scholarly journals Aislamiento y caracterización de bacterias rojas no sulfurosas provenientes del humedal de la Mixtequilla, Veracruz (México)

2019 ◽  
pp. 33-38
Keyword(s):  
Carbon Sources ◽  
Terrestrial Ecosystems ◽  
The Other ◽  
Bacteriochlorophyll A ◽  
Energy Sources ◽  
Green Bacteria ◽  
Gram Negative ◽  
Liquid Cultures ◽  
Sulfur Bacteria ◽  
Pure Cultures

Aislamiento y caracterización de bacterias rojas no sulfurosas provenientes del humedal de la Mixtequilla, Veracruz (México) María Teresa Núñez Cardona, Magdalena Chávez Hernández y Martha Signoret Poillon Departamento el Hombre y su ambiente, Laboratorio de Ecología Microbiana, Universidad Autónoma Metropolitana-Xochimilco. Calzada del Hueso 1100. Col. Villa Quietud, 04960. Maestría en Ciencias Agropecuarias UAM-X. DOI: https://doi.org/10.33017/RevECIPeru2011.0019/ RESUMEN Las bacterias fotosintéticas están ampliamente distribuidas en los ecosistemas acuáticos y terrestres. De manera general, se les ha dividido en bacterias rojas y verdes (sulfurosas y no sulfurosas), las bacterias rojas no sulfurosas (BRNS) son las más versátiles en cuanto a su metabolismo se refiere ya que son capaces de utilizar un amplio rango de compuestos orgánicos como fuentes de carbono y/o energía. En los últimos años se les ha utilizado para la biorremediación de agua y suelos contaminados, así como para la producción de biofertilizantes y herbicidas; son de gran utilidad en la biotecnología y en la medicina. Pese a su gran utilidad, en México se ha estudiado poco a este grupo de microorganismos. Con el fin de contribuir al conocimiento de las bacterias fotótrofas, se aislaron y caracterizaron 10 cultivos de BRNS provenientes de muestras de agua colectadas en el humedal de la Mixtequilla, Veracruz. Para la caracterización de los cultivos bacterianos se consideró su morfología celular sus propiedades pigmentarias y su capacidad para utilizar diferentes compuestos orgánicos como únicas fuentes de carbono y/o energía. De acuerdo con los resultados obtenidos, los cultivos líquidos presentaron color marrón, café, rosa y rojo (característicos de las bacterias rojas fotótrofas), en todos se observó la presencia de células con formas de bacilos y su respuesta a la tinción de Gram fue negativa, todas produjeron bacterioclorofila a y en algunos cultivos se detectó espiriloxantina y licopeno. Diez cultivos fueron capaces de utilizar al piruvato, succínato, propionato, glicerol, acetato, etanol y extracto de la levadura; ocho utilizaron maltosa, manosa y sacarosa. Los sustratos menos utilizados fueron lactosa, benzoato, sacarosa, metanol y cisteína. Con base en lo expuesto por algunos autores y las características registradas en los cultivos de BRNS aisladas, se presume en éstos la presencia de miembros de los géneros Rhodopseudomonas, Rhodobacter, Rhodovulum y Rhodobium. Descriptores: Bacterioclorofila a, Bacterias rojas no sulfurosas, Rhodopseudomonas, Mixtequilla. ABSTRACT Phototrophic bacteria are widely distributed in aquatic and terrestrial ecosystems. These microorganisms are divided in purple and green bacteria (sulfur and nonsulfur), All of them are anaerobic and anoxygenic. Purple non sulfur bacteria (PNSB) are metabolically the most versatile, they are able to use a broad range of organic compounds as carbon and energy sources; by the other hand, they are chemoheterotrophic in the dark with minimal oxygen quantities. In the last years PNSB has been used in biorremediation, agriculture, biotechnology and medicine. The aim of this study was to isolate and to characterize purple non sulfur bacteria from la Mixtequilla wetland. It was obtained ten pure cultures of PNSB isolated from water samples collected at the Mixtequilla. Properties such as morphology, pigment and the use of different energy donors and carbon sources were used for characterizing PNSB. Results showed that liquid cultures were red and brown in color; Gram negative rods, and all produce bacteriochlorophyll a. The cultures mainly use as carbon and energy sources to piruvate, succinate, propionate, glycerol, acetate, ethanol and yeast extract; eight cultures use maltose, manose and sucrose; few cultures use lactose, benzoate, methanol and cysteine. According with these properties in the cultures there are members of the Rhodopseudomonas, Rhodobacter, Rhodovulum and Rhodobium genera. Keywords: bacteriochlorophyll a, purple non sulfur bacteria, Rhodopseudomonas, Mixtequilla.

Chemoautotrophic sulfur bacteria in the marine environment. I. Isolation, cultivation, and distribution

1969 ◽  
Vol 15 (4) ◽  
pp. 345-353 ◽  
Author(s):  
Frank W. Adair ◽  
K. Gundersen
Keyword(s):  
Energy Source ◽  
Small Volume ◽  
Elemental Sulfur ◽  
The Other ◽  
Mineral Salts ◽  
Gram Negative ◽  
Thiobacillus Thioparus ◽  
Sulfur Bacteria ◽  
Seawater Samples ◽  
Chemoautotrophic Bacteria

Chemoautotrophic sulfur bacteria were isolated in pure form from estuarine, neritic, and oceanic environments by the use of small-volume enrichment cultures. Thiosulfate was the only energy source added to the medium. Bicarbonate and carbon dioxide were the carbon sources.The bacteria were found in seawater samples collected at the surface and at a depth of 30 meters. Clay and mud sediments contained chemoautotrophs and heterotrophic pseudomonads with the capacity to oxidize thiosulfate.The isolated microorganisms differed greatly in their morphologies. Cells ranged in shape from vibrios to several varieties of rods which occurred alone, in pairs, in long chains, and in clusters. All of the bacteria were aerobic, Gram-negative, and non-sporulating.Growth characteristics with respect to the formation of elemental sulfur, production of tetrathionate, and final pH varied markedly. Colonies on thiosulfate – mineral salts agar were all 1 mm or less in diameter. A test, of two of the chemoautotrophs indicated a need for seawater in the growth medium.Out of a total of six different chemoautotrophic bacteria, one was identified as a strain of Thiobacillus thioparus. Another was facultatively autotrophic. The other four types were not compatible with the descriptions of any of the known thiobacilli.

scholarly journals Risorse e popolazione umana

2020 ◽  
pp. 21-45
Author(s):  
Nicolò Bellanca ◽  
Luca Pardi
Keyword(s):  
Cultural Evolution ◽  
Fossil Fuels ◽  
Homo Sapiens ◽  
Biological Evolution ◽  
Terrestrial Ecosystems ◽  
The Other ◽  
Energy Sources ◽  
Living Space ◽  
History Of ◽  
Rules Of The Game

The history of the genus Homo, and of the sapiens species in particular, is different from that of other species due to the extreme importance of cultural evolution compared to biological evolution. But from the discovery of how to use fire and generate it, up to the invention of the steam engine, man essentially lives, like the other organisms of the biosphere, on the energy flow guaranteed by solar radiation. With the encounter between machines and fossil fuels and the entry into the era of engines, the rules of the game change radically, and the activities of Homo sapiens change in extent and intensity, in such a way as to progressively reduce the living space of all other animal and plant species, except for the allied and commensal ones. The global industrialized society arising from the meeting between machines and fossil sources is presently facing two fundamental difficulties: the gradual saturation of terrestrial ecosystems with the waste of social and economic metabolism, and the finiteness of fossil energy sources, which are not easy replacement due to their special chemical-physical properties.

Disinfection of Fruits with Activated Water

2019 ◽  
Vol 10 ◽  
pp. 1864-1872
Author(s):  
Prof. Teodora P. Popova
Keyword(s):  
Antimicrobial Activity ◽  
Aqueous Solutions ◽  
Antimicrobial Properties ◽  
The Other ◽  
Gram Negative Bacteria ◽  
High Antimicrobial Activity ◽  
Gram Negative ◽  
E Coli ◽  
Number Of Microorganisms ◽  
Lower Effect

The effect of ionized aqueous solutions (anolytes and catholyte) in the processing of fruits (cherries, morellos, and strawberries) for decontamination has been tested. Freshly prepared analytes and catholyte without the addition of salts were used, as well as stored for 7 months anolytes, prepared with 0.5% NaCl and a combination of 0.5% NaCl and 0.5% Na2CO3. The anolyte prepared with a combination of 0.5% NaCl and 0.5% Na2CO3, as well as the anolyte obtained with 0.5% NaCl, exhibit high antimicrobial activity against the surface microflora of strawberries, cherries, and sour cherries. They inactivate E. coli for 15 minutes. The other species of the fam. Enterobacteriaceae were also affected to the maximum extent, as is the total number of microorganisms, especially in cherries and sour cherries. Even stored for 7 months, they largely retain their antimicrobial properties. Anolyte and catholyte, obtained without the addition of salts, showed a lower effect on the total number of microorganisms, but had a significant effect on Gram-negative bacteria, and especially with regard to the sanitary indicative E. coli.

Polityka klimatyczno-energetyczna Unii Europejskiej

2014 ◽  
pp. 104-121
Author(s):  
Aleksandra Kułaga
Keyword(s):  
Negative Impact ◽  
Renewable Energy Sources ◽  
Energy System ◽  
The Other ◽  
Energy Sources ◽  
Climate Protection ◽  
The European Union ◽  
Eu Member States ◽  
The Subject ◽  
Climate And Energy Policy

The article is devoted to the subject of the goals of the climate and energy policy of the European Union, which can have both a positive, and a negative impact on the environmental and energy policies. Positive aspects are the reduction of greenhouse gas emissions, diversification of energy supplies, which should improve Europe independence from energy imports, and increasing the share of renewable energy sources (RES) in the national energy system structures. On the other hand, overly ambitious targets and actions can lead to large losses for the economies of EU Member States. The article also highlights the realities prevailing in the international arena and noncompliance of international actors with global agreements on climate protection.

scholarly journals Anoxygenic photo- and chemosynthesis of phototrophic sulfur bacteria from an alpine meromictic lake

2021 ◽  
Author(s):  
Francesco Di Nezio ◽  
Clarisse Beney ◽  
Samuele Roman ◽  
Francesco Danza ◽  
Antoine Buetti-Dinh ◽  
...  
Keyword(s):  
Carbon Fixation ◽  
Meromictic Lake ◽  
Purple Sulfur Bacterium ◽  
Phototrophic Sulfur Bacteria ◽  
Anaerobic Microorganisms ◽  
Sulfur Bacteria ◽  
Pure Cultures ◽  
Chlorobium Phaeobacteroides ◽  
Anoxic Environment ◽  
Dark Carbon Fixation

Abstract Meromictic lakes are interesting ecosystems to study anaerobic microorganisms due their permanent stratification allowing the formation of a stable anoxic environment. The crenogenic meromictic Lake Cadagno harbors an important community of anoxygenic phototrophic sulfur bacteria responsible for almost half of its total productivity. Besides their ability to fix CO2 through photosynthesis, these microorganisms also showed high rates of dark carbon fixation via chemosyntesis. Here, we grew in pure cultures three populations of anoxygenic phototrophic sulfur bacteria previously isolated from the lake, accounting for 72.8% of the total microbial community, and exibiting different phenotypes: 1) the motile, large-celled purple sulfur bacterium (PSB) Chromatium okenii, 2) the small-celled PSB Thiodictyon syntrophicum, and 3) the green sulfur bacterium (GSB) Chlorobium phaeobacteroides. We measured their ability to fix CO2 through photo- and chemo-synthesis, both in situ in the lake and in laboratory under different incubation conditions. We also evaluated the efficiency and velocity of H2S photo-oxidation, an important reaction in the anoxygenic photosynthesis process. Our results confirm that phototrophic sulfur bacteria strongly fix CO2 in the presence of light and that oxygen increases chemosynthesis at night, in laboratory conditions. Moreover, substancial differences were displayed between the three selected populations in terms of activity and abundance.

Species differences in effect of gram-negative endotoxin on circulation

1961 ◽  
Vol 200 (6) ◽  
pp. 1197-1202 ◽  
Author(s):  
Hiroshi Kuida ◽  
Robert P. Gilbert ◽  
Lerner B. Hinshaw ◽  
Joel G. Brunson ◽  
Maurice B. Visscher
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricular ◽  
Species Differences ◽  
The Other ◽  
Short Segment ◽  
Gram Negative ◽  
Microscopic Studies ◽  
Significant Mechanism ◽  
Dramatic Fall ◽  
Made In

Studies were made in 5 monkeys, 7 rabbits, and 33 cats of the effect of gram-negative endotoxin on aortic, pulmonary artery (PAP), and portal venous (PVP) pressures; and on changes in weight of a short segment of intestine. Studies of blood pooling were also made in 12 cats. The responses in these species were compared with those previously observed in the dog. Although variable degrees of hypotension developed at one time or another in all animals following injection of endotoxin, the early precipitous hypotension that characteristically occurs in the dog was observed only in the cat. However, in this species the dramatic fall in pressure could be ascribed to pulmonary vascular constriction and acute right ventricular hypertension and failure, and not to splanchnic pooling. PAP also became elevated in the monkey and the rabbit, but usually was of lesser magnitude and did not appear to explain the development of the relatively late hypotension that occurred in these species. The absence of significant increases in gut weight and the minor increments in PVP in all animals indicate that in none of these species is hepatic vein constriction and splanchnic pooling a significant mechanism in producing early shock as it is in the dog. Pathologic gross and microscopic studies in the monkey and gross examinations in the other species supported this conclusion.

scholarly journals In Vitro and In Vivo Antibacterial Activities of DW-224a, a New Fluoronaphthyridone

2006 ◽  
Vol 50 (6) ◽  
pp. 2261-2264 ◽  
Author(s):  
Hee-Soo Park ◽  
Hyun-Joo Kim ◽  
Min-Jung Seol ◽  
Dong-Rack Choi ◽  
Eung-Chil Choi ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
The Other ◽  
Vitro Activity ◽  
Gram Negative Bacteria ◽  
In Vitro Activity ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

ABSTRACT DW-224a showed the most potent in vitro activity among the quinolone compounds tested against clinical isolates of gram-positive bacteria. Against gram-negative bacteria, DW-224a was slightly less active than the other fluoroquinolones. The in vivo activities of DW-224a against gram-positive bacteria were more potent than those of other quinolones.

Integration analysis of the carbon sources and sinks in terrestrial ecosystems, China

2021 ◽  
Vol 41 (19) ◽  
Author(s):  
赵宁，周蕾，庄杰，王永琳，周稳，陈集景，宋珺，丁键浠，迟永刚 ZHAO Ning
Keyword(s):  
Carbon Sources ◽  
Terrestrial Ecosystems ◽  
Sources And Sinks ◽  
Integration Analysis

scholarly journals Rapid Detection and Evaluation of Clinical Characteristics of Emerging Multiple-Drug-Resistant Gram-Negative Rods Carrying the Metallo-β-Lactamase GeneblaIMP

1998 ◽  
Vol 42 (8) ◽  
pp. 2006-2011 ◽  
Author(s):  
Yoichi Hirakata ◽  
Koichi Izumikawa ◽  
Toshiyuki Yamaguchi ◽  
Hiromu Takemura ◽  
Hironori Tanaka ◽  
...  
Keyword(s):  
Resistance Gene ◽  
Rapid Detection ◽  
Clinical Characteristics ◽  
The Other ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
Drug Resistant ◽  
Gram Negative ◽  
Multiple Drug Resistant ◽  
Tract Infections

Gram-negative rods (GNR) carrying the transferable carbapenem resistance gene blaIMP, includingPseudomonas aeruginosa and Serratia marcescens, have been isolated from more than 20 hospitals in Japan. Although the emergence of such multiple-drug-resistant bacteria is of utmost clinical concern, little information in regard to the distribution ofblaIMP-positive GNR in hospitals and the clinical characteristics of infected patients is available. To address this, a system for the rapid detection of theblaIMP gene with a simple DNA preparation and by enzymatic detection of PCR products was developed. A total of 933 ceftazidime-resistant strains of GNR isolated between 1991 and 1996 at Nagasaki University Hospital, Nagasaki, Japan, were screened for theblaIMP gene; 80 isolates were positive, including 53 P. aeruginosa isolates, 13 other glucose-nonfermenting bacteria, 13 S. marcescens isolates, and 1 Citrobacter freundii isolate. Most of the patients from whom blaIMP-positive organisms were isolated had malignant diseases (53.8%). The organisms caused urinary tract infections, pneumonia, or other infections in 46.3% of the patients, while they were just colonizing the other patients evaluated. It was possible that blaIMP-positive P. aeruginosa strains contributed to the death of four patients, while the other infections caused by GNR carryingblaIMP were not lethal. DNA fingerprinting analysis by pulsed-field gel electrophoresis suggested the cross transmission of strains within the hospital. The isolates were ceftazidime resistant and were frequently resistant to other antibiotics. Although no particular means of pathogenesis ofblaIMP-positive GNR is evident at present, the rapid detection of such strains is necessary to help with infection control practices for the prevention of their dissemination and the transmission of the resistance gene to other pathogenic bacteria.

Species interactions in mixed-community crystalline biofilms on urinary catheters

2007 ◽  
Vol 56 (11) ◽  
pp. 1549-1557 ◽  
Author(s):  
Sarah M. Macleod ◽  
David J. Stickler
Keyword(s):  
Urinary Tract ◽  
Species Interactions ◽  
The Other ◽  
Experimental Investigations ◽  
Crystal Formation ◽  
Urinary Catheters ◽  
E Coli ◽  
Pure Cultures ◽  
Providencia Stuartii

Previous experimental investigations of the crystalline biofilms that colonize and block urinary catheters have focussed on their formation by pure cultures of Proteus mirabilis. In the urine of patients undergoing long-term catheterization, P. mirabilis is commonly found in mixed communities with other urinary tract pathogens. Little is known about the effect that the other species have on the rate at which P. mirabilis encrusts catheters. In the present study, a set of data on the nature of the bacterial communities on 106 catheter biofilms has been analysed and it was found that while species such as Providencia stuartii and Klebsiella pneumoniae were commonly associated with P. mirabilis, when Escherichia coli, Morganella morganii or Enterobacter cloacae were present, P. mirabilis was rarely or never found. The hypothesis that the absence of P. mirabilis from some biofilm communities could be due to its active exclusion by other species has also been examined. Experiments in laboratory models showed that co-infection of P. mirabilis with M. morganii, K. pneumoniae or E. coli had no effect on the ability of P. mirabilis to encrust and block catheters. Co-infection with Ent. cloacae or Pseudomonas aeruginosa, however, significantly increased the time that catheters took to block (P <0.05). The growth of Ent. cloacae, M. morganii, K. pneumoniae or E. coli in the model for 72 h prior to superinfection with P. mirabilis significantly delayed catheter blockage. In the case of Ent. cloacae, for example, the mean time to blockage was extended from 28.7 h to 60.7 h (P ≤0.01). In all cases, however, P. mirabilis was able to generate alkaline urine, colonize the biofilms, induce crystal formation and block the catheters. The results suggest that although there is a degree of antagonism between P. mirabilis and some of the other urinary tract organisms, the effects are temporary and whatever the pre-existing urinary microbiota, infection with P. mirabilis is thus likely to lead to catheter encrustation and blockage.

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