• Journal of Applied Biological Chemistry
• /
• 제56권3호
• /
• pp.165-170
• /
• 2013

The SCO3388 gene from Streptomyces coelicolor is homologous to tmrB, the tunicamycin resistance gene of Bacillus subtilis. The SCO3388-inactivation strain (SY-tbl-1) was generated by replacing SCO3388 with thiostrepton resistance gene. Spores of S. coelicolor derivatives were prepared on mannitol-soy flour (MS) agar on which SY-tbl-1 displayed no significant defect in growth and development. When plated on R4 agar, spores of SYtbl-1 displayed retardation in growth and sporulation, whereas its mycelium gave rise to normal growth. Thus, SCO3388 is suggested to be involved in the dormant spore germination. Expression of SCO3388 under the ermE1 promoter restored but only partially the ability to sporulate in SY-tbl-1. Neither SY-tbl-1 nor SY-tbl-1/ermE1p-SCO3388 showed a difference in tunicamycin resistance to the wild type whereas, interestingly, the introduction of ermE1p-SCO3388 dramatically enhanced spore survival to heat and detergent treatments, suggesting that SCO3388 might play a role in the maintenance of spore cell wall integrity.

• Journal of Microbiology and Biotechnology
• /
• 제15권5호
• /
• pp.1115-1119
• /
• 2005

The photoheterotrophic $H_2$ production of Rhodobacter sphaeroides was significantly increased through disruption of the genes coding for uptake hydrogenase and poly-${\beta}$-hydroxybutyrate (PHB) synthase (Lee et al., Appl. Microbiol. Biotechnol. 60: 147-153, 2002). In this work, we further removed the B800-850 light-harvesting (LH) complex from the strain and found an increase in $H_2$ production at the light-saturating cell growth (${\ge}10$ Watts $[W]/m^2$). Neither the mutant nor the wild-type produced more $H_2$ at the brighter light. Accordingly, light does not appear to be limited for the $H_2$ production by the presence of B800-850. However, increase in the level of the spectral complexes resulted in decrease of $H_2$ production. Thus, although the B875 is essential for light harvesting, the consumption of cellular energy for the synthesis of B800-850 and the surplus LH complexes may reduce the energy flow into the $H_2$ production of R. sphaeroides.

• Journal of Microbiology and Biotechnology
• /
• 제12권2호
• /
• pp.286-291
• /
• 2002

Histone deacetylase I (HDAC1) works as one of the components in a nucleosome remodeling (NuRD) complex that consists of several proteins, including metastasis-associated protein 1 (MTA1). Since the protein-protein interaction of HDAC1 and MTA1 would appear to be important for both the integrity and functionality of the HDAC1 complex, the interruption of the HDAC1 and MTA1 interaction may be an efficient way to regulate the biological function of the HDAC1 complex. Based on this idea, a yeast two-hybrid system was constructed with HDAC1 and MTA1 expressing vectors in the DNA binding and activation domains, respectively. To verify the efficiency of the assay system, 3,500 microbial metabolite libraries were tested using the paper disc method, and KB0699 was found to inhibit the HDAC1 and MTA1 interaction without any toxicity to the wild-type yeast. Furthermore, KB0699 blocked the interaction of HDAC1 and MTA1 in an in vitro GST pull down assay and induced morphological changes in B16/BL6 melanoma cells, indicating the interruption of the HDAC1 complex function. Accordingly, these results demonstrated that the yeast assay strain developed in this study could be a valuable tool for the isolation of a HDAC1 complex disruptor.

• Journal of Microbiology and Biotechnology
• /
• 제17권3호
• /
• pp.474-480
• /
• 2007

Fusarium wilt of cucumbers was effectively controlled by Escherichia coli expressing an endochitinase gene (chiA), and the rate was as effective (60.0%) as the wild-type strain S. proteamaculans 3095 (55.0%) where the gene was cloned. However, live cells of soil inoculated E. coli host harboring the chiA gene did not proliferate but declined 100-fold from $10^8$ CFU during the first week and showed less than 10 cells after day 14, suggesting that E. coli was able to express and produce the chitinase enzyme to the soil even as the population was gradually decreasing. Because the majority of the strains was alive for only a short period of time and the Fusarium-affected seedlings showed symptoms of wilting within 7-10 days, it seems that the pathogen control was decided early after the introduction of the biocontrol agent, eliminating the survival of the antagonist. These results indicated that soil inoculated E. coli could sufficiently express and produce the recombinant protein to control the pathogen, and root or soil colonization of the antagonist might not be a significant factor in determining the efficacy of biological control.

• Journal of Microbiology and Biotechnology
• /
• 제20권1호
• /
• pp.127-131
• /
• 2010

In this study, Corynebacterium glutamicum and its derived mutants were used to demonstrate the relationship between proline, glutamate, and ornithine. The maximum ornithine production was shown in the culture medium (3,295.0 mg/l) when the cells were cultured with 20 mM proline, and was 15.5 times higher than in the presence of 1 mM proline. However, glutamate, which is known as an intermediate in the process of converting proline to ornithine, did not have any positive effect on ornithine production. This suggests that the conversion of proline to ornithine through glutamate, is not possible in C. glutamicum. Comparative analysis between the wild-type strain, SJC 8043 ($argF^-$, $argR^-$), and SJC 8064 ($argF^-$, $argR^-$, and $ocd^-$), showed that C glutamicum could regulate ornithine production by ornithine cyclodeaminase (Ocd) under proline-supplemented conditions. Therefore, proline directly caused an increase in the endogenous level of ornithine by Ocd, which would be a primary metabolite in the ornithine biosynthesis pathway.

• Journal of Microbiology and Biotechnology
• /
• 제24권8호
• /
• pp.1118-1122
• /
• 2014

The present study shows that DR1114 (Hsp20), a small heat shock protein of the radiation-resistant bacterium Deinococcus radiodurans, enhances tolerance to hydrogen peroxide ($H_2O_2$) stress when expressed in Escherichia coli. A protein profile comparison showed that E. coli cells overexpressing D. radiodurans Hsp20 (EC-pHsp20) activated the redox state proteins, thus maintaining redox homeostasis. The cells also showed increased expression of pseudouridine (psi) synthases, which are important to the stability and proper functioning of structural RNA molecules. We found that the D. radiodurans mutant strain, which lacks a psi synthase (DR0896), was more sensitive to $H_2O_2$ stress than wild type. These suggest that an increased expression of proteins involved in the control of redox state homeostasis along with more stable ribosomal function may explain the improved tolerance of EC-pHsp20 to $H_2O_2$ stress.

• Journal of Microbiology and Biotechnology
• /
• 제24권9호
• /
• pp.1238-1244
• /
• 2014

Dephosphocoenzyme A (CoaE) catalyzes the last step in the biosynthesis of the cofactor coenzyme A. In this study, we report the identification and application of CoaE from Stretomyces peucetius ATCC27952. After expression of coaE, the protein was found to have a molecular mass of 28.6 kDa. Purification of the His-tagged fused CoaE protein was done by immobilized metal-affinity chromatography, and then in vitro enzymatic coupling assay was performed. The increasing NADH consumption with time shed light on the phosphorylating activity of CoaE. Furthermore, the overexpression of coaA and coaE independently under the $ermE^*$ promoter in the doxorubicin -producing wild type strain, resulted in 1.4- and 1.5-fold enhancements in doxorubicin production, respectively. In addition, the overexpression of both genes together showed a 2.1-fold increase in doxorubicin production. These results established a positive role for secondary metabolite production from Streptomyces peucetius.

• Asian-Australasian Journal of Animal Sciences
• /
• 제33권2호
• /
• pp.360-372
• /
• 2020

Objective: Specific genomic sites can be recognized and permanently modified by genome editing. The discovery of endonucleases has advanced genome editing in pigs, attenuating xenograft rejection and cross-species disease transmission. However, off-target mutagenesis caused by these nucleases is a major barrier to putative clinical applications. Furthermore, off-target mutagenesis by genome editing has not yet been addressed in pigs. Methods: Here, we generated genetically inheritable α-1,3-galactosyltransferase (GGTA1) knockout Yucatan miniature pigs by combining transcription activator-like effector nuclease (TALEN) and nuclear transfer. For precise estimation of genomic mutations induced by TALEN in GGTA1 knockout pigs, we obtained the whole-genome sequence of the donor cells for use as an internal control genome. Results: In-depth whole-genome sequencing analysis demonstrated that TALEN-mediated GGTA1 knockout pigs had a comparable mutation rate to homologous recombination-treated pigs and wild-type strain controls. RNA sequencing analysis associated with genomic mutations revealed that TALEN-induced off-target mutations had no discernable effect on RNA transcript abundance. Conclusion: Therefore, TALEN appears to be a precise and safe tool for generating genomeedited pigs, and the TALEN-mediated GGTA1 knockout Yucatan miniature pigs produced in this study can serve as a safe and effective organ and tissue resource for clinical applications.

• Journal of Microbiology and Biotechnology
• /
• 제16권5호
• /
• pp.795-798
• /
• 2006

The phosphoenolpyruvate-dependent carbohydrate phosphotransferase system (PTS) is responsible for the simultaneous transfer and phosphorylation of various carbon sources in Escherichia coli. The ptsG gene encoding the enzyme $IICB^{Glc}$, the membrane component of the glucose-specific PTS, is repressed by Mlc and activated by the CRP cAMP complex; various other factors, such as Fis, FruR, and ArcA, are also known to be involved in ptsG regulation. Thus, in an attempt to discover a novel gene affecting the regulation of ptsG, a mutant with a decreased ptsG transcription in the presence of glucose compared with the wild-type strain was screened using transposon random mutagenesis. The mutant was found to have a transposon insertion in yhjV, a putative gene encoding a transporter protein whose function is yet unknown.

• 한국미생물·생명공학회지
• /
• 제16권3호
• /
• pp.182-186
• /
• 1988

원형질체 융합기술에 의한 Penicillium verruculosum 균주개량 가능성을 검토하였다. 영양요 구변이주간의 원형질 융합체 165주중 cellulase 고생산 융합체로 선별된 6주의 cellulase 활성은 야생주에 비해 2배이상, 모균주에 비해 1.2-4.4배의 증가를 나타냈다. Cellulase 고생산 융합체는 유전적 안정성조사, DNA 함량 및 핵염색 비교검토를 통해 핵융합이 일어난 것으로 확인되었고, 핵형이 이수체이며 4 개월 이상의 계대배양 후에도 자연형질 분리가 거의 일어나지 않는 것으로 보아 이들 융합체의 안정성이 매우 높은 것으로 인정되었다.