45%. Strategy of prevention and treatment of AR should be worked out according to the epidemic feature of AR.


Asunto(s)
Rinitis Alérgica/epidemiología , Adolescente , Alérgenos , Animales , Asma/epidemiología , Niño , Preescolar , Conjuntivitis Alérgica/epidemiología , Femenino , Humanos , Masculino , Polen , Prevalencia , Factores de Riesgo , Encuestas y Cuestionarios
13.
Materials (Basel) ; 7(1): 576-590, 2014 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-28788476

RESUMEN

Based on the experimental results and the finite element analysis, a constitutive model is proposed for two phase shape memory alloys by introducing a compensative volumetric strain into a constrained relationship between the two phases, accounting for the reduced constraint due to the growth of martensite band. The pseudoelasticity of NiTi shape memory alloy micro-tube, subjected to pure tension, is analyzed and compared with the experimental results. It can be seen that the pseudoelastic behavior, especially the phenomena of a stress drop during tension processes, can be well described with the proposed model. The proposed model separates the complicated constitutive behavior of a shape memory alloy (SMA) into simple responses arising respectively from its two phases, taking into account laminar microstructure, the thickness of martensite phase and the interaction between the two phases, and provides an easy but comprehensive method for the description of the constitutive behavior of SMAs under complex thermomechanical loading.

14.
Sheng Wu Gong Cheng Xue Bao ; 19(2): 236-9, 2003 Mar.
Artículo en Zh | MEDLINE | ID: mdl-15966329

RESUMEN

Cellulosic material is the most abundant renewable carbon source in the world. Cellulose may be hydrolyzed using cellulase to produce glucose, which can be used for production of ethanol, organic acids, and other chemicals. Cellulase is a complex enzyme containing endoglucanase (EC 3.2.1.4), exoglucanase (EC 3.2.1.91) and cellobiase (EC 3.2.1.21). The hydrolysis of natural cellulose to glucose depends on the synergism of these three components. The mostly used cellulase produced by Trichoderma reesei has high activity of endoglucanase and exoglucanase, but the activity of cellobiase is relatively low. Therefore, improving the activity of cellobiase in cellulase reaction system is the key to enhance the sacchrification yield of cellulosic resources. Aspergillus niger LORRE 012 was a high productivity strain for cellobiase production. It was found that the spores of this strain were rich in cellobiase. In this work, the cellobiase was immobilized efficiently by simply entrapping the spores into calcium alginate gels instead of immobilizing the pure cellobiase proteins. The immobilized cellobiase was quite stable, and its half-life was 38 days under pH 4.8, 50 degrees C. The thermal stability of the immobilized cellobiase was improved, and it was stable below 70 degrees C. The suitable pH range of the immobilized cellobiase was pH 3.0 - 5.0, with the optimal pH value 4.8. The Km and Vmax value of the immobilized cellobiase were 6.01 mmol/L and 7.06 mmol/min x L, respectively. In repeated batch hydrolysis processes, 50 mL of substrate (10 g/L cellobiose) and 10 mL of immobilized beads containing cellobiase were added into a 150 ml flask. After reacting at pH 4.8, 50 degrees C for several hours, the hydrolysate was harvested for assay, and the immobilized beads were used for the next batch hydrolysis with the fresh substrate. This process was repeated, and the yield of enzymatic hydrolysis kept higher than 97% during 10 batches. The continuous hydrolysis process was carried out in a column reactor (inside diameter 2.8 cm, inside height 40 cm) packed with the immobilized beads. Using 10 g/L cellobiose as substrate, the hydrolysis yield reached 98% under 0.4 h (-1) dilution rate and pH 4.8, 50 degrees C. After corncob was treated by 1% dilute acid, the cellulosic residue (100 g/L) was used as substrate, and hydrolyzed by the cellulase (15 IFPU/g substrate) from Trichoderma reesei, at pH 4.8, 50 degrees C for 48 h. The concentration of reducing sugar in the hydrolysate was only 48.50 g/L (hydrolysis yield 69.5%). When the hydrolysate was further treated by the immobilized cellobiase, the cellobiose was hydrolyzed into glucose, and the feedback inhibition caused by the cellobiose accumulation disappeared sharply. By the synergism of immobilized cellobiase and the cellulase from T. reesei left in the hydrolysate, other oligosaccharides were mostly converted to monosaccharides. At 48 h, the reducing sugar concentration was increased to 58.78 g/L, the hydrolysis yield of the corncob residue was improved to 84.2%, and the ratio of the glucose in the total reducing sugar was increased from 53.6% to 89.5%. The reducing sugars converted from corncob could be used further in the fermentation of valuable industrial products. This research results were meaningful in the conversion and utilization of renewable biomass.


Asunto(s)
beta-Glucosidasa/química , beta-Glucosidasa/metabolismo , Aspergillus niger/enzimología , Biotecnología , Celobiosa/metabolismo , Estabilidad de Enzimas , Concentración de Iones de Hidrógeno , Cinética , Temperatura
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