scholarly journals A THERMOPHILIC MICROBE PRODUCING DEXTRANASE FROM HEATED SUGAR CANE

2010 ◽  
Vol 5 (3) ◽  
pp. 224-227
Author(s):  
Afaf Baktir ◽  
Zumrotul Koiriyah ◽  
Ali Rohman
Keyword(s):  
Carbon Source ◽  
Liquid Medium ◽  
Sugar Cane ◽  
Room Temperature ◽  
Solid Medium ◽  
Optimum Temperature ◽  
Blue Dextran ◽  
Optimum Ph

A thermophilic aerobe microorganism designated NP4, was isolated from the heated sugar cane. It grew on dextran, and produced a thermoactive extracellular dextranase. Screening and isolation was done by assay of dextranase activity semi quantitatively on solid medium containing blue dextran. It provided several colonies with different morphology exhibited decolourized zones around, on culture plates containing blue dextran 2000R. The screening resulted in isolation of one microbe which efficiently assimilate dextran as carbon source. Dextranase production from the choised strain in liquid medium was conducted at room temperature for 8 hours with shaking speed of 125 rpm. The dextranase enzyme showed optimum pH of 8 and optimum temperature of 60 oC. Keywords: thermophilic aerobe, sugar cane, dextranase activity.

DECOMPOSITION OF 2,2-DICHLOROPROPIONIC ACID BY SOIL BACTERIA

1959 ◽  
Vol 5 (3) ◽  
pp. 255-260 ◽  
Author(s):  
Lyman A. Magee ◽  
Arthur R. Colmer
Keyword(s):  
Carbon Source ◽  
Liquid Medium ◽  
Soil Bacteria ◽  
Sole Carbon Source ◽  
Solid Medium ◽  
Chloride Ion ◽  
Inhibitory Effect ◽  
Mineral Salts ◽  
Selective Media ◽  
Enrichment Techniques

Eight bacteria capable of decomposing 2,2-dichloropropionate (dalapon) were isolated from soil by means of enrichment techniques and selective media. The decomposition was demonstrated by the clearing of a solid medium containing mineral salts, dalapon, and CaCO3; by a lowering of the pH of a liquid medium containing dalapon as the carbon source; by the increase in chloride ion in the liquid medium; and by the consumption of oxygen by three of the isolates when dalapon was the sole carbon source. Six of these were tentatively classified as Agrobacterium and two were tentatively classified as Pseudomonas, although there was much overlapping of characteristics. These organisms and many unidentified actinomycetes, molds, and bacteria, including a Micrococcus species, overcame the inhibitory effect of dalapon on an agar-decomposing bacterium when grown on the same plate.

scholarly journals The Oxidizing Enzymes of Sugarcane: Tyrosinase (Polyphenol oxidase)

1969 ◽  
Vol 50 (2) ◽  
pp. 113-130
Author(s):  
Alex G. Alexander
Keyword(s):  
Ascorbic Acid ◽  
Polyphenol Oxidase ◽  
Room Temperature ◽  
Distilled Water ◽  
Optimum Temperature ◽  
Meristematic Tissue ◽  
Manganese Zinc ◽  
Mesh Screen ◽  
Freeze Dried ◽  
Optimum Ph

A study was made of the distribution and properties of tyrosinase (polyphenol oxidase) in sugarcane. The enzyme was extracted with phosphate buffer (pH 7) from freeze-dried tissues which had been ground to pass a 60-mesh screen. Tyrosinase was assayed spoctrophotometrically at 390 mµ by measuring the optical density increase of a buffered mixture of catechol and enzyme. Fractionation of cane extracts with ammonium sulfate showed that tyrosinase is precipitated readily from 20- to 70-percent saturation. The richest source of the enzyme was meristematic tissue. Considerable activity was also obtained from leaves — 1 and 0, whereas only traces of the enzyme were present in both 8 to 10 and 1 to 3 nodes and internodes. Tyrosinase preparations were heat-sensitive, losing most of their activity within 2-1: hours of extraction at room temperature (28-29°C.) and laboratory temperature (19-21°C). In contrast, to cane peroxidase, no recuperative capacity was evident after inactivation by boiling. Substrates acted upon by tyrosinase included tyrosine, catechol, DOPA (3,4, dihydroxyphenylalanine), pyrogallol, guaicol, resorcinol, hydroquinone, and paracresol. No reaction was observed with phenol or metacresol. Optimum temperature was about 21°C, and optimum pH was 7.5. Apparent Km was 4.0 X 10-3 mols of catechol per liter. Thiourea and hydroxylamine markedly inhibited the enzyme at concentrations of 1 umol/ml.  Cysteine, ascorbic acid, and cyanide caused virtually complete inhibition at this concentration. Carbon monoxide likewise inhibited. Tyrosinase which was inactivated by KCN was reactivated following prolonged dialysis against distilled water and addition of copper. No other metal tested (molybdenum, manganese, zinc, iron, magnesium) served to reactivate the catalyst. Possible roles and significance of cane tyrosinase are discussed.

A liquid medium for the production of Kabatiella zeae conidia

1979 ◽  
Vol 25 (9) ◽  
pp. 1100-1102 ◽  
Author(s):  
Francisco J. B. Reifschneider ◽  
Deane C. Arny
Keyword(s):  
Liquid Medium ◽  
Room Temperature ◽  
Low Cost ◽  
Potassium Phosphate ◽  
High Yield ◽  
Optimum Temperature ◽  
Gradual Reduction ◽  
Conidial Production ◽  
Ph Values ◽  
Short Time

A liquid medium, designated as Kabatiella zeae medium (KZM), containing 10.0 g of carboxymethylcellulose, 5.0 g of maltose, 1.5 g of peptone, 1.0 g of monobasic potassium phosphate, 1 L of distilled water, is described. Peptone was found to be the component most influential in stimulating sporulation. The optimum temperature for conidial production was 25 °C. In shake culture about 107 conidia/mL were produced in 5 days at room temperature (about 21 °C) when KZM was seeded with 4-day-old colony plugs. The optimum for conidial production was pH 5 with only a slight gradual reduction to pH 9. However, fungal development was abnormal at pH values of 4 and 5. Of the 29 isolates tested, only two did not sporulate in KZM or in any other medium. Because of the high yield of conidia in a short time, the ease of preparation and use, and its low cost, KZM is especially useful where large amounts of inoculum are needed.

scholarly journals A Novel 6-Benzyl Ether Benzoxaborole Is Active against Mycobacterium tuberculosisIn Vitro

2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Nipul Patel ◽  
Theresa O'Malley ◽  
Yong-Kang Zhang ◽  
Yi Xia ◽  
Bjorn Sunde ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Liquid Medium ◽  
Inhibitory Concentration ◽  
Solid Medium ◽  
Eukaryotic Cells ◽  
Intracellular Bacteria ◽  
Benzyl Ether ◽  
Content Type ◽  
Resistant Mutants

ABSTRACT We identified a novel 6-benzyl ether benzoxaborole with potent activity against Mycobacterium tuberculosis. The compound had an MIC of 2 μM in liquid medium. The compound was also able to prevent growth on solid medium at 0.8 μM and was active against intracellular bacteria (50% inhibitory concentration [IC50] = 3.6 μM) without cytotoxicity against eukaryotic cells (IC50 > 100 μM). We isolated resistant mutants (MIC ≥ 100 μM), which had mutations in Rv1683, Rv3068c, and Rv0047c.

Immobilization and Characterization of Tannase and its Haze-removing

2009 ◽  
Vol 15 (6) ◽  
pp. 545-552 ◽  
Author(s):  
Erzheng Su ◽  
Tao Xia ◽  
Liping Gao ◽  
Qianying Dai ◽  
Zhengzhu Zhang
Keyword(s):  
Kinetic Parameter ◽  
High Activity ◽  
Green Tea ◽  
Storage Stability ◽  
Residual Activity ◽  
Black Tea ◽  
Optimum Temperature ◽  
Oolong Tea ◽  
Optimum Ph

Tannase was effectively immobilized on alginate by the method of crosslinking-entrapment-crosslinking with a high activity recovery of 76.6%. The properties of immobilized tannase were investigated. Its optimum temperature was determined to be 35 ° C, decreasing 10 °C compared with that of free enzyme, whereas the optimum pH of 5.0 did not change. The thermal and pH stabilities of immobilized tannase increased to some degree. The kinetic parameter, Km, for immobilized tannase was estimated to be 11.6 × 10-4 mol/L. Fe2+ and Mn2+ could activate the activity of immobilized tannase. The immobilized tannase was also applied to treat the tea beverage to investigate its haze-removing effect. The content of non-estern catechins in green tea, black tea and oolong tea increased by 52.17%, 12.94% and 8.83%, respectively. The content of estern catechins in green tea, oolong tea and black tea decreased by 20.0%, 16.68% and 5.04%, respectively. The anti-sediment effect of green tea infusion treated with immobilized tannase was significantly increased. The storage stability and reusability of the immobilized tannase were improved greatly, with 72.5% activity retention after stored for 42 days and 86.9% residual activity after repeatedly used for 30 times.

Influence of Surfactants on Biodegradation of Chlordane by Wood-Rotting Fungus

2013 ◽  
Vol 361-363 ◽  
pp. 908-911
Author(s):  
Peng Fei Xiao ◽  
Tie Xue You ◽  
Yu Zhen Song ◽  
Shan Ying ◽  
Jian Qiao Wang
Keyword(s):  
Liquid Medium ◽  
Degradation Rate ◽  
Solid Medium ◽  
Fungal Growth ◽  
Tween 80 ◽  
Positive Effects ◽  
Lower Effect ◽  
Triton X

Wood-rotting fungus,Phlebia lindtneriGB 1027, was tested in toxicity assays with three surfactants in order to select surfactants for degradation assays of chlordane. Tween 80 and Triton X-100 appeared to have lower effect on the fungal growth on solid medium, while higher effect of fungal growth was observed in solid medium with SDS. Tween 80 had positive effects both on the chlordane degradation and the fungal growth. When fungus was incubated on PDB liquid medium with Tween 80 of 10 CMC after 20 d, 78.6% of chlordane was removed. In the treatments with Triton X-100, this strain showed comparatively greatest degradation rate (70.8%) of chlordane at a concentration of 2 CMC. However, when Triton X-100 concentration was higher than 2 CMC (5 and 10 CMC), the enhancement for the biodegradation of chlordane decreased.

scholarly journals Properties of a new fungal b-galactosidase with potential application in the dairy industry

1999 ◽  
Vol 30 (3) ◽  
pp. 265-271 ◽  
Author(s):  
Rubens Cruz ◽  
Vinícius D'Arcádia Cruz ◽  
Juliana Gisele Belote ◽  
Marcelo de Oliveira Khenayfes ◽  
Claudia Dorta ◽  
...  
Keyword(s):  
Hydrolytic Activity ◽  
Industrial Applications ◽  
Transferase Activity ◽  
Optimum Temperature ◽  
Milk Whey ◽  
Beneficial Effects ◽  
Optimum Ph ◽  
Semi Solid ◽  
Good Productivity ◽  
Hydrolysis Of

<FONT FACE="Symbol">b</font>-Galactosidase or <FONT FACE="Symbol">b</font>-D-galactoside-galactohydrolase (EC. 3.2.1.23) is an important enzyme industrially used for the hydrolysis of lactose from milk and milk whey for several applications. Lately, the importance of this enzyme was enhanced by its galactosyltransferase activity, which is responsible for the synthesis of transgalactosylated oligosaccharides (TOS) that act as functional foods, with several beneficial effects on consumers. Penicillium simplicissimum, a strain isolated from soil, when grown in semi-solid medium showed good productivity of <FONT FACE="Symbol">b</font>-galactosidase with galactosyltransferase activity. The optimum pH for hydrolysis was in the 4.04.6 range and the optimum pH for galactosyltransferase activity was in the 6.07.0 range. The optimum temperature for hydrolysis and transferase activity was 55-60°C and 50°C, respectively, and the enzyme showed high thermostability for the hydrolytic activity. The enzyme showed a potential for several industrial applications such as removal of 67% of the lactose from milk and 84% of the lactose from milk whey when incubated at their original pH (4.5 and 6.34, respectively) under optimum temperature conditions. When incubated with a 40% lactose solution in 150 mM McIlvaine buffer, pH 4.5, at 55°C the enzyme converted 86.5% of the lactose to its component monosaccharides. When incubated with a 60% lactose solution in the same buffer but at pH 6.5 and 50°C, the enzyme can synthetize up to 30.5% TOS, with 39.5% lactose and 30% monosaccharides remaining in the preparation.

scholarly journals Characterization of Biosynthetic Enzymes for Ectoine as a Compatible Solute in a Moderately Halophilic Eubacterium, Halomonas elongata

1999 ◽  
Vol 181 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Hisayo Ono ◽  
Kazuhisa Sawada ◽  
Nonpanga Khunajakr ◽  
Tao Tao ◽  
Mihoko Yamamoto ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Apparent Molecular Mass ◽  
Optimum Temperature ◽  
Sds Page ◽  
Halomonas Elongata ◽  
Optimum Ph

ABSTRACT 1,4,5,6-Tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) is an excellent osmoprotectant. The biosynthetic pathway of ectoine from aspartic β-semialdehyde (ASA), in Halomonas elongata, was elucidated by purification and characterization of each enzyme involved. 2,4-Diaminobutyrate (DABA) aminotransferase catalyzed reversively the first step of the pathway, conversion of ASA to DABA by transamination with l-glutamate. This enzyme required pyridoxal 5′-phosphate and potassium ions for its activity and stability. The gel filtration estimated an apparent molecular mass of 260 kDa, whereas molecular mass measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was 44 kDa. This enzyme exhibited an optimum pH of 8.6 and an optimum temperature of 25°C and had Km s of 9.1 mM forl-glutamate and 4.5 mM for dl-ASA. DABA acetyltransferase catalyzed acetylation of DABA to γ-N-acetyl-α,γ-diaminobutyric acid (ADABA) with acetyl coenzyme A and exhibited an optimum pH of 8.2 and an optimum temperature of 20°C in the presence of 0.4 M NaCl. The molecular mass was 45 kDa by gel filtration. Ectoine synthase catalyzed circularization of ADABA to ectoine and exhibited an optimum pH of 8.5 to 9.0 and an optimum temperature of 15°C in the presence of 0.5 M NaCl. This enzyme had an apparent molecular mass of 19 kDa by SDS-PAGE and a Km of 8.4 mM in the presence of 0.77 M NaCl. DABA acetyltransferase and ectoine synthase were stabilized in the presence of NaCl (>2 M) and DABA (100 mM) at temperatures below 30°C.

scholarly journals Immobilization of Isolated Lipase From Moldy Copra(Aspergillus Oryzae)

2011 ◽  
Vol 8 (2) ◽  
pp. 896-902
Author(s):  
Seniwati Dali ◽  
A. B. D. Rauf Patong ◽  
M. Noor Jalaluddin ◽  
Pirman ◽  
Baharuddin Hamzah
Keyword(s):  
Thermal Stability ◽  
Aspergillus Oryzae ◽  
Immobilized Lipase ◽  
Optimum Temperature ◽  
Adsorption Method ◽  
Ph Optimum ◽  
Optimum Ph ◽  
Recovery Technique ◽  
Free Lipase

Enzyme immobilization is a recovery technique that has been studied in several years, using support as a media to help enzyme dissolutions to the reaction substrate. Immobilization method used in this study was adsorption method, using specific lipase fromAspergillus oryzae. Lipase was partially purified from the culture supernatant ofAspergillus oryzae. Enzyme was immobilized by adsorbed on silica gel. Studies on free and immobilized lipase systems for determination of optimum pH, optimum temperature, thermal stability and reusability were carried out. The results showed that free lipase had optimum pH 8,2 and optimum temperature 35 °C while the immobilized lipase had optimum 8,2 and optimum temperature 45 °C. The thermal stability of the immobilized lipase, relative to that of the free lipase, was markedly increased. The immobilized lipase can be reused for at least six times.

Copper-Catalyzed Tandem Multi-Component Approach to 1,3-Oxazines at Room Temperature by Cross-Dehydrogenative Coupling Using Methanol as C1 Feedstock

Synlett ◽  
2018 ◽  
Vol 29 (09) ◽  
pp. 1171-1175 ◽  
Author(s):  
Paran Borpatra ◽  
Mohit Deb ◽  
Pranjal Baruah
Keyword(s):  
Carbon Source ◽  
Room Temperature ◽  
Inert Atmosphere ◽  
Environmentally Benign ◽  
Metal Catalyst ◽  
Methylene Carbon ◽  
One Pot ◽  
Dehydrogenative Coupling ◽  
Tert Butyl Hydroperoxide ◽  
Component Approach

A copper(II)-catalyzed multi-component one-pot approach for the synthesis of 1,3-oxazines at room temperature is reported here. Methanol is used as the solvent as well as the carbon source. The methylene carbon of the oxazine product comes from methanol via formaldehyde. tert-Butyl hydroperoxide is used as the oxidant. The reaction uses an environmentally benign metal catalyst and oxidant. No inert atmosphere or precaution is required for the reaction. Most importantly, the reaction avoids the use of carcinogenic formaldehyde.

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