• Korean Journal of Organic Agriculture
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• v.3 no.1
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• pp.23-42
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• 1994

This paper studied earthworm populations in fields under practical cultivation in the Eastern Harzforeland (Germany). The examined sites differed insignificantly in their climatic and soil conditions. The examination was a comparison between a field and a narrow edge or meadow. A combination of Oktett method and handsortin was used. The five different habitates seven earthworm species were discoverd. The most frequently foundd were A. rosea, A. caliginosa, and A. chlorotica. There were clear differences in species between the habitates of each site. Generally the edge or the meadow contained one (Zoeberitz) or two (Zscherben) more species than the field. The composition of species differed between 1990 and 1992. In the dry Autumn of 1991 there were less species found at both sites. The occurance of earthworm species depends on the weather. Moisture influencing similiarity of abundance and bio-mass were recorded in three out of four habitates. Starting on a high level in Autumn 1990 the abundance as well as biomass decreased until Autumn 1991 and increased the following year. The number from 1990 were never reached again during the examination. One year of normal precipita-tion was not enough to return the population to the beginning level. Great differences in the number of earthworms between the compared habitats suggest that the edges and meadows are a potential immigration source into a field which is poor on earthworms. Structrues of distribution near the edge refer to a migration from a high populated edge into an almost empty field.

• The Korean Journal of Mycology
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• v.50 no.4
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• pp.373-381
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• 2022

Strain E4, an unrecorded species of dimorphic fungi, was isolated from the gut of earthworms collected in Gyeonggi Province, South Korea. Nucleotide sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region revealed that this species is a member of the genus Blastobotrys, Blastobotrys illinoisensis. Strain E4 differed from its closest known species, B. mokoenaii and B. malaysiensis, by harboring 3-5 and 12-14 nucleotide substitutions in the D1/D2 and ITS regions, respectively. Phylogenetic analysis based on concatenated sequences of the D1/D2 region of the LSU rRNA gene and the ITS region also indicated that strain E4 belongs to the Blastobotrys clade and is distinct from other related species in the clade. The previously unreported isolate could be distinguished from closely related species by its inability to ferment carbon sources. To our knowledge, this is the first report on the isolation of Blastobotrys species from the gut of earthworms in Korea. The strain used was E4 (=KCTC 27831=JCM 33428).

• Applied Biological Chemistry
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• v.32 no.4
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• pp.393-400
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• 1989

The amounts of $^{14}CO_2$ evolved during the $^{14}C-bentazon$ aging in soil for 3 and 6 months were 6.1 and 14.8% of the original radioactivity, respectively. The presence of earthworms in soil tended to increase the uptake of $^{14}C-bentazon$ by the roots of rice plants, even if it was not statistically significant. The evolution of $^{14}CO_2$ from $^{14}C-bentazon$ in soil increased in the presence of rice plants and earthworms compared with in the absence of them. The uptake of $^{14}C-bentazon$ residues by rice plants decreased remarkably with increasing the aging period within the limit of 3 months both in the absence and presence of earthworms, but there is not much difference between 3-month-aging and 6-month-aging. Much larger amounts of $^{14}C-labelled$ compounds were translocated to the shoots, compared with the data from a previous investigation using maize plants. The amount of non-extractable bound residue increased remarkably with the aging period up to 3 months. The polarity of the compounds extracted from soil increased with the aging and the growing of rice plants, indicating the formation of some polar metabolites.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.231-238
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• 2014

BACKGROUND: Biochar (BC) has a great potential for enhancing soil fertility and carbon sequestration while facilitating beneficial waste disposition. Therefore, it is essential to assess and mitigate any inadvertent consequences associated with soil biochar amendment. Earthworm activity is very vital in the soil system, yet there are a limited number of studies that have examined their impact resulting from biochar application to soil. METHODS AND RESULTS: In this study, the survival, growth, reproductive tests, and oxidative DNA damage tests (measured by 8-hydroxydeoxyguanosine (8-OHdG) and catalase (CAT) activities) to assess the potential toxicity to earthworm Eisenia fetida in artificial soil amended with BCs were investigated. The BCs derived from perilla meal, sesame meal, and pumpkin seed were pyrolyzed at 300 and $550^{\circ}C$, and then amended with soil at a rate of 5%. All the earthworms survived, but lost weight compared to control soil after 28 day incubation period. Moreover, the BC-amended soils did not significantly affect the cocoon numbers of earthworms. Slightly higher concentrations of 8-OHdG and CAT were observed in earthworms present in BC-treated soil than those in control soil. Furthermore, the 8-OHdG concentrations in the soil amended with BC produced at $550^{\circ}C$ were greater than those at $300^{\circ}C$, and it slightly decreased as the incubation time increased. CONCLUSION: These observations could be due to higher contents of toxic metal(loid)s and also higher pH in BCs pyrolyzed at $550^{\circ}C$ than $300^{\circ}C$. While BC is efficiently being used in agricultural fields, this study suggests that it is required to assess the unintended negative impacts of BC on soil ecosystems.

• Korean Journal of Environmental Biology
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• v.28 no.4
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• pp.212-217
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• 2010

Soil pollution by heavy metals has become a significant environmental concern due to a variety of human activities. Specially toxicity caused by excessive mercury exposure is now being recognized as a widespread environmental problem and is continuing to attract a great deal of public concerns. The earthworms are very important animals that aerate the soil with their burrowing action and enrich the soil by decomposing organic matters. Especially the earthworm Eisenia fetida is routinely used in ecotoxicological studies. The levels of DNA damage in earthworms treated with HgCl2 and ionizing radiation were investigated in this study. Genotoxic effects were evaluated in the earthworm's coelomocytes using the comet assay (Single Cell Gel Electrophoresis; SCGE). The results showed that the mercury chloride and radiation were responsible for the genotoxic effects on earthworms. The level of DNA damage significantly increased after the treatment of mercury chloride combined with ionizing radiation. The combined treatment of $HgCl_2$ and ionizing radiation had a greater genotoxicity. This study is amenable to further study such as enzyme activation assay.

• The Korean Journal of Pesticide Science
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• v.4 no.4
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• pp.56-60
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• 2000

A study was performed to determine the maintenance conditions of the earthworm, Lumbricus rubellus, for the acute toxicity test. To fine out climatic and soil conditions, the earthworms were maintained in artificial soil consisting of sand, clay mineral and peat at different levels of conditions for 14 days. Lumbricus rubellus led to an increase of biomass at temperature $22{\pm}2^{\circ}C$, soil pH $7.0{\pm}1$ and moisture 40%. And four fungicides were tested for acute toxicities to Lumbricus rubellus, according to the optimum condition. The test earthworms were exposed to each pesticide with various concentration gradients. After 14 days, the number of surviving earthworms and their weight alteration during the test period was determined. The 14-day $LC_{50}$ values for the Lumbricus rubellus, of carbendazim, benomyl, thiophanate-methyl and thiabendazole were determined to be 59, 53, 64 and 36 mg/ kg soil dry weight, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.4
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• pp.105-111
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• 2004

When the clitellate tiger worms(Eisenia fetida) were fed with paper mill sludge, sewage sludge of agricultural-urban area and sewage sludge of agricultural area, number of cocoons produced by individual clitellate earthworm for 104 days were 11.8, 8.6 and 3.5, respectively. However, clitellate earthworms that had been fed with sewage sludge of agricultural-urban area for 52 days or fed with sewage sludge of agricultural area for 95 days could not produce cocoons, whereas the earthworms that were fed with paper mill sludge kept producing cocoons through the investigating period. The hatchability of cocoons produced by the clitellate tiger worms(Eisenia fetida) fed with sewage sludge of agricultural-urban region, sewage sludge of agricultural region and paper mill sludge were 42.8%, 38.3% and 39.2%, respectively. And hatching periods of cocoons were 33.8~36.0 days, which were not affected by the kinds of sludges. However, the cocoons produced by clitellate earthworms which had been fed with sewage sludge for about 1.5 months could not hatch at all. Death rates of second generation hatched from cocoons produced by tiger worms(Eisenia fetida) which had been fed with the sewage sludge from agricultural-urban region and the sewage sludge from agricultural region reached to 100% and 90% at 60 days after hatching, respectively, whereas death rate of second generation fed with paper mill sludge reached to 16%.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.72-81
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• 2004

For disposal food wastes which is about 30% portion of tatal organic wastes, vermicomposting is more environmental-friendly treatment than lanfill, incineration, etc. Recently, the interest has been increasing but there are many problems on management of vermicopmposting in field especially. This study was conducted to investigate an optimal factors, which are limit NaCl conc., the mixing rate of food wastes and casting for growth of an earthworm related to efficient vermicomposting. The limit conc. of NaCl was 0.5% and in case of feeding food wastes to earthworms as a prey only, most earthworms were dead in a few hours due to excessive degradation of organic materials and high NaCl conc. However as feeding with the casting of proper mixing rate(3:7), most earthworms were survived until finishing composting. It was investigated the increaser degree of matureness of food wastes, the higher conc. of NaCl, therefore for efficient vermicomposting, it seemed proper mixing rate of food wastes and the casting is better than matureness of food wastes. and the most suitable mixing rate was 3:7 food wastes and the casting.

• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.369-383
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• 2012

This experiment was carried out to investigate the optimal stocking rate of earthworm populations grown under different stocking rates. The stocking rate in terms of ratio of biomass of earthworms to biomass of feeds(organic resources) is an important factors for biomass productivity of earthworms and vermicast production. The different stocking rates were 1:16(S-1), 1:32(S-2), 1:48(S-3) and 1:64(S-4), as the ratios of biomass of earthworm to biomass of organic dairy cow manure, respectively. The stocking rate of 1:32(S-2) and 1:46(S-3) were obtained a higher values on increasing rates and conversion efficiency of organic matter to earthworm biomass than other stocking rates. Thus, a stocking rates of 1:32 and 1:46 estimated an optimal stocking rates for maximum biomass productivity of earthworms. A stocking rate of 1:16(S-1) showed a significantly highest values of vermicast production and ratios of vermicasts during the rearing periods.($$P{\leq_-}0.05$$) A stocking rate of 1:48(S-3) showed a highest values of the number of cocoons and vermicasts production per earthworm biomass among the treatment ($$P{\leq_-}0.05$$) The contents of nitrogen, available phosphorus, cation exchange capacity and exchangeable cations of vermicasts tended to increase with stocking rate and rearing progressed. Vermicasts have a great deal of potential for crop production and protection in sustainable organic cropping systems.

• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.391-402
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• 2021

Earthworms play an important role in soil fertilization, interacting continually with microorganisms. This study aims to demonstrate the existence of beneficial microorganisms living in the earthworm's immune system, the coelomic fluid. To achieve this goal, a molecular identification technique was performed, using cytochrome c oxidase I (COI) barcoding to identify abundant endogenic earthworms inhabiting the temperate zone of Rabat, Morocco. Then, 16S rDNA and ITS sequencing techniques were adopted for bacteria and fungi, respectively. Biochemical analysis, showed the ability of bacteria to produce characteristic enzymes and utilize substrates. Qualitative screening of plant growth-promoting traits, including nitrogen fixation, phosphate and potassium solubilization, and indole acetic acid (IAA) production, was also performed. The result of mitochondrial COI barcoding allowed the identification of the earthworm species Aporrectodea molleri. Phenotypic and genotypic studies of the sixteen isolated bacteria and the two isolated fungi showed that they belong to the Pseudomonas, Aeromonas, Bacillus, Buttiauxella, Enterobacter, Pantoea, and Raoultella, and the Penicillium genera, respectively. Most of the isolated bacteria in the coelomic fluid showed the ability to produce β-glucosidase, β-glucosaminidase, Glutamyl-β-naphthylamidase, and aminopeptidase enzymes, utilizing substrates like aliphatic thiol, sorbitol, and fatty acid ester. Furthermore, three bacteria were able to fix nitrogen, solubilize phosphate and potassium, and produce IAA. This initial study demonstrated that despite the immune property of earthworms' coelomic fluid, it harbors beneficial microorganisms. Thus, the presence of resistant microorganisms in the earthworm's immune system highlights a possible selection process at the coelomic fluid level.