Soil Microbiology Research Papers - Academia.edu (original) (raw)

Phospholipid fatty acid (PLFA) analysis of a soil microbial community was coupled with 13C isotope tracer analysis to measure the community’s response to addition of 35 μg of [13C]toluene ml of soil solution−1. After 119 h of incubation... more

Phospholipid fatty acid (PLFA) analysis of a soil microbial community was coupled with 13C isotope tracer analysis to measure the community’s response to addition of 35 μg of [13C]toluene ml of soil solution−1. After 119 h of incubation with toluene, 96% of the incorporated 13C was detected in only 16 of the total 59 PLFAs (27%) extracted from the soil. Of the total 13C-enriched PLFAs, 85% were identical to the PLFAs contained in a toluene-metabolizing bacterium isolated from the same soil. In contrast, the majority of the soil PLFAs (91%) became labeled when the same soil was incubated with [13C]glucose. Our study showed that coupling 13C tracer analysis with PLFA analysis is an effective technique for distinguishing a specific microbial population involved in metabolism of a labeled substrate in complex environments such as soil.

The efficacy of a new rhamnolipid biosurfactants mixture to enhance the removal of pyrene from a soil artificially contaminated was investigated. The molar solubilization ratio (MSR) and the partition coefficient between the micelles and... more

The efficacy of a new rhamnolipid biosurfactants mixture to enhance the removal of pyrene from a soil artificially contaminated was investigated. The molar solubilization ratio (MSR) and the partition coefficient between the micelles and water (log K(m)) were found to be 7.5 x 10(-3) and 5.7, respectively. From soil column studies, the pyrene removal increased linearly with the concentration of the injected biosurfactants solution above the effective critical micellar concentration (0.4 g L(-1)). Flushing with a 5.0 g L(-1) biosurfactants solution increased the pyrene concentration in the effluent by 178 times. At high biosurfactants' concentrations (2.5 and 5.0 g L(-1)), the cumulative pyrene recovery reached 70%. This pyrene remobilization takes place independently of the soil organic carbon solubilization. This study provides a combination of batch and column experiments in order to find the conditions for effective soil remediation using a new rhamnolipids mixture.

Five new meroterpenoids, purpurogenolides A-E (1-5), and four known metabolites (6-9) were isolated from the solid substrate fermentation cultures of the fungus Penicillium purpurogenum MHz 111. The structures of the new meroterpenoids... more

Five new meroterpenoids, purpurogenolides A-E (1-5), and four known metabolites (6-9) were isolated from the solid substrate fermentation cultures of the fungus Penicillium purpurogenum MHz 111. The structures of the new meroterpenoids were elucidated by analysis of spectroscopic and spectrometric data (1D and 2D NMR, IR, and HRESIMS). The absolute configurations of 1 and 5 were determined by single-crystal X-ray crystallographic analysis, and those of 2-4 were elucidated on the basis of experimental and calculated electronic circular dichroism spectra. Compounds 2-4 and 6 showed inhibition of nitric oxide production in lipopolysaccharide-activated BV-2 microglial cells with IC50 values of 0.8-30.0 μM.

Sporotrichosis is the most common subcutaneous mycosis in South America. Classic infection is associated with traumatic inoculation of soil, vegetables, and organic material contaminated with Sporothix schenckii. Animals of various... more

Sporotrichosis is the most common subcutaneous mycosis in South America. Classic infection is associated with traumatic inoculation of soil, vegetables, and organic material contaminated with Sporothix schenckii. Animals of various species, including humans, are affected by this disease. This subcutaneous mycosis is an infection of implantation. The most frequent clinical form is the lymphocutaneous form. The fixed cutaneous form is characterized by infiltrated nodular, ulcerated, or erythematosquamous lesions located on exposed areas where fungal inoculation occurred. The disseminated cutaneous forms have mainly been observed among immunosuppressed patients, especially human immunodeficiency virus-positive individuals. Sporotrichosis is the only subcutaneous mycosis for which direct examination or histology is of little or no value for diagnosis. The diagnosis rests solely on the isolation of S schenckii in culture. Since 1998, researchers from Brazil suggested that feline transmis...

BackgroundFungi strongly influence ecosystem structure and functioning, playing a key role in many ecological services as decomposers, plant mutualists and pathogens. The Mediterranean area is a biodiversity hotspot that is increasingly... more

BackgroundFungi strongly influence ecosystem structure and functioning, playing a key role in many ecological services as decomposers, plant mutualists and pathogens. The Mediterranean area is a biodiversity hotspot that is increasingly threatened by intense land use. Therefore, to achieve a balance between conservation and human development, a better understanding of the impact of land use on the underlying fungal communities

Twenty-one strains of a novel ascomycetous yeast species were isolated from soil collected in three kinds of natural forest, namely a dry dipterocarp forest, a mixed deciduous forest and a pine forest, in Nam Nao National Park, Phetchabun... more

Twenty-one strains of a novel ascomycetous yeast species were isolated from soil collected in three kinds of natural forest, namely a dry dipterocarp forest, a mixed deciduous forest and a pine forest, in Nam Nao National Park, Phetchabun province, Thailand. The strains formed asci containing one to four ovoid to reniform ascospores, assimilated glucose, galactose and glycerol, fermented glucose and galactose vigorously and contained ubiquinone Q-6, indicating that they belonged to the genus Tetrapisispora. A comparative analysis of the small subunit rDNA (SSU rDNA) and the D1/D2 domain of the large subunit rDNA (LSU rDNA) of all available sequences for ascomycetous yeasts confirmed that the strains were phylogenetically related to the genus Tetrapisispora. All strains had identical nucleotide sequences in the D1/D2 domain of the LSU rDNA and differed from the nearest species, Tetrapisispora arboricola IFO 10925(T), by 6.4% nucleotide substitutions. The strains differed from Tetrapisispora arboricola by the ability to assimilate D-gluconic acid, the inability to grow on 50% glucose medium, the nuclear DNA base composition and deliquescent asci. The strains were differentiated from the other four species of Tetrapisispora on the basis of trehalose assimilation, the ability to grow on 50% glucose or 10% NaCl plus 5% glucose, vitamin requirement, the nuclear DNA base composition and the type of ascus. Based on the characteristics mentioned above, the strains are recognized as a single novel species of the genus Tetrapisispora and the name Tetrapisispora namnaonensis sp. nov. is proposed. The type strain is TN1-01(T) (=TISTR 5828(T)=JCM 12664(T)=CBS 10093(T)).

To evaluate the sustainable phosphorous management in maize (Zea mays L.) through seed inoculation with phosphorous solubilizer microorganism (PSM), a field experiment was conducted during spring 2012 at Agronomic Research... more

To evaluate the sustainable phosphorous management in maize (Zea mays L.) through
seed inoculation with phosphorous solubilizer microorganism (PSM), a field experiment was conducted
during spring 2012 at Agronomic Research Farm, University of Agriculture, Faisalabad. The experiment
was laid out in RCBD (Randomized Complete Block Design) with factorial arrangement with three
replications using the net plot size of 6.0 m x 3.0 m. The experiment was comprised of two factors. Fac tor
A (Level of phosphorus) was consist of three treatments I (recommended dose of phosphorus 120kg ha
-1
)
II (75% of recommended dose of phosphorus 90kg ha
-1
) III (50% of recommended dose of phosphorus
60kg ha
-1
) and Factor B (seed inoculation) also consist of three treatments I (control) , II (seed inoculation
with Bacillus spp.) and III (seed inoculation with Pseudomonas spp.). Maize Hybrid (DKC-6142) was
sown using seed rate of 25 kg ha
-1
keeping row to row distance 60 cm and plant to plant distance 20 cm.
All other agronomic practices and inputs were kept normal and uniform for all treatments. The data was
recorded using standard procedures for various agronomic traits. The data obtained was analyzed by
using Fisher’s analysis of variance technique and difference among treatment means was compared
using least significant difference test (LSD) at 5% probability. Both the different level of the phosphorus
and inoculation with phosphorus solubilizer microorganism significantly affected the yield related
parameters of maize but had non- significant effect on the number of cobs per plant, plant height, and
starch content. Regarding single strains better effects were achieved in pseudomonas as compared to
bacillus. Inoculation with pseudomonas in combination with the fertilizer application at the rate of 120 kg
per hectare significantly increased the number of grains row per cob (18.667), thousand grain weight
(482.67g), grain yield(5.60 tha
-1)
biological yield (15.60 tha
-1)
) respectively. It was concluded that
inoculation with pseudomonas species in combination with the phosphorus fertilizer application at t he rate
of 120 kg per hectare was more beneficent for the growth and yield of maize as compared to inoculation
with bacillus in combination with phosphorous fertilizer.

Enterococci, no more regarded as GRAS (Generally Recognized As Safe) organism, are emerging as an important source of nosocomial infections worldwide. The main contributors in pathogenesis of enterococci are the presence of various... more

Enterococci, no more regarded as GRAS (Generally Recognized As Safe) organism, are emerging as an important source of nosocomial infections worldwide. The main contributors in pathogenesis of enterococci are the presence of various virulent factors and antibiotic resistance genes. We aimed to examine the prevalence, dissemination, antibiotic resistance and virulent factors associated with enterococci from bulk soil (BS). A total of 372 enterococci were isolated from 500 soil samples. PCR was used to identify the isolates up to species level and for carriage of 16 virulence genes including hospital associated marker (i.e. IS16). E. faecium (77%), E. faecalis (10%), E. hirae (4%) and E. casseliflavus (1%) were the major species isolated. The efaAfs was the most dominant gene (100%), followed by gelE (78.9%), sprE (76.3%) and esp (13%) in E. faecalis isolates. The E. faecium carried largely efaAfm (86.8%) and acm (50.3%) genes. Presence of entP (10%), entA (8.3%) and entB (6.9%) genes ...

In this study, total heavy metal contents and their relationships with soil microbiological characteristics were investigated in agricultural soils which were with polluted heavy metals. Total heavy metal content of the soils varied from... more

In this study, total heavy metal contents and their relationships with soil microbiological characteristics were investigated in agricultural soils which were with polluted heavy metals. Total heavy metal content of the soils varied from 0.95 to 3.20 μg Cd g –1 , 17.10 to 42.33 μg Co g –1 , 18.43 ...

Acidic northern wetlands are an important source of methane, one of the gases that contributes to global warming. Methane oxidation in the surface of these acidic wetlands can reduce the methane flux to the atmosphere up to 90 percent.... more

Acidic northern wetlands are an important source of methane, one of the gases that contributes to global warming. Methane oxidation in the surface of these acidic wetlands can reduce the methane flux to the atmosphere up to 90 percent. Here the isolation of three methanotrophic microorganisms from three boreal forest sites is reported. They are moderately acidophilic organisms and have a soluble methane monooxygenase. In contrast to the known groups of methanotrophs, 16S ribosomal DNA sequence analysis shows that they are affiliated with the acidophilic heterotrophic bacterium Beijerinckia indica subsp. indica.