Isolation, characterization, and identification ofGeobacillus thermodenitrificansHRO10, an α-amylase and α-glucosidase producing thermophile

2005 ◽  
Vol 51 (8) ◽  
pp. 685-693 ◽  
Author(s):  
Thaddeus C Ezeji ◽  
Arite Wolf ◽  
Hubert Bahl
Keyword(s):  
Carbon Source ◽  
Type Strain ◽  
Culture Supernatant ◽  
Amylase Activity ◽  
Inorganic Nitrogen ◽  
Hydrolysis Product ◽  
Aerobic Bacteria ◽  
Optimum Temperature ◽  
Geobacillus Thermodenitrificans ◽  
Selective Enrichment

Thermophilic and amylolytic aerobic bacteria were isolated from soil through a selective enrichment procedure at 60 °C with starch as the carbon source. One of the isolates designated as HRO10 produced glucose aside from limit dextrin as the only hydrolysis product from starch and was characterized in detail. The starch-degrading enzymes produced by strain HRO10 were determined to be α-amylase and α-glucosidase. Whereas the α-amylase activity was detected exclusively in the culture supernatant, α-glucosidase occurred intracellular, extracellular, or on the surface of the bacteria depending on the growth phase. The optimum temperature and pH required for the growth of strain HRO10 were about 50 °C and pH 6.5 to 7.5. The strain used different carbohydrates as the carbon source, but the maximum production of α-amylase occurred when 1.0% (w/v) starch or dextrin was used. The use of organic vs. inorganic nitrogen favored the production of α-amylase in strain HRO10. The metal ions Li+, Mg2+, and Mn2+stimulated the production of both enzymes. Identification of strain HRO10 by physiological and molecular methods including sequencing of the 16S rDNA showed that this strain belongs to the species Geobacillus thermodenitrificans. Biochemically, strain HRO10 differs from the type strain DSM 465 only in its ability to hydrolyze starch.Key words: thermophilic, amylolytic, α-amylase, α-glucosidase, Geobacillus thermodenitrificans.

Development of mutants of Gliocladium virens tolerant to benomyl

1990 ◽  
Vol 36 (7) ◽  
pp. 484-489 ◽  
Author(s):  
G. C. Papavizas ◽  
D. P. Roberts ◽  
K. K. Kim
Keyword(s):  
Carbon Source ◽  
Type Strain ◽  
Wild Type Strain ◽  
Carbon Sources ◽  
Sclerotium Rolfsii ◽  
Wild Type ◽  
Gliocladium Virens ◽  
Rhizosphere Competence ◽  
Filter Paper Cellulase ◽  
Type Strains

Aqueous suspensions of conidia of Gliocladium virens strains Gl-3 and Gl-21 were exposed to both ultraviolet radiation and ethyl methanesulfonate. Two mutants of Gl-3 and three of Gl-21 were selected for tolerance to benomyl at 10 μg∙mL−1, as indicated by growth and conidial germination on benomyl-amended potato dextrose agar. The mutants differed considerably from their respective wild-type strains in appearance, growth habit, sporulation, carbon-source utilization, and enzyme activity profiles. Of 10 carbon sources tested, cellobiose, xylose, and xylan were the best for growth, galactose and glucose were intermediate, and arabinose, ribose, and rhamnose were poor sources of carbon. The wild-type strains and the mutants did not utilize cellulose as the sole carbon source for growth. Two benomyl-tolerant mutants of Gl-3 produced less cellulase (β-1,4-glucosidase, carboxymethylcellulase, filter-paper cellulase) than Gl-3. In contrast, mutants of Gl-21 produced more cellulase than the wild-type strain. Only Gl-3 provided control of blight on snapbean caused by Sclerotium rolfsii. Wild-type strain Gl-21 and all mutants from both strains were ineffective biocontrol agents. Key words: Gliocladium, benomyl tolerance, Sclerotium, rhizosphere competence.

Statistical Analysis of Growth and Amylase Production by Aspergillus flavus grown on Different Carbon Sources

2013 ◽  
Vol 2 (1) ◽  
Author(s):  
M O Oyewale
Keyword(s):  
Carbon Source ◽  
Aspergillus Flavus ◽  
Amylase Activity ◽  
Carbon Sources ◽  
Dry Weight ◽  
Soluble Starch ◽  
Optimum Growth ◽  
Amylase Production ◽  
Level Of Significance ◽  
Cassava Peel

The mycelial dry weight and dinitrosalicylic acid (D.N.S.A.) method was used to determine growth and amylase production by Aspergillus flavus grown on different carbon sources. Growth of the fungus was determined at 24 h intervals over a period of six days by the dry mycelial weight methods, while the amylase activity in the culture filtrates of A. flavus was determined by the D.N.S.A method. A total of 45 samples were prepared to determine growth and amylase activity of Aspergillus flavus grown on different carbon sources. The concentration of the various carbon sources ranges between 0.4 to 2% W/V. Duncan’s multiple range test was used to determine the level of significance of the different carbon sources for effective growth and amylase production by Aspergillus flavus. Aspergillus flavus demonstrated the capability to produce significant growth and amylase activities in the medium containing soluble starch, sorghum and cassava peel as sole carbon source. The amount of mycelial dry weight produced from soluble starch, sorghum and cassava peel is significantly higher than those produced from other carbon sources. The data revealed that there is a correlation between growth and amylase production by Aspergillus flavus. The available data from this study showed that soluble starch is the best carbon source for optimum growth and amylase production by A flavus while sorghum and cassava peel are close substitute for optimum growth and amylase production by Aspergillus flavus. Keywords: Growth, amylase activity and Aspergillus flavus

scholarly journals Pseudomonas moraviensis sp. nov. and Pseudomonas vranovensis sp. nov., soil bacteria isolated on nitroaromatic compounds, and emended description of Pseudomonas asplenii

2006 ◽  
Vol 56 (11) ◽  
pp. 2657-2663 ◽  
Author(s):  
Ludmila Tvrzová ◽  
Peter Schumann ◽  
Cathrin Spröer ◽  
Ivo Sedláček ◽  
Zdena Páčová ◽  
...  
Keyword(s):  
Dna Hybridization ◽  
Type Strain ◽  
Additional Data ◽  
Sequence Similarity ◽  
Rrna Gene ◽  
Gram Negative Bacteria ◽  
Selective Enrichment ◽  
Gene Sequence Analysis ◽  
Emended Description ◽  
Pseudomonas Jessenii

Two strains of Gram-negative bacteria isolated from soil by selective enrichment with nitroaromatics were subjected to a polyphasic taxonomic study. On the basis of 16S rRNA gene sequence analysis, the two strains were found to belong to the genus Pseudomonas, within the Gammaproteobacteria. Strain 1B4T shared the highest sequence similarity with Pseudomonas koreensis DSM 16610T (99.5 %) and Pseudomonas jessenii CCM 4840T (99.3 %), and strain 2B2T with Pseudomonas asplenii DSM 17133T (98.9 %), Pseudomonas fuscovaginae DSM 7231T (98.9 %) and Pseudomonas putida DSM 291T (98.7 %). On the basis of phylogenetic analysis, DNA–DNA hybridization and phenotype, including chemotaxonomic characteristics, two novel species, Pseudomonas moraviensis sp. nov. with the type strain 1B4T (=CCM 7280T=DSM 16007T) and Pseudomonas vranovensis sp. nov. with the type strain 2B2T (=CCM 7279T=DSM 16006T), are proposed. The description of P. asplenii was emended on the basis of additional data obtained in this study.

scholarly journals Reductive, Coenzyme A-Mediated Pathway for 3-Chlorobenzoate Degradation in the Phototrophic BacteriumRhodopseudomonas palustris

2001 ◽  
Vol 67 (3) ◽  
pp. 1396-1399 ◽  
Author(s):  
Paul G. Egland ◽  
Jane Gibson ◽  
Caroline S. Harwood
Keyword(s):  
Carbon Dioxide ◽  
Carbon Source ◽  
Reductive Dechlorination ◽  
Coenzyme A ◽  
Rhodopseudomonas Palustris ◽  
Aromatic Acid ◽  
Enzyme Assays ◽  
Acetyl Coa ◽  
Selective Enrichment ◽  
Anaerobic Dechlorination

ABSTRACT We isolated a strain of Rhodopseudomonas palustris(RCB100) by selective enrichment in light on 3-chlorobenzoate to investigate the steps that it uses to accomplish anaerobic dechlorination. Analyses of metabolite pools as well as enzyme assays suggest that R. palustris grows on 3-chlorobenzoate by (i) converting it to 3-chlorobenzoyl coenzyme A (3-chlorobenzoyl–CoA), (ii) reductively dehalogenating 3-chlorobenzoyl–CoA to benzoyl-CoA, and (iii) degrading benzoyl-CoA to acetyl-CoA and carbon dioxide.R. palustris uses 3-chlorobenzoate only as a carbon source and thus incorporates the acetyl-CoA that is produced into cell material. The reductive dechlorination route used by R. palustris for 3-chlorobenzoate degradation differs from those previously described in that a CoA thioester, rather than an unmodified aromatic acid, is the substrate for complete dehalogenation.

Stimulation of dextranase production by oxidized dextran

1970 ◽  
Vol 16 (9) ◽  
pp. 841-844 ◽  
Author(s):  
Robert G. Brown
Keyword(s):  
Carbon Source ◽  
Nitrogen Source ◽  
Enzyme Production ◽  
Inorganic Nitrogen ◽  
Penicillium Funiculosum ◽  
Inorganic Nitrogen Source ◽  
Oxidized Dextran ◽  
Excess Glucose ◽  
Stimulation Of

Penicillium funiculosum, Penicillium lilacinum, and Spicaria violacea produced excellent yields of dextranase if ketodextran replaced dextran as a carbon source. Ketodextrans I and II having degrees of substitution of 2 and 20% respectively were used in this study. P. funiculosum grew equally well on dextran and ketodextran I but less well on ketodextran II. Addition of a readily metabolizable carbohydrate such as glucose, sucrose, or galactose stimulated growth on ketodextran II, resulting in better dextranase production. However, excess glucose reversed this increase in enzyme production. Replacement of an inorganic nitrogen source with an organic one further stimulated dextranase production during growth of P. funiculosum on ketodextran II.

THE EFFECTS OF TEMPERATURE UPON PANCREATIC AMYLASE IN SELECTED REPTILES AND AN AMPHIBIAN

1967 ◽  
Vol 45 (2) ◽  
pp. 227-232 ◽  
Author(s):  
Yvette Abrahamson ◽  
Michael Maher
Keyword(s):  
Thermal Stability ◽  
Amylase Activity ◽  
Effect Of Temperature ◽  
Maximum Temperature ◽  
Pancreatic Amylase ◽  
Optimum Temperature ◽  
Preferred Temperatures ◽  
Effects Of Temperature ◽  
Subcellular Level ◽  
Thermal Stability Of

The effect of temperature on pancreatic amylase was studied on three species of reptiles and one amphibian. Pancreata were removed from the animals, homogenized, and assayed for amylase activity by the Caraway procedure. Assays were conducted at various temperatures to determine the optimum temperature of activity and the maximum temperature for thermal stability of pancreatic amylase. It appears that between reptiles and amphibians, and also among species of reptiles, there are thermally dependent differences at the subcellular level which are similar to the differences in the preferred temperatures of the animals.

scholarly journals Isolation and risk assessment of Geotrichum spp. in the white shrimp (Litopenaeus vannamei Boone, 1931) from culture ponds

2017 ◽  
Vol 43 (4) ◽  
pp. 755-765
Author(s):  
José Luis Ochoa ◽  
Norma Ochoa-Alvarez ◽  
Maria Antonia Guzmán-Murillo ◽  
Sergio Hernandez ◽  
Felipe Ascencio
Keyword(s):  
Culture Supernatant ◽  
Amylase Activity ◽  
Primary Cultures ◽  
Opportunistic Pathogen ◽  
White Shrimp ◽  
Fungal Culture ◽  
Baja California Sur ◽  
La Paz ◽  
Fungal Adhesion ◽  
Great Mortality

The present study was done in order to identify the fungus invading some of the supralittoral ponds used for shrimp aquaculture in the CIBNOR facilities in La Paz, Baja California Sur (BCS), México during the summer season. From the walls and bottoms of the ponds, two strains of Geotrichum spp. were isolated and morphologically identified. Fungal adhesion towards hemocytes and primary cultures of various white shrimp (Litopeneaus vannamei) tissues (gill, tegument, and gut) was analyzed to determine infectivity. Extracellular protease, lipase, and amylase activity were evaluated as virulence factors. Survival of shrimp postlarvae (PL8) exposed to fungal culture supernatant or to their filaments was also investigated. The results showed that shrimp tegument cells and hemocytes were very susceptible to Geotrichum spp. invasion, and that this fungus provokes great mortality of post-larvae. Hence, Geotrichum spp. could be considered an opportunistic pathogen that might represent a serious health risk to shrimp in culture.

scholarly journals Curtobacterium flaccumfaciens pv. beticola, A New Pathovar of Pathogens in Sugar Beet

Plant Disease ◽  
2007 ◽  
Vol 91 (6) ◽  
pp. 677-684 ◽  
Author(s):  
Yong-Fang Chen ◽  
Yan-Ni Yin ◽  
Xiao-Mei Zhang ◽  
Jian-Hua Guo
Keyword(s):  
Sugar Beet ◽  
Type Strain ◽  
Genetic Relatedness ◽  
Tween 80 ◽  
Optimum Temperature ◽  
Dna Homology ◽  
Genetic Characteristics ◽  
Gram Positive Bacteria ◽  
Wide Range ◽  
Micro Organisms

Bacterial leaf spot of sugar beet was first discovered in 1995 in Inner Mongolia of China. The pathogen was shown to be a bacterium with properties of gram-positive bacteria: small irregular rods, lateral flagella, aerobic, and catalase-positive. The colonies of sugar beet strains produced a pale-yellow pigment. The optimum temperature for the bacteria to grow was 24 to 27°C. The bacteria could utilize a wide range of organic compounds, including hydrolyzed casein, starch, esculin and Tween 80, and released H2S from cysteine, cystine, and Na2S2O3·5H2O, but could not produce urease, oxidase, or indole. The cell wall peptidoglycan was based on ornithine (type B2β). The predominant menaquinone was MK-9. Polar lipids contained several glycosyldiacyl-glycerols. The DNA G+C content of a type strain of the new pathovar, T30T, was 67.5%. DNA-DNA homology between T30T and Curtobacterium flaccumfaciens pv. flaccumfaciens (International Collection of Micro-Organisms from Plants, New Zealand [ICMP] 2584) was 70.1%. The new pathovar and C. flaccumfaciens pv. flaccumfaciens had 99.9% identity in DNA sequence of 16S rRNA. Close genetic relatedness was observed for the representatives of the species Curtobacterium flaccumfaciens, but a low level of similarity between the different pathovars was found. Based on these physiological, biochemical, chemotaxonomic, phylogenetic, and genetic characteristics, we demonstrate that the pathogen represents a new pathovar of C. flaccumfaciens, for which we propose the name Curtobacterium flaccumfaciens pv. beticola pv. nov. The type strain is T30T (=ATCC BAA-144T).

scholarly journals The effect of thiourea on ureide metabolism in Neurospora crassa

1973 ◽  
Vol 136 (3) ◽  
pp. 749-755 ◽  
Author(s):  
Jasti Nirmala ◽  
Killampalli Sivarama Sastry
Keyword(s):  
Neurospora Crassa ◽  
Nitrogen Source ◽  
Type Strain ◽  
Wild Type Strain ◽  
Inorganic Nitrogen ◽  
Wild Strain ◽  
Sole Nitrogen Source ◽  
Wild Type ◽  
Selective Toxicity ◽  
In The Wild

The wild-type strain of Neurospora crassa Em 5297a can utilize allantoin as a sole nitrogen source. The pathway of allantoin utilization is via its conversion into allantoic acid and urea, followed by the breakdown of urea to ammonia. This is shown by the inability of the urease-less mutant, N. crassa 1229, to grow on allantoin as a sole nitrogen source and by the formation of allantoate and urea by pre-formed mycelia of this mutant. In the wild strain (Em 5297a) thiourea is tenfold more toxic on an allantoin medium than on an inorganic nitrogen medium; allantoin as well as urea counteract thiourea toxicity in the allantoin nitrogen medium. This selective toxicity of thiourea for the mould utilizing allantoin nitrogen does not, however, result in an impairment of allantoin uptake, allantoinase activity or the formation of urea from allantoin. The only process affected by thiourea is the synthesis of urease; urea antagonizes this effect of thiourea in N. crassa.

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