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1.
一组纤维素分解菌复合系NSC-7的酶活表达特性   总被引:2,自引:0,他引:2  
为了揭示一组具有降解纤维素和林丹双重功能的细菌复合系NSC-7的降解活性, 本文对该菌系的分解能力、纤维素酶活性和半纤维素酶活性进行测定。结果表明, NSC-7在14 d内, 可降解稻秆干重的 73.6%, 其中降解纤维素82.1%, 半纤维素58.2%, 木质素5.4%。用广泛采用的酶活测定方法测定了4种纤维素酶和半纤维素酶活性, 在培养的第8天, 内切酶、总纤维素酶、外切酶和b-糖苷酶活性都达到最大值, 分别为4.48 U/mL、7.51 U/mL、15.83 U/mL和25.78 U/mL。在培养的第5天, 半纤维素酶活性达到最高值为280.9 U/mL, 其平均值比纤维素酶活性高43.71倍。  相似文献   

2.
筛选两株稻杆降解放线菌   总被引:2,自引:0,他引:2  
【目的】筛选能够同时降解纤维素、半纤维素、木质素的微生物菌株,并研究其对稻杆的降解效果。【方法】采用羧甲基纤维素钠、半纤维素平板水解圈法、苯胺蓝平板脱色法进行初筛;利用DNS法测定胞外酶活性;在含有2%稻秆的液体发酵培养基中摇瓶培养10天后,洗去菌体测定稻杆失重率、木质纤维素类物质降解率,同时测定稻杆断裂拉力进行复筛。【结果】筛选出两株能够同时高效降解木质纤维素的放线菌A3和A6,其纤维素和半纤维素酶活较高,最高纤维素全酶活、β-葡萄糖苷酶活、外切酶活和内切酶活分别为:12.84和12.85、6.23和6.53、24.56和17.80、14.00和18.80 U/mL;最高半纤维素酶活分别为:83.05和52.98 U/mL;木质素酶活较低,菌株A3和A6的木素过氧化物酶最大值为:12.72和14.67 U/mL,锰过氧化物酶最大值分别为:22.48和24.67 U/mL,漆酶最大值分别为:28.40和33.04 U/mL。经形态学、培养特征和分子生物学分析,两株菌株鉴定为链霉菌,对稻杆均有较好的降解效果,在第10 d后稻杆断裂拉力测定值分别比初始时降低62.67%和66.67%;稻杆失重率在31.50%和35.83%;菌株A3对纤维素、半纤维素、木质素降解率为38.73%、33.16%和20.68%,菌株A6为47.69%、28.64和22.59%。【结论】放线菌A3和A6对纤维素、半纤维素、木质素均具有降解作用,且酶活较高,具有较好的应用前景。  相似文献   

3.
复合菌系WSD-5具有高效的分解能力和产酶能力,以探明WSD-5的协同分解机理和优化高效组合为目的,通过纯培养分离手段,获得了11株细菌和3株真菌。16S rDNA比对结果表明,细菌分别为Pseudomonas sp.、Pseudomonas aeruginosa、Achromobacter sp.、Stenotrophomonas sp.、Bacillus fusiformis、Bacillus cereus、Brevundimonas sp.、Ochrobactrum sp.、Cytophaga sp.、Benzo(a)pyrene-degrading bacter、Flavobacterium sp.的近缘种;26S rDNA比对结果表明3株真菌分别为Pseudallescheria boydii、Coprinus cinereus的近缘种。分离菌株中有4株细菌和3株真菌能在CMC平板上产生透明圈,但以糖化力法测定酶活结果只有3株真菌具有产酶能力。3株真菌的酶活动态测定结果,酶活的高峰均出现在7?14 d,并且呈现多峰变化;3株真菌的酶活种类表现为,滤纸酶活性、纤维素内切酶活性和外切酶活性均以菌株F1最高,分别达到了1.05、5.53和0.56 U/mL,β-葡萄糖甘酶活性和木聚糖酶活性以菌株FC最高,分别达到0.44和58.95 U/mL,其木聚糖酶活为F1最高值的6倍。  相似文献   

4.
本研究探讨了一组具有分解纤维素和农药林丹双重功能的复合菌系NSC-7的培养特性和稳定性。NSC-7在14 d的培养过程中, 使稻秆分解73.6%; 用GC-MS测定结果发酵液中检测到10种化合物成分, 其中峰值较大的依次为乙酸、甘油、丁酸、丙酸; NSC-7在-80℃冷冻和冻干条件下保存4年后仍具有稳定的秸秆分解能力和纤维素内切酶活性; 经90℃高温处理30 min后, 仍能够保持分解能力, 105℃处理30 min后转接2次就能恢复分解能力, 显示出很高的保存稳定性和热稳定性。利用DGGE分析多次继代接种过程的培养物结果条带基本没有变化, 表明NSC-7的菌种组成稳定。  相似文献   

5.
中温(37℃)纤维素分解菌的筛选及混合培养研究   总被引:3,自引:0,他引:3  
目的:筛选纤维素分解菌,构建复合微生物菌系进行混合培养,获得降解纤维素能力强的复合菌系.方法:从高温阶段堆肥样品、腐熟肥料、牛粪和土壤中筛选出能较好降解纤维素的菌株,进行单独与混合发酵培养,测其酶活.结果:获得降解纤维素能力较强的细菌3株、霉菌4株、放线菌2株.按不同的接种比例构建了4组复合微生物菌系,4个组合的滤纸失重率分别达到41.52%、44.94%、41.82%、37.11%,液体发酵的平均CMC酶活分别为624U/g、988U/g、769U/g、1041U/g,固体发酵的平均CMC酶活分别为4240U/g、5289U/g、4807U/g、5344U/g.结论:综合分析复合菌系滤纸条降解能力、CMC酶活、FAP酶活表明,组合二分解纤维素能力明显强于其他几个组合.  相似文献   

6.
纤维素高效降解菌YN1的筛选及其降解特性   总被引:6,自引:3,他引:3       下载免费PDF全文
为了获得降解天然纤维素的微生物菌株,并用于农田秸秆腐熟及竹林地稻壳促腐。从牛羊粪堆肥中筛选出一株纤维素降解菌YN1,对其进行了形态和系统发育分析;测定了YN1的液、固体发酵酶活;进行了YN1对纤维素的失重测定;对YN1在纤维素表面上的定殖及其对纤维素的降解进行了电镜观察。经菌株形态分析和ITS基因序列分析,将YN1鉴定为曲霉(Aspergillussp.);在YN1菌株的液体发酵培养第3天,内切酶、外切酶、β-糖苷酶和总纤维素酶活性都达到最大值,分别为95.7、14.6、20.5和26.6U/mL,固体发酵培养第5d各酶活均达到峰值,依次为1192.2、100.6、136.9和210.7U/g;在失重测定中,YN1在7d内可降解41.87%的秸秆,31.59%的稻壳;在扫描电镜下可明显观察到YN1对滤纸、秸秆和稻壳的降解。YN1可有效降解天然纤维素,对农田秸秆腐熟及竹林地稻壳促腐具有较好的应用前景。  相似文献   

7.
棉秸秆降解高温菌株的筛选及产酶分析   总被引:2,自引:1,他引:1       下载免费PDF全文
从新疆地区分离具有降解棉秸秆纤维素功能的菌株,得到4株耐高温真菌(50°C)。纤维素酶学性质分析表明,该4株菌的纤维素酶具有良好的耐酸性(最适pH为4.5)和耐高温性(最高达60°C)。以羧甲基纤维素钠(CMC-Na)、微结晶纤维素、棉花、滤纸、淀粉、果胶为底物测定酶活力,滤纸酶活力(FPA)最高达2.63 U/mL、淀粉酶活力最高达6.17 U/mL、果胶酶活力最高达5.86 U/mL。4株真菌酶学特性分析表明,该系列菌株在秸秆生物质利用方面有很大的应用潜力。  相似文献   

8.
酸性土壤中高效半纤维素降解菌的筛选与鉴定   总被引:5,自引:0,他引:5  
【目的】筛选能够适应南方酸性土壤的高效半纤维素降解菌株,并进行鉴定,确定菌株的安全性。【方法】采用半纤维素平板水解圈法和胞外酶测定法进行菌株筛选,通过拮抗实验构建复合微生物菌系。利用培养特征、形态学、生理生化特征和分子生物学方法进行菌株鉴定。【结果】筛选出效果稳定,互不拮抗的高效半纤维素降解放线菌4株(NA9、NA10、NA12和NA13),半纤维素酶活分别为:217.6、229.8、221.1和211.8 U/mL。真菌2株NF1和NF7,半纤维素酶活为217.7和244.2 U/mL。复合微生物菌系半纤维素酶活可达299.0 U/mL。经鉴定菌株NA9、NA10、NA12和NA13为链霉菌中的哥斯达黎加链霉菌(Streptomyces costaricanus)。菌株NF1为亮白曲霉(Aspergillus candidus),菌株NF7为黄蓝状菌(Tarlaromyces flavus)。  相似文献   

9.
以棉籽壳为基质栽培紫孢侧耳(Pleurotussapidus),分别在菌丝长满期、菇蕾期、一茬菇和二茬菇时测定培养料中纤维素和半纤维素含量的变化以及纤维素酶(CMC酶)和半纤维素酶活性的变化。结果表明:从接种到一茬菇时期,纤维素酶、半纤维素酶活不断升高,此后,迅速降低;基质中两种酶的底物含量降低速度以菇蕾一一茬菇时最大。菇蕾期后,两种底物的减少量多,菇蕾期以前较少。菇蕾期以前半纤维素降解稍多,菇蕾期以后纤维素降解较多。  相似文献   

10.
【背景】利用微生物处理秸秆引起研究者的广泛关注。【目的】筛选生长速度快、木质纤维素降解酶活性强的真菌菌株,用于植物秸秆降解和高效利用。【方法】从自然界采集的样品中分离纯化真菌菌株,利用PDA-愈创木酚和PDA-羧甲基纤维素钠平板初筛,再经过液体发酵检测漆酶酶活、羧甲基纤维素酶酶活及菌丝生长速率复筛目的菌株,通过内转录间隔区(internal transcribed spacer,ITS)测序法对目的菌株进行鉴定,对目的菌株产漆酶和羧甲基纤维素酶活力进行测定及酶学性质研究。【结果】从样品中分离纯化到18株真菌,通过初筛筛选出9株产木质纤维素降解酶真菌菌株,再经过复筛,筛选出一株产漆酶、羧甲基纤维素酶活力高、菌丝生长快的菌株M1,经过分子生物学鉴定M1为糙皮侧耳(Pleurotus ostreatus),其漆酶酶活为(243.59±1.11)U/mL,羧甲基纤维素酶酶活为(36.03±0.63) U/mL。在5 d的培养期内,菌丝生长速率为(9.43±0.32) mm/d。对菌株M1的发酵粗酶液的酶学性质进行了检测分析,结果表明,所产的漆酶在pH5.0-6.5相对酶活为90%以上,在pH ...  相似文献   

11.
从沙蜇触手提取刺丝囊细胞毒素,并对该毒素进行溶血活性、致死活性、SOD活性和抗肿瘤活性的研究。结果显示,沙蜇毒素具有明显的溶血活性,其半溶血率(HU50)约为10.5μg/ml;该毒素还对草鱼显示出较强的致死活性,半致死量(LD50)为50μg毒素/g鱼;同时该毒素具有明显的SOD活性和抗肿瘤活性,当毒素浓度为18μg/ml时其总SOD活性为161 U/mg,而毒素浓度为1 mg/ml时,该毒素对肝癌细胞Bel-7402表现出显著的抑制效果,其抑制率达到54.9%。因此,有必要对沙蜇毒素内的生物活性组分进行深入研究,为沙蜇毒素的开发利用提供依据。  相似文献   

12.
In the present investigation the acetone extracts of macroalgae Ulva lactuca and Enteromorpha intestinalis were tested for antioxidant, antimicrobial and cytotoxic potential. Antioxidant activity was evaluated by measuring the scavenging capacity of tested samples on DPPH and superoxide anion radicals, reducing the power of samples and determination of total phenolic and flavonoid compounds in extracts. As a result of the study, U. lactuca extract was found to have a better free radical scavenging activity (IC50 = 623.58 μg/ml) than E. intestinalis extract (IC50 = 732.12 μg/ml). Moreover, the tested extracts had effective ferric reducing power and superoxide anion radical scavenging. The total content of phenol in extracts of U. lactuca and E. intestinalis was 58.15 and 40.68 μg PE/mg, while concentrations of flavonoids were 39.58 and 21.74 μg RE/mg, respectively. Furthermore, among the tested species, extracts of U. lactuca showed a better antimicrobial activity with minimum inhibitory concentration values ranging from 0.156 to 5 mg/ml, but it was relatively weak in comparison with standard antibiotics. Bacillus mycoides and Bacillus subtilis were the most susceptible to the tested extracts. Contrary to this Aspergillus flavus, Aspergillus fumigatus and Penicillium purpurescens were the most resistant. Finally, cytotoxic activity of tested extracts was evaluated on four human cancer cell lines. Extract of E. intestinalis expressed the stronger cytotoxic activity towards all tested cell lines with IC50 values ranging from 74.73 to 155.39 μg/ml.  相似文献   

13.
Herbal medications have been used for relief of symptoms of disease. Regardless of the great advances observed in current medicine in recent decades, plants still make a significant contribution to health care. An alarming increase in bacterial strains resistant to a number of antimicrobial agents demands that a renewed effort be made to seek antibacterial agents effective against pathogenic bacteria resistant to or less sensitive to current antibiotics. Anti-bacterial activity of Azadirachta indica stem bark was tested against pathogenic Salmonella paratyphi and Salmonella typhi using various solvent extracts. The in vitro anti-bacterial activity was performed by agar well diffusion method and the results were expressed as the average diameter of zone of inhibition of bacterial growth around the well. The ethanol and methanol extracts showed better anti-bacterial activity with zone of inhibition (20–25 mm) when compared with other tested extracts and standard antibiotic Erythromycin (15 mcg) with zone of inhibition (13–14 mm). Using Fisher’s exact test of significance difference was found between two Salmonella strains sensitivity patterns against tested extracts (P  0.035). Extracts of A. indica stem bark also exhibited significant antioxidant activity, thus establishing the extracts as an antioxidant. The results obtained in this study give some scientific support to the A. indica stem bark for further investigation of compounds and in future could be used as drug.  相似文献   

14.
15.
With the aim to explore the potentiality of new chemical scaffolds for the design of new antimalarials, a set of new indeno[2,1-c]quinolines bearing different basic heads has been synthesized and tested in vitro against chloroquine sensitive (CQ-S) and chloroquine resistant (CQ-R) strains of Plasmodium falciparum. Most of the synthesized compounds exhibited a moderate antiplasmodial activity, inhibiting the growth of both CQ-S and CQ-R strains of P. falciparum with IC50 ranging from 0.24 to 6.9 μM and with a very low resistance index. The most potent compounds (1.2–1.3-fold the CQ on the W-2 strain) can be considered as promising ‘lead compounds’ to be further optimized to improve efficacy and selectivity against Plasmodia.  相似文献   

16.
Bacteria can produce nitrogenous compounds via both primary and secondary metabolic processes. Many bacterial volatile nitrogenous compounds produced during the secondary metabolism have been identified and reported for their antioxidant, antibacterial, antifungal, algicidal and antitumor activities. The production of these nitrogenous compounds depends on several factors, including the composition of culture media, growth conditions, and even the organic solvent used for their extraction, thus requiring their identification in specific conditions. In this review, we describe the volatile nitrogenous compounds produced by bacteria especially focusing on their antimicrobial activity. We concentrate on azo-compounds mainly pyrazines and pyrrolo-pyridines reported for their activity against several microorganisms. Whenever significant, extraction and identification methods of these compounds are also mentioned and discussed. To the best of our knowledge, this is first review describing volatile nitrogenous compounds from bacteria focusing on their biological activity.  相似文献   

17.
18.
Covering from 1963 to 2017.This review provides a summary of some secondary metabolites isolated from the genera Curvularia and Bipolaris from 1963 to 2017. The study has a broad objective. First to afford an overview of the structural diversity of these genera, classifying them depending on their chemical classes, highlighting individual examples of chemical structures. Also some information regarding their biological activities are presented. Several of the compounds reported here were isolated exclusively from endophytic and pathogenic strains in culture, while few from other sources such as sea Anemone and fish. Some secondary metabolites of the genus Curvularia and Bipolaris revealed a fascinating biological activities included: anti-malarial, anti-biofouling, anti-larval, anti-inflammatory, anti-oxidant, anti-bacterial, anti-fungal, anti-cancer, leishmanicidal and phytotoxicity. Herein, we presented a bibliography of the researches accomplished on the natural products of Curvularia and Bipolaris, which could help in the future prospecting of novel or new analogues of active metabolites from these two genera.  相似文献   

19.
Sixteen eudesmane-type sesquiterpenes, including six unknown ones (1−6), were isolated from the aerial part of A. tournefortiana. NMR, HERIS-MS, IR spectra and ECD calculation assigned their relative and absolute configurations. Six (6, 7, 9, 13, 15, and 16) were tested for cytotoxic and anti-inflammatory activities, and seven (6, 7, 8, 12, 13, 15, and 16) were tested for antimicrobial activity. Among them, compound 15 showed significant cytotoxicity with IC50 values in the range of 1.49–5.30 μM and moderate antimicrobial activity.  相似文献   

20.
Owing to extremely high salinity and harsh environmental conditions, T. articulata is one of the most abundant wild plants growing in the deserts of Saudi Arabia. Such plants may contain novel compounds to display promising biological activities. Here, in this study, we evaluate the biological activities of methanolic extracts of fresh leaves, dry leaves, stem, and roots of T. articulata. The antioxidant activity was determined by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and total phenolic and flavonoid content were determined using standard colorimetric methods. Whereas antimicrobial and ant-proliferative activities were determined by standard well-diffusion and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) methods, respectively. Our results demonstrate that all methanolic extracts of T. articulata showed antioxidant activity, however, the methanolic extract of dry leaves exhibits promising antioxidant effect with IC₅₀ value 49.08 ± 1.98, which was strongly supported by total phenolic (409.92 ± 6.03 mg GAE/g DW) and flavonoid (177.71 mg QE/g DW) content. Although, antimicrobial activity was also exhibited by all the methanolic extracts, however, methanolic extract of dry leaves exhibits promising antimicrobial activity in Gram-positive bacteria Staphylococcus epidemidis. Furthermore, MTT assay revealed that all methanolic extracts exhibit antiproliferative activity in MCF-7 (breast cancer) and RKO (colorectal cancer) cells with IC₅₀ values ranges from 219 ± 5.112 µg/ml to 253 ± 5.231 µg/ml and 220 ± 4.330 µg/ml to 325 ± 6.213 µg/ml, respectively. However, the most promising antiproliferative effect was displayed by methanolic extract of dry leaves with IC₅₀ values 219 ± 5.112 µg/ml and 220 ± 4.330 µg/ml, respectively. In summary, these findings provide evidence that T. articulata has promising biological activities and can be used for many pharmaceutical activities in the future.  相似文献   

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