• Korean Journal of Microbiology
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• v.34 no.3
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• pp.96-100
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• 1998

The effects of electron acceptors and acclimation of inoculum on the anaerobic degradation of benzene, toluene, and m-xylene (BTX) were investigated to enhance the rate of degradation by estuarine sediment inoculum. With the fresh sediment inocula, degradation of BTX ensued after a 10-week acclimation period, and 37~61% of benzene and 57~61% of toluene were degraded after 16 weeks. Sediments from heavily contaminated sites showed higher degradation rates of BTX. After a 6-month of acclimation, degradation onset rapidly from the time of BTX addition and no difference was found among the sediment inocula. Single compound of BTX was slowly degraded in the methanogenic conditions, however, the degradation of BTX mixture was slow in the denitrifying conditions. Although the degradation rate of m-xylene was the fastest among the components of BTX mixture, longer acclimation enhanced the degradation rate of BTX, especially that of benzene. When the culture fluids were tested with Microtox, anaerobic degradation of BTX reduced the toxicity of BTX as well.

• Journal of Microbiology
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• v.35 no.3
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• pp.193-199
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• 1997

From several industrial wastewaters, 14 bacterial strains which degrade benzene, toluene, o-xylene, m-xylene, or p-xylene (BTX) were obtained. These strains were characterized as to their species composition and the substrate range, kinetic parameters and the substrate interactions were investigated. Although BTX components have a similar chemical structure, isolated strains showed different substrate ranges and kinetic parameters. None of the strains could degrade all of BTX components and most of them showed an inhibition (Haldane) kinetics on BTX, BTX mixtures were removed under inhibitory substrate interactions with variation in the intensity of inhibition. For a complete degradation of BTX, a defined mixed culture containing three different types of patyways was constructed and all of the BTX components were simultaneously degraded with the totla removal rate of 225.69 mg/g biomass/h Judging from the results, the obtained mixed culture seems to be useful for the treatment of BTX-contaminated wastewater or groundwater as well as for the removal of BTX from the contaminated air stream.

• KSBB Journal
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• v.16 no.1
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• pp.61-65
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• 2001

In this study, a BTX degrading microbial consortium was obtained from the activated sludges of a BTX releasing sewage water and city sewage water treatment plant. The MY microbial consortium was developed for benzene and toluene degradation, whereas the MA microbial consortium was developed for xylene isomers. The major microorganism of the MA consortium was identified as Rhodococcus ruber DSM 43338T, whereas that of the MY consortium was Rhodococcus sp. In terms of the degradation of a single component, the removal rate of benzene was fastest and decreased in order; toluene, o-xylene, p-xylene and m-xylene. For degradation of mixed BTX, most BTX were degraded within 108 hours and the degradation rate showed either stimulatory or inhibitory effects depending on the composition. MA and MY microbial consortium obtained in this study may be used effectively to remove BTX biologically.

• Journal of Environmental Science International
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• v.7 no.3
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• pp.393-400
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• 1998

A microorganism, Klebsiella gr. 47, capable of degrading BTX(benzene, toluene and xylene) was isolated from oil-contaminated soil and its characteristics of BTX degradation were investigated. When benzene and toluene were fed to Klebstella gr. 47 simulataneously, they showed competitive ingibition. The degradation rate of xylene was enhanced as much as 3 times when xylene was fed with benzene or toluene. Degradation rate of benzene and toluene was also enhanced by cocultured with Alcaligenes xylosoxidans. When benzene-adapted microorganism was used, each BTX compound was degraded efficiently within 5 hours.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.30 no.1
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• pp.9-11
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• 2019

Botulinum toxin (BTX) has been widely used to treat muscle spasms in many voice disorders. Most commercially available forms of BTX require reconstitution before use, which may increase the risk of contamination and requires careful titration. Recently, a liquid-type BTX type A (BTX-A) has been developed, which should simplify the procedure and enhance its efficacy. In this session, I will discuss about the differences of BTX-A from existing types and the practical issues associated with it.

• Journal of Oral Medicine and Pain
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• v.30 no.3
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• pp.345-351
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• 2005

The purpose of this double-blind study was to evaluate clinical effects of botulinum toxin type A (BTX-A) injection on myofascial pain syndrome (MPS) involving upper trapezius and compare with those of lidocaine injection. 21 patients presenting with active TrP1 and/or TrP2 in the upper trapezius over 6 months were selected for this study. The subjects were randomly divided into two groups; one group injected with BTX-A (15 unit of $Botox^{(R)}$ / 0.3 ml per trigger point (TrP)) and the other group injected with 0.5% lidocaine (0.3 ml /TrP). The clinical effects were evaluated by VAS and PPT at baseline, 2, 4, 6 and 8 weeks after treatment. BTX-A group showed persistent decrease of VAS values and increase of PPT values following treatment. While there was no significant difference in VAS values between BTX-A and lidocaine groups (p=0.347), there was significant difference in PPT values after treatment between two groups (p=0.000). The subjects received BTX-A showed noticeable improvement in PPT values after treatment, suggesting more reliable effect of BTX-A injection compared with lidocaine injection. The results of this study support that the direct injection of BTX-A to a TrP is an effective and safe treatment for MPS involving upper trapezius.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.46.1-46.6
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• 2015

Background: The purpose of this study was to evaluate the change of food intake after different dosages of botulinum toxin A (BTX) injection in the animal model. Additionally, the dimensional and histological change at 14 days after BTX injection was also evaluated. Methods: The comparative study was performed using the BTX injection model in rats (n = 5 for each group). Group 1 was the saline-injected group. Group 2 was the 5-unit BTX-injection group to each masseter muscle. Group 3 was the 10-unit BTX-injection group to each masseter muscle. Food intake rates and body weight were checked daily before and after BTX injection until 10 days. All animals were sacrificed at 14 days after BTX injection, and the specimens underwent hematoxylin and eosin stain and immunohistochemical staining for myosin type II (MYH2). Results: The recovery of food intake in groups 2 and 3 decreased significantly compared with group 1 from day 2 to day 7 and day 9 after injection (p < 0.05). The BTX-treated masseter muscles were significantly smaller than those in group 1 (p = 0.015). The immunohistochemical findings demonstrated that the expression of MYH2 was significantly higher in group 3 compared to groups 1 and 2 (p < 0.001). Conclusions: BTX injection to the masseter muscle in rats demonstrated short food-intake-rate reduction with recovery until 10 days after injection. The thickness of the masseter muscle and MYH2 expression were significantly changed according to the injected dose of BTX.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.335-338
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• 2000

To separate BTX degrading microorganisms, four kinds of activated sludges were obtained from waste water treatment plants and VOC generating plants, and adjusted 500 mg/L of BTX for three months. Y consortia degraded benzene and toluene in either individual or mixed compounds fast whereas A consortia degraded p-, m-, o-xylene fast.

• Journal of Soil and Groundwater Environment
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• v.11 no.4
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• pp.25-32
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• 2006

In this study, a novel bioreactor system using a diffuser type hollow fiber membranes (hollow fiber membrane diffuser, HFMD) was applied to investigate the feasibility and biodegradation capacity for the treatment of a gaseous mixture consisting of benzene, toluene and p-xylene(BTX). First, A mixed culture pre-acclimated to toluene effectively biodegraded the BTX mixture at an overall removal efficiency of approximately 70% for a 20-day operational period. It was found that the biodegradation of toluene was slightly inhibited because of the presence of benzene and p-xylene. Second, the elimination capacity (EC) of total BTX increased up to 360 $g/m^3/hr$, which was substantially higher than maximum ECs for BTEX reported in the biofiltration literature. Consequently, the hollow fiber membrane diffuser was considered as an alternative method over other conventional VOC-treating technologies such as biofilters.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.624-628
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• 1998

The aromatic organic solvents(BTX) were decomposed in the fixed bed reactor packed with a 0.5% $Pt/{\gamma}-Al_2O_3$ catalyst, then, supercritical carbon dioxide(SC-$CO_2$) was used as the reaction media. And the conversion was dependent on the inlet concentration of BTX and the molar density of SC-$CO_2$. The conversion of BTX was decreased with increasing of inlet concentration, and was increased with temperature and pressure. The maximum conversion of benzene was 98.5% at $300^{\circ}C$ and 204.1 atm, and that of toluene and xylene were 82.0 and 76.5%, respectively, at $350^{\circ}C$ and 204.1 atm. The intermediate products of partial oxidation were identified as benzaldehyde, phenol, benzenemethanol, and so on. The BTX can be effectively converted into harmless $CO_2$ and $H_2O$ at appropriate operating condition. Thus, the nontoxic recovery process was suggested as the removal method of BTX.