scholarly journals Identification and Occurrence of Perfect Stage and Cultural and Morphological Variants of Colletotrichum gloeosporioides from Guava in Puerto Rico

1969 ◽  
Vol 56 (2) ◽  
pp. 171-180
Author(s):  
Lii-Jang Liu
Keyword(s):  
Puerto Rico ◽  
Optimum Temperature ◽  
Temperature Range ◽  
Optimum Ph ◽  
Conidial Stage ◽  
Colletotrichum Spp ◽  
Morphological Variants ◽  
Ph Range ◽  
Optimum Ph Range

Two strains of Colletotrichum spp., one dark and one light, were isolated from diseased fruits of guava in Puerto Rico. The isolates differ in cultural appearance, physiologic characteristics, and size of conidia. The optimum temperature range for mycelial growth of the dark strain lies between 24° and 28° C. The optimum temperature range for the light strain lies between 28° and 32° C. The optimum pH range for both strains lie between 5 and 7. Perithecia were produced when the dark strain was crossed with the light strain, or grown alone in potato dextrose agar at 24° to 28° C. Perithecia obtained from both isolates were typical of Glomerella cingulata. Ascospore isolations consistently resulted in the recovery of typical C. gloeosporioides cultures. Although conidia produced by the dark strain are significantly longer than those of the light strain, their perithecia are indistinguishable. Both strains are identified as C. gloeosporioides, the conidial stage of G. cingulata. The formation of the sexual stage of C. gloeosporioides in vitro in Puerto Rico has not been reported hitherto.

scholarly journals Vitamin A and carotenoids. The enzymic conversion of β-carotene into retinal in hog intestinal mucosa

1969 ◽  
Vol 114 (4) ◽  
pp. 689-694 ◽  
Author(s):  
Noel H. Fidge ◽  
Frank Rees Smith ◽  
DeWitt S. Goodman
Keyword(s):  
Intestinal Mucosa ◽  
Gel Filtration ◽  
Maximal Activity ◽  
Enzyme Preparations ◽  
Optimum Ph ◽  
Tween 40 ◽  
Ph Range ◽  
Optimum Ph Range ◽  
Β Carotene

The conversion of β-carotene into retinal was studied in vitro with enzyme preparations from homogenates of hog intestinal mucosa. The hog mucosal enzyme was purified about 27-fold by precipitation with ammonium sulphate, chromatography on DEAE-Sephadex and gel filtration on Sephadex G-200. The reaction displayed a narrow optimum pH range (approx. 7·8–8·2). The enzyme was stimulated strongly by the addition of thiols, and was inhibited by thiol inhibitors and by the chelating agents αα′-bipyridyl and o-phenanthroline. The reaction required the addition of an appropriate detergent (or bile salt); maximal activity was obtained by addition of an appropriate combination of detergents and lipid (specifically Tween 40, sodium glycocholate and sphingomyelin). The reaction displayed Michaelis kinetics with Km1·3×10−6m and Vmax.1·1nmole of retinal formed/hr. (for 0·7mg. of enzyme protein). The properties of the hog enzyme are similar to those previously reported for a less purified rat enzyme preparation.

scholarly journals Thermostable Alkaline Phytase from Alcaligenes sp. in Improving Bioavailability of Phosphorus in Animal Feed: In Vitro Analysis

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ponnuswamy Vijayaraghavan ◽  
R. Raja Primiya ◽  
Samuel Gnana Prakash Vincent
Keyword(s):  
Inorganic Phosphate ◽  
Animal Feed ◽  
Alkaline Phytase ◽  
Optimum Ph ◽  
Green Pea ◽  
Ph Range ◽  
Vitro Analysis ◽  
Optimum Ph Range ◽  
In Vitro Analysis

A bacterial isolate, Alcaligenes sp. secreting phytase (EC 3.1.3.8), was isolated and characterized. The optimum conditions for the production of phytase included a fermentation period of 96 h, pH 8.0, and the addition of 1% (w/v) maltose and 1% (w/v) beef extract to the culture medium. This enzyme was purified to homogeneity and had an apparent molecular mass of 41 kDa. The optimum pH range and temperature for the activity of phytase were found to be 7.0-8.0 and 60°C, respectively. This enzyme was strongly inhibited by 0.005 M of Mn2+, Mg2+, and Zn2+. In vitro studies revealed that the phytase from Alcaligenes sp. released inorganic phosphate from plant phytates. Phytase released 1930 ± 28, 1740 ± 13, 1050 ± 31, 845 ± 7, 1935 ± 32, and 1655 ± 21 mg inorganic phosphate/kg plant phytates, namely, chick pea, corn, green pea, groundnut, pearl pea, and chick feed, respectively.

Effects of incubation fluid pH and fibrolytic enzymes on the in vitro fermentation of pure substrates, assessed using the Reading Pressure Technique (RPT)

2002 ◽  
Vol 2002 ◽  
pp. 208-208 ◽  
Author(s):  
D. Colombatto ◽  
F. L. Mould ◽  
M. K. Bhat ◽  
E. Owen
Keyword(s):  
In Vitro Fermentation ◽  
Commercial Enzyme ◽  
Fibrolytic Enzymes ◽  
Optimum Activity ◽  
Ph Values ◽  
Optimum Ph ◽  
Ph Conditions ◽  
Ph Range ◽  
Optimum Ph Range

Modern feeding practices often lead to ruminal conditions being sub-optimal for fibre digestion. It has been speculated that fibrolytic enzymes, which usually show optimum activity at pH values below 6.0, may be of benefit when applied to diets of high producing animals. This study used a commercial enzyme mixture (EM), already identified as effective; to investigate its optimum pH range with respect to activity and its impact on the fermentation profiles of pure substrates, under differing pH conditions.

scholarly journals Haem disorder in modified myoglobins. Effect of reconstitution procedures

1983 ◽  
Vol 215 (1) ◽  
pp. 117-122 ◽  
Author(s):  
M B Ahmad ◽  
J R Kincaid
Keyword(s):  
Selective Oxidation ◽  
High Spin ◽  
Chromatographic Purification ◽  
Optimum Ph ◽  
Ph Range ◽  
Optimum Ph Range

Apomyoglobin was reconstituted with deuterohaem derivatives under various conditions. The fraction of disordered component, which is characterized by a 180 degree rotation of the haem group, for the various preparations was determined by n.m.r. spectroscopy. By using the procedures described, it was shown that the fraction of disordered component is minimized if the reconstitution is carried out with high-spin ferric haem derivatives within an experimentally determined optimum pH range of 8-9.5. Use of low-spin derivatives in either the ferrous or ferric forms leads to substantial increases in the fraction of disordered form. Attempted removal of the disordered form by selective oxidation and chromatographic purification was not effective.

CHARACTERISTICS OF FOUR RHIZOBIOPHAGES ACTIVE AGAINST RHIZOBIUM MELILOTI

1957 ◽  
Vol 3 (4) ◽  
pp. 651-668 ◽  
Author(s):  
D. T. Parker ◽  
O. N. Allen
Keyword(s):  
Rhizobium Meliloti ◽  
The Other ◽  
Cross Reactions ◽  
Thermal Death ◽  
Optimum Ph ◽  
Ph Range ◽  
Optimum Ph Range ◽  
Standard Techniques

Four phage isolates for strains of Rhizobium meliloti were obtained from sewage and held soil and purified by standard techniques. Plaque sizes ranged from 1.0 to 4.0 mm. The titers of these phages remained unchanged after 24 months' storage at 0° and 4 °C. None of the phages lysed all of the 38 strains of R. meliloti tested, although 29 of these strains were lysed by one of the phages. Of 292 other strains of rhizobia isolated from 108 species of 50 leguminous genera, one of the phages lysed six strains, another, five strains, while the other two phages did not lyse any. None of the phages lysed any of the 40 strains of Agrobaderium and Chromobaderium species tested. Inactivation rates of the four phages by their homologous antisera were linear up to 90% inactivation. Cross-reactions with heterologous antisera showed weak serological relationships between some of the phages. The latent periods of growth ranged from 80 to 90 minutes to 170–180 minutes. Burst sizes of rhizobia infected by the four phages ranged from 80 to 317 particles per bacterium after an adsorption period of 60 minutes at 30 °C. The optimum pH range was 6.4–7.8. Thermal death points in broth were 51 °C, 53 °C, 61 °C, and 70 °C, respectively, for the four phages.

scholarly journals The subcellular distribution of triphosphoinositide phosphomonoesterase in guinea-pig brain

1972 ◽  
Vol 128 (3) ◽  
pp. 579-586 ◽  
Author(s):  
A. Sheltawy ◽  
M. Brammer ◽  
D. Borrill
Keyword(s):  
Guinea Pig ◽  
Subcellular Fractions ◽  
Assay System ◽  
Acid Phosphatases ◽  
Alkaline Phosphatases ◽  
Pig Brain ◽  
Optimum Ph ◽  
Ph Range ◽  
Guinea Pig Brain ◽  
Optimum Ph Range

1. Some properties of the triphosphoinositide phosphomonoesterase from the homogenates of guinea-pig brain were studied. The enzyme has an optimum pH range 6.7–7.3, is stimulated with KCl at a concentration of 0.1m, and under these conditions has Km1.43×10-4m. 2. A factor from the ‘pH5 supernatant’ of guinea-pig brain stimulates the enzyme activity over and above the stimulation produced by KCl. Subcellular fractions of guinea-pig brain varied in their response to the ‘pH5 supernatant’. Maximum stimulation was observed with the P1 fraction, containing myelin and nuclei. 3. An assay system for the enzyme was developed that contained optimum concentrations of both KCl and the ‘pH5 supernatant’. Acid phosphatases were inhibited by NaF, but, in contrast with previous work, no EDTA was added to the assay system to inhibit the alkaline phosphatases. This reagent inhibited the triphosphoinositide phosphomonoesterase. It was estimated that the remaining fraction of non-specific phosphatases can account for only 14% of the observed triphosphoinositide phosphomonoesterase activity. 4. Subcellular fractions of guinea-pig brain were characterized by electron microscopy and subcellular markers. The triphosphoinositide phosphomonoesterase exhibited a distribution between the fractions similar to that of 5′-nucleotidase, but different from that of alkaline phosphatase.

scholarly journals Protease from Aspergillus oryzae: Biochemical Characterization and Application as a Potential Biocatalyst for Production of Protein Hydrolysates with Antioxidant Activities

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Ruann Janser Soares de Castro ◽  
Helia Harumi Sato
Keyword(s):  
Aspergillus Oryzae ◽  
Biochemical Characterization ◽  
Antioxidant Activities ◽  
Soy Protein Isolate ◽  
Antioxidant Properties ◽  
Protein Isolate ◽  
Protein Hydrolysates ◽  
Optimum Temperature ◽  
Temperature Range ◽  
Ph Range

This study reports the biochemical characterization of a protease from Aspergillus oryzae LBA 01 and the study of the antioxidant properties of protein hydrolysates produced with this protease. The biochemical characterization showed that the enzyme was most active over the pH range 5.0–5.5 and was stable from pH 4.5 to 5.5. The optimum temperature range for activity was 55–60°C, and the enzyme was stable at temperatures below 45°C. The activation energy (Ea) for azocasein hydrolysis and temperature quotient (Q10) were found to be 37.98 kJ mol−1 and 1.64–1.53 at temperature range from 30 to 55°C, respectively. The enzyme exhibited t1/2 of 97.63 min and a D value of 324.31 at the optimum temperature for activity (57.2°C). Protease from A. oryzae LBA 01 was shown as a potentially useful biocatalyst for protein hydrolysis, increasing the antioxidant activities of soy protein isolate, bovine whey protein, and egg white protein from 2.0- to 10.0-fold.

Coagulation/flocculation of dye-containing solutions using polyaluminium chloride and alum

2009 ◽  
Vol 59 (7) ◽  
pp. 1343-1351 ◽  
Author(s):  
M. Hasani Zonoozi ◽  
M. R. Alavi Moghaddam ◽  
M. Arami
Keyword(s):  
Dye Removal ◽  
Coagulant Dosage ◽  
Optimum Ph ◽  
Ph Range ◽  
Influence Of Ph ◽  
Acid Blue ◽  
Ph Variations ◽  
Optimum Ph Range ◽  
Low Dosage ◽  
Polyaluminium Chloride

This study aims to compare the performance of Polyaluminium Chloride (PAC) and alum as coagulants to remove a specific type of dye (Acid Blue 292 (AB292)) from dye-containing solution. For this purpose, the influence of pH, coagulant dosage, coagulant aids (kaolinite and bentonite), and initial dye concentration on dye removal efficiency were examined. According to the results, removal of AB292 was absolutely dependent on the pH variations. The maximum dye removal occurred when pH was 7 and 5 for PAC and alum, respectively. Both coagulants efficiently removed the dye (about 85%) with a relatively low dosage (40 mg/l) in their optimum pH range. By adding kaolinite as a coagulant aid, the removal efficiencies tended to increase, especially for lower dosages of PAC and alum. With the increase of initial dye concentration, PAC and alum represented different behaviors. In the case of PAC, Q (the amount of the removed dye per unit mass of coagulant) increased at first and reached to a maximum value, 2.1 mg dye/mg PAC, and then decreased rapidly. While for alum, Q steadily increased with the increase of dye concentration and reached to 2.8 mg dye/mg alum. No reduction of Q occurred for alum with the increase of dye concentration in the range of 25–250 mg/l.

scholarly journals Corynespora Leaf Spot of Papaya (Carica papaya L.) in Puerto Rico

1969 ◽  
Vol 55 (4) ◽  
pp. 411-425
Author(s):  
Pedro Luis Meléndez ◽  
Julio Bird Piñero
Keyword(s):  
Puerto Rico ◽  
Puerto Rican ◽  
Carica Papaya ◽  
Corynespora Cassiicola ◽  
Optimum Temperature ◽  
Santa Cruz ◽  
Highly Pathogenic ◽  
Optimum Ph ◽  
Pathogenicity Tests ◽  
Main Station

The fungus Corynespora cassiicola (Berk. & Curt.) Wei, causal agent of "greasy spot" or "papaya decline" in St. Croix, was found invading papaya plants of both Solo and Puerto Rican varieties in the Gurabo and Isabela Substations and in the Solis field in the Main Station. Plants of both varieties in the field appeared severely affected by the fungus as evidenced by heavy spotting on the foliage and the stems and by premature defoliation of the trees. Pathogenicity tests conducted with three isolates of the fungus isolated from Gurabo (Gurabo isolate), from Isabela (Isabela isolate), and from diseased-papaya plants from St. Croix (Santa Cruz isolate), proved that it is highly pathogenic to both Solo and Puerto Rican papayas. Optimum temperature and optimum pH for growth of the fungus, as well as the best medium for growth and sporulation, were determined. Cultural characteristics, response to varying temperatures, morphology, and symptoms expressed by inoculated plants of both papaya varieties were similar for all three isolates studied.

scholarly journals Rice Blast in Puerto Rico

1969 ◽  
Vol 62 (3) ◽  
pp. 290-300
Author(s):  
Lii-Jang Liu
Keyword(s):  
Puerto Rico ◽  
Rice Straw ◽  
Rice Blast ◽  
Mycelial Growth ◽  
Potato Dextrose Agar ◽  
Pyricularia Oryzae ◽  
In Vitro Tests ◽  
Optimum Temperature ◽  
Pathogenicity Tests

Rice blast, which had not been observed during the last six decades in Puerto Rico, reappeared recently in Manatí and in the Gurabo Substation, affecting Brazos, a cultivar introduced from Texas. Pathogenicity tests, as well as studies on the conidial morphology, showed that the fungus isolated from typical blast lesions is Pyricularia oryzae Cav. The physiology of the fungus and its sporulation on various media also were studied. The optimum temperature range, both for mycelial growth and for germination of conidia, was found to be between 24 to 28° C. Sporulation occurred satisfactorily on potato-dextrose agar enriched with coconut milk, and on steamed corn and barley, and rice-straw-decoction agars. In vitro tests with fungicides benomyl, pentachloronitrobenzene, mancozeb, chloroneb, and captan indicated that the first two compounds are the most effective in inhibiting mycelial growth of P. oryzae.

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