• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2001.06a
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• pp.163-164
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• 2001

A number of bacterial species produce extracellular lipases. Among them, many lipase genes have been cloned and sequenced. A comparison of primary sequences revealed only very limited sequence homology among them. Based on the sequence homologies and molecular sizes (Mr), bacterial lipases were classified into four discrete groups. From soil samples taken around Taejon, five different lipase-producing bacteria were isolated; Proteus vulgaris K80, Bacillus stearothermophilus Ll, B. pumilus B26, Staphylococcus haemolyticus L62, S. aureus B56. Nucleotide sequence analysis showed that Staphylococcus lipase genes (L62 and B56) composed of pre-pro-mature parts, Bacillus lipase genes (Ll and B26) pre-mature parts, and Proteus lipase gene (K80) mature part only. In addition, the molecular sizes of their mature parts were quite different from 19,000 to 45,000. Finally, they had very little homology (less than 20％) in their amino acid sequences. Judging from the above results, lipase K80 belonged to bacterial lipase Group I, lipase L1 and lipase B26 Group III, and lipase L62 and lipase B56 Group IV. This diversity in their primary structures was also reflected in their enzymatic properties; temperature effects, pH effects, substrate specificity, detergent effects, and so on.

• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.142-144
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• 2002

Two different extracellular lipases were produced by an anaerobic bacterium, Selenomonas lipolytica. A major lipase, lipase I, was isolated, which showed optimum activity at pH 6.0 and at $45^{\circ}C$. It showed a molecular weight of 240 kDa and was a tetramer of a subunit having molecular weight of 60 kDa, which is different from the known bacterial lipases.

• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.1907-1915
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• 2017

Lipases are important enzymes with biotechnological applications in dairy, detergent, food, fine chemicals, and pharmaceutical industries. Specifically, hormone-sensitive lipase (HSL) is an intracellular lipase that can be stimulated by several hormones, such as catecholamine, glucagon, and adrenocorticotropic hormone. Bacterial hormone-sensitive lipases (bHSLs), which are homologous to the C-terminal domain of HSL, have ${\alpha}/{\beta}-hydrolase$ fold with a catalytic triad composed of His, Asp, and Ser. These bHSLs could be used for a wide variety of industrial applications because of their high activity, broad substrate specificity, and remarkable stability. In this review, the relationships among HSLs, the microbiological origins, the crystal structures, and the biotechnological properties of bHSLs are summarized.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.155-160
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• 2005

Abstract A direct approach was used to retrieve active lipases from Paenibacillus polymyxa genome databases. Twelve putative lipase genes were tested using a typical lipase sequence rule built on the basis of a consensus sequence of a catalytic triad and oxyanion hole. Among them, six genes satisfied the sequence rule and had similarity (about 25%) with known bacterial lipases. To obtain the six lipase proteins, lipase genes were expressed in E. coli cells and lipolytic activities were measured by using tributyrin plate and pnitrophenyl caproate. One of them, contig 160-26, was expressed as a soluble and active form in E. coli cell. After purifying on Ni-NTA column, its detailed biochemical properties were characterized. It had a maximum hydrolytic activity at $30^{\circ}C$ and pH 7- 8, and was stable up to $40^{\circ}C$ and in the range of pH 5- 8. It most rapidly hydrolyzed pNPC$_6$ among various PNPesters. The other contigs were expressed more or less as soluble forms, although no lipolytic activities were detected. As they have many conserved regions with lipase 160-26 as well as other bacterial lipases throughout their equence, they are suggested as true lipase genes.

• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.515-524
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• 2020

With the increasing demand for enzymes in industrial applications there is a growing need to easily produce industrially important microbial enzymes. This study was carried out to screen the indigenous refinery bacterial isolates for their production of two industrially important enzymes i.e. lipase and protease. A total of 15 bacterial strains were isolated using Soil Extract Agar media from the oil-contaminated environment and one was shown to produce high quality lipase and protease enzymes. The culture conditions (culture duration, temperature, source of nitrogen, carbon, and pH) were optimized to produce the optimum amount of both the lipase (37.6 ± 0.2 Uml-1) and the protease (41 ± 0.4 Uml-1) from this isolate. Productivity of both enzymes was shown to be maximized at pH 7.5 in a medium containing yeast extract and peptone as nitrogen sources and sucrose and galactose as carbon sources when incubated at 35 ± 1℃ for 48 h. Bacterial strain SAB06 was identified as Bacillus licheniformis (MT250345) based on biochemical, morphological, and molecular characteristics. Further studies are required to evaluate and optimize the purification and characterization of these enzymes before they can be recommended for industrial or environmental applications.

• Journal of Microbiology
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• v.44 no.6
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• pp.583-590
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• 2006

In this study, an organic solvent tolerant bacterial strain was isolated. This strain was identified as Pseudomonas sp. strain S5, and was shown to degrade BTEX (Benzene, Toluene, Ethyl-Benzene, and Xylene). Strain S5 generates an organic solvent-tolerant lipase in the late logarithmic phase of growth. Maximum lipase production was exhibited when peptone was utilized as the sole nitrogen source. Addition of any of the selected carbon sources to the medium resulted in a significant reduction of enzyme production. Lower lipase generation was noted when an inorganic nitrogen source was used as the sole nitrogen source. This bacterium hydrolyzed all tested triglycerides and the highest levels of pro-duction were observed when olive oil was used as a natural triglyceride. Basal medium containing Tween 60 enhanced lipase production to the most significant degree. The absence of magnesium ions ($Mg^{2+}$) in the basal medium was also shown to stimulate lipase production. Meanwhile, an alkaline earth metal ion, $Na^+$, was found to stimulate the production of S5 lipase.

• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.1097-1103
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• 2020

Bacterial surface display systems have been developed for various applications in biotechnology and industry. Particularly, the discovery and design of anchoring motifs is highly important for the successful display of a target protein or peptide on the surface of bacteria. In this study, an efficient display system on Escherichia coli was developed using novel anchoring motifs designed from the E. coli mipA gene. Using the C-terminal fusion system of an industrial enzyme, Pseudomonas fluorescens lipase, six possible fusion sites, V¹⁴⁰, V¹⁷⁶, K¹⁷⁹, V²²⁶, V²³², and K²³⁴, which were truncated from the C-terminal end of the mipA gene (MV¹⁴⁰, MV¹⁷⁶, MV¹⁷⁹, MV²²⁶, MV²³², and MV²³⁴) were examined. The whole-cell lipase activities showed that MV¹⁴⁰ was the best among the six anchoring motifs. Furthermore, the lipase activity obtained using MV¹⁴⁰ as the anchoring motif was approximately 20-fold higher than that of the previous anchoring motifs FadL and OprF but slightly higher than that of YiaTR232. Western blotting and confocal microscopy further confirmed the localization of the fusion lipase displayed on the E. coli surface using the truncated MV¹⁴⁰. Additionally the MV¹⁴⁰ motif could be used for successfully displaying another industrial enzyme, α-amylase from Bacillus subtilis. These results showed that the fusion proteins using the MV¹⁴⁰ motif had notably high enzyme activities and did not exert any adverse effects on either cell growth or outer membrane integrity. Thus, this study shows that MipA can be used as a novel anchoring motif for more efficient bacterial surface display in the biotechnological and industrial fields.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.320-327
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• 2004

Three hundreds thirty two bacterial colonies which were able to degrade crude oil were isolated from soil sam­ples that were contaminated with oil in Daejeon area. Among them, one bacterial strain was selected for this study based on its higher oil degrading ability, and this selected bacterial strain was identified as Acinetobactor sp. B2 through physiological-biochemical tests and analysis of its 16S rRNA sequence. Acinetobactor sp. B2 was able to utilize various carbohydrates but did not utilize trehalose and mannitol as a sole carbon source. Acinetobactor sp. B2 showed a weak resistance to antibiotics such as kanamycin, streptomycin, tetracycline and spectinomycin, but showed a high resistance up to mg/ml unit to heavy metals such as Ba, Li, Mn, AI, Cr and Pb. The optimal growth temperature of Acinetobactor sp. B2 was $30^{\circ}C.$ The lipase produced by Acinetobactor sp. B2 was purified by ammonium sulfate precipitation, DEAE-Toyopearl 650M ion exchange chromatography and Sephadex gel filtration chromatography. Its molecular mass was about 60 kDa and condition for the optimal activity was observed at $40^{\circ}C$ and pH 10, respectively. The activation energy of lipase for the hydrolysis of p­nitrophenyl palmitate was 2.7 kcal/mol in the temperature range of 4 to $37^{\circ}C,$ and the enzyme was unstable at the temperature higher than $60^{\circ}C.$ The Michaelis constant $(K_m)\;and\;V_{max}$ for p-nitrophenyl palmitate were 21.8 uM and $270.3\;{\mu}M\;min^{-1}mg^{-1},$ respectively. This enzyme was strongly inhibited by 10 mM $Cd^{2+},\;Co^{2+},\;Fe^{2+},\;Hg^{2+},$ EDTA and 2-Mercaptoethalol.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.661-667
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• 2013

Lipase-producing bacterial strains were isolated from Antarctic soil samples using the tricaprylin agar plate method. Seven strains with relatively strong lipase activities were selected. All of them turned out to be Bacillus pumilus strains by the 16S rRNA gene sequence analysis. Their corresponding lipase genes were cloned, sequenced, and compared. Finally, three different Bacillus pumilus lipases (BPL1, BPL2, and BPL3) were chosen. Their amino acid sequence identities were in the range of 92-98% with the previous Bacillus pumilus lipases. Their optimum temperatures and pHs were measured to be $40^{\circ}C$ and pH 9. Lipase BPL1 and lipase BPL2 were stable up to $30^{\circ}C$, whereas lipase BPL3 was stable up to $20^{\circ}C$. Lipase BPL2 was stable within a pH range of 6-10, whereas lipase BPL1 and lipase BPL3 were stable within a pH range of 5-11, showing strong alkaline tolerance. All these lipases exhibited high hydrolytic activity toward p-nitrophenyl caprylate ($C_8$). In addition, lipase BPL1 showed high hydrolytic activity toward tributyrin, whereas lipase BPL2 and lipase BPL3 hydrolyzed tricaprylin and castor oil preferentially. These results demonstrated that the three Antarctic Bacillus lipases were alkaliphilic and had a substrate preference toward short- and medium-chain triglycerides. These Antarctic Bacillus lipases might be used in detergent and food industries.

• Journal of Life Science
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• v.11 no.5
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• pp.457-463
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• 2001

A bacterial strain SC-22 which produced alkaline lipase was isolated from salf-fermented shrimps. Strains SC-22 was identified as Staphylococcus xylosus. An alkaline lipase excreted by Staphylococcus xylosus SC-22 was purified by ammonium sulfate predipitation and column chromatography on Sephadex G-100 and DEAE-Sephace. The specific activity of purified lipase was 756U/mg of protein with 17.2% yield. The approximate molecular weight of the purified enzyme was 47 kDa. The partially purified lipase preparation had and optimum temperature of 4$0^{\circ}C$, an optimum pH of 8.0, and a stable of 5~10. Lipase activities were enhanced by salt ions such as $Ca^{2+}$, $Mg^{2+}$,N $a^{2+}$ while inhibited remarkably by heavy metal ions, C $u^{2+}$ and P $b^{2+}$.EX> 2+/.