• International Journal of Oral Biology
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• v.31 no.1
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• pp.7-10
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• 2006

Mitis-salivarius sucrose bacitracin(MSB) medium is widely used in the selective isolation of mutans streptococci(MS), a designation for a group of oral cariogenic species. Recently, we have isolated three bacterial strains grown on MSB agar from human dental plaques. The three strains exhibited biochemical characteristics similar to those of the biotype IV of MS, with the exception that they manifested a positive reaction for arginine deaminase. The objective of this study was to identify and characterize these three clinical isolates. The bacteria were identified with biochemical tests as well as by 16S rDNA cloning and sequencing. In order to compare the antibiotics susceptibility of the clinical isolates with that of type strain, the minimum inhibitory concentrations of 9 antibiotics were determined using broth dilution assays. The results identified all of our three clinical isolates as Enterococcus faecalis. All E. faecalis strains were found to be susceptible to penicillin G, amoxicillin, augmentin, and vancomycin, but were resistant to ciprofloxacin, cefuroxim axetil, and clindamycin. Our findings indicate that E. faecalis is capable of growing on MSB agar, and suggest that the MSB medium be improved so that only MS should be recoverable on the medium, as originally devised for their selection.

• Journal of Microbiology
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• v.43 no.2
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• pp.204-208
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• 2005

The objective of this study was to both isolate and identify non-mutans streptococci organisms (non­MSO) from dental plaques recovered on mitis-salivarius sucrose bacitracin agar (MSB) plates. The dental plaque samples, which had been collected from 63 human subjects, were diluted and plated on MSB. The bacteria growing on the MSB plates were then identified with biochemical tests, as well as with 16S rDNA cloning and sequencing techniques. Our data indicated that bacteria from 30 subjects had been recovered on the MSB plates. Among the 21 typical colonies selected from the 30 subjects, 12 colonies, derived from 10 subjects, were identified as non-MSO. These 12 colonies were determined to be Streptococcus anginosus (8 colonies), S. sanguinis (1 colony), and Pantoea agglomerans (3 colonies). These results strongly suggest that a new selective medium will be required for the reliable isolation of mutans streptococci.

• Korean Journal of Medicinal Crop Science
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• v.5 no.1
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• pp.49-55
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• 1997

This study was conducted to establish mass propagation system from the tissue culture using immature embryos in Eleutherococcus senticosus. Immature embryos from seeds were removed under the microscope and placed on MS, $MSB_5\;and\;B_5$ medium containing several plant growth regulators. While the calli were well formed on media containing 2 mg/l of 2, 4-D, 2 mg/l of 2, 4-D and 0.7 mg/l of TDZ, shoot regeneration was better on MS medium with combinations of high concentrations of TDZ and low concentrations of 2, 4-D. Treatment of 2, 4-D alone was better than treatment of TDZ alone in callus induction, but plant regeneration was reversed. The results of callus formation and shoot regeneration on $MSB_5\;and\;B_5$ media were similar to those of MS media. The rate of callus formation was nearly 100% when 2, 4-D was added to $B_5$, medium on concentration of 2 mg/l or 0.7 mg/l. TDZ showed very significant effect on the formation of multiple shoots.

• Restorative Dentistry and Endodontics
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• v.8 no.1
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• pp.31-44
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• 1982

Streptococcus mutans strains were isolated from dental plaques of carious lesions of 53 patients on mitis-salivarius-bacitracin (MSB) and mitis-salivarius(MS) medium as a supplement. The epidemiological investigation was carried out to determine the biotypes and serotypes of S. mutans isolates. For the serotyping, autoclaved extract antigens from the isolates and serotype-specific antisera against seven known serotypes of S. mutans were prepared. The serotypes of the isolates were demonstrated in immunodiffusion test. In addtition, the prevalence of ${\beta}$-hemolysis on 5% sheep blood agar plate in restricted anaerobic condition and yellow pigment production on 5% sucrose agar plate in less anaerobic condition among the isolates were investigated. The results were as follows: 1. Forty-eight S. mutans strains were isolated from dental plaque samples of 33 patients (62.3%) among 53 patients. 2. Of the isolates, some strains were not grown on MSB medium. 3. Serotype c S. mutans was found in 60.6%, serotype d was found in 30.3% of the patients who were known to harbor S. mutans. 4. Of. the isolates, serotype c isolates were most prevalent (43.8%), serotype d isolates were 25.0%, and serotype b, e, f and g isolates were also found but in lower frequencies. Serotype a S. mutans were not detected. 5. The correlation between serotype and biotype of the isolates was found in 78.6% of the typing cases. 6. Strains revealed ${\beta}$-hemolysis were in 52.1% of the isolates, strains produced yellow pigment were in 47.9% of the isolates, and with one exception, all the strains were belong to serotype c, e and f. 7. The majority of the isolates which revealed ${\beta}$-hemolysis appeared to be yellow pigmented, these isolates were belong to serotype c, e and f.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.2
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• pp.186-192
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• 2010

Streptococcus mutans, one of the major causal agents of dental caries, is component of the dental plaque. It produces various organic acids such as lactic acid which is the end-product of glycolysis, and this leads to dental caries. A new system using species-specific monoclonal antibodies was developed to detect Streptococcus mutans in saliva. The system quickly detects salivary Streptococcus mutans in 30min and classifies the result into two levels. The purpose of this study was to investigate correlation between monoclonal antibody-based detecting system and selective medium-based detecting methods. Children's deft indices were also compared with Streptococcus mutans counts in MSB agar plate. Subjects consisted of 15 children in the age of 3 to 6 years. They were assigned to three groups : Group I(deft index = 3), Group II(deft index $\leqq$3), Group III(deft index $\geqq$4). The results are as follows : 1. The rate of children with positive response was 13.3% and with negative response was 86.7% in the result of Saliva-checkTM Mutans test kit. 2. There was a positive correlation between monoclonal antibody-based detecting system and selective medium-based detecting methods(p<0.05). 3. Streptococcus mutans counts in MSB agar plate were irrelevant to deft of children(p=0.34).

• Journal of Microbiology and Biotechnology
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• v.20 no.11
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• pp.1471-1480
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• 2010

An extremely thermostable xylanase gene, xynB, from the hyperthermophilic bacterium Thermotoga maritima MSB8 was successful expressed in Kluyveromyces lactis. The response surface methodology (RSM) was also applied to optimize the medium components for the production of XynB secreted by the recombinant K. lactis. The secretion level (102 mg/l) and enzyme activity (49 U/ml) of XynB in the optimized medium (yeast extract, lactose, and urea; YLU) were much higher than those (56 mg/l, 16 U/ml) in the original medium (yeast extract, lactose, and peptone; YLP). The secretory efficiency of mature XynB was also improved when using the YLU medium. When the mRNA levels of 13 characterized secretion-related genes in the K. lactis cultured in YLP and YLU were detected using a semiquantitative RT-PCR method, the unfolded protein response (UPR)-related genes, including ero1, hac1, and kar2, were found to be up-regulated in the K. lactis cultured in YLU. Therefore, the nutrient ingredients, especially the nitrogen source, were shown to have a significant influence on the XynB secretory efficiency of the host K. lactis.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.137-143
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• 1994

In an attempt to optimize the in vitro-regeneration conditions necessary for the genetic manipulation of tomato species, we examined several hybrid lines and wild species (peruvianum, pimpinellifolium, glandulosum) of Lycopersicon for. their, different regeneration ability. The basal medium used for callus growth and organogenesis was MSB (MS + B5) supplemented with three combinations of TDZ (Thidiazuron) 0.5mg/L+NAA 0.5mg/L, BA 2.0mg/L+NAA0.05 mg/L, and zeatin 3.0 mg/L + IAA 0.02 mg/L. In the genotype of Lycopenicon grandulosum, combination of TDZ and NAA was more effective in inducing shoot and root differentiation than those of BA and NAA or zeatin and IAA. When all genotypes tested were considered, however combination of zeatin and IAA was shown to be the best in shoot regeneration. Result indicate that callus and organogenesis of Lycopenicon species are dependent upon the hormone types and plant genotypes, but MSB medium with zeatin 3.0 mg/L + IAA 0.02 mg/L maybe appropriate for genotype-independent plant regeneration system of Lycopercicon species. We also tried TDZ as a cytokinin source in tomato tissue culture and found it highly significant in tomato regeneration system.

• Weed & Turfgrass Science
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• v.7 no.1
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• pp.35-45
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• 2018

The seaweed Ulva spp., which is frequently bloomed in coastal areas, have negatively affected on marine ecosystem and industrial activities. Therefore, many researches have been conducted to solve this problem in the worldwide. In this study, we carried out several experiments to develop the methods for effectively controlling Ulva growth through an alone or mixture application of chemical and temperature. Three chemical mixtures ($H_2O_2$+N-vanillylnonanamide; $H_2O_2$+nonanoic acid; $H_2O_2$+sodium citrate), those had a synergistic effect to the death of Ulva australis (ULAUS), were found out. On the other hand, the death of ULAUS was significantly enhanced and accelerated as some chemicals were briefly treated with warm water of $40^{\circ}C$ rather than $25^{\circ}C$, showing that peracetic acid 100 ppm, sodium percarbonate 100 ppm, and hydrogen peroxide 30 ppm has a better activity than that of sodium chlorite 200 ppm and menadione sodium bisulfite 4 ppm. In addition, a strong synergistic effect to the death of ULAUS thallus was also observed when the sodium citrate 1,000 ppm (pH 3.0) or acetic acid 200 ppm (pH 3.5) solution prepared in f/2 medium were treated in a short time at $40^{\circ}C$. However, an additive effect was only appeared as pH values of their solutions were increased to 8.0. Taken together, It seemed that our results could be developed as one of an eco-friendly practical measures useful for alleviating Ulva bloom in the future.