The Potential Use of Chicken-Drop Micro-Organisms for Oil Spill Remediation

An examination of chicken-drop micro-organisms for oil spill remediation is presented in this work. The chicken droppings contained aerobic heterotrophs (1.2×10⁸ CFU g^–1), total fungi (3.4×10⁴ CFU g^–1) and crude oil (transniger pipeline crude, TNP) degrading bacteria (1.5×10⁶ CFU g^–1). The crude oil degraders were identified as species of Micrococcus, Bacillus, Pseudomonas, Enterobacter, Proteus, Klebsiella, Aspergillus, Rhizopus, and Penicillium. Pseudomonas aeruginosa CDB-06 and species of Bacillus CDB-08 and Penicillium CDF-10 degraded the crude oil at exceedingly high rates. Pseuedomonas aeruginosa CDB-06 degraded 65.5 percent of the crude oil after 16 days, while Bacillus sp. CDB-08, and Penicillium sp. CDF-10 degraded 65.3 percent, and 53.3 percent, respectively of the crude oil over the same period. The chicken droppings also had a pH 7.3, 18.5 percent moisture content, 2.3 percent total nitrogen, and 0.5 percent available phosphorus. Addition of oil polluted soil (10 percent (v/w) pollution level) with chicken droppings enhanced degradation of the crude oil in the soil. 68.2 percent of the crude oil was degraded in the soil amended with chicken droppings, whereas only 50.7 percent of the crude oil was degraded in the unamended soil after 16 days. The amendment raised the acidic reaction (pH 5.7) of the oil-polluted soil to alkaline (pH 7.2) within 16 days. Chicken droppings could, therefore, be used in an integrated oil pollution abatement program.     

Effect of bioremediation on the growth of Okro (<Emphasis Type="Italic">Abelmoshus esculetus</Emphasis>) in the Niger Delta soils

This paper communicates the effect of bioremediation on the performance of Okro plant (Abelmoshus esculentus) in a typical Niger Delta soil that has received 5% crude oil pollution level. Biodegrading bacteria such as Pseudomonas fluorescen, Acinetobacteria iwofii, Bacillus subtilus, Arthrobacter globiformis that was isolated from previously polluted soils was introduced into the samples. The treatment combinations are as follows (A) = control without crude oil; B = soil + crude oil, (C) = soil + crude oil + microbes, (D) = soil + crude oil + microbes, (E) = soil + crude oil + microbes + fertilizer (F) soil + microbes and (G) = soil + fertilizer. The treatment (E) gave the highest number of leaves, % crop emergence, plant biomass, microbial population and degradation of petroleum hydrocarbon compared to any of the treatments that had received crude oil. This suggested that fertilizer application does not only stimulate microbial growth but it provides the plant with more available nutrients required for plant growth.     

微生物对石油污染物的降解作用

针对油井附近落地油污染地表土壤的问题,利用热蒸发色谱技术,对油污土壤中加入微生物对原油的降解特征进行了实验研究。实验结果表明,在油污土壤中加入微生物,对落地油有明显的降解作用,可以减轻石油生产过程中油污对土壤的破坏和对环境的污染。随着微生物降解作用的不断进行,土壤中污油的相对降解速度逐渐加快,相对降解率逐渐增加。生物处理法的过程较简单,处理费用低,处理效果好,一般不会产生二次污染。     

石油污染生物修复技术研究

本文概述了影响石油污染物生物降解修复处理的多种因素，对石油污染生物处理技术的发展进行了展望。其中主要影响因素包括：菌种的影响，菌种在不同的环境中和对不同碳链长度的碳氢化合物表现出不同的降解效率；石油物质本身物理化学特性的影响，如石油物质在水体或土壤中的浓度以及石油的粘度、沸点、折射率等特性；生存环境条件的影响，在接种入高效率的降解菌或利用土著微生物进行降解时，降解率受到生存环境中各种条件的影响，如表面活性剂、光照条件、吸附剂的利用、营养盐、共代谢底物、氧气、温度、盐度等。     

The Effect of Sublethal Concentrations of Crude Oil on the Growth and Metabolism of Cowpea (Vigna unguiculata) Seedlings

Summary The effect of crude oil contaminated soil at various sublethal concentrations (0.25%, 0.5%, 1.0% and 2.0%) on the growth and metabolism of cowpea (Vigna unguiculata) seedlings was studied. The results showed that crude oil induced environmental stress in the seedlings. This is indicated by the increase in free sugar, total protein and amino acids and a decrease in chlorophyll contents of the leaves of 12-day-old seedlings. The activities of total amylase and starch phosphorylase from the cotyledon and mitotic activity of the meristems of the root of 4-day-old seedling were inhibited by the various concentrations except at 0.5%, which showed stimulation of cellular and metabolic activities relative to seedlings in the control treatment.     

Estimation of “environmentally sensitive” dispersal ratios for chemical dispersants used in crude oil spill control

The toxicities of two dispersants (Biosolve and OSD 9460), Forcados light crude oil and their mixtures based on ratios 6:1, 9:1, and 12:1 (v/v) were evaluated against the juvenile stage of African catfish, Clarias gariepinus, in laboratory bioassays. On the basis of the derived toxicity indices, Biosolve (96-h LC₅₀ = 0.211 μl/l) was found to be about 27,284 times more toxic than crude oil (96-h LC₅₀ = 5.757 ml/l) and 6,450 times more toxic than OSD 9460 (96-h LC₅₀ = 1.361 ml/l). OSD 9460 was also found to be four times more toxic than crude oil when acting alone against C. gariepinus. Toxicity evaluations of the mixtures of crude oil/dispersants mixtures varied, depending largely upon the proportion of addition of the mixture components. The interactions between mixture of crude oil and Biosolve at the test ratios of 6:1, 9:1, and 12:1 were found to conform with the model of synergism (SR = 7,655, 14,876, and 8,792, respectively), and the mixtures were therefore more toxic than the crude oil acting singly. Similarly, the interactions between mixture of crude oil and OSD 9460 at the test ratios of 6:1 and 9:1 also conformed to the model of synergism (SR = 2.2 and 1.84, respectively). Interactions between the dispersant OSD 9460 and the crude oil at test ratio 12:1, however, conformed to the model of antagonism (SR = 0.84), indicating that the mixture was less toxic than crude oil acting alone. The results of the emulsification potential of OSD 9460 and Biosolve [measured in terms of optical transmittance (%)] prepared at the dispersal ratios 6:1, 9:1, and 12:1 revealed that the dispersal ratio of 6:1 achieved the highest emulsification of the crude oil with optical transmittance value of 4% and 6%, respectively. Estimation of an “environmentally sensitive” dispersal ratio for OSD 9460 and Biosolve revealed the optimum dispersal ratio for OSD 9460 range between ratios 7.5:1 and 9:1, while for Biosolve such an optimum dispersal ratio was indeterminate within the range of test dispersal ratios. The implications of these results in setting manufacturer’s and regulatory dispersal ratios for chemical dispersants used for oil spill control were discussed.     

Depolymerization of polyaromatic hydrocarbons by Penicillium spp. inhabit the phyllosphere of urban ornamental plants

A variety of anthropogenic sources release hazardous polyaromatic hydrocarbons (PAHs) into the phyllosphere which is an excellent niche for diverse fungi, and some of them have PAHs degradation capabilities. Therefore, this research attempted to determine the PAHs (phenanthrene, anthracene, naphthalene, and pyrene) degradation capability of phyllosphere inhabited Penicillium species. The leaf samples were collected from highly polluted urban areas (Panchikawatta, Pettah, Orugodawatta, Maradana, Sapugaskanda, and Colombo Fort) in Sri Lanka to isolate fungal species inhabiting the phyllosphere. Furthermore, their distribution patterns among the leaf tissue layers were studied using bright-field microscopic observations. Moreover, the best PAH degraders were screened out using plate assays and confirmed through High Performance Liquid Chromatography (HPLC) analysis. Further, their enzymatic activities during the PAHs degradation were analyzed. As per the microscopic observations, the highest fungal distribution was in the upper epidermis of the leaves followed by the fungal distribution in the interspaces of palisade mesophyll layers. Out of isolated fungal species, two Penicillium spp. (Penicillium citrinum P₂₃B-91 and Penicillium griseofulvum P₉B - 30) showed the highest PAHs (phenanthrene, anthracene, naphthalene, and pyrene) degradation capabilities. Manganese peroxidase (MnP) enzyme dominated phenanthrene degradation in P. griseofulvum P₉B - 30, which showed the highest phenanthrene degradation ability (61%). In addition, P. citrinum P23B-91 was good at degrading anthracene (88%) and also displayed a higher MnP activity during the anthracene degradation than laccase and lignin peroxidase activities. The discoveries from the toxicity assay during the PAHs degradation processes revealed that the produced byproducts had no toxic effects on the fungal growth cycle and the phyllosphere. Therefore this phyllosphere Penicillium spp. are ideal for the bioremediation of polluted air in urbanized areas.     

In-vitro toxicity of cyclophosphamide and etoposide intermediates/metabolites produced by three white rot fungi

Aim of the present study is to determine the in-vitro cell cytotoxic effect of native and transformed cancer drugs (cyclophosphamide and etoposide) using three different white rot fungi (Ganoderma lucidum, Phanerochaete chrysosporium and Trametes versicolor). At 3, 6, 9, 12 and 15 days, experiments were done on a mouse monocyte macrophage cell line (Raw 264.7). After biodegradation, the altered compounds were found to be harmful to the Raw 264.7 cells. The maximal cytotoxicity of cyclophosphamide transformed products (TPs) were determined to be 2.4%, 7.3% and 7% respectively, against G. lucidum, P. chrysosporium and T. versicolor, respectively. With G. lucidum, P. chrysosporium and T. versicolor, the etoposide toxicity was 1.5%, 8% and 2.7% respectively. P. chrysosporium-mediated biodegradation resulted in the maximum toxicity, at 8%, on the 12th day for etoposide and 7.3% on the 3rd day for cyclophosphamide. After biodegradation by fungi, the toxicity of these two anticancer agents was reduced in the form of metabolites, but each fungus showed unique capacity for toxicity removal.     

Effects of drilling fluids on marine bacteria from a Nigerian offshore oilfield

Two marine bacterial isolates from drill mud cuttings obtained from Agbara oilfield,Staphylococcus sp. andBacillus sp., were cultured aerobically in the presence of varying concentrations (0, 25, 50, and 75 μg/ml) of drilling fluids to determine the effects of concentration of toxicants on their growth. With the exception of Clairsol, Enviromul, and Baroid mineral oil, which had little or no effect, the exponential growth ofBacillus sp. was depressed by all other test chemicals. Additionally, all test chemicals except Clairsol had no effect on lag phase of growth ofBacillus sp. WithStaphylococcus sp. the depressive effect on the exponential phase of growth was shown by almost all test chemicals. There was enhancement of both growth rate and generation times ofStaphylococcus sp. and decrease of those ofBacillus sp. with increasing concentrations of drilling fluids. These results show that while some drilling fluids may be stimulatory or depressive to bacterial growth, others may be without effect.     

Morphological and anatomical effects of crude oil on <Emphasis Type="Italic">Pistia stratiotes</Emphasis>

Fresh whole plants of Pistia stratiotes were exposed to varying doses of crude oil (0–100 ppm) for 28 days at normal temperature of 30 ± 2°C. Samples were taken weekly during this period for determination of changes in leaf area, root length, number of leaves, and number of sprouts. The cross-section of one terminal end of the major roots and cellular distribution of the meristematic region were also examined. The results show that crude oil was toxic to the plant at all concentrations in all investigated parameters for as low as 10 ppm. Association was also observed between crude oil toxicity and certain metals inherent in the crude oil such as manganese and lead. Cell shape disruptions, changes in mitotic indices, and the distortion of cellular anatomy and structure at the apical region also characterized the presence of crude oil in the environment of P. stratiotes. P. stratiotes may not be a good bio-accumulator of crude oil but may be used for the detection of pollution.     

Chromosomal genes conferring tolerance to heavy metal (Ag) toxicity

Bacterial strains were isolated from sediment samples from the Thames River. Successive transfer growth of the various strains on nutrient agar containing increasing concentrations of AgNO₃ revealed that three of the bacterial isolates were found to be capable of tolerating high concentrations of AgNO₃ ranging from 20 to 80 mM on a solid medium and up to 10 mM AgNO₃ in liquid medium. Molecular characterization and identification based on 16S rDNA gene sequencing of three strains of bacteria that are tolerant to silver nitrate showed that the major tolerant strains include the superbug, Shewanella oneidensis, Pseudomonas sp. and Bacillus sp. Protein extraction and two-dimensional (2D) sodium dodecyl sulfate SDS-polyacrylamide gel electrophoresis (PAGE) of the protein extracts in bacteria exposed to very high concentrations of AgNO₃ revealed a general reduction in the number of expressed proteins, although two protein spots were conspicuously over expressed in the exposed bacteria compared to control. The N-terminal amino acid sequence analysis of the protein spots identified the major up-regulated proteins as the outer membrane protein To1C (45.2 kDa) and the structural protein of the flagellar filament, flagellin (28.34 kDa), encoded for by the to1C and fliC genes, respectively. The roles of these genes in a number of multi-drug resistant pathogen and potentials for biotechnological applications in toxic metal control for treatment of contaminated ecosystems and biomining were discussed.     

原油及产品对藻类毒性影响研究

藻类具有种类繁多，个体小，生长繁殖迅速，对毒物的毒性敏感等特点，它长时间在水中生长，能客观地反映原油及产品对水体污染所产生的毒害综合效应。实验室中毒性研究通常采用纯种藻类培养来评价油的急性和早期毒性影响。经过实验室研究及原油泄漏现场调查研究表明：在含油的生态系统中油能刺激藻类的生长。在油污染过的水体中，原油中的轻烃和较易挥发的组分对藻类的毒性影响最大，原油泄漏的短期毒性影响和二次影响同等重要，油对藻类种群结构也具有重要的毒性影响。     

Physiological responses of Avicennia marina seedlings to the phytotoxic effects of the water-soluble fraction of light Arabian crude oil

Stomatal behavior, growth performance and the accumulation of polynuclear aromatic hydrocarbons (PAHs) were evaluated in seedlings of the mangrove Avicennia marina (Forssk.) Vierh., treated with a water-soluble fraction (WSF) of Abu-Dhabi light Arabian crude oil through foliar spraying or soil application.Irregular stomatal behavior and weak stomatal control over transpiration were observed during the first 24 hours, where stomatal resistances of plants sprayed with 150 and 300 g PAHs plant^–1 were significantly lower than that of the control plants. After six weeks, all treated plants showed no significant difference in their relative growth rate (RGR) or in the net assimilation rate (NAR) compared with the control plants.Tri-aromatic hydrocarbons were the most accumulated in tissues of the treated plants. Penta- and hexa-aromatics, on the other hand, were undetectable in the WSF and consequently in the treated plants. A linear relationship was observed between the dose applied to plants and the amounts of tissue accumulated PAHs (r ²=0.515 for soil application and r ²=0.984 for foliar spray). In plants sprayed with 300 g PAHs plant^–1, the total PAHs accumulated were more than that accumulated in plants treated through soil application.These findings suggest that: aqueous extraction of crude oil tends to signify the percentage of the low molecular weight PAHs, e.g. naphthalene, to the total PAHs; disturbed stomatal behavior in the first day of the treatment may be due to the venting of the volatile low molecular weight aromatic hydrocarbons (e.g. benzene, toluene, and xylenes) through the stomata; and uptake of water-soluble hydrocarbons by plants is equally possible through both of the root system and the foliage. The ecological implications of these finding are discussed in relation to oil pollution of mangrove stands under field conditions.     

Protective influence of Vitamins against Petroleum-induced free radical toxicity in Rabit

The effect of exposure to crude oil contaminated diet on the blood antioxidant defence system, lipid peroxidation, lipid profile as well as possible protective roles of vitamins E and C were studied in rabbits. Oxidative stress induction by crude oil was indicated by significantly (P < 0.05) increased lipid peroxidation and a non-significant (P < 0.05) decrease in superoxide dismutase and catalase activities. A similar pattern was also detected in the lipid profile: total cholesterol and LDL-cholesterol insignificantly (P < 0.05) increased while HDL-cholesterol and triglyceride significantly decreased relative to rabbits fed normal diet. The reciprocal relationship between HDL-cholesterol and LDL-cholesterol in addition to compromised antioxidant enzymes could predispose exposed animals to coronary heart disease. However, pre-treatment of the diet with vitamins C and E exhibited a protective role on the toxic effect of crude oil on lipid profile, lipid peroxidation as well as antioxidant enzymes. The order of protection was vitamin E + C > vitamin E > vitamin C. These observations seemed to suggest that the protective role of vitamins C and E is synergistic. The protective role of the vitamins is probably time-dependent as significant (P < 0.05) restoration of lipid profile as well as antioxidant enzymes activities to control values was effected after four weeks of exposure. It is therefore suggested that toxic effect of crude oil may be reduced by dietary supplementation of vitamins C and E.     

石油污染土壤原位生物修复的强化实验研究

为研究添加营养物质和高效降解石油微生物对油污土壤生物修复的作用,通过分层土柱的方法,连续监测了不同条件下不同土层的含水率、石油烃含量、细菌数量及脱氢酶活性。结果表明:添加营养物质同时接种高效微生物可使降解效果明显改善,降解率比在自然条件下提高近50%,而单纯添加营养物质不接种高效微生物可使降解率比在自然条件下提高约25%。降解初期,上层土壤降解效果较好,而到中后期,中下层降解效果好于上层。微生物数量和脱氢酶活性与石油降解率之间存在良好的相关性,脱氢酶活性比微生物数量更能反映修复过程中微生物的存活状态。添加营养物质和高效降解石油微生物对油污土壤原位生物修复具有强化作用。     

Bioconversion of sugarcane bagasse into a protein-rich product by white rot fungus

The fungus Pleurotus ostreatus NRRL-2366 degraded 56.7% and 45.9% of untreated and chemically pretreated (delignified) sugarcane bagasse, respectively, during 14-day incubation in a submerged fermentation process. The biodegradation percentages of cellulose, hemicellulose and lignin were 33.0%, 72.5% and 14.5%, respectively. An increment of 22.6% of crude protein content in the residual fermented material was observed. Chemical composition of the end-product and its amino acids profile were reported.     

Bioremediation of cutting fluids contaminated soil by Pleurotus tuber-regium Singer

This study investigated the effect of inoculation of Pleurotus tuber-regium, a Nigerian white rot fungus, period of incubation, different levels of contamination on cutting fluids degradation in contaminated soil over 30, 60, and 90 days. Control for different levels of cutting fluids was also used to compare rates of bioremediation of the contaminant in the soil. At the end of each incubation period, the mycelia-ramified substrate was separated from the soil layer and dried. The soil samples were analyzed for physico-chemical parameters; total petroleum hydrocarbon, lignin content by determining the acid detergent fraction (ADF), heavy metals content of the soil using flame atomic absorption spectrophotometer, and changes in the polyphenol oxidase and peroxidase activities were also determined after 1, 2, and 3 months. P. tuber-regium improved the nutrient status of the soil and increased enzyme activity was recorded. A reduction in the pH and heavy metal contents of the soil at all levels of cutting fluids concentrations was detected. The lignin in the rice straw decreased from 34.50% in the control to 8.06% at 30% cutting fluids concentration after 3 months of incubation. The highest TPH loss of 30.84% was recorded at 20% cutting fluids contamination after 3 months compared to 13.75% at the onset of the experiment. The improvement of the nutrient contents of the soil, bioaccumulation of heavy metals, degradation of TPH, lignin, and increased activity of polyphenol oxidase and peroxidase was due to biodegradation of the cutting fluids.     

Slope and pig slurry rate may increase the transfer of chemical elements by surface water runoff

There is a need to evaluate the interference of pig slurry rate and the terrain slope in the chemical elements losses from the soil. This work aimed to quantify water and chemical element losses by surface runoff due to terrain slope and pig slurry rate (PS) in two soils with contrasting textures. Two trials were evaluated in 2018 and 2019 in Cambisol and Nitisol. Rates of 0, 22.5, 45, and 90 m³ ha⁻¹ yr⁻¹ of PS were applied superficially in sites with slopes ranging from 10% to 35%. Perennial forage grass Tifton 85 (Cynodon dactylon) was grown as summer crop and ryegrass (Lolium multiflorum) was sown in the cold seasons in a field environment. Were determined the runoff, the volume of water, and chemical elements (Al, Ca, P, Mg, Cd, Cr, Cu, Mn, Fe, Pb, and Zn) lost by the surface runoff after natural rainfall. Increasing land slope elevated water losses substantially, on average 23.4 times in Cambisol and 10.8 times in Nitisol. This increase resulted in average increases of 27.6 and 12.4 times in the losses of the chemical elements analyzed for Cambisol and Nitisol, respectively. There was a reduction in water losses by surface runoff due to increased PS rates applied in both sites. The increased PS rate affected the losses of Cr and Cu in Cambisol and P, Mg, Cd, and Cu in Nitisol. The clayey soil potentiated the water and chemical elements losses by surface runoff in relation to the soil with lower clay content. Regardless of the soil, water and chemical element losses are maximized at higher slopes.     

Application of Bacillus subtilis strain for microbial-enhanced oil recovery

In order to improve the oil recovery, injection of exogenous bacteria into the oil reservoir is one of the most widely used microbial flooding methods. In this study, a screened strain of Bacillus subtilis (B. subtilis) was introduced to perform the microbial flooding. The biosurfactants produced by B. subtilis was one kind of cyclic lipopeptides, which could reduce the surface tension of the culture solution from 68 mN/m to 25 mN/m and also decrease the interfacial tension of water/oil from 25.6 to 4.6 mN/m. Emulsification tests indicated that the strain and the biosurfactants could degrade and emulsify the crude oil. In the oil displacement experiments, oil recovery was increased by 32.4% by injecting fermentation broth into the simulated formation. By respectively performing the emulsification and oil displacement tests, it was demonstrated that the biosurfactants and degradation of the microbes in the heavy components of the crude oil are the main factors to enhance the oil recovery. Besides, the optimal cultural temperature for strain of B. subtilis was set as 40°C. Nevertheless, the strain was inappropriate for the oil displacement under acidic conditions. In addition, the hydrophilic sands and an optimal culture solution volume of 0.7 pore volume (PV) would be in favor of the oil recovery. It was further confirmed that the efficiency of microbial flooding was much higher than that of the chemical oil displacement.     

TRANSPORT AND FATE OF ATRAZINE IN MIDWESTERN RIPARIAN BUFFER STRIPS1

ABSTRACT: The fate of pesticides entering the Riparian Buffer Strips (RBS) has not been well documented. This study compared the transport and fate of atrazine in soil of three‐, five‐, and nine‐year‐old switchgrass (Panicum virgatum L.) RBS to that in adjacent soils cropped to a corn‐soybean rotation or a grass‐alfalfa pasture. Undisturbed soil columns were collected from the RBS and cropped areas within the Bear Creek watershed, near Roland, Iowa. Atrazine and bromide breakthrough curves obtained using intact soil columns under saturated conditions were described by a two‐region, mobile‐immobile transport model. Preferential flow of bromide and atrazine was evident in five‐and nine‐year‐old RBS soil, but there was little difference in transport characteristics between these two RBS soils and the adjacent cropped soils. There was a trend towards an increase in dispersion coefficients between the five‐and nine‐year‐old RBS sites, which suggests an increased degree of preferential flow with increasing RBS age. Despite similar texture and organic C contents, atrazine sorption was significantly greater in RBS soil than the adjacent cropped soil. Cropped soil degraded atrazine faster than the RBS soil. The rapid degradation of atrazine in the corn‐soybean soil adjacent to the five‐year‐old RBS (atrazine half‐life of 19 days) appeared to be due to a larger population of atrazine‐degrading microorganisms. Atrazine‐degrading microorganisms in the corn‐soybean soil were 50,940 cells g^‐1 soil compared with 2,970 cells g^‐4 soil in 5‐year‐old RBS soil which resulted in 60 percent mineralization of [¹⁴C‐UL‐atrazine] in the corn‐soybean soil.