The absence of psychrophilic Thiobacillus ferrooxidans and acidophilic heterotrophic bacteria in cold, tailings effluents from a uranium mine

1994 ◽  
Vol 40 (1) ◽  
pp. 60-63 ◽  
Author(s):  
Deborah Berthelot ◽  
L. G. Leduc ◽  
G. D. Ferroni
Keyword(s):  
Thiobacillus Ferrooxidans ◽  
Incubation Temperature ◽  
Heterotrophic Bacteria ◽  
Uranium Mine ◽  
Temperature Range ◽  
Colony Forming Units ◽  
Iron Oxidizers

Iron-oxidizing autotrophs (mainly Thiobacillus ferrooxidans) and acidophilic heterotrophs were recovered and quantified at an incubation temperature of 18 °C, in four tailings-effluent samples obtained from the environment of a uranium mine in Ontario, Canada. The samples were collected during winter when the temperatures of the effluents were in the range 0.5–5.0 °C. Iron-oxidizing autotrophs were recovered in the four samples and their numbers ranged from 3 ± 2 to 185 ± 18 colony-forming units/mL; acidophilic heterotrophs were recovered in three of the four samples and their numbers ranged from 13 ± 3 to 2517 ± 859 colony-forming units/mL. Forty-six of the iron-oxidizer isolates and 63 of the acidophilic heterotrophic isolates were examined for their ability to grow at temperatures of 4, 18, 21, and 37 °C. None of the isolates was psychrophilic, although 96% of the iron oxidizers and 54% of the acidophilic heterotrophs were psychrotrophs; less that 5% of the isolates for both nutritional types were capable of growth at 37 °C. In addition, the isolates were categorized as 'broader temperature range psychrotrophs,' 'narrower temperature range psychrotrophs,' 'intermediates,' or mesophiles, and the narrower temperature range psychrotrophs were found to be numerically predominant.Key words: psychrotrophs, psychrophiles, Thiobacillus ferrooxidans, acidophilic heterotrophic bacteria.

Temperature studies of iron-oxidizing autotrophs and acidophilic heterotrophs isolated from uranium mines

1993 ◽  
Vol 39 (4) ◽  
pp. 384-388 ◽  
Author(s):  
Deborah Berthelot ◽  
L. G. Leduc ◽  
G. D. Ferroni
Keyword(s):  
Water Samples ◽  
Mine Water ◽  
Thiobacillus Ferrooxidans ◽  
Incubation Temperature ◽  
Temperature Growth ◽  
Temperature Range ◽  
Uranium Mines ◽  
Iron Oxidizing Bacteria ◽  
Colony Forming Units ◽  
Growth Profiles

Iron-oxidizing autotrophs and acidophilic heterotrophs were quantified at an incubation temperature of 18 °C in several samples obtained from the bioleaching areas of two uranium mines in Ontario, Canada. All samples were mine-water samples with temperatures in the range 13–18 °C. Iron-oxidizing autotrophs ranged from 2683 ± 377 to 245 000 ± 20 205 colony-forming units∙mL−1 and were always numerically superior to acidophilic heterotrophs, which ranged from 40 ± 8 to 9650 ± 161 colony-forming units∙mL−1. For each sample, approximately 20 isolates of each nutritional group were examined for the ability to grow at temperatures of 4, 18, 21, and 37 °C, respectively; overall, 559 isolates of iron-oxidizing bacteria (predominantly Thiobacillus ferrooxidans) and 252 acidophilic heterotrophic isolates were examined and categorized as 'broader temperature range psychrotrophs,' 'narrower temperature range psychrotrophs,' 'intermediates,' or mesophiles. Although psychrotrophic representatives of both groups were abundant, no psychrophiles were recovered from any of the samples. For the iron oxidizers, the temperature growth profiles of the isolates were similar from sample to sample. For the acidophilic heterotrophs, the temperature growth profiles varied considerably among samples.Key words: psychrotrophs; Thiobacillus ferrooxidans; uranium mines.

scholarly journals Growth characterisation of Staphylococcus aureus in milk: a quantitative approach

2009 ◽  
Vol 27 (No. 6) ◽  
pp. 433-453 ◽  
Author(s):  
A. Medveďová ◽  
Ľ. Valík ◽  
Z. Sirotná ◽  
D. Liptáková
Keyword(s):  
Staphylococcus Aureus ◽  
Growth Rate ◽  
Incubation Temperature ◽  
Food Poisoning ◽  
Raw Milk ◽  
Lag Phase ◽  
Phase Duration ◽  
Temperature Range ◽  
Root Model ◽  
Toxigenic Strains

<i>Staphylococcus aureus</i> is a pathogenic bacterium that induces several of human illnesses. The staphylococcal enterotoxin (SE) production as the results of previous growth of toxigenic strains is the most crucial problem which may lead to the staphylococcal food poisoning outbreaks in humans. That is why the growth of three strains of <i>Staphylococcus aureus</i> was characterised in milk and modelled in dependence of temperature. For the lag phase duration of <i>S. aureus</i> 2064, the Davey model was used with the following result: ln(1/lag) = 1.973 – 87.92/<i>T</i> + 285.09/<i>T</i><sup>2</sup> (<i>R</i><sup>2</sup> = 0.962). The dependence of the growth rate on incubation temperature was modelled by the Ratkowsky square root model and Gibson in sub-optimal and whole temperature range, respectively. The validation of both models showed high significance of the growth rate data fitting. The optimal temperature of <i>T</i><sub>opt</sub> = 38.5°C was resulted from Gibson model for the <i>S. aureus</i> 2064 growth in milk. For practical purpose, the time necessary for the increase of <i>S. aureus</i> by 3 log counts was also calculated within the growth temperature range. These data may provide useful information e.g. for the producers using raw milk in their artisanal cheese practice as the specific strains were used in this study.

Seasonal changes in heterotrophic bacteria under fast ice near Syowa station, Antarctica

1989 ◽  
Vol 35 (2) ◽  
pp. 329-333 ◽  
Author(s):  
Hiroo Satoh ◽  
Kimio Fukami ◽  
Kentaroo Watanabe ◽  
Eiji Takahashi
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Seasonal Changes ◽  
Heterotrophic Bacteria ◽  
Seasonal Succession ◽  
Austral Spring ◽  
Syowa Station ◽  
Colony Forming Units ◽  
Algal Assemblages ◽  
Fast Ice

Seasonal changes in the number of heterotrophic bacteria and the species composition of their communities were investigated in the fast ice area of Syowa station (69°00′S, 39°35′E), from May 1983 to January 1984. Numbers of heterotrophic bacteria under the fast ice began to increase in October and the maximum number of colony-forming units/mL (2.4 × 102) were obtained in late December. The changes in bacterial numbers coincided well with those of particulate organic carbon, suggesting that the growth of heterotrophic bacteria depends on the supply of particulate organic carbon from ice algal assemblages which grow rapidly at the bottom of sea ice during the austral spring. Vibrionaceans in the communities in September accounted for as much as 35% of the isolates, whereas in December, they were not detected at all. These results indicate that there is a seasonal succession in the bacterial communities between September and December.Key words: heterotrophic bacteria, vibrionaceans, fast ice, Antarctica.

Quantitative ecology of psychrophilic bacteria in an aquatic environment and characterization of heterotrophic bacteria from permanently cold sediments

1979 ◽  
Vol 25 (12) ◽  
pp. 1433-1442 ◽  
Author(s):  
L. G. Leduc ◽  
G. D. Ferroni
Keyword(s):  
Incubation Temperature ◽  
Heterotrophic Bacteria ◽  
Sulfate Reducing Bacteria ◽  
Gram Positive ◽  
Sulfate Reducing ◽  
Quantitative Ecology ◽  
Physiological Group ◽  
Sulfur Oxidizing ◽  
Reducing Bacteria

Aerobic heterotrophic bacteria, anaerobic heterotrophic bacteria, ammonifying bacteria, sulfur-oxidizing bacteria, and sulfate-reducing bacteria were quantitated in Fairbank Lake, an oligotrophic to mesotrophic lake with a permanently cold hypolimnion, as a function of depth in three seasons. Representatives of each physiological group were recovered at an incubation temperature of 2 °C and for all the physiological groups the 2 °C counts were usually higher than the 37 °C counts, although sulfate-reducing bacteria were not recoverable at an incubation temperature of 37 °C. In addition, the numbers of each physiological type were generally higher in the sediments than in the water column, except in the case of sulfate-reducing bacteria for which the counts were low and often below the detection limit. Aerobic heterotrophic bacteria usually outnumbered the other physiological groups surveyed, and winter minima were characteristic of some of the physiological groups. A relatively stable density of anaerobic heterotrophic bacteria, as a function of sediment depth, was observed when the incubation temperature was 2 °C. At 37 °C, these anaerobes were not detected, and this was true for sulfate-reducing bacteria at both temperatures.Heterotrophic bacterial isolates from the permanently cold sediments were examined with regard to Gram reaction, the obligate or facultative nature of anaerobes, ability to use ecologically important substrates, psychrophilic type, and temperature range for growth. Isolates recovered at 2 °C were predominantly Gram-negative bacilli, whereas isolates recovered at 37 °C were predominantly Gram-positive bacilli. The anaerobic isolates were mainly Gram-positive bacilli regardless of the isolation temperature, and most of those examined were obligately anaerobic. Many of the isolates tested were positive for gelatinase, chitinase, amylase, and lipase, but none was positive for cellulase. Most of the sediment isolates were facultatively psychrophilic and a considerable fraction of the 37 °C isolates were facultative psychrophiles.

scholarly journals Impact of temperature on the biological properties of soil

2016 ◽  
Vol 30 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Agata Borowik ◽  
Jadwiga Wyszkowska
Keyword(s):  
Granulometric Composition ◽  
Soil Microorganisms ◽  
Climate Changes ◽  
Incubation Temperature ◽  
Heterotrophic Bacteria ◽  
Biological Properties ◽  
Colony Development ◽  
Soil Microbiological Activity ◽  
Different Soils ◽  
Properties Of Soil

AbstractThe aim of the study was to determine the response of soil microorganisms and enzymes to the temperature of soil. The effect of the temperatures: 5, 10, 15, 20, and 25°C on the biological properties of soil was investigated under laboratory conditions. The study was performed using four different soils differing in their granulometric composition. It was found that 15°C was the optimal temperature for the development of microorganisms in soil. Typically, in the soil, the highest activity of dehydrogenases was observed at 10-15°C, catalase and acid phosphatase – at 15°C, alkaline phosphatase at 20°C, urease and β-glucosidase at 25°C. The highest colony development index for heterotrophic bacteria was recorded in soils incubated at 25°C, while for actinomycetes and fungi at 15°C. The incubation temperature of soil only slightly changed the ecophysiological variety of the investigated groups of microorganisms. Therefore, the observed climate changes might have a limited impact on the soil microbiological activity, because of the high ability of microorganisms to adopt. The response of soil microorganisms and enzymes was more dependent on the soil granulometric composition, organic carbon, and total nitrogen than on its temperature.

scholarly journals Antibacterial activity in three Chaetoceros microalgae species cultures by using antibiotics

2021 ◽  
Vol 56 (2) ◽  
pp. 111-121
Author(s):  
Yira D. Tapia-Gallardo ◽  
Miguel A. Del Río-Portilla ◽  
Ceres A. Molina-Cárdenas ◽  
M. del Pilar Sánchez-Saavedra
Keyword(s):  
Growth Rate ◽  
Antibacterial Activity ◽  
Heterotrophic Bacteria ◽  
Cell Concentration ◽  
Growth Parameters ◽  
Bacterial Load ◽  
Partial Reduction ◽  
Antibiotic Concentration ◽  
Colony Forming Units ◽  
Mutualistic Relationship

Diatoms, such as Chaetoceros, grow in a mutualistic relationship with bacteria. However, in some cases, it is necessary to grow them in bacteria-free cultures. To reduce bacterial load, antibiotics are used, and on certain occasions it is necessary to use a mixture with more than one antibiotic. This work aimed to obtain a quick and effective protocol to reduce the bacterial load and evaluate the response of three Chaetoceros species with aquacultural importance. Single and mix antibiotics were used. Microalgal and bacterial growth was measured. The growth parameters for diatoms showed that the significantly highest cell concentration was for C. muelleri (3.15 x106 cells mL-1) and the lowest values to C. calcitrans (2.98 x106 cells mL-1). The significantly highest growth rate was for C. calcitrans (0.77 divisions per day), and the lowest values for Chaetoceros sp. (0.60 divisions per day). The growth parameters for heterotrophic bacteria showed that the significantly highest bacterial load was for Chaetoceros sp. (19.16 x106 CFU (Colony-Forming Units) mL-1) and the lowest values were for C. calcitrans (12.23 x106 CFU mL-1). The growth rate of the heterotrophic bacteria present in Chaetoceros cultures was similar among the three studied species. Streptomycin® and sulfate G41® produced a partial reduction of bacterial load. The most effective treatment for all three species was the use of an antibiotic mix composed of ampicillin® (250 μg mL-1), kanamycin® (200 μg mL-1), neomycin® (50 μg mL-1), and streptomycin® (100 μg mL-1) for three days. The mix prepared with the highest antibiotic concentration produced a reduction of bacteria (100%) for three days; however, it also induced a significant reduction of the growth of the three Chaetoceros species.

scholarly journals THERMOPHILIC ORGANOTROPHIC BACTERIA OF THE GENUS MEIOTHERMUS IN ALKALINE HYDROTHERMS OF PRIBAIKALYE (BURYATIA)

2015 ◽  
Vol 4 (2) ◽  
pp. 30-32
Author(s):  
Valentina Grygoryevna Budagaeva ◽  
Darima Dondokovna Barkhutova
Keyword(s):  
Baikal Region ◽  
Microbial Mats ◽  
Hot Springs ◽  
Heterotrophic Bacteria ◽  
Hot Spring ◽  
Optimal Growth ◽  
Temperature Range ◽  
Hydrolytic Bacteria ◽  
Pure Cultures ◽  
Ph Range

Aerobic, facultative anaerobic hydrolytic bacteria are widespread in the sediments and microbial mats of alkaline hot springs in Baikal region (Buryatia). Typical representatives of hydrolytic bacteria are alkalotermophylic bacilli which are capable of utilizing organic matter in alkaline hot spring waters. Two pure cultures of bacteria growing on acetate, pyruvate and soetone were isolated from the microbial mat of Baikal region thermal springs (Buryatia). These strains were non-sporeforming straight or curved rods that morphologically similar to the representatives of the genus Meiothermus. Bacteria on agar medium formed small smooth pink colonies. Ecophysiological properties of isolates are studied (with respect to temperature and pH). Optimal growth temperature of culture Um-14-2-1 was 450C, the temperature range was 35-600C. The temperature range of strain Al-14-3 was 30-60C, with an optimum 50 C. The pH range of strain Um-14-2-1 is 6.5 to 9.5, the optimum of 8.0. The pH range of strain Al-14-3 is 6.5 to 9.5, the optimum of 8.5. Two thermophilic heterotrophic bacteria are similar to the genus Meiothermus by morphophysiological properties and the ability to thermophile, and are moderate thermophiles.

Changes in fungal populations during storage of Dalbergia bark

1981 ◽  
Vol 59 (6) ◽  
pp. 1102-1106
Author(s):  
D. K. Sandhu ◽  
D. S. Arora
Keyword(s):  
Aspergillus Nidulans ◽  
Common Species ◽  
Temperature Range ◽  
Colony Forming Units ◽  
Wide Range ◽  
Fungal Populations

Nineteen species of fungi were isolated during a 16-week successional study on Dalbergia bark. The most common species present throughout the succession were Aspergillus nidulans and A. fumigatus. Maximum colony forming units (CFU) were recorded during the 3rd week. The highest temperature recorded during the succession was 47 °C. In culture, most of the fungi showed a wide range of temperatures for growth, i.e. 15–47 °C; some were confined to a temperature range of 15–37 °C or 15–32 °C. Most of the fungi, except Acrophialophora fusispora, could utilize cellulose. Only seven fungi showed some lignin utilizing capacity.

Evaluation and use of a low nutrient medium and reduced incubation temperature to study bacterial contamination in the water supply of dental units

1994 ◽  
Vol 40 (2) ◽  
pp. 127-131 ◽  
Author(s):  
H. N. Williams ◽  
H. Quinby ◽  
E. Romberg
Keyword(s):  
Water Supply ◽  
Nutrient Medium ◽  
Bacterial Contamination ◽  
Bacterial Population ◽  
Incubation Temperature ◽  
Stagnant Water ◽  
Bacterial Colony ◽  
Colony Forming Units ◽  
Peptone Medium ◽  
Incubation Temperatures

A low nutrient medium, dilute peptone, and reduced incubation temperatures (25 or 30 °C) were used to recover bacteria from dental unit water supply. Significantly greater numbers of bacterial colony-forming units were recovered on the dilute peptone medium than on the enriched media, blood agar or trypticase soy agar. Lower incubation temperatures yielded greater numbers of colony-forming units on all media. The bacterial population in dental unit water supply following stagnation in the supply lines and flushing of the lines was studied using dilute peptone incubated at 25 °C. No significant differences in the numbers of colony-forming units were found in stagnant water versus fresh water. Flushing the water lines for 10 min did not significantly reduce the numbers of colony-forming units.Key words: dental unit water, water contamination, bacterial contamination.

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