scholarly journals Bioremediation of lead polluted soil from Obio/Akpor local Government Area, rivers state using African Catfish and tilapia fish bones

2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Daniel UI ◽  
Nwanya A
Keyword(s):  
Lead Concentration ◽  
Polluted Soil ◽  
Soil Samples ◽  
African Catfish ◽  
Polluted Soils ◽  
Lead Battery ◽  
Fish Bones ◽  
Two Samples ◽  
Lead Metal ◽  
Rivers State

A study was undertaken to compare the bones of two fin fish-African Catfish (Clarias gariepinus) and Tilapia (Oreochromis niloticus), in the bioremediation of lead polluted soils. Six soil samples containing different sources of lead were collected from Obio-Akpor LGA, Rivers State. African catfish and Tilapia fishes were sourced from the market; the bones were extracted and dried (using a hot oven). The bones were then crushed with a blender, and weighed using analytical measuring scale. The crushed bones were mixed with lead polluted soil samples and left in the laboratory, in cool transparent plates for 3 weeks and 3 days for group one samples, while group two samples were left in the laboratory for 1 week and 3 days. The results revealed that for group one samples; Acid battery soil mixed with Catfish bones reduced the lead concentration from 3122.30mg/kg to 2574.50mg/kg. Lead battery soil mixed with Tilapia bones reduced the lead concentration from 6718.15mg/kg to 1184.15mg/kg, while Lead metal soil mixed with both Catfish+Tilapia bones increased the lead concentration from 8807.65mg/kg to 11874.50mg/kg. For group two samples; Acid battery soil mixed with both Catfish+Tilapia bones reduced the lead concentration from 3706.75mg/kg to 3144.45mg/kg. Lead metal soil mixed with Catfish bone reduced the lead concentration from 15940.50mg/kg to 3903.90mg/kg, while Lead battery soil mixed with Tilapia bones increased the lead concentration from 6439.20mg/kg to 11671.50mg/kg. The study revealed that Catfish bones, at different weights can be used in the bioremediation of lead polluted soils and the reduction was higher, than using Tilapia or the combination of the fish bones.

scholarly journals Culture-Dependent and Metagenomic Profiling of Eukaryal Diversity in Petroleum Hydrocarbon-Polluted Soil from B-Dere, Gokana, Rivers State, Nigeria

2021 ◽  
pp. 64-73
Author(s):  
D. N. Ogbonna ◽  
I. R. Udotong ◽  
N. Basi ◽  
R. R. Nrior
Keyword(s):  
Polluted Soil ◽  
Soil Samples ◽  
Shotgun Sequencing ◽  
Next Generation ◽  
Polluted Soils ◽  
Fungal Isolates ◽  
Total Dna ◽  
Rivers State ◽  
Generation Sequencing ◽  
Culture Dependent

B-Dere is one of the communities in Ogoniland and a major oil producing area in Rivers State where oil exploration and production activities commenced 50 years ago and is now characterized by oil fields and installations that have remained dormant for several decades. Past spills, lack of maintenance, oil trapping and damage to oil infrastructures have been common sight in this region and the environment has been without remediation over the years. B-Dere community has suffered surface water pollution throughout its creeks with massive hydrocarbons for years without remediation. The aim of this study was to determine the Culture- dependent and Metagenomic studies of fungal diversity in petroleum polluted soils in B-Dere community in Gokana LGA of Rivers State, Nigeria. This is to profile fungal communities through next-generation techniques by shotgun sequencing of total DNA isolates directly from the oil polluted environment. Soil samples were collected aseptically with hand auger at a depths of 0-15 and 15-30 cm and made up to a composite sample and transported to the laboratory for analysis using standard microbiological methods for culture- dependent analysis while the Metagenomic studies was carried out at the Microbial Insights, Incorporated; United State of America. In this study next-generation sequencing techniques by shotgun sequencing of total DNA methods were used for identification of fungal isolates from the crude oil polluted soils in B-Dere. Deoxyribonucleic acid (DNA) extraction from crude oil polluted soil samples was performed using ZymoBiomics DNA extraction kits (Zymo Research, Inc; USA). DNA sequencing was performed by the next generation sequencing technique to determine the nucleotide sequence of all eukaryal community structure present in the polluted soil sample using ITS region. Results of the culture-dependent technique showed that only two fungal genera namely Penicillium sp and Aspergillus sp were isolated and identified while the soil was mainly dominated by the genera Penicillium (73.33%), followed by the Rhodotorula (6.54%), Dactylellina(5.09%), Kalmanozyma(2.56%), Fereydounia(1.89%), Xerochrysium(1.36%), Arthrobotrys (1.14%) and Diutina (0.77%) by the metagenomic analysis. However the three major groups were classified as Ascomycota, Basidiomycota and Mucoromycota with Ascomycota having the highest taxonomic reads of 86.76%. However, a total of 60 eukaryal species were identified, in the metagenomic study. In conclusion, these fungal strains can be used in bioremediation process and oil pollution reduction in soil ecosystems because of their high activity in aliphatic hydrocarbon degradation and cell surface hydrophobicity. The next-generation techniques by shotgun sequencing assays appear to be suitable alternatives for rapid identification of the above mentioned fungal isolates.

scholarly journals Mycoflora of Crude Oil Polluted Soils of Ukwa West of Abia State Nigeria

2021 ◽  
pp. 1-9
Author(s):  
J. M. Madu ◽  
A. I. Ogbonna ◽  
C. I. C. Ogbonna
Keyword(s):  
Crude Oil ◽  
Soil Sample ◽  
Critical Role ◽  
Organic Matter Content ◽  
Chemical Properties ◽  
Polluted Soil ◽  
Soil Samples ◽  
Polluted Soils ◽  
Physico Chemical ◽  
Starch Agar

Aim: Bioremediation of soil play a critical role in removing pollutants from crude oil polluted soil. To investigate the mycoflora of crude oil polluted area of Ukwa West Local Government in the present Abia State. Methodology: Portions of the soil samples collected from three (3) locations were plated out separately on Yeast Starch Agar, Starch Agar, and Cellulose Agar using soil plate methods. The culture plates were examined after 5-7 and 14 days for the presence of fungi. Pure cultures of the isolates were obtained by subculturing and the physico-chemical properties of the soil samples were determined using standard methods. Results: Twenty species (20) of fungi were isolated from the crude oil polluted soil sample and represented by their respective genera. Eight (8) species of Aspergillus representing 40%, two (2) species of Thermomyces representing 10% each, and one (1) species of Penicillium, Cladosporium, Cunninghamella, Curvularia, Trichoderma, Scopulariopsis, Sporotrichum and Basipetospora representing 5% each. Aspergillus species were predominant which include among others A. fumigatus, A. niger, A. parasiticus, A. oryzae, A. terreus. The physico-chemical properties of the soil sample were found to be varied and have affected the distribution and population of fungi. The pH values ranged from 4.81- 5.58 as compared to the control ranging from 5.72- 6.50 for soil samples A, B and C. The moisture content values ranged between 26.46-29.59% as compared to the control ranging from 29.41-32.51%. The soil was found to be high in organic matter content with values of 70.3-82.7% as compared to the control which was 94% for each of the locations. Conclusion: Crude oil polluted soils of Ukwa West of Abia State, Nigeria is rich in fungal biodiversity with the soil’s samples having different physico-chemical properties.

Mycorestoration of crude oil polluted soil using Pleurotus tuberregium

2021 ◽  
Vol 66 (1) ◽  
pp. 73-84
Author(s):  
Beckley Ikhajiagbe ◽  
Kingsley Enerijiofi ◽  
Paul Umendu
Keyword(s):  
Crude Oil ◽  
Pollution Control ◽  
Polluted Soil ◽  
Soil Samples ◽  
Fruiting Bodies ◽  
Soil Environment ◽  
Polluted Soils ◽  
Brachystegia Nigerica ◽  
Asystasia Gangetica ◽  
Pleurotus Tuberregium

Crude oil contamination is known to cause unwholesome damage to man, his environment comprising of soil, air and water bodies as well as other forms of life. This study determined the effect of crude oil polluted soils on the composition of different microorganisms and plants and the growth of Pleurotus tuberregium. Oil polluted soils in bowls were amended with sawdust from Brachystegia nigerica as substrate. Fruiting bodies and the diameter of the mushroom cap were found to increase with increasing weeks of exposure to oil as against the control which had no fruiting bodies throughout the experiment. Pepperomia pellucida was found to be the predominant weed (n = 20), followed by Asystasia gangetica (n = 11). The bacterial and fungal counts were higher at the oil polluted soil attached to sclerotia than the control. The growth of Pleurotus tuberregium in the polluted soil samples showed its ability to degrade and utilize hydrocarbon as the source of carbon and energy, thereby remediating the contaminated soil environment. This work has shown that the fungus has bioremediation and pollution control capacity.

scholarly journals Bioremediation Efficiency of Bacillus amyloliquefaciens and Pseudomonas aeruginosa with the Nutrient Amendment on Crude Oil Polluted the Soil

2019 ◽  
pp. 1-13
Author(s):  
David N. Ogbonna ◽  
Renner R. Nrior ◽  
Festus E. Ezinwo
Keyword(s):  
Crude Oil ◽  
Bacillus Amyloliquefaciens ◽  
Heterotrophic Bacteria ◽  
Polluted Soil ◽  
Total Petroleum Hydrocarbon ◽  
Polluted Soils ◽  
Fish Waste ◽  
Goat Manure ◽  
Nutrient Amendment ◽  
Rivers State

Aim: To assess the Bioremediation efficiency of Bacillus amyloliquefaciens and Pseudomonas aeruginosa strain CL 9 with nutrient amendment using bio-stimulating agents such as Fish waste and Goat manure on crude oil polluted soils in Rivers State, Nigeria. Study Design: The study employs experimental design, statistical analysis of the data and interpretation. Place and Duration of Study: A portion of Rivers State University demonstration farmland in Nkpolu-Oroworukwo, Mile 3 Diobu area of Port Harcourt, Rivers State was used for this study. The piece of land is situated at Longitude 4°48’18.50’’N and Latitude 6o58’39.12’’E measuring 5.4864 m x 5.1816 m with a total area of 28.4283 m2. Bioremediation monitoring lasted for 56 days, analysis carried out weekly (per 7 days interval). Methodology: Seven (7) experimental plots were employed using a Randomized Block Design each having dimensions of 100 x 50 x 20 cm (Length x Breadth x Height) were formed and mapped out on agricultural soil and left fallow for 6 days before contamination on the seventh day; after which it was allowed for 21 days for proper contamination and exposure to natural environmental factors to mimic crude oil spill site. Thereafter bio stimulating agents usually referred to as nutrient amendment organics in this study (fish waste and goat manure) and bio-augmenting microorganisms were applied. Soil profile before and after contamination was assayed while parameters like Nitrate, Sulphate, Phosphate, Total Organic Carbon (TOC) and Total Petroleum Hydrocarbon (TPH), were monitored throughout the experimental period. Microbial analyses such as Total Heterotrophic Bacteria (THB), Total Heterotrophic Fungi (THF), Hydrocarbon Utilizing Bacteria (HUB) and Hydrocarbon Utilizing Fungi (HUF) were recorded. Bioremediation efficiency was estimated from percentage (%) reduction of Total Petroleum Hydrocarbon (TPH) from day 1 to the residual hydrocarbon at day 56 of bio augmented/ biostimulation plots with the control. Results: Results revealed amount of remediated hydrocarbon and % Bioremediation efficiency at 56 days in the different treatment plots (initial TPH contamination value of  9296.83  mg/kg) in a decreasing order as follows: PS+Bac+Pse+GF+FW (8032.825 mg/kg; 86.40%) >PS+GF+FW (6867.825 mg/kg; 73.87%) >PS+Bac+Pse (6587.825mg/kg; 70.86%) >PS+FW (6441.825mg/kg; 69.29%) >PS+GF (5909.825 mg/kg; 63.57%) >CTRL 2 (Polluted soil without amendment) (3604.825mg/kg; 38.78%). Microbiological results showed increased colonial values with increase time exposure. The results observed on day 56 indicate that Polluted soil + Bacillus + Pseudomonas (10.11 Log10 CFU/g) > Polluted soil but un-amended soil (8.76 Log10 CFU/g) > unpolluted soil (8.68 Log10 CFU/g). Comparatively, Polluted soil +Bacillus + Pseudomonas expressed higher heterotrophic bacteria of 9.77 and 9.67 Log10 CFU/g while fungal counts recorded 6.04 and 6.82 Log10 CFU/g. Conclusion: Study showed that bioremediation of crude oil-polluted soils with bacteria singly is less effective but a combination with other organic nutrients is a better palliative measure. Therefore, amendment with organic nutrients like Goat manure and Fish wastes is recommended for crude oil polluted soils due to its high nutrient content as substrates for biostimulation of indigenous and augmenting biodegrading microbes. This process could be a source of enhanced natural attenuation of oil-contaminated environments in Nigeria.

scholarly journals Microbiological and Physicochemical Evaluation of Oil-polluted Soil from Major Auto Mechanic Shops in Port Harcourt Metropolis, Rivers State, Nigeria

2020 ◽  
pp. 1-10
Author(s):  
Janet Olufunmilayo Williams ◽  
Prekebi Peter Akemi
Keyword(s):  
Control Sample ◽  
Pollution Index ◽  
Sole Source ◽  
Polluted Soil ◽  
Soil Samples ◽  
Port Harcourt ◽  
Physicochemical Evaluation ◽  
The Mean ◽  
Ph Level ◽  
Rivers State

The capability of microorganisms to utilize spent oil in polluted soil from some major auto mechanic workshops in Port Harcourt metropolis as the sole source of carbon and energy was studied. Soil samples were collected from three (3) Auto mechanic workshops (Mile 3 Mechanic Village (N 4º48' 34.07'', E 6º59' 10.17''), Ikoku Mechanic Workshop (N 4º47' 54.28'', E 6º59' 36.42'') and Elekahia Zone H Mechanic Workshop (N4º49' 11.62'', E 7º1' 16.58'') in Port Harcourt, Rivers State, Nigeria from depths of 0–30 cm, 30–60 cm and 60–90 cm at the same spot from each station. Soil samples were analysed microbiologically and physicochemically using standard methods. The control sample was obtained behind the Biology Building of Rivers State University, Port Harcourt. The results of the total heterotrophic bacterial and fungal counts showed that the microbial load was high at a depth of 0 to 30 cm for all the samples analysed including the control. With 60-90 cm depth, low microbial counts were obtained. The total heterotrophic bacterial counts from the three mechanic workshops ranged from 6.8 X 108 to 2.3 X 109cfu/g while the total heterotrophic fungal counts ranged from 1.3 X 106 to 8.0X 106 cfu/g. The spent oil-utilizing microbial populations ranged from1.0 X 105 to 3.0 X 106cfu/g and1.0 X 105 to 8.0 X 105 cfu/g for the bacterial and fungal counts respectively. Five spent oil utilizing bacterial isolates of the genera, Pseudomonas, Klebsiella, Bacillus, Micrococcus and Proteus and five fungal isolates of the genera, Penicillium, Candida, Rhizopus, Fusarium and Aspergillus were obtained from spent oil-polluted soil in this study. The pollution index of the different physicochemical parameters obtained from the different sample stations was as follows: Electrical Conductivity (EC): Mile 3 had the highest with the mean of 12.50 ±0.0-13.20±0.0µs/cm, while Ikoku had the lowest with mean of 10.99 ± 0.0-11.50 ± 0.0 µs/cm. Ikoku had the highest pH level with mean of 7.0 ± 0.0- 8.5 ± 0.0 while Mile 3 had the lowest pH level with mean of 6.5 ± 0.0-7.59 ± 0.0. Ikoku had the highest Total Organic Carbon (TOC) with mean of 17.55 ± 0.0-20.60 ± 0.0 mg/kg while Elekahia had the lowest with the mean of 16.99 ± 0.0-18.0 ± 0.0 mg/kg. Ikoku had the highest Total Hydrocarbon Content (THC) with mean of 38,862 ± 0.0-40,500 ± 0.0 mg/kg while Mile 3 had the lowest with the mean of 20,550 ± 0.0-30,000 ± 0.0 mg/kg. From the Pollution Index Analysis, Ikoku Auto Mechanic Workshop is more contaminated with Spent oil than Mile 3 and Elekahia.

scholarly journals Characterization of Indigenous Bacterial Communities in Crude-Oil Impacted Sites at Obagi Town, Onelga, Rivers State, Nigeria

Fine Focus ◽  
2016 ◽  
Vol 2 (1) ◽  
pp. 7-14
Author(s):  
Chioma Blaise Chikere ◽  
Chinyere Augusta Ajuzieogu ◽  
Michael Chukwugoziem Miller
Keyword(s):  
Crude Oil ◽  
Heterotrophic Bacteria ◽  
Bacterial Species ◽  
Polluted Soil ◽  
Soil Samples ◽  
Isolation And Characterization ◽  
Significant Difference ◽  
Rivers State ◽  
Hydrocarbon Utilizing Bacteria

Hydrocarbon utilizers are expected to be indigenous in crude-oil polluted environments. The isolation and characterization of hydrocarbon utilizers is often a key strategy in bioremediation of hydrocarbon-polluted environments. In this study, crude-oil polluted soil samples from Obagi town, Onelga, Rivers state were enumerated and characterized for putative hydrocarbon utilizing bacterial populations. Biochemical characterization identified five bacterial species representative of five genera: Bacillus, Pseudomonas, Acinetobacter, Micrococcus and Staphylococcus. Amongst the genera of bacteria isolated, Bacillus had the highest frequency of occurrence (40%). The mean count of total heterotrophic bacteria was 1.7 X 107 cfu/g, while hydrocarbon utilizing bacteria (HUB) count mean density was 1.0 X 107 cfu/g for the three soil samples. Statistical analyses revealed no significant difference at p>0.05 between Total Heterotrophic Bacterial (THB) and Hydrocarbon Utilizing Bacterial (HUB) counts, suggesting that most of the bacteria present in the sampled sites were hydrocarbon utilizers. Findings from this study suggest the presence of indigenous putative hydrocarbon utilizing bacteria in the crude-oil polluted soil of Obagi town. Hence, a promising potential exists for future bioremediation studies on the site.

scholarly journals Biosorption Potentials of Pleurotus tuber-regium (Fr.) Sing in Lead and Cadmium Polluted Soil

2022 ◽  
Vol 1 (1) ◽  
pp. 1-3
Author(s):  
O.C.U. Adumanya ◽  
◽  
B.C. Onwubuche ◽  
S.A. Nwinee ◽  
G.A. Umensofor ◽  
...  
Keyword(s):  
Lead Concentration ◽  
Environmental Pollutants ◽  
Polluted Soil ◽  
Soil Samples ◽  
Distilled Water ◽  
Intrinsic Properties ◽  
Lead And Cadmium ◽  
Ad Libitum ◽  
Dose Dependent ◽  
Humus Soil

Background/Aim: The heavy metals, cadmium (Cd) and lead (Pb), are often implicated as environmental pollutants. Therefore, the biosorption potential of Pleurotus tuber-regium in lead and cadmium polluted soil was investigated by this work. Methods: Four kilograms of each humus soil sample was weighed into eight different black nursery cellophane bags and polluted with 0.5 g, 1.0 g and 2.0 g of lead and cadmium in triplicate. Pleurotus sclerotia were then planted in these polluted soil samples, and distilled water was added ad libitum. Results: The results showed that the growth performance was dose-related in lead-polluted soil. The Pleurotus tuber regium mushroom in the lead-polluted soil samples indicated a dose-dependent absorbed lead concentration in the results. Cadmium-polluted soil samples did not support the growth of the Pleurotus tuber regium mushroom at the various concentrations of cadmium used after day 30. Therefore, the findings suggest that the Pleurotus tuber regium mushroom and its sclerotia have intrinsic properties for the absorption of lead and cadmium. Conclusion: The findings suggest that the Pleurotus tuber regium mushroom and its sclerotia have intrinsic properties for the absorption of lead and cadmium.

scholarly journals Complementary Use of Magnetometric Measurements for Geochemical Investigation of Light REE Concentration in Anthropogenically Polluted Soils

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 457
Author(s):  
Piotr Fabijańczyk ◽  
Jarosław Zawadzki
Keyword(s):  
Soil Samples ◽  
Soil Conditions ◽  
Soil Cores ◽  
Light Rare Earth ◽  
Polluted Soils ◽  
Chemical Measurements ◽  
Geochemical Investigation ◽  
Light Rare Earth Elements ◽  
Soil Magnetic Susceptibility ◽  
Geophysical Measurements

The purpose of this study was to use fast geophysical measurements of soil magnetic susceptibility (κ) as supplementary data for chemical measurements of selected light rare earth elements (REEs) in soil. In order to ensure diversity in soil conditions, anthropogenic conditions and types of land use, seven areas were selected, all located in regions subjected to past or present industrial pollution. Magnetometric parameters were measured using a selected magnetic sensor that was specially designed for measurements of soil cores and were used to classify collected soil cores into six distinctive types. The analysis of REEs concentrations in soil was carried out taking into account the grouping of collected soil samples based on the type of study area (open, forested and mountain), and additionally on the measured magnetometric parameters of collected soil cores. A use of magnetometric measurements provided different, but complementary to chemical measurements information, which allowed to obtain deeper insight on REEs concentrations in soils in studied areas.

scholarly journals Behavior of Eucalyptus grandis and E. cloeziana seedlings grown in arsenic-contaminated soil

2010 ◽  
Vol 34 (3) ◽  
pp. 985-992 ◽  
Author(s):  
Roseli Freire Melo ◽  
Luiz Eduardo Dias ◽  
Jaime Wilson Vargas de Mello ◽  
Juraci Alves Oliveira
Keyword(s):  
Root System ◽  
Plant Height ◽  
Contaminated Soil ◽  
Dry Matter ◽  
Eucalyptus Grandis ◽  
Soil Samples ◽  
Mining Activities ◽  
Polluted Soils ◽  
Interveinal Chlorosis ◽  
Apical Bud

Arsenic has been considered the most poisonous inorganic soil pollutant to living creatures. For this reason, the interest in phytoremediation species has been increasing in the last years. Particularly for the State of Minas Gerais, where areas of former mining activities are prone to the occurrence of acid drainage, the demand is great for suitable species to be used in the revegetation and "cleaning" of As-polluted areas. This study was carried out to evaluate the potential of seedlings of Eucalyptus grandis (Hill) Maiden and E. cloeziana F. Muell, for phytoremediation of As-polluted soils. Soil samples were incubated for a period of 15 days with different As (Na2HAsO4) doses (0, 50, 100, 200, and 400 mg dm-3). After 30 days of exposure the basal leaves of E. cloeziana plants exhibited purple spots with interveinal chlorosis, followed by necrosis and death of the apical bud at the 400 mg dm-3 dose. Increasing As doses in the soil reduced root and shoot dry matter, plant height and diameter in both species, although the reduction was more pronounced in E. cloeziana plants. In both species, As concentrations were highest in the root system; the highest root concentration was found in E. cloeziana plants (305.7 mg kg-1) resulting from a dose of 400 mg dm-3. The highest As accumulation was observed in E. grandis plants, which was confirmed as a species with potential for As phytoextraction, tending to accumulate As in the root system and stem.

scholarly journals The use of N HNO3 to determine copper and zinc levels in heavy-metal polluted tropical soils

2021 ◽  
Vol 905 (1) ◽  
pp. 012001
Author(s):  
A K Salam ◽  
M Milanti ◽  
G Silva ◽  
F Rachman ◽  
I M T D Santa ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Tropical Soils ◽  
Correlation Study ◽  
Relative Strength ◽  
Soil Samples ◽  
Water Spinach ◽  
Polluted Soils ◽  
Chemical Extractants ◽  
Soil Zn ◽  
Zinc Levels

Abstract This study compared N HNO3 to other methods to determine plant available heavy metals in heavy-metal polluted soils. Soil samples were obtained from an experimental field treated with industrial waste after 22 years of the amendment and employed to conduct the comparative and correlation study. Soil samples were analyzed for Cu using various methods, planted in a glass house with several plants, and analyzed for soil and plant Cu and Zn. The relative strength of the chemical extractants followed the order of N HNO3 ≈ N HCl > Buffered DTPA ≈ Unbuffered DTPA > M CaCl2 ≈ N NH4OAc pH 7. A high correlation was observed for soil extracted Cu by M CaCl2 or N NH4OAc pH 7 or N HCl vs. Buffered DTPA and N HNO3 or N NH4OAc pH 7 vs. N HCl. High correlations of plant and soil Cu extracted by N HNO3 were shown by caisim, water spinach, land spinach, and corn, while plant and soil Zn were shown by caisim, water spinach, land spinach, and lettuce.

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