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PubMed1999

Bioremediation of phenols and polycyclic aromatic hydrocarbons in creosote contaminated soil using ex-situ landtreatment.

Soil from a former creosoting plant containing phenols and polycyclic aromatic hydrocarbons, was remediated using an ex-situ landtreatment process. Total 16 USEPA priority PAH and total phenol were reduced from 290 mg/kg and 40 mg/kg to < 200 mg/kg and 2 mg/kg, respectively. The bioremediation process involved soil mixing, aeration, and slow release fertilizer addition. The indigenous populations of PAH and phenol utilizing populations of microorganisms were shown to increase during the treatment process, indicating that biostimulation was effective. The most extensive degradation was apparent with the 2- and 3-ring PAH, with decreases of 97% and 82%, respectively. The higher molecular weight 3- and 4-ring PAH were degraded at slower rates, with reductions of 45% and 51%, respectively. Six-ring PAH were degraded the least with average reductions of < 35%. The residual concentrations of PAH and total phenol obtained in the study allowed the treated soil to be disposed of as low level contaminated landfill.

Air↗
PubMed2003

Enhanced bioremediation of n-alkane in petroleum sludge using bacterial consortium amended with rhamnolipid and micronutrients.

The purpose of the present study was to investigate possible methods to enhance the rate of biodegradation of oil sludge from crude oil tank bottom, thus reducing the time usually required for bioremediation. Enhancement of biodegradation was achieved through bioaugmentation and biostimulation. About 10% and 20% sludge contaminated sterile and non-sterile soil samples were treated with bacterial consortium (BC), rhamnolipid biosurfactant (RL) and nitrogen, phosphorus and potassium (NPK) solution. Maximum n-alkane degradation occurred in the 10% sludge contaminated soil samples. The effects of treatment carried out with the non-sterile soil samples were more pronounced than in the sterile soils. Maximum degradation was achieved after the 56th day of treatment. n-Alkanes in the range of nC8-nC11 were degraded completely followed by nC12-nC21, nC22-nC31 and nC32-nC40 with percentage degradations of 100%, 83-98%, 80-85% and 57-73% respectively. Statistical analysis using analysis of variance and Duncan's multiple range test revealed that the level of amendments, incubation time and combination of amendments significantly influenced bacterial growth, protein concentration and surface tension at a 1% probability level. All tested additives BC, NPK and RL had significant positive effects on the bioremediation of n-alkane in petroleum sludge.

Alkanes↗
PubMed2004

Stimulation of bacterial decolorization of an azo dye by extracellular metabolites from Escherichia coli strain NO3.

This study provides an attempt to use the extracellular metabolites of a dye-decolorizing strain, Escherichia coli strain NO3, as a biostimulator to entice E. coli strain NO3 into a beneficial mode of metabolism for an economically feasible decolorization. Addition of supernatants containing metabolites from growth and decolorization cultures triggered an enhancement of decolorization rates. Although extracellular metabolites play a crucial role for stimulating decolorization, they still cannot enable decolorization alone without involvement of biodecolorizers (E. coli strain NO3). Substantial decreases in oxidation-reduction potential to negative levels were observed during anaerobic decolorization in the presence of the metabolites. Results of repeated batch cultures also showed that serial acclimation of E. coli strain NO3 significantly increased decolorization capability. Supplements of metabolites seem to derepress glucose inhibition on decolorization by E. coli strain NO3. The metabolites produced from higher dye-concentration decolorization led to more enhancement of the bacterial decolorization.

Azo Compounds↗
PubMed2002

Mitogenic potential inducible by He:Ne laser in human lymphocytes in vitro.

The objective of the study was to investigate the mitogenic and genotoxic effects of He:Ne laser irradiation (632.8 nm) on human peripheral lymphocytes in vitro. We used the cytokinesis-block micronucleus assay, which incorporates cytochalasin B to inhibit cytokinesis while karyokinesis proceeds normally leading to the appearance of proliferating lymphocytes as binucleated cells. Also micronuclei will appear in cases of genotoxicologically-affected cells. Buffy coat leukocytes were exposed to 10 mW He:Ne laser at energy densities of 1, 2, 3 and 5 J/cm(2). Cells were then cultured in media 199 without any supplementation for 24, 48, 72 and 96 h adding cytochalasin B 24 h before harvesting of cells. Our results showed that laser-induced lymphocytes proliferate throughout the four consecutive days post-laser irradiation. The difference in the frequency of micronuclei between pre- and post-laser irradiation indicates that a He:Ne laser at such energy densities 1, 2, 3 and 5 J/cm(2) does not induce micronucleus formation. These results shed some light on the mechanism encountered by lymphocytes in the process of He:Ne laser-induced biostimulation.

Blood↗
PubMed2002

Field demonstration of successful bioaugmentation to achieve dechlorination of tetrachloroethene to ethene.

A laboratory microcosm study and a pilot scale field test were conducted to evaluate biostimulation and bioaugmentation to dechlorinate tetrachloroethene (PCE) to ethene at Kelly Air Force Base. The site groundwater contained about 1 mg/L of PCE and lower amounts of trichloroethene (TCE) and cis-1,2-dichloroethene (cDCE). Laboratory microcosms inoculated with soil and groundwater from the site exhibited partial dechlorination of TCE to cDCE when amended with lactate or methanol. Following the addition of a dechlorinating enrichment culture, KB-1, the chlorinated ethenes in the microcosms were completely converted to ethene. The KB-1 culture is a natural dechlorinating microbial consortium that contains phylogenetic relatives of Dehalococcoides ethenogenes. The ability of KB-1 to stimulate biodegradation of chlorinated ethenes in situ was explored using a closed loop recirculation cell with a pore volume of approximately 64,000 L The pilot test area (PTA) groundwater was first amended with methanol and acetate to establish reducing conditions. Under these conditions, dechlorination of PCE to cDCE was observed. Thirteen liters of the KB-1 culture were then injected into the subsurface. Within 200 days, the concentrations of PCE, TCE, and cis-1,2-DCE within the PTA were all below 5 microg/L, and ethene production accounted for the observed mass loss. The maximum rates of dechlorination estimated from field date were rapid (half-lives of a few hours). Throughout the pilot test period, groundwater samples were assayed for the presence of Dehalococcoides using both a Dehalococcoides-specific PCR assay and 16S rDNA sequence information. The sequences detected in the PTA after bioaugmentation were specific to the Dehalococcoides species in the KB-1 culture. These sequences were observed to progressively increase in abundance and spread downgradient within the PTA. These results confirm that organisms in the KB-1 culture populated the PTA aquifer and contributed to the stimulation of dechlorination beyond cDCE to ethene.

Bacteria↗
PubMed2005

Stable isotope evidence for biodegradation of chlorinated ethenes at a fractured bedrock site.

Stable carbon isotope analysis of chlorinated ethenes and ethene was performed at a site contaminated with trichloroethene (TCE), a dense non-aqueous phase liquid (DNAPL). The site is located in fractured bedrock and had variable groundwater hydraulic gradients during the study due to a local excavation project. Previous attempts to biostimulate a pilot treatment area at the site resulted in the production of cis-1,2-dichloroethene (cis-DCE), the first product of reductive dechlorination of TCE. Cis-DCE concentrations accumulated however, and there was no appreciable production of the breakdown products from further reductive dechlorination, vinyl chloride (VC) and ethene (ETH). Consequently, the pilot treatment area was bioaugmented with a culture of KB-1, a natural microbial consortium known to completely reduce TCE to nontoxic ETH. Due to ongoing dissolution of TCE from DNAPL in the fractured bedrock, and to variable hydraulic gradients, concentration profiles of dissolved TCE and its degradation products cis-DCE, VC, and ETH could not convincingly confirm biodegradation of the chlorinated ethenes. Isotopic analysis of cis-DCE and VC, however, demonstrated that biodegradation was occurring in the pilot treatment area. The isotope values of cis-DCE and VC became significantly more enriched in 13C over the last two sampling dates (in one well from -17.6%o to -12.8%o and from -22.5%o to -18.2%o for cis-DCE and VC, respectively). Quantification of the extent of biodegradation in the pilot treatment area using the Rayleigh model indicated that, depending on the well, between 21.3% and 40.7% of the decrease in cis-DCE and between 15.2% and 36.7% of the decrease in VC concentrations can be attributed to the effects of biodegradation during this time period. Within each well, the isotope profile of TCE remained relatively constant due to the continuous input of undegraded TCE due to DNAPL dissolution.

Biodegradation, Environmental↗
PubMed2005

Laboratory study of treatment of trichloroethene by chemical oxidation followed by bioremediation.

Studies were conducted with columns containing soil and emplaced trichloroethene (TCE) to investigate the potential for TCE source zone remediation with chemical oxidation followed by biologically mediated reductive dehalogenation. Following permanganate flushing of four columns, which resulted in rapid but incomplete removal of TCE DNAPL, no biological activity was observed following the addition of distilled water amended with ethanol and acetate, including two of the four columns that were bioaugmented with a TCE-dechlorinating microbial culture. Flushing with unsterilized site groundwater led to consumption of acetate and ethanol, accompanied by manganese reduction and methanogenesis. Reductive dechlorination of TCE to cis-1,2-dichloroethene (cis-DCE) followed the onset of ethanol and acetate biodegradation in bioaugmented columns only. Partial dechlorination of TCEto ethene was observed only in one of the bioaugmented columns after it was inoculated for a third time. At the end of the study (290 days), a trace amount of cis-DCE was observed in one of the two columns which was not bioaugmented. Reduced conditions created by biostimulation were also conducive to reduction of Mn(IV) from MnO2 in both bioaugmented and nonbioaugmented columns resulting in an increased dissolved manganese (Mn2+) concentration in groundwater.

Acetates↗
PubMed2001

Bioremediation of diesel-contaminated soils: evaluation of potential in situ techniques by study of bacterial degradation.

The development of a simple laboratory methodology allows the implementation of in situ bioremediation of polluted soils with diesel fuel. In this investigation microbiological and chemical analyses and a suitable bioreactor design, were very useful for suggesting the best ways to improve biodegradation extents in a diesel-enriched soil. Biostimulation with inorganic nitrogen and phosphorus produced the best results in a simple bioreactor, with biodegradation extents higher than 90% after 45 days. Also, the addition of activated sludge from a domestic wastewater plant increased the degradation rate to a great extent. In both cases, microbiological studies showed the presence of Acinetobacter sp. degrading most of the hydrocarbons. Simultaneously, a diesel fuel release (approximately 400,000 l) was studied. Samples taken in polluted soil and water revealed that bacteria from the genus Acinetobacter were predominant. In plate studies, Acinetobacter colonies produced a whitish substance with the characteristics of a biosurfactant. Remarkably, the presence of this product was evident at the field site, both in the riverbanks and in the physical recovery plant. The study of the similarities between laboratory results and the diesel spill site strongly suggested that natural conditions at the field site allowed the implementation of in situ bioremediation after physical removal of LNAPL (light nonaqueous-phase liquids).

Biodegradation, Environmental↗
PubMed2003

Immunomodulatory effects of low-intensity near-infrared laser irradiation on contact hypersensitivity reaction.

BACKGROUND/PURPOSE: Contact hypersensitivity (CHS) reaction is a useful model for studying the skin immune system and inflammatory reactions in the skin. In this study, an experimental model of CHS reaction was employed to assess immunomodulatory effects of near-infrared (near-IR) low-intensity laser (LIL) irradiation, which is used as adjuvant therapy in dermatology, physical medicine, rheumatology, etc., because of its declared anti-inflammatory, biostimulative and analgesic effects. METHODS: The effects of near-IR LIL irradiation (lambda=904 nm, irradiance 60 mW/cm2, fluence 3.6 J/cm2) on CHS reaction to 1-chloro-2,4-dinitrochlorobenzene (DNCB) in Albino Oxford rats were examined by irradiating experimental groups of animals before the induction phase of CHS reaction, while nonirradiated animals and animals that received vehicle instead of hapten served as controls. Ear-swelling assay, histopathological examination of H&E preparations of ear skin, computer-assisted image analysis of dermal infiltrate, ear skin organ culture with the determination of cutaneous production of tumour necrosis factor-alpha (by ELISA assay) and nitric oxide (by Griess' assay) were used for measuring the effects of LIL in the elicitation phase of CHS reaction. Cellularity, dendritic cell content, flow cytometry and proliferation assays (spontaneous and in the presence of IL-2 and concanavalin A) of the draining lymph node cells (DLNC) were performed for the assessment of LIL irradiation effects in the induction phase. RESULTS: In the irradiated group of animals, ear swelling was significantly diminished compared to control animals (101+/-11.5% vs. 58+/-11.6%, P<0.01). This was accompanied by a highly significant decrease in the density of dermal infiltrate (22+/-0.81 vs. 14.2+/-1.75 cells per unit area, P<0.01) and a significant decrease in nitrite levels in the medium conditioned by organ-cultured ear skin (17.63+/-1.91 vs. 3.16+/-1.69 microM NaNO2; P<0.01), while TNF-alpha concentration was not changed. Cellularity and dendritic cell content in DLNC population, as well as the expression of TCR-alpha, CD4, CD8 and CD25, were not changed between irradiated and nonirradiated animals. Proliferation rates of DLNC cultured for 72 h were significantly lower in irradiated animals (17.3+/-4.1 vs. 13.9+/-0.9 x 103 c.p.m.; P<0.01). In cultures of DLNC with added rIL-2 or 0.5 microg/ml of concanavalin A, proliferation rates were also significantly decreased in irradiated animals (34.7+/-3.5 vs. 31.2+/-2. c.p.m. in IL-2-supplemented culture, P<0.01; 70.9+/-6.4 vs. 58.3+/-9.1 x 103 c.p.m. in concanavalin A-supplemented culture, P<0.01). However, this effect was overcome in the presence of the higher concentration of concanavalin A (2.5 microg/ml) (nonirradiated 38.7+/-3.1, irradiated 123.1+/-7.3 x 103 c.p.m., P<0.01). CONCLUSION: LIL irradiation showed a systemic immunomodulatory effect on CHS reaction to DNCB in rats. Decreased ear swelling observed in the elicitation phase was associated with diminished proliferative responses of the DLNC in the induction phase of CHS reaction. Further experimental work is needed to examine the possible mechanisms of these effects.

Animals↗
PubMed2001

Bioremediation of an area contaminated by a fuel spill.

In order to decontaminate a large area of restricted access contaminated by a fuel spill, laboratory and field studies were developed in two steps: (a) monitoring of the laboratory experiment on bacterial growth under aerobic and anaerobic conditions with and without addition of nutrients; and (b) use of the best conditions obtained in (a) for the decontamination of the soil. A hydraulic barrier was installed both to clean the aquifer and to avoid migration of hydrocarbons as a consequence of their solution in the groundwater and subsequent displacement. The objective was to create an ideal environment for the treatment of the affected area that favoured the growth of the indigenous bacteria (Pseudomonas and Arthrobacter) that biodegrade the hydrocarbons. Monitoring of the changes in the total concentration of petroleum hydrocarbons in the soil subjected to bacterial action was performed by gas chromatography. In a field study, the progress of biodegradation of hydrocarbons was evaluated in situ by changes in subsurface CO2/O2 levels by means of an analyser equipped with an infrared detector. Biostimulation and oxygen were the most influential factors for the biodegradation of the hydrocarbons. The use of bioventing of the soil was shown as an excellent technology to promote in situ bioremediation of the polluted area.

Air Movements↗
PubMed2002

Human fibroblast alterations induced by low power laser irradiation at the single cell level using confocal microscopy.

Low power laser irradiation is regarded to have a significant role in triggering cellular proliferation and in treating diseases of diverse etiologies. The present work contributes to the understanding of the mechanisms of action by studying low power laser effects in human fibroblasts. Confocal laser scanning microscopy is used for irradiation and observation of the same area of interest allowing the imaging of laser effects at the single cell level and in real time. Coverslip cultures were placed in a small incubation chamber for in vivo microscopic observation. Laser stimulation of the cells was performed using the 647 nm line of the confocal laser through the objective lens of the microscope. Mitochondrial membrane potential (delta psi(m)), intracellular pH, calcium alterations and generation of reactive oxygen species (ROS) were monitored using specific fluorescent vital probes. The induced effects were quantified using digital image processing techniques. After laser irradiation, a gradual alkalinization of the cytosolic pH and an increase in mitochondrial membrane potential were observed. Recurrent spikes of intracellular calcium concentration were also triggered by laser. Reactive oxygen species were generated as a result of biostimulation. No such effects were monitored in microscopic fields other than the irradiated ones.

Cells, Cultured↗
PubMed2001

Development of specific oligonucleotide probes for the identification and in situ detection of hydrocarbon-degrading Alcanivorax strains.

The genus Alcanivorax comprises diverse hydrocarbon-degrading marine bacteria. Novel 16S rRNA-targeted oligonucleotide DNA probes (ALV735 and ALV735-b) were developed to quantify two subgroups of the Alcanivorax/Fundibacter group by fluorescence in situ hybridization (FISH), and the conditions for the single-mismatch discrimination of the probes were optimized. The specificity of the probes was improved further using a singly mismatched oligonucleotide as a competitor. The growth of Alcanivorax cells in crude oil-contaminated sea water under the biostimulation condition was investigated by FISH with the probe ALV735, which targeted the main cluster of the Alcanivorax/Fundibacter group. The size of the Alcanivorax population increased with increasing incubation time and accounted for 91% of the 4',6-diamidino-2-phenylindole (DAPI) count after incubation for 2 weeks. The probes developed in this study are useful for detecting Alcanivorax populations in petroleum hydrocarbon-degrading microbial consortia.

Base Sequence↗
PubMed2003

Helium-neon laser irradiation stimulates migration and proliferation in melanocytes and induces repigmentation in segmental-type vitiligo.

Low-energy helium-neon lasers (632.8 nm) have been employed in a variety of clinical treatments including vitiligo management. Light-mediated reaction to low-energy laser irradiation is referred to as biostimulation rather than a thermal effect. This study sought to determine the theoretical basis and clinical evidence for the effectiveness of helium-neon lasers in treating vitiligo. Cultured keratinocytes and fibroblasts were irradiated with 0.5-1.5 J per cm2 helium-neon laser radiation. The effects of the helium-neon laser on melanocyte growth and proliferation were investigated. The results of this in vitro study revealed a significant increase in basic fibroblast growth factor release from both keratinocytes and fibroblasts and a significant increase in nerve growth factor release from keratinocytes. Medium from helium-neon laser irradiated keratinocytes stimulated [3H]thymidine uptake and proliferation of cultured melanocytes. Furthermore, melanocyte migration was enhanced either directly by helium-neon laser irradiation or indirectly by the medium derived from helium-neon laser treated keratinocytes. Thirty patients with segmental-type vitiligo on the head and/or neck were enrolled in this study. Helium-neon laser light was administered locally at 3.0 J per cm2 with point stimulation once or twice weekly. The percentage of repigmented area was used for clinical evaluation of effectiveness. After an average of 16 treatment sessions, initial repigmentation was noticed. Marked repigmentation (>50%) was observed in 60% of patients with successive treatments. Basic fibroblast growth factor is a putative melanocyte growth factor, whereas nerve growth factor is a paracrine factor for melanocyte survival in the skin. Both nerve growth factor and basic fibroblast growth factor stimulate melanocyte migration. It is reasonable to propose that helium-neon laser irradiation clearly stimulates melanocyte migration and proliferation and mitogen release for melanocyte growth and may also rescue damaged melanocytes, therefore providing a microenvironment for inducing repigmentation in vitiligo.

Adolescent↗
PubMed2001

Physical principles in therapeutic apheresis.

Physical modality could have some impact on new apheresis technologies because it is nonbiologic and controllable for its operating conditions. In this article, the application of electromagnetic force and light scattering force to bioseparation and biostimulation was explored.

Blood Component Removal↗
PubMedDate not supplied

Effects of bull exposure and body growth on onset of puberty in Bunaji and Friesian x Bunaji heifers.

A total of ninety seven pre-pubertal Bunaji (BJ) and Friesian-Bunaji (FR x BJ) heifers were allotted randomly to two treatments groups for a period of 15 months. The treatment groups consisted of the followings: Mature Bull Exposure (MBE) and No Bull Exposure (NBE). Heifers were body condition scored and their live weights recorded on 28 days consecutive intervals. A heifer tactile stimulation in bull bio-stimulation. was considered to have attained puberty if she displayed oestrus, had a palpable corpus luteum with an associated P4 concentration > 1 ng x mL(-1). The onset of puberty was significantly earlier in MBE heifers (23.1 +/- 0.4 months) than NBE heifers (26.4 +/- 0.4 months). The mean ages at puberty for MBE-BJ, NBE-BJ, MBE-FR x BJ, NBE-FR x BJ were 24.3, 27.8, 22.1 and 25.0 months respectively. More MBE heifers (70.8%) attained puberty between 17 and 24 months of age than NBE heifers (18.3%) and on the same ages, more FR x BJ heifers (62.0%) than BJ heifers (25.5%). The mean live weight of MBE heifers at puberty (224.4 +/- 4.2 kg) was significantly lower than that of the NBE heifers (255.8 +/- 4.2 kg). The FR x BJ heifers attained puberty at a significantly higher live weight (270.2 +/- 4.2 kg) than the BJ heifers (228.6 +/- 4.2 kg). The use of a vasectomised bull especially in some elite farms that rely on artificial insemination services may be an effective management tool that can decrease age at puberty. More work is required to determine the relative contribution of visual, auditory, olfactory, pheromonal and tactile stimulation in bull biostimulation.

Age Factors↗
PubMedDate not supplied

Ultrastructural aspects of reactivity of regional lymph nodes on pulmonary inflammation and following endobronchial laser therapy.

The purpose of this study is the evaluation of reactivity of the regional lymph nodes on infectious-destructive process in the lung, and the efficacy of different therapeutical tactics. Examination of 7 regional lymph nodes from 7 patients with pulmonary inflammation showed marked manifestations of acute lymphadenitis. Generally speaking, these lymph nodes were enlarged and manifested signs of severe cell alteration and damaged processes of lymphocyte reproduction and migration. In 10 lymph nodes from 10 patients with similar pulmonary pathology receiving the same therapeutical measures combined with laser therapy course, neither lymphadenitis nor cell alteration signs were found. The results indicate the high plastic abilities of the lymph nodes and the efficacy of laser biostimulation.

Biopsy↗
PubMed2000

Biodegradation of methyl tertiary-butyl ether (MTBE) and other fuel oxygenates.

Methyl tertiary-butyl ether (MTBE) has been added to gasoline in the U.S. for the last decade in order to meet the mandates of the 1990 Clean Air Act. This law decreed that gasoline sold in many locations must contain oxygenates to improve combustion and minimize air pollution. Unfortunately, this widespread use has led to the contamination of some soils and aquifers, and remediation is now required. Bioremediation has proven to be an environmentally responsible and cost-effective approach to remediating petroleum spills; this article reviews the potential that bioremediation may also be appropriate for remediating MTBE contamination. There is now good evidence that MTBE can be degraded by bacteria and fungi under aerobic conditions, and promising indications that the process also occurs under methanogenic and ferric iron-reducing conditions. Yet, apparently it is not a widespread phenomenon. The challenge is to find effective bioremediation strategies that maximize this biodegradation so that it can be used reliably in cleaning contaminated sites. Both simple biostimulation and more complex bioaugmentation protocols are being developed to meet this pressing need.

Air Pollutants↗
PubMed2004

ESR detection of 1O2 reveals enhanced redox activity in illuminated cell cultures.

Low-energy visible light (LEVL) has previously been found to modulate various processes in different biological systems. One explanation for the stimulatory effect of LEVL is light-induced reactive oxygen species formation. In the present study, both sperm and skin cells were illuminated with LEVL and were found to generate singlet oxygen (1O2). The detection of 1O2 was performed using a trapping probe, 2,2,6,6-tetramethyl-4-piperidone, coupled with electron paramagnetic resonance spectroscopy. In addition, we have shown that, together with O2 generation, LEVL illumination increases the reductive capacity of the cells, which explains the difficulties encountered in 1O2 detection. The potential of visible light to change the cellular redox state may explain the recently observed biostimulative effects exerted by LEVL.

Animals↗