Etude morphologique, physiologique et taxonomique de Bacillus azotoformans

1978 ◽  
Vol 24 (5) ◽  
pp. 608-617 ◽  
Author(s):  
F. Pichinoty ◽  
M. Durand ◽  
C. Job ◽  
M. Mandel ◽  
J. -L. Garcia
Keyword(s):  
Enrichment Culture ◽  
Tween 80 ◽  
Mean Value ◽  
Thiosulfate Reductase ◽  
Gram Positive Bacteria ◽  
Fermentative Activity ◽  
Phenylalanine Deaminase ◽  
Type C ◽  
Oxidase Reaction ◽  
Bacillus Azotoformans

Seventeen strains of the new species Bacillus azotoformans were isolated by enrichment culture in peptone broth inoculated with pasteurized soil and then incubated under N2O at 32 °C. The bacterium is a Gram-negative rod, motile with peritrichous flagella, which produces oval spores without exosporia in swollen sporangia. However, the cells have thick walls, mesosomes, and persistent septa characteristic of Gram-positive bacteria. The bacterium lacks fermentative activity, does not attack carbohydrates, has complex growth requirements, and will grow anaerobically only if one of the following electron acceptors is present: NO3−, NO2−, N2O, S4O6−−, or fumarate. Nitrate, nitrite, and nitrous oxide are denitrified with the production of N2. The microorganism is mesophilic, gives a positive oxidase reaction, synthesizes a type c cytochrome, and does not hydrolyse gelatin, starch, or "Tween 80." Poly-β-hydroxybutyric acid is synthesized when the bacterium is grown in a medium containing DL-3-hydroxybutyrate. The following enzymes are present: nitrate reductase A, respiratory nitrite reductase, tetrathionate and fumarate reductases, and L-glutamate dehydrogenase. The following enzymes are absent: thiosulfate reductase, urease, lecithinase, arginine dihydrolase, phenylalanine deaminase, and catalase. For the 17 strains, the mean value of the G + C percent of the DNA is 39.8 ± 1.2. All the strains are highly similar.

Efficacy of Nisin-Coated Polymer Films To Inactivate Salmonella Typhimurium on Fresh Broiler Skin†

2000 ◽  
Vol 63 (9) ◽  
pp. 1189-1196 ◽  
Author(s):  
NANDINI NATRAJAN ◽  
BRIAN W. SHELDON
Keyword(s):  
Salmonella Typhimurium ◽  
Shelf Life ◽  
Brain Heart Infusion ◽  
Tween 80 ◽  
Linear Low Density Polyethylene ◽  
Packaging Films ◽  
Gram Positive Bacteria ◽  
Subsequent Storage ◽  
Infusion Agar ◽  
Treatment Application

Nisin is an antimicrobial peptide produced by the food-grade microorganism Lactococcus lactis subsp. lactis. This peptide inhibits many gram-positive bacteria, and when combined with chelating agents it inhibits gram-negative bacteria such as Salmonella sp. The efficacy of packaging films treated with nisin-containing formulations to reduce Salmonella contamination of fresh broiler drumstick skin and increase the refrigerated shelf life was investigated. Three films (5.1 cm2) of varying hydrophobicities (polyvinyl chloride [PVC], linear low density polyethylene, nylon) were coated with one of three liquid formulations (pH 3.5 to 3.8) composed of 100 μg/ml nisin and varying concentrations of citric acid, EDTA, and Tween 80. The treated films were applied either wet or dry to 5.1-cm2 broiler drumstick skin samples inoculated with a nalidixic acid-resistant (NAr) strain of Salmonella Typhimurium. After incubation at 4°C for 24 h the populations of surviving Salmonella TyphimuriumNAr organisms were recovered from the skin and film samples using a rinse procedure and enumerated on brain heart infusion agar containing 800 ppm NA. Log reductions (untreated versus treated skin) in Salmonella TyphimuriumNAr populations ranged from 0.4 to 2.1. Treatment formulation compositions and wet versus dry treatment application also influenced the extent of kill. The shelf life of refrigerated broiler drumsticks was extended by 0.6 to 2.2 days following a 3-min immersion in a nisin-containing treatment solution and subsequent storage in a foam tray pack containing a nisin-treated PVC overwrap and a nisin-treated absorbent tray pad. These findings demonstrated that Salmonella Typhimurium and spoilage microorganism populations on the surface of fresh broiler skin and drumsticks can be significantly reduced using immersion treatments, absorbent tray pads, and packaging films treated with nisin-containing formulations.

scholarly journals AKTIVITAS ANTIMIKROBA EKSTRAK DAUN JAMBU BIJI DARI BEBERAPA KULTIVAR TERHADAP Staphylococcus aureus ATCC 25923 DENGAN HOLE-PLATE DIFFUSION METHOD

2003 ◽  
Vol 9 (1) ◽  
pp. 49-51
Author(s):  
Farida Lanawati Darsono ◽  
Stephanie Devi Artemisia
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Traditional Medicine ◽  
Tween 80 ◽  
Antibacterial Activities ◽  
Psidium Guajava ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Gram Positive Bacteria ◽  
Activity Test

A study has been performed on the antimicrobial activities of jambu biji (Psidium guajava Linn) leaves from several cultivars (red, white and yellow cultivar) against Staphylococcus aureus ATCC 25923 representing the Gram positive bacteria. The reason for conducting this research is that the leaves of jambu biji are frequently used in traditional medicine as a remedy against diarrhoea. The hole-plate diffusion method was used for conducting the antimicrobial activity test with antibiotics (Ampicilline trihidrat) as reference standards. The extracts of jambu biji for each cultivar were obtained by reflux with ethanol 96 percent. The concentrations of the extracts applied to the holes were 10 percent, 20 percent, and 30 percent w/v, the extracts were reconstituted with tween 80 and ethanol 96 percent. Based on the result of the study, it can be concluded that the extract of jambu biji from each cultivar with the concentration of 10 percent, 20 percent, and 30 percent w/v showed antibacterial activities against Staphylococcus aureus ATCC 25923. The result obtained statictically evaluated using Anava Factorial 3x3 and furthery tested for significancy (a = 0.05). Based on the results of study, it can be concluded that the extract of jambu biji leaves from red cultivar, white cultivar and yellow cultivar showed antibacterial activities against Staphylococcus aureus ATCC 25923.

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 Development of Microemulsion Containing Alpinia galanga Oil and Its Major Compounds: Enhancement of Antimicrobial Activities

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 265
Author(s):  
Nattakanwadee Khumpirapang ◽  
Srikanjana Klayraung ◽  
Singkome Tima ◽  
Siriporn Okonogi
Keyword(s):  
Tween 80 ◽  
Active Pharmaceutical Ingredient ◽  
Antimicrobial Activities ◽  
Methyl Eugenol ◽  
Gram Negative Bacteria ◽  
Alpinia Galanga ◽  
Killing Rate ◽  
Gram Positive Bacteria ◽  
Fungal Inhibition ◽  
Bacterial Concentrations

The aim of the present study was to develop a microemulsion (ME) containing Alpinia galanga oil (AGO), 1,8-cineole (C), or methyl eugenol (M) as an active pharmaceutical ingredient (API) for enhancing their antimicrobial activities. Agar diffusion, broth microdilution, and killing kinetics were used for antimicrobial evaluations. The ME composed of 30% API, 33.4% Tween 80, 16.6% ethanol, and 20% water appeared as translucent systems with droplet size and polydispersity index of 101.1 ± 1.3 nm and 0.3 ± 0.1, 80.9 ± 1.1 nm and 0.4 ± 0.1, and 96.6 ± 2.0 nm and 0.2 ± 0.1 for ME-AGO, ME-C, and ME-M, respectively. These ME formulations showed minimum bacterial concentrations of 3.91–31.25 µg/mL and 50% fungal inhibition concentrations of 1.83 ± 0.27–0.46 ± 0.13 µg/mL, 2–4 times stronger, and faster kinetic killing rate than their respective API alone. Keeping the ME formulations at 4 °C, 25 °C, and 40 °C for 12 weeks did not affect their activities against fungi and Gram-negative bacteria, but the high temperature of 40 °C decreased their activities against Gram-positive bacteria. It is concluded that ME is a promising delivery system for AGO and its major compounds to enhance their water miscibility and antimicrobial activities.

scholarly journals Methanobacterium kanagiense sp. nov., a hydrogenotrophic methanogen, isolated from rice-field soil

2011 ◽  
Vol 61 (6) ◽  
pp. 1246-1252 ◽  
Author(s):  
Koji Kitamura ◽  
Takashi Fujita ◽  
Shinji Akada ◽  
Akio Tonouchi
Keyword(s):  
Carbon Dioxide ◽  
Rice Field ◽  
Enrichment Culture ◽  
Sequence Similarity ◽  
Carbon Sources ◽  
Rrna Gene ◽  
Field Soil ◽  
Bacteria Growth ◽  
Gram Positive Bacteria ◽  
Rice Field Soil

A pure culture of an obligately anaerobic, hydrogenotrophic, methanogenic archaeon, designated strain 169T, which grows with hydrogen and carbon dioxide as the sole energy and carbon sources, was isolated from an anaerobic propionate-oxidizing enrichment culture originally obtained as an inoculant from rice-field soil in Japan. Cells of strain 169T were non-motile, Gram-reaction-variable and rod-shaped or slightly curved rods with rounded ends (1.6–5.0×0.35–0.5 µm). Strain 169T had fimbriae at both ends of the cell (up to ~10 per cell) but did not possess flagella. Ultrathin sections showed a single-layered, electron-dense cell wall about 6 nm thick, which is typical of Gram-positive bacteria. Growth was observed at 15 °C–45 °C (optimum 40 °C), at pH  6.5–9.6 (optimum pH 7.5–8.5) and in 0–70 g NaCl l−1 (0–1.2 M) (optimum 5 g NaCl l−1; 0.086 M). Strain 169T utilized only hydrogen and carbon dioxide as energy and carbon sources. The DNA G+C content was 39.3 mol%. The results of 16S rRNA gene sequence analysis indicated that strain 169T was most closely related to Methanobacterium subterraneum DSM 11074T (96.8 % sequence similarity) and Methanobacterium formicicum DSM 1535T (96.4 %). On the basis of its morphological, physiological and phylogenetic characteristics, strain 169T ( = DSM 22026T = JCM 15797T) represents a novel species of the genus Methanobacterium, for which the name Methanobacterium kanagiense sp. nov. is proposed.

Heritability of immunological characteristics in Florida Scrub-Jays (Aphelocoma coerulescens)

2013 ◽  
Vol 91 (11) ◽  
pp. 789-794 ◽  
Author(s):  
Travis E. Wilcoxen ◽  
Raoul K. Boughton ◽  
Gina M. Morgan ◽  
Stephan J. Schoech
Keyword(s):  
Immune Function ◽  
Natural Populations ◽  
Mean Value ◽  
Natal Philopatry ◽  
Florida Scrub ◽  
Gram Positive Bacteria ◽  
Aphelocoma Coerulescens ◽  
Immunological Phenotype ◽  
The Mean

The degree to which immunological phenotype is under genetic control as opposed to plasticity in response to variable environmental conditions remains largely unknown in natural populations. We assessed different aspects of immune function in father–son pairs in Florida Scrub-Jays (Aphelocoma coerulescens (Bosc, 1795)), a species with high natal philopatry, to determine if the responses were heritable. Specifically, we examined heritability of the (i) heterophil to lymphocyte ratio, (ii) ability to kill the Gram-negative bacteria Escherichia coli in an in vitro challenge, and (iii) ability to kill the Gram-positive bacteria Staphylococcus aureus in an in vitro challenge. The heritability (h2) of each of the three measures described above was estimated as twice the slope of the regression (2β) from the mean value for each measure for sons on the mean value of the same measure for the father. Heritability estimates were high for all measures: heterophil to lymphocyte ratios (h2 = 1.54 ± 0.31) and E. coli (h2 = 1.84 ± 0.12) and S. aureus (h2 = 1.13 ± 0.16) killing abilities. Our results show a strong correlation between father and son immune function, as well as the influential nature of genetic inheritance and potential environmental effects associated with high natal philopatry on physiology.

scholarly journals Intensification process in thyme essential oil nanoemulsion preparation based on subcritical water as green solvent and six different emulsifiers

2021 ◽  
Vol 10 (1) ◽  
pp. 430-439
Author(s):  
Omid Ahmadi ◽  
Hoda Jafarizadeh-Malmiri
Keyword(s):  
Xanthan Gum ◽  
Subcritical Water ◽  
Tween 80 ◽  
Sodium Caseinate ◽  
Pharmaceutical Formulations ◽  
Mean Value ◽  
Tween 20 ◽  
Colloidal Solutions ◽  
Plant Essential Oils ◽  
High Thermodynamic Stability

Abstract In order to alter the solubility and bioavailability of various functional lipids and plant essential oils (EOs), it is possible to prepare their oil in water (O/W) nanoemulsions. Thyme O/W nanoemulsions were prepared under subcritical water conditions (at 120°C and pressure of 1.5 atm for 2 h), using Tween 20, Tween 80, saponin, Arabic gum, xanthan gum, and sodium caseinate as emulsifiers. Results indicated that nanoemulsions with minimum mean droplet size of 11.5 and 12.6 nm were produced using Tween 20 and 80, respectively. Moreover, nanoemulsions with minimum polydispersity index (0.139) and maximum mean value of zeta potential (−24.5 mV) were provided utilizing xanthan gum and saponin, respectively. Results also revealed that the prepared nanoemulsions using saponin had maximum antioxidant activity based on percentage of scavenging ability (40.6%) and bactericidal effects against Streptococcus mutans as manifested in the formed clear zone (diameter of 21 mm). Morphological assessment of all the prepared nanoemulsions demonstrated that spherical thyme nanodroplets were formed in the colloidal solutions which revealed that all the prepared nanoemulsions had high thermodynamic stability due to the minimum surface energy level of the formed nanodroplets. This can increase applications of the prepared thyme O/W nanoemulsions in the aqueous food and pharmaceutical formulations.

scholarly journals Use of Micellar Delivery Systems to Enhance Curcumin’s Stability and Microbial Photoinactivation Capacity

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1777
Author(s):  
Victor Ryu ◽  
Silvette Ruiz-Ramirez ◽  
Piyanan Chuesiang ◽  
Lynne A. McLandsborough ◽  
David Julian McClements ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Sodium Citrate ◽  
Effective Interaction ◽  
Tween 80 ◽  
Citrate Buffer ◽  
Surfactant Micelles ◽  
Gram Positive Bacteria ◽  
Surfactant Solutions ◽  
Sodium Citrate Buffer ◽  
Water Dispersibility

Microbial photoinactivation using ultraviolet (UV) or visible light can be enhanced by photosensitizers. This study assessed the efficacy of encapsulating a food-grade photosensitizer (curcumin) in surfactant micelles on its water dispersibility, chemical stability, and antimicrobial activity. Stock curcumin-surfactant solutions were prepared with Surfynol 465 (S465) or Tween 80 (T80) (5 mM sodium citrate buffer). The antimicrobial activity of curcumin-loaded surfactant solutions was determined by monitoring the inactivation of Escherichia coli O157: H7 and Listeria innocua after 5-min irradiation with UV-A light (λ = 365 nm). The solutions mixed with the bacterial suspensions contained 1 µM curcumin and each surfactant below, near, and above their critical micelle concentrations (CMCs). The addition of surfactants at any level to the curcumin solution enhanced its dispersibility, stability, and efficacy as a photosensitizer, thereby enhancing its antimicrobial activity. Gram-positive bacteria were more susceptible than Gram-negative bacteria when curcumin-loaded micelles were used against them. The photoinactivation efficacy of curcumin-surfactant solutions depended on the pH of the solution (low > high), surfactant type (S465 > T80), and the amount of surfactant present (below CMC ≥ near CMC > above CMC = unencapsulated curcumin). This result suggests that excessive partitioning of curcumin into micelles reduced its ability to interact with microbial cells. Synergistic antimicrobial activity was observed when S465 was present below or near the CMC with curcumin at pH 3.5, which could be attributed to a more effective interaction of the photosensitizer with the cell membranes as supported by the fluorescence lifetime micrographs. The use of a micelle-based delivery system facilitates adsorption and generation of reactive oxygen species in the immediate environment of the microbial cell, enhancing photoinactivation.

scholarly journals THE DISTRIBUTION OF FRIEDLÄNDER'S BACILLI OF DIFFERENT TYPES

1930 ◽  
Vol 52 (4) ◽  
pp. 539-545 ◽  
Author(s):  
Louis A. Julianelle
Keyword(s):  
Type A ◽  
Immune Serum ◽  
Type B ◽  
Serological Type ◽  
Sugar Fermentation ◽  
Precipitin Reaction ◽  
Different Types ◽  
Fermentative Activity ◽  
Type C ◽  
Ferment Lactose

In a study of the distribution of the specific types of Friedländer's bacillus, it is shown that: (1) Of 80 strains 52 per cent belong to Type A, 15 per cent to Type B, 9 per cent to Type C, and 24 per cent to Group X. (2) Type A contains for the most part strains derived from diseases of man and more than 70 per cent are associated with pneumonia in man. (3) Type B includes the greatest number of strains from animal sources, while the heterogeneous strains comprising Group X come from the greatest variety of diseases. It was demonstrated that in a patient suffering with pneumonia due to Friedländer's bacillus (Type A), a specific precipitin reaction of the urine occurred in the corresponding (Type A) immune serum. A study of the sugar fermentation reactions of Friedländer's bacillus shows that (1) there is no correlation between serological type and fermentative activity; (2) the fermentation reactions are variable and therefore not reliable for distinguishing Friedländer's bacillus from closely allied organisms; (3) the strains of Group X show the greatest variation in fermentation, and (4) of 15 strains unable to ferment lactose, 13 belong to Type A.

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