• Mycobiology
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• 제48권6호
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• pp.501-511
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• 2020

Xylophagous termites are capable of degrading lignocellulose by symbiotic gut microorganisms along with the host's indigenous enzymes. Therefore, the termite gut might be a potential niche to obtain natural yeasts with celluloytic, xylanolytic and ethanologenic traits required for bioethanol production from lignocellulosic biomass. In this study, we cultured 79 yeasts from three different termites viz. Coptotermes heimi, Odontotermes javanicus and Odontotermes obesus. After suitable screening methods, we identified 53 yeasts, which belonged to 10 genera and 16 different species of both ascomycetous and basidiomycetous yeasts. Most yeasts in the present study represent their first-ever isolation from the termite gut. Representative strains of identified yeasts were evaluated for their cellulolytic, xylanolytic, and ethanologenic abilities. None of the isolates showed cellulase activity; 22 showed xylanolytic activity, while six produced substantial quantities of ethanol. Among xylanolytic cultures, Pseudozyma hubeiensis STAG 1.7 and Hannaella pagnoccae STAG 1.14 produced 1.31 and 1.17 IU of xylanase. Among ethanologenic yeasts, the strains belonging to genera Candida and Kodamaea produced high amount of ethanol. Overall, highest ethanol level of 4.42 g/L was produced by Candida tropicalis TS32 using 1% glucose, which increased up to 22.92 g/L at 35 ℃, pH 4.5 with 5% glucose. Fermentation of rice straw hydrolysate gave 8.95 g/l of ethanol with a yield of 0.42 g/g using the strain TS32. Our study highlights the gut of wood-feeding termites as a potential source of diverse yeasts that would be useful in the production of xylanase and bioethanol.

• 한국환경농학회지
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• 제41권2호
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• pp.115-124
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• 2022

BACKGROUND: Methane is a major greenhouse gas attributed to global warming partly contributed by agricultural activities from ruminant fermentation and rice paddy fields. Methanotrophs are microorganisms that utilize methane. Their unique metabolic lifestyle is enabled by enzymes known as methane monooxygenases (MMOs) catalyzing the oxidation of methane to methanol. Rice absorbs, transports, and releases methane directly from soil water to its stems and the micropores and stomata of the plant epidermis. Methylobacterium species associated with rice are dependent on their host for metabolic substrates including methane. METHODS AND RESULTS: Methylobacterium spp. isolated from rice were evaluated for methane oxidation activities and screened for the presence of sMMO mmoC genes. Qualitatively, the soluble methane monooxygenase (sMMO) activities of the selected strains of Methylobacterium spp. were confirmed by the naphthalene oxidation assay. Quantitatively, the sMMO activity ranged from 41.3 to 159.4 nmol min^-1 mg of protein^-1. PCR-based amplification and sequencing confirmed the presence and identity of 314 bp size fragment of the mmoC gene showing over 97% similarity to the CBMB27 mmoC gene indicating that Methylobacterium strains belong to a similar group. CONCLUSION(S): Selected Methylobacterium spp. contained the sMMO mmoC gene and possessed methane oxidation activity. As the putative methane oxidizing strains were isolated from rice and have PGP properties, they could be used to simultaneously reduce paddy field methane emission and promote rice growth.

• Natural Product Sciences
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• 제27권4호
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• pp.217-227
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• 2021

This study is a record of ethnomedicinal knowledge in Begumganj province focussed on medicinal plants and their local uses for primary health care. The aim was to document and preserve the ethnomedicinal knowledge used by traditional healers of Begumganj upazila, Bangladesh, to treat human diseases and evaluate the relative efficacy of the medicinal plants. The uses of medicinal plants were documented as an ethnomedicinal data sheet using direct observation, field interview, plant interview and group interview techniques from December 2012 to January 2014 in the study area. Data were collected from 98 traditional healers through a questionnaire survey and analyzed through informant consensus factor and fidelity level. This study revealed comprehensive relationship among various diseases and families, forms and parts of plants and modes of preparation. Overall, 75 plant species under 71 genera of 47 families were documented, which are used to treat 41 diseases. Data analysis revealed that 41.33%, 14.67%, 36% and 8% of the medicinal plant species were herbs, shrubs, trees, and climbers, respectively. Leaves were the most used parts, followed by stem, root, fruit, bark, latex and rhizome. The most frequently treated diseases were dysentery, rheumatism and skin diseases. This is the first ethnobotanical survey, which recorded the importance of medicinal plants in Begumganj upazila, Bangladesh. This study can contribute to preserving the indigenous knowledge on the traditional use of medicinal plants in this region and new drug development with attracting future generations towards traditional healing practice.

• Biomolecules & Therapeutics
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• 제18권2호
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• pp.211-218
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• 2010

Acanthopanax koreanum Nakai (Araliaceae) is a medicinal plant indigenous to Korea. The root and stem barks of Acanthopanax species have been used as a tonic and sedative as well as in the treatment of rheumatism and diabetes. In our study, three lignans, eleutheroside E (EE), tortoside A (TA), and syringaresinol (SY), were isolated from the stem and root of A. koreanum in an effort to study the immunomodulating effect. We treated natural killer cells and dendritic cells with lignans (EE, TA, or SY), and analyzed their cytokine (IL-12 and IFN-${\gamma}$) secretion. EE, TA, or SY markedly enhanced IL-12 secretion in mouse lymphoid (DC1) and myeloid type (DC2.4) dendritic cells after 48 hr of treatment. There were no significant differences in the cytokine stimulatory effects between EE, TA, or SY. Moreover, treatment of EE, TA, or SY significantly induced IFN-${\gamma}$ secretion by human NK cells (NK92MI) confirmed by ELISA assay. This study suggests that lignans from A. koreanum modulate cytokines, and that such modulation may provide the mechanism of action for many of their therapeutic effects.

• The Plant Pathology Journal
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• 제31권3호
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• pp.278-289
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• 2015

Indigenous strains of Trichoderma species isolated from rhizosphere soils of Tea gardens of Assam, north eastern state of India were assessed for in vitro antagonism against two important tea fungal pathogens namely Pestalotia theae and Fusarium solani. A potent antagonist against both tea pathogenic fungi, designated as SDRLIN1, was selected and identified as Trichoderma viride. The strain also showed substantial antifungal activity against five standard phytopathogenic fungi. Culture filtrate collected from stationary growth phase of the antagonist demonstrated a significantly higher degree of inhibitory activity against all the test fungi, demonstrating the presence of an optimal blend of extracellular antifungal metabolites. Moreover, quantitative enzyme assay of exponential and stationary culture filtrates revealed that the activity of cellulase, ${\beta}$-1,3-glucanase, pectinase, and amylase was highest in the exponential phase, whereas the activity of proteases and chitinase was noted highest in the stationary phase. Morphological changes such as hyphal swelling and distortion were also observed in the fungal pathogen grown on potato dextrose agar containing stationary phase culture filtrate. Moreover, the antifungal activity of the filtrate was significantly reduced but not entirely after heat or proteinase K treatment, demonstrating substantial role of certain unknown thermostable antifungal compound(s) in the inhibitory activity.

• Journal of Microbiology
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• 제42권3호
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• pp.243-247
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• 2004

Sphingomonas chlorophenolica ATCC39723 was successfully labeled with the gfp (green fluorescent protein) gene inserted into the pcpB gene by homologous recombination. As the gfp recombinant was easily distinguished from other indigenous organisms, the population of gfp recombinant was monitored after being released into the soil microcosms. Their population density dropped from 10$\^$8/ to 10$\^$6/ (cfu/$m\ell$) in the non-sterilized soil microcosms during the first 6 days. Moreover, the gfp recombinant was not detected even at lower dilution rates after a certain time period. The recombinant, however, survived for at least 28 days in the sterilized soil microcosms. Although the gfp recombinant did not degrade pentachlorophenol (PCP), this experiment showed the possibility of using gfp as a monitoring reporter system for S. chlorophenolica ATCC39723 and potentially other species of Sphingomonas.

• 생약학회지
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• 제31권1호
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• pp.28-33
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• 2000

Chemical investigation of the stem bark of Alnus hirsuta Turcz var. sibirica (Betulaceae), one of the indigenous Alnus species growing in Korea has led to the isolation of five diarylheptanoids. Structures of these compounds were identified as hirsutenone (1), hirsutanonol (2), oregonin (3), (5S)-1,$7-bis-(3,4-dihydroxyphenyl)-heptan-3-one-5-0-{\beta}-D-glucopyranoside$ (4) and (5R)-1,$7-bis-(3,4-dihydroxyphenyl)-heptane-5-0-{\beta}-D-glucopyranoside$ (5) by the analysis of spectroscopic evidences and comparison with the data of authentic samples.

• Preventive Nutrition and Food Science
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• 제21권2호
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• pp.79-84
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• 2016

Apium graveolens Linn. (Apiaceae) is an indigenous plant of the North and South Americas, Southern Europe, and Asia and has been widely used as a food or a traditional medicine for treatment of inflammation and arthritis. The purpose of this study was to investigate the antioxidant effects of a methanolic extract of A. graveolens (AGE) against liver oxidative stress in an adjuvant-induced arthritic rat model. The AGE (250, 500, and 1,000 mg/kg) was given orally for 24 consecutive days after induction by injecting complete Freund's adjuvant. Liver and spleen weights were recorded. The superoxide anion level, total peroxide (TP), glutathione peroxidase (GPx) activity, superoxide dismutase (SOD) activity, total antioxidant status, and oxidative stress index (OSI) were also measured. AGE treatment significantly decreased the levels of the superoxide anion, TP, and OSI whereas the GPx and SOD activities significantly increased in the liver of the arthritic rats. These results indicated that AGE showed an ameliorative effect against liver oxidative stress in adjuvant-induced arthritic rats by reducing the generation of liver free radicals and increasing the liver antioxidant enzyme activity.

• 대한수의학회지
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• 제2권2호
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• pp.15-24
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• 1962

In the previous report it was demonstrated that aqueous extracts of two Korean indigenous crude drugs, Radix Jingyu and Fructus ponciri, have an excellent tick repellent effect, and also the need for further analytical study of these crude drugs was suggested. In the experiments to be reported herein, attempts were made to find out the active ingredients from Radix Jingyu, since the aqueons extract of Radix Jingyu proved to be mone effective than that of Fructus ponciri. It will be shown that the active ingredient is indicative of Lycaconitine, a known alkaloid. An aqueons solution containing 1.5 Gms of Lycaconitine in tartrate when sprayed on a cow exerted tick repellent effect against Boophilus microplus which lasted approximately 25 days without any harmful influences on cattle. It will also be shown that the oil-fat components of Radix Jingyu act synergistically with Lycaconitine in accelerating and lengthening the effect, although the components alone have no effect under the conditions tested. It was of interest to note that the oil-fat components of Radix Jingyu showed definite repellent effect against the larvae of Boophilus microplus in laboratory experiments by the method newly devised. On the basis of these observations, it was concluded that Lycaconitine can be used as cattle tick repellent, and the evidence seems to warrant a large scale production of Lycaconitine for its widespread use. Further studies on the possible effect of the alkaloid on other genera or species of ticks and related vermins were also indicated.

• 셀메드
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• 제4권4호
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• pp.26.1-26.9
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• 2014

Reactive oxygen species are known to mediate various pathological conditions associated with malaria. In this study, the antioxidant potential of Clerodendrum violaceum leaf extracts, an indigenous antimalarial remedy, was evaluated. Total phenol, flavonoid, selenium, vitamins C and E contents of Clerodendrum violaceum leaf extracts were determined. The free radical scavenging activities of the extracts against DPPH, superoxide anion and hydrogen peroxide coupled with their reducing power were also evaluated in vitro. Moreover, responses of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) in a rodent malaria model to a 4-day administration of Clerodendrum violaceum leaf extracts were also evaluated. The methanolic extract was found to contain the highest amounts of antioxidant compounds/element and also demonstrated the highest free radical scavenging activity in vitro. The results showed a significant decrease (p < 0.05) in SOD and CAT activities with a concurrent significant (p < 0.05) increase in GPx and GR activities in both erythrocytes and liver of untreated Plasmodium berghei NK65-infected animals compared to the uninfected animals. The extracts were able to significantly increase (p < 0.05) SOD and CAT activities and significantly reduce (p < 0.05) GPx and GR activities in both the liver and erythrocytes compared to those observed in the untreated infected animals. The results suggest the augmentation of the antioxidant system as one of the possible mechanisms by which Clerodendrum violaceum extract ameliorates secondary effects of malaria infection, alongside its antiplasmodial effect in subjects.