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Ram Krishna Sadhukhan Subha Manna Samir K. Roy S. L. Chakrabarty 《Applied microbiology and biotechnology》1990,33(6):692-696
Summary The production of amylolytic enzymes by a thermophilic cellulolytic fungus,Myceliophthora thermophila D14 was investigated by batch cultivation in Czapek-Dox medium at 45° C. Among various nitrogenous compounds used, NaNO3 and KNO3 were found to be the best for amylase production. Starch, cellobiose and maltose induced the synthesis of amylase while glucose, fructose, galactose, lactose, arabinose, xylose, sorbitol, mesoinositol and sucrose did not. Calcium ions had the most stimulating effect on enzyme formation amongst many ions investigated. The synthesis of amylolytic enzymes was dependent on growth and occurred predominantly in the mid-stationary phase. The enzyme was active in a broad temperature range (50° C–60° C) and displayed activity optima at 60° C and pH 5.6. 相似文献
3.
Ten obligately anaerobic, cellulolytic mesophilic bacteria were isolated from a municipal solid waste digestor used for biogas
production. The isolates were rod-shaped, spore-forming bacteria in anaerobic conditions, and stained Gram-positive in young
cultures, and hence were identified asClostridium. Small regular translucent and unpigmented colonies were observed on cellulose plates. The strains were gelatinase-negative,
hydrolyzed esculin and starch, and fermented xylose and arabinose. The lecithinase, lipase, and indole tests were negative.
The major fermentation products from cellulose included ethanol and acetate. The morphological and other biochemical characteristics
indicated that these clostridia did not correspond to any previously described species. All the strains produced high activities
of extracellular cellulases in cellulose media and degraded paper.
Offprint requests to: L. Benoit. 相似文献
4.
John Ikuba Ona Peter J. Halling Mercedes Ballesteros 《Biocatalysis and Biotransformation》2019,37(2):77-85
Cassava peels provide a cheap non-food biomass waste that can be hydrolyzed to simple sugars as a useful feedstock. Unlike most crop wastes, they have high starch content as well as lignocellulose. In this study, an enzymatic treatment of cassava peels by various concentrations of amylase and glucoamylase is considered. Steam explosion pre-treatments reduced rate and yield of hydrolysis. Milled peels suspended at 10% w/v yielded a maximum reducing sugar of 0.41?g (as glucose) per gram of peels. HPLC analysis showed that levels of soluble oligosaccharides remained low throughout. A pretreatment with amylase at 95?°C slightly increased rates although final yield was the same. Additional treatment with cellulolytic enzymes increases the total hydrolysis yield to 0.61?g (as glucose) per gram of peels representing 91% of the carbohydrate in cassava peels. 相似文献
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K J Wedekind H R Mansfield L Montgomery 《Applied and environmental microbiology》1988,54(6):1530-1535
The fibrolytic microbiota of the human large intestine was examined to determine the numbers and types of cellulolytic and hemicellulolytic bacteria present. Fecal samples from each of five individuals contained bacteria capable of degrading the hydrated cellulose in spinach and in wheat straw pretreated with alkaline hydrogen peroxide (AHP-WS), whereas degradation of the relatively crystalline cellulose in Whatman no. 1 filter paper (PMC) was detected for only one of the five samples. The mean concentration of cellulolytic bacteria, estimated with AHP-WS as a substrate, was 1.2 X 10(8)/ml of feces. Pure cultures of bacteria isolated on AHP-WS were able to degrade PMC, indicating that interactions with other microbes were primarily responsible for previous low success rates in detecting fecal cellulolytic bacteria with PMC as a substrate. The cellulolytic bacteria included Ruminococcus spp., Clostridium sp., and two unidentified strains. The mean concentration of hemicellulolytic bacteria, estimated with larchwood xylan as a substrate, was 1.8 X 10(10)/ml of feces. The hemicellulose-degrading bacteria included Butyrivibrio sp., Clostridium sp., Bacteroides sp., and two unidentified strains, as well as four of the five cellulolytic strains. This work demonstrates that many humans harbor intestinal cellulolytic bacteria and that a hydrated cellulose source such as AHP-WS is necessary for their consistent detection and isolation. 相似文献
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A group I Bacillus strain, DLG, was isolated and characterized as being most closely related to Bacillus subtilis. When grown on any of a variety of sugars, the culture supernatant of this isolate was found to possess cellulolytic activity, as demonstrated by degradation of trinitrophenyl-carboxymethyl cellulose. Growth in medium containing cellobiose or glucose resulted in the greatest production of cellulolytic activity. The cellulolytic activity was not produced until the stationary phase of growth, and the addition of glucose or cellobiose to a culture in this phase had no apparent effect on enzyme production. Fractionation of the culture supernatant showed that the molecular weight of the enzymatic activity was less than 100,000. Maximum cellulolytic activity in assays was observed at pH 4.8 and at 58C, although maximum thermal stability of the activity. Kinetic experiments suggested that more than one enzyme was acting upon trinitrophenyl-carboxymethyl cellulose. Exocellular protein produced by this Bacillus isolate showed roughly one-fifth the cellulolytic activity displayed by Trichoderma reesei C30 on noncrystalline, cellulosic substrates. In contrast to T. reesei cellulase, the Bacillus enzymatic activity showed no ability to degrade crystalline forms of cellulose, nor was cellobiase activity detectable. 相似文献
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By hybridization experiments with three cloned fragments carrying cellulase genes ofClostridium cellulolyticum, we tried to differentiate 10 cellulolytic mesophilic clostridia, isolated from a municipal solid waste digestor. On the basis of hybridization experiments, three major groups were found among the 10 isolates. The two endoglucanase genes,cel CCA andcel CCB ofC. cellulolyticum, hybridized with nine strains of our isolates, suggesting homology and widespread distribution of these genes. Withcel CCA the strain A31 exhibited a different pattern. In contrast to these nine strains, the strain A11 was found to share no or very weak homology with these two probes, which indicated that this strain of cellulolytic clostridia possesses nonidentical cellulase complex. None of these new strains hybridized withnif genes, indicating that these clostridia did not appear to be nitrogen-fixing bacteria. With other biochemical characteristics, we found that these bacteria appeared to be different from the presently known mesophilic cellulolytic clostridia. 相似文献
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Summary The xylanolytic and cellulolytic activity fromCellulomanas were reduced by high O2 concentrations in continous culture as well as by an air flow passed trough the samples, suggesting an inhibition or inactivation of enzymes in such conditions. 相似文献
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Enumeration and isolation of cellulolytic and hemicellulolytic bacteria from human feces. 总被引:2,自引:1,他引:2 下载免费PDF全文
The fibrolytic microbiota of the human large intestine was examined to determine the numbers and types of cellulolytic and hemicellulolytic bacteria present. Fecal samples from each of five individuals contained bacteria capable of degrading the hydrated cellulose in spinach and in wheat straw pretreated with alkaline hydrogen peroxide (AHP-WS), whereas degradation of the relatively crystalline cellulose in Whatman no. 1 filter paper (PMC) was detected for only one of the five samples. The mean concentration of cellulolytic bacteria, estimated with AHP-WS as a substrate, was 1.2 X 10(8)/ml of feces. Pure cultures of bacteria isolated on AHP-WS were able to degrade PMC, indicating that interactions with other microbes were primarily responsible for previous low success rates in detecting fecal cellulolytic bacteria with PMC as a substrate. The cellulolytic bacteria included Ruminococcus spp., Clostridium sp., and two unidentified strains. The mean concentration of hemicellulolytic bacteria, estimated with larchwood xylan as a substrate, was 1.8 X 10(10)/ml of feces. The hemicellulose-degrading bacteria included Butyrivibrio sp., Clostridium sp., Bacteroides sp., and two unidentified strains, as well as four of the five cellulolytic strains. This work demonstrates that many humans harbor intestinal cellulolytic bacteria and that a hydrated cellulose source such as AHP-WS is necessary for their consistent detection and isolation. 相似文献
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N V Koltukova A A Bondarchuk E A Kovalenko E I Get'man 《Prikladnaia biokhimiia i mikrobiologiia》1990,26(1):50-54
Some physico-chemical properties of the Bacillus mesentericus amylolytic complex were studied, and optimal conditions of starch hydrolysis (pH 7.5-8.0; 45 degrees C) were found. The half-life of amylases at 50 degrees was 75 min. The heat stability of the enzymes increased in the presence of Ca2+ ions. Amylase was stable at pH 7-9 and readily inactivated at pH below 6.0. By physical and chemical characteristics the complex was close to analogous preparations from Bacillus alkalophilic strains. Isoelectrofocusing revealed that the complex consisted at least of two amylolytic enzymes. 相似文献
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Kyoung-Cheol Kim Si-Wouk Kim Myong-Jun Kim Seong-Jun Kim 《Biotechnology and Bioprocess Engineering》2005,10(1):52-59
The study was targeted to saccharify foodwastes with the cellulolytic and amylolytic enzymes obtained from culture supernatant
ofTrichoderma harzianum FJ1 and analyze the kinetics of the saccharification in order to enlarge the utilization in industrial application.T. harzianum FJ1 highly produced various cellulolytic (filter paperase 0.9, carboxymethyl cellulase 22.0, β-glucosidase 1.2, Avicelase
0.4, xylanase 30.8, as U/mL-supernatant) and amylolytic (α-amylase 5.6, β-amylase 3.1, glucoamylase 2.6, as U/mL-supernatant)
enzymes. The 23–98 g/L of reducing sugars were obtained under various experimental conditions by changing FPase to between
0.2–0.6 U/mL and foodwastes between 5–20% (w/v), with fixed conditions at 50°C, pH 5.0, and 100 rpm for 24 h. As the enzymatic
hydrolysis of foodwastes were performed in a heterogeneous solid-liquid reaction system, it was significantly influenced by
enzyme and substrate concentrations used, where the pH and temperature were fixed at their experimental optima of 5.0 and
50°C, respectively. An empirical model was employed to simplify the kinetics of the saccharification reaction. The reducing
sugars concentration (X, g/L) in the saccharification reaction was expressed by a power curve (X=K·t
n) for the reaction time (t), where the coefficient,K andn, were related to functions of the enzymes concentrations (E) and foodwastes concentrations (S), as follow:K=10.894 Ln(E·S
2)-56.768,n=0.0608·(E/S)−0.2130. The kinetic developed to analyze the effective saccharification of foodwastes composed of complex organic compounds could
adequately explain the cases under various saccharification conditions. The kinetics results would be available for reducing
sugars production processes, with the reducing sugars obtained at a lower cost can be used as carbon and energy sources in
various fermentation industries. 相似文献
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目的以健康仔猪肠道及粪便样品为基础,从中筛选产淀粉酶的乳杆菌菌株,并评价其作为益生菌候选菌株潜力。方法用MRS培养基分别从仔猪新鲜粪便和小肠黏膜上分离到乳酸菌,采用改良的产淀粉酶选择性培养基初筛得到能降解淀粉活性的菌株,并研究菌株的淀粉水解活性、抗逆能力、粘附特性及对抗生素的敏感性。结果从备选的485株乳酸菌中筛选得到具有初步淀粉酶活性的菌株25株(占总筛选数量的5.2%),复筛选育得到具有较强淀粉酶活性的乳杆菌3株。进一步研究了这3株乳杆菌的抗逆能力、粘附特性以及对抗生素的耐药性,并对最终选育得到的菌株进行生理生化及16S rRNA分子鉴定。经选育鉴定的罗伊乳杆菌G8-5淀粉降解能力最强,并能耐受pH 3.0的酸度、1.0%的胆盐浓度,在小肠上皮细胞上的粘附效率超过15个以上,并对常用的抗生素具有较高的敏感率。结论罗伊乳杆菌G8-5符合安全益生菌的要求,可以作为产淀粉酶的益生乳杆菌优良的候选菌株。 相似文献
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515 microorganisms of the genus Bacillus which produce starch-degrading enzymes were isolated from natural environments in the course of a screening programme. Treating the Bacillus strains on agar plates with iodine reagent for 30 seconds led to the selection of clones with increased amylolytic activity. This methods is very convenient for the screening of large numbers of amylolytic strains. 相似文献
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A group I Bacillus strain, DLG, was isolated and characterized as being most closely related to Bacillus subtilis. When grown on any of a variety of sugars, the culture supernatant of this isolate was found to possess cellulolytic activity, as demonstrated by degradation of trinitrophenyl-carboxymethyl cellulose. Growth in medium containing cellobiose or glucose resulted in the greatest production of cellulolytic activity. The cellulolytic activity was not produced until the stationary phase of growth, and the addition of glucose or cellobiose to a culture in this phase had no apparent effect on enzyme production. Fractionation of the culture supernatant showed that the molecular weight of the enzymatic activity was less than 100,000. Maximum cellulolytic activity in assays was observed at pH 4.8 and at 58C, although maximum thermal stability of the activity. Kinetic experiments suggested that more than one enzyme was acting upon trinitrophenyl-carboxymethyl cellulose. Exocellular protein produced by this Bacillus isolate showed roughly one-fifth the cellulolytic activity displayed by Trichoderma reesei C30 on noncrystalline, cellulosic substrates. In contrast to T. reesei cellulase, the Bacillus enzymatic activity showed no ability to degrade crystalline forms of cellulose, nor was cellobiase activity detectable. 相似文献
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The chitosan/glucan complex isolated from the mycelia of the fungus, Gongronella butleri USDB 0201 can be cleaved with a heat-stable -amylase at 65 °C for 3 h. This results in the removal of the glucan side chain and gives a chitosan solution with 100 times lower turbidity. It is proposed that chitosan and glucan chains are bound by an (1 to 4) glucosidic bond. Both fungal chitosan and fungal glucan have been purified separately. 相似文献
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Cédric Tarayre Alison Brognaux Julien Bauwens Catherine Brasseur Christel Mattéotti Catherine Millet Jacqueline Destain Micheline Vandenbol Daniel Portetelle Edwin De Pauw Haubruge Eric Frédéric Francis Philippe Thonart 《World journal of microbiology & biotechnology》2014,30(5):1655-1660
The aim of this work was to isolate enzyme-producing microorganisms from the tract of the termite Reticulitermes santonensis. The microorganisms were extracted from the guts and anaerobic (CO2 or CO2/H2) and micro-aerobic atmospheres were used to stimulate growth. Three different strategies were tried out. First, the sample was spread on Petri dishes containing solid media with carboxymethylcellulose, microcrystalline cellulose or cellobiose. This technique allowed us to isolate two bacteria: Streptomyces sp. strain ABGxAviA1 and Pseudomonas sp. strain ABGxCellA. The second strategy consisted in inoculating a specific liquid medium containing carboxymethylcellulose, microcrystalline cellulose, or cellobiose. The samples were then spread on Petri dishes with the same specific medium containing carboxymethylcellulose, microcrystalline cellulose, or cellobiose. This led to the isolation of the mold Aspergillus sp. strain ABGxAviA2. Finally, the third strategy consisted in heating the first culture and spreading samples on agar plates containing rich medium. This led to the isolation of the bacterium Bacillus subtilis strain ABGx. All those steps were achieved in controlled atmospheres. The four enzyme-producing strains which were isolated were obtained by using a micro-aerobic atmosphere. Later, enzymatic assays were performed on the four strains. Streptomyces sp. strain ABGxAviA1 was found to produce only amylase, while Pseudomonas sp. strain ABGxCellA was found to produce β-glucosidase as well. Aspergillus sp. strain ABGxAviA2 showed β-glucosidase, amylase, cellulase, and xylanase activities. Finally, B. subtilis strain ABGx produced xylanase and amylase. 相似文献
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Summary Fifteen strains of yeast, which produced an extracellular amylolytic enzymes, were isolated from nature. One of them produced more than 100 times the enzyme activity in comparison with the 14 strains and the extremely hyperproducing strain of yeast was identified asCandida
sp. 347. Paper chromatograms of the amylolytic enzyme demonstrated activity of amyloglucosidase. The optimum pH for activity of the enzyme was 5.5–6.0 and optimum temperature was 60°C. 相似文献
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A simple, economical and rapid affinity chromatography procedure with dyes as the ligand has been described for the one-step purification of a cold-adapted lactate dehydrogenase. Non-specific elution of Procion blue H-ERD-modified Sepharose yielded homogeneous preparations of lactate dehydrogenase both in column based procedures and in batch wise operations. Low operational temperatures resulted in the enhanced binding of the enzyme to the blue dye. The dissociation constants of the enzyme-dye complexes were 7.2 +/- 0.2 microM and 11.2 +/- 0.2 microM at 5 degrees C and 20 degrees C respectively. 相似文献