• Korean Journal of Veterinary Research
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• v.47 no.4
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• pp.379-387
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• 2007

This study was conducted to investigate the pathogenicity of Paenibacillus (R) polymyxa JB 115 and single oral dose toxicity of culture broth containing (${\beta}$-glucan (CBG-JB 115) produced from P. polymyxa JB 115 in Sprague-Dawely rats of both sexes for 14 days. After oral administration of P. polymyxa JB 115 into rats, we could not find any abnormal clinical signs and variation in the body weight and temperature as compared with control group. We also investigated the acute toxicity of CBG-JB 115. As the results, there were no clinical signs and variance in the body weight and temperature related with CBG-JB 115 in comparison with the control group. From the this experiment, we could not find out any significant pathogenicity and toxicity induced by P. polymyxa JB 115 or by CBG-JB 115. Results of this study demonstrated that consumption of P. polymyxa JB 115 and its culture broth containing (${\beta}$-glucan was not associated with any obvious signs of toxicity in Sprague-Dawely rats even following consumption of large quantities.

• Journal of Life Science
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• v.9 no.1
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• pp.8-14
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• 1999

The growth rate of the A252 strain was increased in tryptic soy broth (TSB) and malt extract-yeast extract medium (ISP-2), but the antifungal activity of culture filtrate was efficient in the media of TSB and nutrient broth. The mycelial growth and the antifungal activity of culture filtrate in TSB medium were optimized at $25^{\circ}C$ and pH 6.5. The growth in 2$\%$TSB concentration was more effective than 1$\%$, but there was no difference of the antifungal activity by the TSB concentrations. The mycelial growth of A252 strain reached to maximum at 72 hr after inoculation, whereas the antifungal activity of culture filtrate was shown to have the highest level at idiophase (60 hr) after inoculation and was decreased a little after 96 hr incubation. The antifungal activity was stable in the pH range of 4 to 11 and evenly at $121^{\circ}C$. The A252 strain was characterized as Streptomyces species by the physiological properties and examination of sporophore me morphology.

• Korean Journal of Agricultural Science
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• v.44 no.1
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• pp.30-39
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• 2017

This study was performed to produce succinic acid from biomass by developing mutants of Cellulomonas flavigena in which the succinate dehydrogenase gene (sdh) is deleted. For development of succinate producing mutants, the upstream and downstream regions of sdh gene from C. flavigena and antibiotic resistance gene (neo, bla) were inserted into pKC1139, and the recombinant plasmids were transformed into Escherichia coli ET12567/pUZ8002 which is a donor strain for conjugation. C. flavigena was conjugated with the transformed E. coli ET12567/pUZ8002 to induce the deletion of sdh in chromosome of this bacteria by double-crossover recombination. Two mutants (C. flavigena H-1 and H-2), in which sdh gene was deleted in the chromosome, were constructed and confirmed by PCR. To estimate the production of succinic acid by the two mutants when the culture broth was fermented with biomass such as CMC, xylan, locust gum, and rapeseed straw; the culture broth was analyzed by HPLC analysis. The succinic acid in the culture broth was not detected as a fermentation products of all biomass. One of the reasons for this may be the conversion of succinic acid to fumaric acid by sdh genes (Cfla_1014 - Cfla_1017 or Cfla_1916 - Cfla_1918) which remained in the chromosomal DNA of C. flavigena H-1 and H-2. The other reason could be the conversion of succinyl-CoA to other metabolites by enzymes related to the bypass pathway of TCA cycle.

• Mycobiology
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• v.48 no.4
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• pp.326-329
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• 2020

Valuable natural compounds produced by a variety of microorganisms can be used as lead molecules for development of new agrochemicals. Furthermore, high-throughput in vitro screening systems with specific modes of action can increase the probability of discovery of new fungicides. In the current study, a rapid assay tested with various microbes was developed to determine the degree of respiratory inhibition of Saccharomyces cerevisiae in two different liquid media, YG (containing a fermentable carbon source) and NFYG (containing a non-fermentable carbon source). Based on this system, we screened 100 fungal isolates that were classified into basidiomycetes, to find microbial secondary metabolites that act as respiratory inhibitors. Consequently, of the 100 fungal species tested, the culture broth of an IUM04881 isolate inhibited growth of S. cerevisiae in NFYG medium, but not in YG medium. The result is comparable to that from treatment with kresoxim-methyl used as a control, suggesting that the culture broth of IUM04881 isolate might contain active compounds showing the inhibition activity for respiratory chain. Based on the assay developed in this study and spectroscopic analysis, we isolated and identified an antifungal compound (-)-oudemansin A from culture broth of IUM04881 that is identified as Oudemansiella venosolamellata. This is the first report that (-)-oudemansin A is identified from O. venosolamellata in Korea. Taken together, the development of this assay will accelerate efforts to find and identify natural respiratory inhibitors from various microbes.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.502-506
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• 1995

A Bacillus strain which produces ${\beta}-galactosidase$ with high transgalactosylation activity, was isolated from soil and tentatively designated as Bacillus sp. A1. When ${\beta}-galactosidase$ from Bacillus sp. A1 reacted with 40% (w/w) lactose, transgalactosylation ratio reached up to 90% at the 70% conversion of the initial lactose. The biosynthesis of the enzyme in Bacillus sp. A1 required lactose as an inducer and was repressed by glucose. Observing that the addition of amino acids to culture medium resulted in enhancing, to a significant extent, both the growth and the enzyme production of the strain, yeast extract and commercially available hydrolysates of protein were examined for the suitability as amino acid source. As it turned out, SMP, an enzymatic hydrolysis product of soybean protein from Fuji Oil Co.(Japan), was the most suitable for optimization of the culture medium. When Bacillus sp. A1 was cultured in the presence of 0.5% SMP and 2% lactose, the enzyme activity increased up to $1.8\;U/m{\ell}-broth$.

• Journal of Applied Biological Chemistry
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• v.54 no.3
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• pp.153-158
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• 2011

Optimal culture conditions were characterized for production of crude biosurfactant of Bacillus subtilis JK-1. During incubation of B. subtilis JK-1, the bacterial growth pattern, changes of the surface tension at variable temperatures, pH and NaCl concentrations in bacterial culture medium were studied. The strain was able to grow and produce biosurfactant at $15-45^{\circ}C$, in the pH range of 6-10, and at 0-10% (w/v) NaCl. In case, culture broth pH was gradually changed to neutral or weak alkaline. Optimal culture conditions for crude biosurfactant production were at $35^{\circ}C$ and pH 7.0 after 48 h incubation and the surface tension of biosurfactant was 24.0 mN/m. Besides, as the concentration of NaCl was increased from 0 to 10% (w/v), the growth was decreased, pH of the culture broth was converted from weak alkaline to acidic, and the surface tension rised.

• Mycobiology
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• v.42 no.2
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• pp.189-192
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• 2014

During a search for neuraminidase inhibitors derived from medicinal fungi, we found that the fermentation broth of Phellinus linteus exhibited potent neuraminidase inhibitory activity. Through bioassay-guided fractionation, two active compounds were purified from the ethyl acetate-soluble portion of the fermentation broth of P. linteus. These structures were identified as inotilone (1) and 4-(3,4-dihydroxyphenyl)-3-buten-2-one (2) by spectroscopic methods. Compounds 1 and 2 inhibited H1N1 neuraminidase activity with $IC_{50}$ values of 29.1 and 125.6 $125.6{\mu}M$, respectively, in a dose-dependent manner. They also exhibited an antiviral effect in a viral cytopathic effect reduction assay using MDCK cells. These results suggest that compounds 1 and 2 from the culture broth of P. linteus would be good candidates for the prevention and therapeutic strategies towards viral infections.

• Korean Journal of Agricultural Science
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• v.43 no.1
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• pp.100-108
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• 2016

An auxin-producing bacteria (strain 5-1) was isolated from button mushroom compost in Boryeong-Si, Chungcheongnam-Do. The 5-1 strain was classified as a novel strain of Enterobacter aerogenes based on chemotaxonomic and phylogenetic analyses. The isolated E. aerogenes 5-1 was confirmed to produce indole-3-acetic acid (IAA), one of the auxin hormones, using TLC and HPLC analyses. When the concentration of IAA was assessed by performing HPLC quantitative analysis, a maximum concentration of IAA of $109.9mgL^{-1}$ was detected in the culture broth incubated in R2A medium containing 0.1% L-tryptophan for 24 h at $35^{\circ}C$. Acidification of the culture was deemed caused by an increase of IAA because a negative relationship between IAA production and pH was observed. Supplementation with a known precursor of IAA production, L-tryptophan, appeared to induce maximal production at 0.1% concentration, but it reduced production at concentrations above 0.2%. To investigate the growth-promoting effects to crops, the culture broth of E. aerogenes 5-1 was used to inoculate water cultures and seed pots of mung bean and lettuce. In consequence, adventitious root induction and root growth of mung bean and lettuce were two times higher than those of the control.

• Transactions of the Korean hydrogen and new energy society
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• v.13 no.4
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• pp.321-329
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• 2002

Clostridium butyricum, Lactobacillus amylophillus, Lactobacillus amylovorus, Lactobacillus acidophillus, AI-9 produced hydrogen and /or organic acids using glucose, lactose and starch at the anaerobic culture conditions. Cl. butyricum NCIB 9576 evolved 1,700 ml H2/L-culture broth and accumulated butyric acid, acetic acid, propionic acid and ethanol in its culture broth when lactose was used as a carbon source during 24 hrs of fermentation. L. amylovorus ATCC 33620 accumulated lactic and acetic acids and some reducing sugars when starch was used as a carbon source without hydrogen production. Instead of starch as a carbon source, L. amylovorus ATCC 33620 produced lactic acid from algal biomass during fermentation and the acid-heat or freeze-thaw pretreatment of algal biomass accelerate the lactic acid fermentation.

• Microbiology and Biotechnology Letters
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• v.27 no.1
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• pp.1-7
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• 1999

A fungus, Penicillium sp. PS-113, isolated from soil showed the high phosphate-solubilizing activity in patato dextrose broth-rock phosphate to produce free phosphates to the culture broth with the concentrations of 585 ppm against rock phosphate. In this medium, the optimum temperature and initial pH to solubilize rock phosphate were 30$^{\circ}C$ and pH 7.5, respectively. In order to make the mass production of the conidia from this fungus, we cultured in on various solid-based media like barley, corn, wheat, rice, rice bran, and compost. As a result, the fungus highly produced conidia ranging from 2.1 to $5.1{\times}10_9$ conidia/g${\cdot}$media on these solid media except compost-based medium, which was 0 times less than others. Effects of inoculation of the phosphate solubilizing fungus as a biofertilizer were studied in perlite-based pot cropped with Zea mays Suwon 19. Inoculation of Penicillium sp. PS-113 increased in plant height (1.4 times), plant weight (5.2~8.1 times) and root length (1.1~1.2 times) at 60-day cultivation, compared to Hogland solution either without $NH_4H_2PO_4$ or displace $NH_4H_2PO_4$ to powdered rock phosphate, a phosphorus source for plant growth.