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Simplified method to obtain enhanced expression of tau protein from E. coli and one-step purification by direct boiling 从大肠杆菌中获得增强表达的tau蛋白的简化方法及直接煮沸一步纯化
Pub Date : 2017-02-01 DOI: 10.1080/10826068.2016.1275012
V. Krishnakumar, S. Gupta
ABSTRACT Tau is an intrinsically disordered protein responsible for maintaining the structure and stability of axonal microtubules. However, in certain disease conditions including Alzheimer’s disease, tau protein may undergo biochemical and structural changes to form intracellular aggregates. Since tau is a proline- and arginine-rich eukaryotic protein, heterologous expression in Escherichia coli often results in poor yield and has been a major technical challenge. In the current work, we have improved the expressed yield of tau by overcoming codon bias problem and established a simplified protocol for efficient extraction. The reported method has two distinct features: (i) enhanced tau expression (upto eightfold) by supplementing deficient tRNAs that aid in rapid translation and (ii) direct boiling of expressed E. coli cells to extract tau with no separate cell lysis step. We further demonstrate that tau extracted by the direct boiling method is similar to tau purified by size-exclusion chromatography exhibiting similar structural and biophysical characteristics including aggregation propensity. Since morphologies and in vitro toxicity of fibrillar tau aggregates were also similar, tau extracted by the one-step direct boiling method can be used for tau aggregation assays without any additional purification.
Tau蛋白是一种内在无序蛋白,负责维持轴突微管的结构和稳定性。然而,在包括阿尔茨海默病在内的某些疾病条件下,tau蛋白可能经历生化和结构变化以形成细胞内聚集体。由于tau是一种富含脯氨酸和精氨酸的真核蛋白,因此在大肠杆菌中外源表达往往导致产量低,并且一直是主要的技术挑战。在目前的工作中,我们通过克服密码子偏倚问题提高了tau蛋白的表达量,并建立了一种简化的高效提取方案。报道的方法有两个明显的特点:(i)通过补充有助于快速翻译的缺陷trna来增强tau表达(高达8倍);(ii)直接煮沸表达的大肠杆菌细胞以提取tau,而不需要单独的细胞裂解步骤。我们进一步证明,直接煮沸法提取的tau蛋白与尺寸排除色谱法纯化的tau蛋白相似,具有相似的结构和生物物理特征,包括聚集倾向。由于纤维状tau聚集体的形态和体外毒性也相似,因此一步直接煮沸法提取的tau可以用于tau聚集分析,而无需任何额外的纯化。
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引用次数: 18
Optimizations of particle size and pulp density for solubilization of rock phosphate by a microbial consortium from activated sludge 微生物群对活性污泥中磷矿增溶的粒径和浆密度优化
Pub Date : 2017-02-01 DOI: 10.1080/10826068.2016.1275008
C. Xiao, Xiaoyan Wu, Tingting Liu, Guang Xu, R. Chi
ABSTRACT Microbial solubilization of rock phosphate is getting more and more attention recently. However, the microorganisms used in previous studies were mostly single or known species, and seldom studies focused on the mixed microorganisms or microbial consortia from natural environments. In this study, a microbial consortium taken from activated sludge was used to solubilize two different mid-low-grade rock phosphates. The results showed that the microbial consortium could effectively solubilize the rock phosphates in National Botanical Research Institute’s phosphate growth medium and released soluble phosphorus in the broth. The biomass increased gradually, whereas the pH decreased sharply during the solubilizing process. The maximum phosphorus solubilization was recorded at particle size of 150 µm. Higher or lower than this optimal particle size, the phosphorus solubilization decreased. The phosphorus solubilization gradually decreased with a larger pulp density from 1 to 5%, and the optimal pulp density was 1%. The solubilization level of microbial consortium varied with different rock phosphates. The results revealed that the soluble phosphorus released from high-silicon ore was higher than which from high-magnesium ore. A strong positive correlation between biomass and phosphorus solubilization in the broth was observed from regression analysis results, and the phosphorus solubilization also had a significant negative correlation with pH in the broth.
微生物对磷酸盐岩的增溶作用近年来受到越来越多的关注。然而,以往研究中使用的微生物大多是单一或已知的物种,很少有研究关注自然环境中的混合微生物或微生物群落。在这项研究中,从活性污泥中提取的微生物联合体被用来溶解两种不同的中低品位的岩石磷酸盐。结果表明,该菌群能有效地溶解国家植物研究所磷酸盐生长培养基中的岩石磷酸盐,并释放出肉汤中的可溶性磷。在增溶过程中,生物量逐渐增加,pH急剧下降。粒径为150µm时,磷的增溶量最大。高于或低于该最佳粒径,磷的增溶作用都会减小。在1 ~ 5%的矿浆密度范围内,磷的增溶作用随着矿浆密度的增大而逐渐降低,最佳矿浆密度为1%。微生物联合体的增溶水平因不同的岩石磷酸盐而异。结果表明,高硅矿石的可溶性磷释放量高于高镁矿石。回归分析结果表明,生物量与肉汤中磷的增溶率呈显著正相关,而磷的增溶率与肉汤pH呈显著负相关。
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引用次数: 4
Production of a protease inhibitor from edible mushroom Agaricus bisporus and its statistical optimization by response surface methodology 食用菌双孢蘑菇蛋白酶抑制剂的制备及其响应面法统计优化
Pub Date : 2017-01-31 DOI: 10.1080/10826068.2017.1286851
Reena Vishvakarma, A. Mishra
ABSTRACT The production of a protease inhibitor from Agaricus bisporus through solid-state fermentation was studied. The purpose was to produce protease inhibitor from natural, cheap, and readily available carbon and nitrogen sources. Solid-state fermentation enhanced the mycelia growth and also gave a higher yield of the product. Further, fungal growth and other production parameters were statistically optimized. The specificity of the inhibitor was tested and was effective against trypsin. Screening of significant factors (wheat bran, cyanobacterial biomass, initial pH, temperature, incubation period, and moisture content and inoculum size) was performed using Plackett–Burman design. Central composite design was used to determine the optimized values of the significant variables which were found to be temperature (27.5°C), incubation time (156 hr), cyanobacterial biomass (1 g), and moisture content (50%) and gave a statistical yield of 980 PIU/g which was 25.6% higher than experimental yield (780 PIU/g). The inhibitor was purified by ammonium sulfate precipitation and diethylaminoethyl (DEAE) cellulose chromatography (yield 43.89% and 0.21%, respectively) and subjected to reversed-phase HPLC to validate its identity. Since protease inhibitors act against proteases, finding ample therapeutic roles; the isolated protease inhibitor from A. bisporus can also be a probable medicinal agent after its further characterization.
摘要研究了双孢蘑菇固态发酵生产蛋白酶抑制剂的工艺条件。目的是从天然的、廉价的、容易获得的碳和氮源中生产蛋白酶抑制剂。固态发酵促进了菌丝的生长,提高了产品的产量。进一步对真菌生长及其他生产参数进行统计优化。对该抑制剂的特异性进行了测试,结果表明该抑制剂对胰蛋白酶有效。采用Plackett-Burman设计筛选重要因素(麦麸、蓝藻生物量、初始pH、温度、潜伏期、水分含量和接种量)。采用中心组合设计确定温度(27.5℃)、孵育时间(156 hr)、蓝藻生物量(1 g)和水分含量(50%)为显著变量的最优值,统计产率为980 PIU/g,比实验产率(780 PIU/g)提高25.6%。采用硫酸铵沉淀法和DEAE纤维素层析法纯化该抑制剂(得率分别为43.89%和0.21%),并进行反相高效液相色谱验证。由于蛋白酶抑制剂对蛋白酶起作用,发现充足的治疗作用;从双孢酵母中分离得到的蛋白酶抑制剂在进一步鉴定后也可能是一种药物。
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引用次数: 3
Endoglucanase and xylanase production by Bacillus sp. AR03 in co-culture 芽孢杆菌AR03共培养产内切葡聚糖酶和木聚糖酶
Pub Date : 2017-01-20 DOI: 10.1080/10826068.2017.1280826
J. Hero, J. Pisa, N. Perotti, C. Romero, M. A. Martínez
ABSTRACT The behavior of three isolates retrieved from different cellulolytic consortia, Bacillus sp. AR03, Paenibacillus sp. AR247 and Achromobacter sp. AR476-2, were examined individually and as co-cultures in order to evaluate their ability to produce extracellular cellulases and xylanases. Utilizing a peptone-based medium supplemented with carboxymethyl cellulose (CMC), an increase estimation of 1.30 and 1.50 times was obtained by the co-culture containing the strains AR03 and AR247, with respect to enzyme titles registered by their individual cultivation. On the contrary, the extracellular enzymatic production decreased during the co-cultivation of strain AR03 with the non-cellulolytic Achromobacter sp. AR476-2. The synergistic behavior observed through the combined cultivation of the strains AR03 and AR247 might be a consequence of the consumption by Paenibacillus sp. AR247 of the products of the CMC hydrolysis (i.e., cellobiose and/or cello-oligosaccharides), which were mostly generated by the cellulase producer Bacillus sp. AR03. The effect observed could be driven by the requirement to fulfill the nutritional supply from both strains on the substrate evaluated. These results would contribute to a better description of the degradation of the cellulose fraction of the plant cell walls in nature, expected to an efficient utilization of renewable sources.
摘要从不同的纤维素水解菌群中分离出3株芽孢杆菌AR03、Paenibacillus sp. AR247和Achromobacter sp. AR476-2,并对其单独和共培养的产胞外纤维素酶和木聚糖酶的能力进行了研究。在以蛋白胨为基础的培养基中添加羧甲基纤维素(CMC),与菌株AR03和AR247共培养,其单独培养的酶标增加了1.30和1.50倍。相反,AR03与非纤维素降解无色杆菌AR476-2共培养时胞外酶产量下降。通过AR03和AR247菌株的联合培养观察到的协同行为可能是Paenibacillus sp. AR247消耗CMC水解产物(即纤维素糖和/或纤维素寡糖)的结果,这些产物主要由纤维素酶产生者芽孢杆菌sp. AR03产生。观察到的效果可能是由于需要满足所评估的底物上两种菌株的营养供应。这些结果将有助于更好地描述自然界中植物细胞壁纤维素部分的降解,有望有效利用可再生资源。
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引用次数: 14
An experimental strategy validated to design cost-effective culture media based on response surface methodology 一种基于响应面法设计高性价比培养基的实验策略得到了验证
Pub Date : 2017-01-19 DOI: 10.1080/10826068.2017.1280825
J. L. Navarrete-Bolaños, M. G. Téllez-Martínez, R. Miranda-López, H. Jiménez-Islas
ABSTRACT For any fermentation process, the production cost depends on several factors, such as the genetics of the microorganism, the process condition, and the culture medium composition. In this work, a guideline for the design of cost-efficient culture media using a sequential approach based on response surface methodology is described. The procedure was applied to analyze and optimize a culture medium of registered trademark and a base culture medium obtained as a result of the screening analysis from different culture media used to grow the same strain according to the literature. During the experiments, the procedure quantitatively identified an appropriate array of micronutrients to obtain a significant yield and find a minimum number of culture medium ingredients without limiting the process efficiency. The resultant culture medium showed an efficiency that compares favorably with the registered trademark medium at a 95% lower cost as well as reduced the number of ingredients in the base culture medium by 60% without limiting the process efficiency. These results demonstrated that, aside from satisfying the qualitative requirements, an optimum quantity of each constituent is needed to obtain a cost-effective culture medium. Study process variables for optimized culture medium and scaling-up production for the optimal values are desirable.
对于任何发酵工艺,生产成本取决于几个因素,如微生物的遗传、工艺条件和培养基组成。在这项工作中,描述了使用基于响应面方法的顺序方法设计具有成本效益的培养基的指导方针。根据文献对同一菌种不同培养基筛选分析得到的注册商标培养基和基础培养基进行了分析和优化。在实验过程中,该程序定量地确定了适当的微量营养素阵列,以获得显著的产量,并在不限制工艺效率的情况下找到最少数量的培养基成分。所得培养基的效率比注册商标培养基低95%,并且在不限制工艺效率的情况下,将基础培养基中的成分数量减少了60%。这些结果表明,除了满足质量要求外,每种成分的最佳数量需要获得具有成本效益的培养基。研究最佳培养基的工艺变量,并扩大生产以获得最佳值。
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引用次数: 11
High-level expression of a biologically active staphylokinase in Pichia pastoris 一种生物活性葡萄激酶在毕赤酵母中的高水平表达
Pub Date : 2017-01-19 DOI: 10.1080/10826068.2016.1252924
H. Faraji, M. Ramezani, H. Sadeghnia, K. Abnous, F. Soltani, B. Mashkani
ABSTRACT Staphylokinase (SAK) as the third generation thrombolytic molecule is a promising agent for the treatment of thrombosis. SAK variant of SAKфC was expressed in Pichia pastoris strains KM71H and GS115. The codon adaptation index of SAK was improved from 0.75 to 0.89. The expression of recombinant SAK (rSAK) reached to its maximum (310 mg/L of the culture medium) after 48-hr stimulation with 3% methanol and remained steady until day 5. The maximum activity of the enzyme was at pH 8.6 and 37°C. It was highly active at temperatures 20–37°C and pH ranges of 6.8–9 (relative residual activity more than 80%). It was determined that rSAK was 73.8% of the total proteins secreted by P. pastoris KM71H into the culture media. The specific activities of rSAK were measured as 9,002 and 21,042 U/mg for the nonpurified and purified proteins, respectively. The quantity of the purified protein (>99% purity) was 720 µg/mL with a purification factor of 2.34. Western blot analysis showed two bands of nearly 22 and 18.6 kDa. It was concluded that P. pastoris is a proper host for expression of biologically active and endotoxin-free rSAK due to its high expression and low protein impurity in culture supernatant.
葡萄激酶(Staphylokinase, SAK)作为第三代溶栓分子,是治疗血栓形成的一种很有前景的药物。SAKфC的SAK变体在毕赤酵母菌株KM71H和GS115中表达。SAK的密码子适应指数由0.75提高到0.89。重组SAK (rSAK)的表达量在3%甲醇刺激48小时后达到最大值(310 mg/L培养基),并保持稳定至第5天。该酶在pH 8.6、37℃条件下活性最高。在温度20 ~ 37℃,pH值6.8 ~ 9范围内具有较高的活性(相对残留活性大于80%)。结果表明,ppastoris KM71H向培养基中分泌的rSAK蛋白占总蛋白的73.8%。纯化蛋白和非纯化蛋白的rSAK比活性分别为9002 U/mg和21042 U/mg。纯化蛋白的纯度为720µg/mL,纯化系数为2.34,纯度大于99%。Western blot分析显示两个条带接近22和18.6 kDa。结果表明,酵母培养上清液中具有较高的表达量和较低的蛋白杂质,是表达具有生物活性且无内毒素的rSAK蛋白的适宜宿主。
{"title":"High-level expression of a biologically active staphylokinase in Pichia pastoris","authors":"H. Faraji, M. Ramezani, H. Sadeghnia, K. Abnous, F. Soltani, B. Mashkani","doi":"10.1080/10826068.2016.1252924","DOIUrl":"https://doi.org/10.1080/10826068.2016.1252924","url":null,"abstract":"ABSTRACT Staphylokinase (SAK) as the third generation thrombolytic molecule is a promising agent for the treatment of thrombosis. SAK variant of SAKфC was expressed in Pichia pastoris strains KM71H and GS115. The codon adaptation index of SAK was improved from 0.75 to 0.89. The expression of recombinant SAK (rSAK) reached to its maximum (310 mg/L of the culture medium) after 48-hr stimulation with 3% methanol and remained steady until day 5. The maximum activity of the enzyme was at pH 8.6 and 37°C. It was highly active at temperatures 20–37°C and pH ranges of 6.8–9 (relative residual activity more than 80%). It was determined that rSAK was 73.8% of the total proteins secreted by P. pastoris KM71H into the culture media. The specific activities of rSAK were measured as 9,002 and 21,042 U/mg for the nonpurified and purified proteins, respectively. The quantity of the purified protein (>99% purity) was 720 µg/mL with a purification factor of 2.34. Western blot analysis showed two bands of nearly 22 and 18.6 kDa. It was concluded that P. pastoris is a proper host for expression of biologically active and endotoxin-free rSAK due to its high expression and low protein impurity in culture supernatant.","PeriodicalId":20393,"journal":{"name":"Preparative Biochemistry and Biotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74529145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 11
Lipid production by yeasts grown on crude glycerol from biodiesel industry 以生物柴油工业生产的粗甘油为原料的酵母产脂
Pub Date : 2017-01-12 DOI: 10.1080/10826068.2016.1244689
K. T. Souza, C. L. Ramos, R. Schwan, D. R. Dias
ABSTRACT The main carbon source used for growth by four yeast strains (Yarrowia lipolytica CCMA 0357, Y. lipolytica CCMA 0242, Wickerhamomyces anomalus CCMA 0358, and Cryptococcus humicola CCMA 0346) and their lipid production were evaluated, using different concentrations of crude and pure glycerol and glucose. Whereas crude glycerol (100 g/L) was the main carbon source used by Y. lipolytica CCMA 0357 (nearly 15 g/L consumed at 120 hr) and W. anomalus CCMA 0358 (nearly 45.10 g/L consumed at 48 hr), pure glycerol (150 g/L) was the main one used by C. humicola CCMA 0346 (nearly 130 g/L consumed). On the other hand, Y. lipolytica CCMA 0242 used glucose (100 g/L) as its main source of carbon (nearly 96.48 g/L consumed). Y. lipolytica CCMA 0357 demonstrated the highest lipid production [about 70% (wt/wt)], forming palmitic (45.73% of fatty acid composition), stearic (16.43%), palmitoleic (13.29%), linolenic (10.77%), heptadecanoic (4.07%), and linoleic (14.14%) acids. Linoleic acid, an essential fatty acid, was produced by all four yeast strains but in varying degrees, representing 70.42% of the fatty acid profile of lipids produced by C. humicola CCMA 0346.
摘要采用不同浓度的粗甘油和纯甘油和葡萄糖,研究了4株酵母菌(多脂耶氏酵母CCMA 0357、多脂耶氏酵母CCMA 0242、异常Wickerhamomyces anomalus CCMA 0358和隐球菌humicola CCMA 0346)的主要碳源及其产脂量。粗甘油(100 g/L)是聚脂Y. lipolytica CCMA 0357 (120 h消耗近15 g/L)和W. anomalus CCMA 0358 (48 h消耗近45.10 g/L)的主要碳源,而纯甘油(150 g/L)是humicola CCMA 0346的主要碳源(消耗近130 g/L)。另一方面,Y. lipolytica CCMA 0242以葡萄糖(100 g/L)为主要碳源(消耗近96.48 g/L)。Y. lipolytica CCMA 0357显示出最高的脂质产量[约70% (wt/wt)],形成棕榈酸(脂肪酸组成的45.73%)、硬脂酸(16.43%)、棕榈油酸(13.29%)、亚麻酸(10.77%)、十七烷酸(4.07%)和亚油酸(14.14%)。四种酵母菌株均产生必需脂肪酸亚油酸,但程度不同,占C. humicola CCMA 0346产生的脂质脂肪酸谱的70.42%。
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引用次数: 21
Growth of microalgae Botryococcus sp. in domestic wastewater and application of statistical analysis for the optimization of flocculation using alum and chitosan 微藻芽孢球菌在生活废水中的生长及明矾和壳聚糖絮凝优化的统计分析应用
Pub Date : 2017-01-05 DOI: 10.1080/10826068.2016.1244686
P. Gani, Norshuhaila Mohamed Sunar, H. Matias-Peralta, Ab Aziz Abdul Latiff, S. F. Z. Mohamad Fuzi
ABSTRACT Microalga biomass has been recognized as a sustainable bio-product to replace terrestrial biomass in biofuel production. The microalga industry has high operating costs, specifically on harvesting and biomass recovery. Therefore, the development of an efficient harvesting method is crucial to the minimization of production cost. A statistical analysis through response surface methodology was used to investigate the optimization of harvesting efficiency using alum and chitosan as a coagulant. Growth rate and biomass productivity were also determined. This research revealed that the harvesting efficiency using alum was 99.3%, with optimum dosage and pH of 177.74 mg L−1 and 8.24, respectively. Chitosan achieved 94.2% biomass recovery at an optimal dosage of 169.95 mg L−1 at pH of 12. Moreover, Botryococcus sp. achieved the maximum growth of 0.7551 µmax d−1, with an average total biomass productivity of 9.81 mg L−1 d−1 in domestic wastewater. Overall, this study shows that both alum and chitosan coagulants have great potential for efficient microalgal biomass recovery. It suggests that domestic wastewater as a potential growth medium for the large-scale production of microalga biomass.
微藻生物质已被认为是一种可持续的生物产品,可以替代陆地生物质用于生物燃料生产。微藻产业的运营成本很高,特别是在收获和生物质回收方面。因此,开发一种高效的采收方法对降低生产成本至关重要。采用响应面法对明矾和壳聚糖作为混凝剂的收获效率进行了优化研究。测定生长速率和生物量生产力。结果表明,明矾在最佳投加量为177.74 mg L−1、最佳pH为8.24时,收获效率为99.3%。壳聚糖的最佳投加量为169.95 mg L−1,pH为12,生物量回收率为94.2%。此外,在生活废水中,Botryococcus p.的最大生长为0.7551µmax d - 1,平均总生物量生产力为9.81 mg L - 1 d - 1。综上所述,本研究表明明矾和壳聚糖混凝剂对微藻生物量的高效回收具有很大的潜力。这表明生活污水是一种潜在的大规模生产微藻生物量的培养基。
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引用次数: 20
Importance of cellulase cocktails favoring hydrolysis of cellulose 混合纤维素酶对纤维素水解的重要性
Pub Date : 2017-01-03 DOI: 10.1080/10826068.2016.1275006
J. Victoria, A. Odaneth, A. Lali
ABSTRACT Depolymerization of lignocellulosic biomass is catalyzed by groups of enzymes whose action is influenced by substrate features and the composition of cellulase preparation. Cellulases contain a mixture of variety of enzymes, whose proportions dictate the saccharification of biomass. In the current study, four cellulase preparation varying in their composition were used to hydrolyze two types of alkali-treated biomass (aqueous ammonia-treated rice straw and sodium hydroxide-treated rice straw) to study the effect on catalytic rate, saccharification yields, and sugar release profile. We found that substrate features affected the extent of saccharification but had minimal effect on the sugar release pattern. In addition, complete hydrolysis to glucose was observed with enzyme preparation having at least a cellobiase units (CBU)/carboxymethyl cellulose (CMC) ratio (>0.15), while a modified enzyme ratio can be used for oligosaccharide synthesis. Thus, cellulase preparation with defined ratios of the three main enzymes can improve the saccharification which is of utmost importance in defining the success of lignocellulose-based economies.
木质纤维素生物质的解聚是由酶群催化的,酶群的作用受底物特征和纤维素酶制剂组成的影响。纤维素酶含有多种酶的混合物,其比例决定了生物质的糖化。在本研究中,采用四种不同组成的纤维素酶制剂对两种碱处理的生物质(氨水处理的稻草和氢氧化钠处理的稻草)进行水解,研究其对催化速率、糖化率和糖释放谱的影响。我们发现底物特征影响糖化程度,但对糖释放模式的影响很小。此外,制备的酶至少具有纤维素酶单位(CBU)/羧甲基纤维素(CMC)比(>0.15),可以完全水解为葡萄糖,而改良的酶比可以用于低聚糖合成。因此,用三种主要酶的确定比例制备纤维素酶可以改善糖化,这对于定义以木质纤维素为基础的经济的成功至关重要。
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引用次数: 14
Use of lignocellulose biomass for endoxylanase production by Streptomyces termitum 利用木质纤维素生物质生产白蚁链霉菌内生木聚糖酶
Pub Date : 2017-01-03 DOI: 10.1080/10826068.2016.1275015
Alenir Naves de Sales, A. D. de Souza, R. O. Moutta, V. Ferreira-Leitão, R. Schwan, D. R. Dias
ABSTRACT Actinobacteria isolates from Brazilian Cerrado soil were evaluated for their ability to produce enzymes of the cellulolytic and xylanolytic complex using lignocellulose residual biomass. Preliminary semiquantitative tests, made in Petri plates containing carboxymethylcellulose and beechwood xylan, indicated 11 potential species producing enzymes, all belonging to the genus Streptomyces. The species were subsequently grown in pure substrates in submerged fermentation and analyzed for the production of enzymes endoglucanase, β-glucosidase, endoxylanase, and β-xylosidase. The best results were obtained for endoxylanase enzyme production with Streptomyces termitum(UFLA CES 93). The strain was grown on lignocellulose biomass (bagasse, straw sugarcane, and cocoa pod husk) that was used in natura or acid pretreated. The medium containing sugarcane bagasse in natura favored the production of the endoxylanase that was subsequently optimized through an experimental model. The highest enzyme production 0.387 U mL−1, (25.8 times higher), compared to the lowest value obtained in one of the trials, was observed when combining 2.75% sugar cane bagasse and 1.0 g L−1 of yeast extract to the alkaline medium (pH 9.7). This is the first study using S. termitum as a producer of endoxylanase.
研究了从巴西塞拉多(Cerrado)土壤中分离的放线菌利用木质纤维素残余生物量产生纤维素水解酶和木聚糖水解复合物的能力。在含有羧甲基纤维素和山毛榉木聚糖的培养皿中进行的初步半定量测试表明,11种可能产生酶的物种都属于链霉菌属。随后在纯底物中进行深层发酵,并分析内切葡聚糖酶、β-葡萄糖苷酶、内切木聚糖酶和β-木糖糖苷酶的产量。以白质链霉菌(UFLA CES 93)产内生木聚糖酶效果最好。该菌株生长在木质纤维素生物质(甘蔗渣、秸秆甘蔗和可可豆荚壳)上,这些生物质在自然或酸预处理中使用。天然含甘蔗渣的培养基有利于内生木聚糖酶的产生,随后通过实验模型对其进行了优化。在碱性培养基(pH 9.7)中加入2.75%甘蔗渣和1.0 g L−1酵母提取物时,酶产量最高,为0.387 U mL−1,是其中一项试验中最低酶产量的25.8倍。这是第一次研究利用白蚁作为内生木聚糖酶的生产者。
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引用次数: 11
期刊
Preparative Biochemistry and Biotechnology
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