• Journal of Microbiology and Biotechnology
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• v.22 no.4
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• pp.437-447
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• 2012

Natural and beneficial associations between plants and bacteria have demonstrated potential commercial application for several agricultural crops. The sunflower has acquired increasing importance in Brazilian agribusiness owing to its agronomic characteristics such as the tolerance to edaphoclimatic variations, resistance to pests and diseases, and adaptation to the implements commonly used for maize and soybean, as well as the versatility of the products and by-products obtained from its cultivation. A study of the cultivable bacteria associated with two sunflower cultivars, using classical microbiological methods, successfully obtained isolates from different plant tissues (roots, stems, florets, and rhizosphere). Out of 57 plant-growth-promoting isolates obtained, 45 were identified at the genus level and phylogenetically positioned based on 16S rRNA gene sequencing: 42 Bacillus (B. subtilis, B. cereus, B. thuringiensis, B. pumilus, B. megaterium, and Bacillus sp.) and 3 Methylobacterium komagatae. Random amplified polymorphic DNA (RAPD) analysis showed a broad diversity among the Bacillus isolates, which clustered into 2 groups with 75% similarity and 13 subgroups with 85% similarity, suggesting that the genetic distance correlated with the source of isolation. The isolates were also analyzed for certain growth-promoting activities. Auxin synthesis was widely distributed among the isolates, with values ranging from 93.34 to 1653.37 ${\mu}M$ auxin per ${\mu}g$ of protein. The phosphate solubilization index ranged from 1.25 to 3.89, and siderophore index varied from 1.15 to 5.25. From a total of 57 isolates, 3 showed an ability to biologically fix atmospheric nitrogen, and 7 showed antagonism against the pathogen Sclerotinia sclerotiorum. The results of biochemical characterization allowed identification of potential candidates for the development of biofertilizers targeted to the sunflower crop.

• Korean Journal of Agricultural Science
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• v.34 no.2
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• pp.161-170
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• 2007

To characterize $\gamma$-glutamyltranspeptidase ($\gamma$-GTP or ggt; EC 2. 3. 2. 2.) gene of Bacillus subtilis BS 62, the $\gamma$-GTP gene of BS 62 was prepared from PCR products amplified with the chromosomal DNA. The $\gamma$-GTP gene of about 2.5 kb was sequenced, and its homology was compared with the other ggt genes which were reported previously. The base sequence of the gene appeared to have an open reading frame of 1,758 bp encoding a protein of 62,175 Da. The coding region was flanked by putative ribosome binding site - AGGAGG of 7th to 12th upstream - and the stem-loof sequence was followed by transcription terminator codon. Homology of the amino acid residues sequence consisting of 587 amino acid residues was found as 98% with Bacillus subtilis gene (BSU49358), 97.4% with that of Bacillus subtilis KX 102, 37% with Pseudomonas sp. A14 (S63255) and 38% with Streptomyces avermitils (AP005028).

• Journal of fish pathology
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• v.28 no.2
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• pp.63-69
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• 2015

The biological characteristics of Bacillus sp.CPB-St as a probiotic strain to control fish streptococcosis was determined. Based on 16S rRNA sequencing, Bacillus sp.CPB-St was identified as Bacillus pumilus and named B. pumilus CPB-St (Abbreviated as CPB-St). Growth inhibitory activity of CPB-St against Streptococcus spp. was examined at three different incubation temperatures ($20^{\circ}C$, $25^{\circ}C$, and $30^{\circ}C$) and three culture media (NA, TSA, and BHIA) based on the diameter of inhibition zone. Its activity (inhibition zone of 11~29 mm) at $20^{\circ}C$ was higher than that (12~21 mm) at $30^{\circ}C$. Its activity (29 mm) in NA media was the same as that (29 mm) in TSA media. However, it was higher than that (22 mm) in BHIA media. The inhibitory activity of CPB-St against Streptococcus spp. was high at pH7. However, its activity was the same at salinity of 0.5% to 3%. CPB-St showed maximum growth after incubation at $25^{\circ}C$ for 48 h. To use CPB-St as probiotics, settlement studies in fish intestine and its efficacy through feeding are needed. CPB-St was highly resistant to gastric juice at pH4 and flounder's bile salt as well as deoxycholic acid at $300{\mu}g/ml$. CPB-St showed optimal viability in 1% NaCl. It showed similar growth in 0% to 7% NaCl. CPB-St could tolerate $-20^{\circ}C$ and $-70^{\circ}C$ for 45 min. There was no difference in the growth of the strain between room temperature and $4^{\circ}C$. Fish diet supplemented with CPB-St could be stored at low temperature without cell loss. Therefore, CPB-St might be used as probiotics to control streptococcosis of fish.

• Korean Journal of Food Science and Technology
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• v.19 no.1
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• pp.54-60
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• 1987

Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) were tested for their effectiveness in inhibiting the growth of microorganisms. Among the test microorganisms, the growth of three yeasts (Saccharomyces cerevisiae, Kloeckera apiculata, Cryptococcus hungaricus), three bacteria (Bacillus subtilu, Lactobacillus cases, Escherichia colt) and two molds (Aspergillus oryzae. Penicillium sp.) was progressively decreased as concentrations of BHA were increased. A. oyzae was completely inhibited with 100ppm of BHA and a majority of the test microorganisms (S. cerevisiae, K. apiculata. C. hungaricus, B. subtilis, A. oryzae) were completely inhibited by 150 ppm of BHA. The growths of L. casei, E. coli and Penicillium sp. were not affected as much as those of other microorganisms by BHA. Final cell yiedls were becoming lower as the concentration of BHA increased. The growth of C. hungaricus and L. casci was slightly inhibited by BHT. Other microorganisms were not effected by the test concentrations of BHT.

• Applied Biological Chemistry
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• v.51 no.4
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• pp.299-304
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• 2008

A ${\beta}$-1,4-endoglucanase gene from Bacillus subtilis H12 was cloned into Escherichia coli JM109 (pBC8) and sequenced. The endoglucanase gene with an insert DNA of 2.5 kb possessed an open reading frame of 1,500 bp encoding a mature protein of 499 amino acids with a calculated molecular mass of 55 kDa. The deduced amino acid sequence showed similarity to those of the known neutral cellulase genes of B. subtilis PAP115 (99.2%) and BSE616 (97.8%), as well as the alkaline gene of Bacillus sp. N4 (55.1%). The endoglucanase activity expressed by E. coli (pBC8) was localized in the periplasmic fraction (80%) and the cytoplasmic fraction (20%). An endoglucanase was purified from the periplasmic fraction by performing gel filtration and anion exchange chromatography. The molecular weight of the purified enzyme was estimated to be 31 kDa by SDS-PAGE, and the maximum activity occurred at pH 7 and $40^{\circ}C$. The enzyme easily hydrolyzed soluble substrates such as carboxymethyl cellulose and barely ${\beta}$-glucan, whereas the sigmacell and xylan, the known insoluble substrates, were not entirely hydrolyzed.

• The Korean Journal of Soil Zoology
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• v.9 no.1_2
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• pp.1-5
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• 2004

Insect pests and their natural enemies of Hibiscus Linne (Malvaceae) were investigated from March 2002 to November 2004. Fourteen insect pest species of 9 families in 5 orders were collected from Hibiscus syriacus: 5 species in Homoptera, 3 species in Lepidoptera, 2 species in Coleoptera, 1 species in Orthoprera, 1species in Hemiptera, 1 spedies in Acarina, and 1 species in Stylommatophora. Especially, Aphis gossypii Glover (Aphididae), Anomis megogona Walker(Noctuidae) and Tetranychus urticae Koch (Tetranychidae) were very important species because of their increasing daminge. The highest donsities were observed from May to June in August in Tetranychus urticae. As the enemies and ento-mopathogens of insect pests on Hibiscus syriacus, 1 species of bacteria, 3 species of fungi, 1 species of fungi, 1 species of Hemiptera, 1 species of Coleoptera, 2 species of Hymenopetera, 2 species of Diptera, and 1 species of Acarina were investigated. As the predators and parasitoids of Aphis gossypii, Aphidoletes aphidoletes aphidimyza Rondani (Cecidomyiidae), Meliscaeva cinctella Zetterstedt (Syrphidae), Harmonia axyridis Pallas (Coccinellidae), and Aphidius gifuensis Ashmead (Braconidae), entomopathogenic fungi, Vericillium lecani naturalis strain (Moniliaceae) and Beauveria bassiana naturalis strain strain (Hypocreaceae) were observed and Bacillus thuringiensis naturalis strain (Bacillaceae), B. bassiana, Metarhizium anisopliae naturalis strain (Hypocreaceae), predators of Tetranychus urticae, Amblyseius sp. (Phytoseiidae), and Orius sp. (Anthocoridae) were observed.

• KSBB Journal
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• v.29 no.3
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• pp.131-138
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• 2014

In this study, we isolated two novel chitinase producing bacterial strains from yellow loess samples collected from Jullanamdo province. The chitinase producing bacteria were isolated based on the zone size of clearance in the chitin agar plates. Both of them were gram positive, rod ($2{\sim}3{\times}0.3{\sim}0.4{\mu}m$), spore-forming, and motility positive. They were facultative anaerobic, catalase positive and hydrolyzed starch, gelatin, and casein. From the 16s rRNA gene sequence analysis, the isolates were labeled as Bacillus licheniformis KYLS-CU01 and B. licheniformis KYLS-CU02. The isolates showed higher extracellular chitinase activities than B. licheniformis ATCC 14580 as a control. The optimum temperature and pH for chitinase production were $40^{\circ}C$ and pH 7.0, respectively. Response Surface Methodology (RSM) was used to optimize the culture medium for efficient production of the chitinase. Under this optimal condition, 1.5 times higher chitinase activity of B. licheniformis KYLS-CU02 was obtained. Extracellular chitinases of the two isolates were purified through ammonium sulfate precipitation and anion-exchange DEAE-cellulose column chromatography. The specific activities of purified chitinase from B. licheniformis KYLS-CU01 and B. licheniformis KYLS-CU02 were 7.65 and 5.21 U/mg protein, respectively. The molecular weights of the two purified chitinases were 59 kDa. Further, the purified chitinase of B. licheniformis KYLS-CU01 showed high antifungal activity against Fusarium sp.. In conclusion, these two bacterial isolates can be used as a biopesticide to control pathogenic fungi.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.359-366
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• 2002

Bacillus polyfermenticus SCD which is commonly called as Bisroot strain is being used for functional foods through the treatment of long-term intestinal disorders, since the live strains in the form of active endospores can successfully reach the target intestine in humans. The cells of B. polyfermenticus SCD were treated for 4h in artificial gastric juice (pH 2.0,3.0) and bile acid. Final viability of the strain in artificial gastric Juice (pH 2.0, 3.0) is reached to 62.8% and 81.2% respectively B. polyfermenticus SCD is resistant to antibiotics such as streptomycin, rifampicin, nystatin and ampicilin. B. polyfermenticus SCD is well known supplies the nutrients by synthesizing vitamin $B_1$, $B_2$, C and K. B. polyfermenticus SCD produces various digestive enzymes and the enzymes enable to completely digest diets in our body. Above all, $\alpha$-amylase and pretense activities are very higher than B. subtilis KCTC 1020, about two fold and twenty five fold respectively. B. polyfermenticus SCD is very stable during long-term storage period in phosphate buffers of wide-range pH, solutions of various concentrations of sodium chloride, 5% glucose solution and water.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1258-1265
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• 2000

In oder to acquire microbial agents that can be utilized for control of aflatoxin produced by Aspergillus. flavus and Asp. parasiticus, antifungal bacteria were isolated. Antifungal bacteria was identified as Bacillus spp. based on morphology and physico-biochemical characteristics. Amount of aflatoxin $B_1$ from Doenjang(soybean paste) prepared with Asp. flavus, Asp. parasiticus, antifungal bacteria(Bacillus sp.), or mixture of Asp. flavus and Asp. parasiticus was 27.2 ppb, 30.3 ppb, 3.4 ppb, and 3.7 ppb, respectively. Aflatoxin $B_1$ was not detected from Doenjang(control) and Doenjang prepared with antifungal bacteria. Content and compositions of free sugars, fatty acid, organic acid and free amino acid in Doenjang prepared with Asp. flavus and Asp. parasiticus, antifungal bacteria and mixture of Asp. flavus and Asp. parasiticus were not significantly different. For volatile flavor compounds of Doenjang prepared with antifungal bacteria, 2-pentyl furan and butanoic acid were disappeared or reduced, while octadecene compounds were produced. However, those of Doenjang prepared with Asp. flavus or Asp. parasiticus and Doenjang(control) were not significantly different. These results suggested that the antifungal bacteria(Bacillus sp.) inhibited production of aflatoxin and that antifungal bacteria did not effect the quality of Doenjang.

• Mycobiology
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• v.45 no.4
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• pp.385-391
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• 2017

The ability of Bacillus subtilis, strain ALICA to produce three mycolytic enzymes (chitinase, ${\beta}$-1,3-glucanase, and protease), was carried out by the chemical standard methods. Bacillus subtilis ALICA was screened based on their antifungal activity in dual plate assay and cell-free culture filtrate (25%) against five different phytopathogenic fungi Alternaria alternata, Macrophomina sp., Colletotrichum gloeosporioides, Botrytis cinerea, and Sclerotium rolfesii. The B. subtilis ALICA detected positive for chitinase, ${\beta}$-1,3-glucanase and protease enzymes. Fungal growth inhibition by both strain ALICA and its cell-free culture filtrate ranged from 51.36% to 86.3% and 38.43% to 68.6%, respectively. Moreover, hyphal morphological changes like damage, broken, swelling, distortions abnormal morphology were observed. Genes expression of protease, ${\beta}$-1,3-glucanase, and lipopeptides (subtilosin and subtilisin) were confirmed their presence in the supernatant of strain ALICA. Our findings indicated that strain ALICA provided a broad spectrum of antifungal activities against various phytopathogenic fungi and may be a potential effective alternative to chemical fungicides.