• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.197-200
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• 2002

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.186-186
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• 2005

• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.162-167
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• 2007

A genetic transfer system for introducing foreign genes to biomining microorganisms is urgently needed. Thus, a conjugative gene transfer system was investigated for a moderately thermophilic, extremely acidophilic biomining bacterium, Acidithiobacillus caldus MTH-04. The broad-hostrange IncP plasmids RP4 and R68.45 were transferred directly into A. caldus MTH-04 from Escherichia coli by conjugation at relatively high frequencies. Additionally the broad-hostrange IncQ plasmids pJRD215, pVLT33, and pVLT35 were also transferred into A. caldus MTH-04 with the help of plasmid RP4 or strains with plasmid RP4 integrated into their chromosome, such as E. coli SM10. The $Km^r\;and\;Sm^r$ selectable markers from these plasmids were successfully expressed in A. caldus MTH-04. Futhermore, the IncP and IncQ plasmids were transferred back into E. coli cells from A. caldus MTH-04, thereby confirming the initial transfer of these plasmids from E. coli to A. caldus MTH-04. All the IncP and IncQ plasmids studied were stable in A. caldus MTH-04. Consequently, this development of a conjugational system for A. caldus MTH-04 will greatly facilitate its genetic study.

• Journal of Biosystems Engineering
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• v.43 no.4
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• pp.394-400
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• 2018

Purpose: This research evaluated five types of nanoparticles to develop a surface-enhanced Raman spectroscopy (SERS) method for the rapid detection of two Bacillus species (Bacillus cereus and Bacillus thuringiensis) that are commonly found on fresh produce, which can cause food poisoning. Methods: Bacterial concentrations were adjusted to a constant turbidity, and a total of $30{\mu}L$ of each Bacillus cell suspension was prepared for each nanoparticle. A point-scan Raman system with laser light source of wavelength 785 nm was used to obtain SERS data. Results: There was no qualitative difference in the SERS data of B. cereus and B. thuringiensis for any of the five nanoparticles. Three gold nanoparticles, stabilized in either citrate buffer or ethanol, showed subtle differences in Raman intensities of two Bacillus species at $877.7cm^{-1}$. Conclusions: Among the three types of nanoparticles, the gold nanoparticles stabilized in citrate buffer showed the lowest standard deviation, followed by gold nanoparticles stabilized in ethanol. This result supports the potential application of gold nanoparticles for SERS-based detection of B. cereus and B. thuringiensis.

• Proceedings of the Microbiological Society of Korea Conference
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• 2003.05a
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• pp.132-133
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• 2003

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.39-44
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• 2010

Acidithiobacillus caldus is an acidophilic, chemolithotrophic bacterium that plays an important role in bioleaching. Gene transformation into A. caldus is difficult, and only the conjugation method was reported successful, which was a relatively sophisticated method. In this research, electrotransformation of A. caldus species was achieved for the first time using A. caldus Y-3 and plasmid pJRD215. Transformants were confirmed by colony PCR specific to the str gene on pJRD215, and the recovery of the plasmid from the presumptive transformants. Optimizations were made and the transformation efficiency was increased from 0.8 to $3.6{\times}10^4$ transformants/${\mu}g$ plasmid DNA. The developed electrotransformation method was convenient in introducing foreign genes into A. caldus.

• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.534-538
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• 2001

The xynA gene encoding an alikali-tolerant endo-1,4-${\beta}$-xylanase (XYN) was cloned from the alkalophilic Bacillus pumilus A-30. The nucleotide sequence of a 974-bp DNA fragment containing the xynA was determined. An ORF of 684 nucleotides that encoded a protein of 228 amino aicds was detected. Asparagine-71 of XYN from B. Pumilus A-30 showed to be highly conservative in alkaline xylanases of family G/11, upon comparing the amino acid sequences of 17 family G/11 xylanases. Site-directed mutation of N71D of the xynA gene resulted in a decrease of 12.4% in the specific acitivity and a significant decline in the enzyme activity in the alkaline pH range.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.678-682
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• 2010

The deletion of sti from the Streptomyces plasmid pIJ101 made its derivative pHZ1358 an efficient vector for gene disruption and replacement. Here, pHZ1358 was further optimized by the construction of a derivative plasmid pJTU1278, in which a cassette carrying multiple cloning sites and a lacZ selection marker were introduced for convenient plasmid construction in E. coli. In addition, the oriT region of pJTU1278 was also deleted, generating a vector (pJTU1289) that can be used specifically for PCR-targeting. The efficient usage of these vectors was demonstrated by the deletion of the gene involved in avermectin biosynthesis in S. avermitilis.

• Journal of Microbiology and Biotechnology
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• v.4 no.1
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• pp.24-29
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• 1994

To examine whether the signal sequence of Bacillus endo-1, 4-glucanase can act functionally in a yeast, a lower eucaryote, two recombinant plasmids were constructed and introduced into Saccharomyces cerevisiae: recombinant plasmid pGCMC10 containing the complete signal sequence of Bacillus endoglucanase, and pGCMC11 without the signal sequence. Secretion of endoglucanase into culture medium was obtained with the yeast transformant containing plasmid pGCMC10. The secreted endoglucanase was glycosylated and was apparently processed to be about 36 kilodaltons (KDa) and 43KDa proteins. The glycosylated endoglucanase from yeast transformant was more thermostable than the nonglycosylated endoglucanase from Escherichia coli transformant.

• Journal of Microbiology and Biotechnology
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• v.16 no.10
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• pp.1650-1655
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• 2006

Bacteria belonging to the genus Paenibacillus are facultatively anaerobic endospore formers and are attracting growing ecological and agricultural interest, yet their genome information is very limited. The present study surveyed the genomic features of P. polymyxa ATCC $842^T$ using pulse-field gel electrophoresis of restriction fragments and sample genome sequencing of 1,747 reads (approximately 17.5% coverage of the genome). Putative functions were assigned to more than 60% of the sequences. Functional classification of the sequences showed a similar pattern to that of B. subtilis. Sequence analysis suggests nitrogen fixation and antibiotic production by P. polymyxa ATCC $842^T$, which may explain its plant growth-promoting effects.