• KSBB Journal
• /
• 제6권3호
• /
• pp.289-297
• /
• 1991

The insecticidal protein gene in the pKL-20-1 clone derived from Bacillus thuringiensis serovar. kurstaki plasmid was subcloned in the plant shuttle vector, pGA643. The 7.3 kb fragment was cloned in the BglII and Hpal sites of pGA643 vector and expressed in E. coli S17-1, which produced insecticidal proteins killing Bombyx mori larvae. The clone was named pHL-20. The protoplast formation, calli induction and plantlet regeneration of Nicotiana tabacum was carried out. A tremendous number of mesophyll protoplasts of N. tabacum were formed, up to 7$\times$105 protoplast per ml, for 20 hours in darkness in the enzyme solution of 0.5% cellulase and 0.1% macerosin, pH 5.8. The viabilities of the protoplasts were maintained above 80% for 6 days in the media containing 2mg/1 of NAA and 1mg/1 of kinetin. Calli were induced from the protoplasts and leaves of the N. tabacum on MS medium containing 0.5mg/1 BAP. Under the culture conditions the protoplasts underwent repeated cell division into calli. Plantlets were regenerated from callus cultures derived from protoplast and leaves. Shoots were induced in a medium containing 1mg/1 of BAP.

• Journal of Microbiology and Biotechnology
• /
• 제26권5호
• /
• pp.946-952
• /
• 2016

The eglS gene in Bacillus amyloliquefaciens encodes an endo-β-1,4-glucanase that belongs to glycosyl hydrolase family 5. In this study, a disruption mutant of gene eglS was constructed to examine its role in bacterial adaptation in plants. The mutant TB2_k, eglS gene inactivated bacterial strain, was remarkably impaired in extracellular cellulase activity. When inoculated on Brassica campestris, the TB2_k population was reduced by more than 60% compared with the wild-type strain in the root, stem, and leaf tissues. Overexpression of eglS in the wild-type strain increased the bacteria population in the plant tissues. Further studies revealed that the transcription level of eglS was correlated with bacterial population. These data demonstrate that endo-β-1,4-glucanase of B. amyloliquefaciens is required for its optimal endophytic colonization.

• Journal of Microbiology and Biotechnology
• /
• 제22권5호
• /
• pp.607-613
• /
• 2012

Improvement of endoglucanase activity was accomplished by utilizing error-prone rolling circle amplification, supplemented with 1.7 mM $MnCl_2$. This procedure generated random mutations in the Bacillus amyloliquefaciens endoglucanase gene with a frequency of 10 mutations per kilobase. Six mutated endoglucanase genes, recovered from six colonies, possessed endoglucanase activity between 2.50- and 3.12-folds higher than wild type. We sequenced these mutants, and the different mutated sites of nucleotides were identified. The mutated endoglucanase sequences had five mutated amino acids: A15T, P24A, P26Q, G27A, and E289V. Among these five substitutions, E289V was determined to be responsible for the improved enzyme activity. This observation was confirmed with site-directed mutagenesis; the introduction of only one mutation (E289V) in the wild-type endoglucanase gene resulted in a 7.93-fold (5.55 U/mg protein) increase in its enzymatic activity compared with that (0.7 U/mg protein) of wild type.

• 한국미생물·생명공학회지
• /
• 제38권4호
• /
• pp.379-384
• /
• 2010

수집한 전통 장류에서 세포외효소(amylase, protease, cellulase, lipase and fibrinolytic enzyme) 분비능이 우수한 미생물을 분리한 후, 16S rRNA 유전자분석과 생리활성 특성을 조사하였다. amylase와 cellulase 분비능은 모든 선발균주에서 표준균주인 Bacillus subtilis KACC 10114보다 높게 나타났다. Protease 분비능은 D2-14균주를 제외한 모든 선발균주에서 활성이 있었으며, lipase 분비능은 D8-8과 K4-1을 제외한 균주에서 활성이 나타났다. 혈전용해 활성은 D8-2를 제외한 모든 선발균주에서 활성이 나타났으며, D8-8과 K4-1이 가장 높은 활성을 나타냈다. 선발균주인 K3-2, K4-1, K11-1-4, K11-1-6, K11-7, K12-3 와K14-9은 그람 양성세균과 그람 음성세균 그리고 효모에서도 높은 항균활성을 나타내었다. 간장 및 된장에서 분리한 균주들을 동정하기 위해 분자수준에서 16S rRNA 유전자 염기서열을 분석한 결과, 거의 Bacillius sp.로 나타났다. 발효과정에서 세포외효소 분비능과 생리활성이 우수한 미생물을 분리, 확보함으로써 전통 장류의 고급화 및 품질향상과 제조공정의 표준화가 가능할 것으로 여겨진다

• Animal Bioscience
• /
• 제34권5호
• /
• pp.867-879
• /
• 2021

Objective: Fibronectin 3 (FN3) and immunoglobulin like modules (Ig) are usually collocated beside modular cellulase catalytic domains. However, very few researches have investigated the role of these modules. In a previous study, we have sequenced and analyzed bacterial metagenomic DNA in Vietnamese goats' rumen and found that cellulase-producing bacteria and cellulase families were dominant. In this study, the properties of modular cellulases and the role of a FN3 in unique endoglucanase belonging to glycosyl hydorlase (GH) family 5 were determined. Methods: Based on Pfam analysis, the cellulases sequences containing FN3, Ig modules were extracted from 297 complete open reading frames (ORFs). The alkaline, thermostability, tertiary structure of deduced enzymes were predicted by AcalPred, TBI software, Phyre2 and Swiss models. Then, whole and truncated forms of a selected gene were expressed in Escherichia coli and purified by His-tag affinity column for assessment of FN3 ability to enhance enzyme activity, solubility and conformation. Results: From 297 complete ORFs coding for cellulases, 148 sequences containing FN3, Ig were identified. Mostly FN3 appeared in 90.9% beta-glucosidases belonging to glycosyl hydrolase family 3 (GH3) and situated downstream of catalytic domains. The Ig was found upstream of 100% endoglucanase GH9. Rarely FN3 was seen to be situated downstream of X domain and upstream of catalytic domain endoglucanase GH5. Whole enzyme (called XFN3GH5 based on modular structure) and truncate forms FN3, XFN3, FN3GH5, GH5 were cloned in pET22b (+) and pET22SUMO to be expressed in single and fusion forms with a small ubiquitin-related modifier partner (S). The FN3, SFN3 increased GH5 solubility in FN3GH5, SFN3GH5. The SFN3 partly served for GH5 conformation in SFN3GH5, increased modules interaction and enzyme-soluble substrate affinity to enhance SXFN3GH5, SFN3GH5 activities in mixtures. Both SFN3 and SXFN3 did not anchor enzyme on filter paper but exfoliate and separate cellulose chains on filter paper for enzyme hydrolysis. Conclusion: Based on these findings, the presence of FN3 module in certain cellulases was confirmed and it assisted for enzyme conformation and activity in both soluble and insoluble substrate.

• Mycobiology
• /
• 제40권2호
• /
• pp.107-110
• /
• 2012

Genes encoding the cellobiohydrolase enzyme (CBHI), designated as cbhI, were isolated from the basidiomycetes Auricularia fuscosuccinea, Pleurotus giganteus, P. eryngii, P. ostreatus, and P. sajor-caju. Initially, the fungal genomic DNA was extracted using a modified cetyltrimethyl ammonium bromide (CTAB) protocol and used as a DNA template. The cbhI genes were then amplified and cloned using the pGEM-T Easy Vector Systems. The sizes of these PCR amplicons were between 700~800 bp. The DNA sequences obtained were similar showing high identity to the cbhI gene family. These cbhI genes were partial consisting of three coding regions and two introns. The deduced amino acid sequences exhibited significant similarity to those of fungal CBHI enzymes belonging to glycosyl hydrolase family 7.

• 한국미생물·생명공학회지
• /
• 제20권5호
• /
• pp.505-510
• /
• 1992

고온성 혐기성 세균인 Clostridium thermocellum의 섬유소 분해 효소 유전자를 pUC9 플라스미드를 이용하여 대장균에 클로닝하였고, 지금까지 클로닝 된 C.thermocellum의 섬유소 분해 유전자들과 제한효소 양상을 비교하여 새로운 유전자임을 알 수 있었다. 대장균에서 섬유소 분해 효소를 열처리와 column chromatography에 의해서 정제를 하였고, 분자량은 40, 000이었다. 이 효소는 pH 5.0과 $65^{\circ}C$에서 CMC에 대해서 최대 활성을 보였고 최종 산물인 포도당과 cellobiose에 의한 활성의 저해는 크게 나타나지 않았다. CMC에 대한 이 효소의 $K_{m}$ 과 $V_{max}$값은 각각 0.39(w/v)와 268 U/mg protein이었다.

• Journal of Microbiology and Biotechnology
• /
• 제24권11호
• /
• pp.1525-1535
• /
• 2014

The xynC gene, which encodes high molecular weight xylanase from Paenibacillus sp. DG-22, was cloned and expressed in Escherichia coli, and its nucleotide sequence was determined. The xynC gene comprised a 4,419bp open reading frame encoding 1,472 amino acid residues, including a 27 amino acid signal sequence. Sequence analysis indicated that XynC is a multidomain enzyme composed of two family 4_9 carbohydrate-binding modules (CBMs), a catalytic domain of family 10 glycosyl hydrolases, a family 9 CBM, and three S-layer homologous domains. Recombinant XynC was purified to homogeneity by heat treatment, followed by Avicel affinity chromatography. SDS-PAGE and zymogram analysis of the purified enzyme identified three active truncated xylanase species. Protein sequencing of these truncated proteins showed that all had identical N-terminal sequences. In the protein characterization, recombinant XynC exhibited optimal activity at pH 6.5 and $65^{\circ}C$ and remained stable at neutral to alkaline pH (pH 6.0-10.0). The xylanase activity of recombinant XynC was strongly inhibited by 1 mM $Cu^{2+}$ and $Hg^{2+}$, whereas it was noticeably enhanced by 10 mM dithiothreitol. The enzyme exhibited strong activity towards xylans, including beechwood xylan and arabinoxylan, whereas it showed no cellulase activity. The hydrolyzed product patterns of birchwood xylan and xylooligosaccharides by thin-layer chromatography confirmed XynC as an endoxylanase.

• Journal of Microbiology and Biotechnology
• /
• 제2권1호
• /
• pp.50-55
• /
• 1992

A genomic library of a mesophilic cellulolytic anaerobe, Clostridium sp. KCTC 8440 DNA was constructed in Escherichia coli using plasmid pUC9. Clones of E. coli exhibiting carboxymethyl cellulose-hydrolyzing activity (CMCase) were isolated and divided into seven types based on the restriction enzyme patterns of recombinant plasmids. E. coli strains carrying type A genes showed activity on carboxymethyl cellulose about 7-8 times greater than clones carrying genes of other types. Restriction maps of the cloned DNA fragments were determined, and homologies between them were investigated. The results suggest that Clostridium sp. KCTC 8440 has seven distinct CMCase genes.

• 생명과학회지
• /
• 제9권4호
• /
• pp.408-413
• /
• 1999

Extracellular capsidiol, sesquiterpenoid phytoalexin, in the medium of pepper (Capsicum annuum L.) suspension cells was not identified from control cells, but highly accumulated in the elicitor-induced cells within 6 hours after the addition of 0.05$\mu\textrm{g}$/$m\ell$ cellulase. Capsidiol production in elicitor-induced cells was markedly suppressed by cytochrome P450 inhibitors, such as ancymidol and ketoconazole demonstrating that biosynthesis of capsidiol is catalyzed by at least on hydroxylation enzyme in the biochemical pathway. Based on protein electrophoresis, two bands, 23.0kDa and 27.5kDa, were identified as newly synthesized polypeptides in the elicitor-induced suspension cells, suggesting that pepper cells which were subjected to elicitor treatment activate specific gene(s) for capsidiol biosynthesis in cultured cells.