Influence of cultivation conditions on the production of a thermostable extracellular lipase from Amycolatopsis mediterranei DSM 43304

Among several lipase-producing actinomycete strains screened, Amycolatopsis mediterranei DSM 43304 was found to produce a thermostable, extracellular lipase. Culture conditions and nutrient source modification studies involving carbon sources, nitrogen sources, incubation temperature and medium pH were carried out. Lipase activity of 1.37 ± 0.103 IU/ml of culture medium was obtained in 96 h at 28°C and pH 7.5 using linseed oil and fructose as carbon sources and a combination of phytone peptone and yeast extract (5:1) as nitrogen sources. Under optimal culture conditions, the lipase activity was enhanced 12-fold with a twofold increase in lipase specific activity. The lipase showed maximum activity at 60°C and pH 8.0. The enzyme was stable between pH 5.0 and 9.0 and temperatures up to 60°C. Lipase activity was significantly enhanced by Fe³⁺ and strongly inhibited by Hg²⁺. Li⁺, Mg²⁺ and PMSF significantly reduced lipase activity, whereas other metal ions and effectors had no significant effect at 0.01 M concentration. A. mediterranei DSM 43304 lipase exhibited remarkable stability in the presence of a wide range of organic solvents at 25% (v/v) concentration for 24 h. These features render this novel lipase attractive for potential biotechnological applications in organic synthesis reactions.     

Effect of culture conditions on lipase production by Fusarium solani in batch fermentation

Lipase (Glycerol ester hydrolase EC 3.1.1.3.) from a Brazilian strain of Fusarium solani FSI has been investigated. The effect of different carbon sources and trace elements added to basal medium was observed with the aim of improving enzyme production. Lipase specific activity was highest (0.45 U mg(-1)) for sesame oil. When this medium was supplemented with trace elements using olive oil, corn oil and sesame oil the lipase specific activity increased to 0.86, 1.89 and 1.64 U mg(-1), respectively, after 96 h cultivation without any considerable biomass increase. The Km of this lipase using pNPP (p-nitrophenylpalmitate) as substrate, was 1.8 mM with a Vmax of 1.7 micromol min(-1) mg protein(-1). Lipase activity increased in the presence of increasing concentrations of hexane and toluene. In contrast, incubation of this enzyme with water-soluble solvents decreased its activity after 10% concentration (v/v) of the solvent. The lipase activity was stable below 35 degrees C but above this temperature activity losses were observed.     

Stable production of human gastric lipase by chromosomal integration in the fission yeast Schizosaccharomyces pombe

Strains of the fission yeast Schizosaccharomyces pombe have been constructed containing single or multiple chromosomally integrated copies of an expression cassette for production of human gastric lipase. Integrant strains of S. pombe secrete active lipase and are stable for lipase production over a minimum of 50 generations in non-selective media. Lipase activity levels for integrant strains containing up to three tandem copies of the expression cassette are strongly correlated with copy number of the cassette in both complete and minimal media. Lipase activity is higher in complete medium than in minimal medium. Strains carrying three chromosomally integrated expression cassette copies can be grown without selection in complete medium and are capable of significantly higher lipase activities than strains containing the expression cassette on a multicopy plasmid. Received: 27 March 1997 / Received revision: 13 August 1997 / Accepted: 25 August 1997     

Identification and over-expression of a thermostable lipase from Geobacillus thermoleovorans Toshki in Escherichia coli

A newly isolated thermophilic strain producing thermostable lipase was identified based on 16S rRNA sequencing, where phylogenetic analysis revealed its closeness to Geobacillus thermoleovorans. Thermostable lipase from this bacterium was cloned using consensus degenerate PCR primers. For over-expression in Escherichia coli, the lipase gene was sub-cloned in pET 15b vector with a strong T7 promotor. Lipase activity was approximately 4.5-fold higher than in the wild-type strain. The lipase enzyme was thermostable at 60 degrees C and pH 8, whereas a 30% residual activity was retained when incubated for 1h at 100 degrees C. Optimum lipase expression was obtained in 2 x YT medium after 70min of induction by IPTG.     

南极假丝酵母脂肪酶A的表面展示及酶学性质研究

采用a凝集素作为载体蛋白,首次将南极假丝酵母脂肪酶A展示在酿酒酵母细胞表面,通过MD平板筛选获得表面展示型的CALA酵母工程菌株。免疫荧光检测显示CALA被成功展示在酵母细胞壁表面,重组子经诱导后能在三丁酸甘油酯板上形成透明圈,说明展示的CALA具有活性。重组酵母在液体培养基培养72 h,活性达到最高,为80.4 U/g干细胞。酿酒酵母展示的CALA最适温度及pH值为70°C和pH 8.0。经50°C保温2 h,仍含有60%水解酶活力。展示的CALA在pH 7.0和pH 8.0溶液中比较稳定。经DMSO处理2 h,展示的CALA仍保持70%的活性。以上结果表明酵母展示的CALA可作为一种有潜质商业用途的全细胞催化剂。     

Purification and characterization of a novel organic solvent-tolerant and cold-adapted lipase from Psychrobacter sp. ZY124

By screening 25 different psychrophilic strains isolated from the Arctic habitat, we isolated a strain capable of producing lipase. We identified this strain as Psychrobacter sp. ZY124 based on the amplified 16S rDNA sequence. The lipase, named as Lipase ZC12, produced from the supernatant of Psychrobacter sp. ZY124 cultured at 15 °C was purified to homogeneity by ammonium sulfate precipitation followed by Phenyl Sepharose FF gel hydrophobic chromatography. Based on the obtained amino acid sequence, Lipase ZC12 is classified as a member of the Proteus/psychrophilic subfamily of lipase family I.1; it has a molecular weight of 37.9 kDa. We also determined that the apparent optimum temperature for Lipase ZC12 activity is 40 °C. Lipase ZC12 shows remarkable organic solvent tolerance by remaining more 50% after incubated with 10–90% different organic solvents. In addition, acyl chain esters with C12 or longer were confirmed to be preferable substrates for Lipase ZC12. Lipase ZC12 also shows better stereoselectivity for (R, S)-1-phenylethanol chiral resolution in n-hexane solvent with (S)-1-phenylethanol (ee_p 92%) and conversion rate (39%) by transesterification reactions. These properties may provide potential applications in biocatalysis and biotransformation in non-aqueous media, such as in detergent, transesterification or esterification and chiral resolution.

     

A novel mono- and diacylglycerol lipase highly expressed in Pichia pastoris and its application for food emulsifier preparation

A mono- and diacylglycerol lipase (MDL) was cloned from Penicillium cyclopium and expressed in Pichia pastoris strain GS115. The recombinant enzyme was named Lipase GH1. High cell density fermentation was performed by culture in a 7.5-L fermenter using BSMG medium, in which the phosphate in basal salt medium was replaced by sodium glycerophosphate (Na₂GP). The maximal lipase activity detected was 18,000 U per mL, and total protein content in the fermentation supernatant was 3.94 g per L. The activity of the liquid enzyme remained stable under alkaline conditions at 4 °C for 6 months and was 50% after one year. Lipase GH1 was used for the synthesis of mono- and diacylglycerols (MAGs and DAGs), which are commonly used emulsifiers for industrial applications. A conversion rate of 84% after 24 h of reaction was obtained using glycerol/oleic acid molar ratio 11:1, water content 1.5 wt%, enzyme dosage 80 U per g, and reaction temperature 35 °C. Lipase GH1 was more efficient for the synthesis of MAGs and DAGs than was Lipase G50 (a similar, commercially available lipase derived from Penicillium camemberti) when oleic acid was used as an acyl donor. Lipase GH1 has potential for food emulsifier preparation.     

Lipase production of Aspergillus oryzae

Aspergillus oryzae produced a small amount of lipase (0.05–0.8 U/wet-g of solid medium) in solid cultures, in contrast to the larger amount (0.46 U/ml) in a shake-flask culture in a modified GYP medium containing 2% glucose, 1% yeast extract and 2% Polypepton. Optimum conditions of lipase production in the submerged culture of A. oryzae were determined in terms of pH, composition of medium, and temperature. In a shake-flask culture at 28°C, the maximum amount of lipase increased to 0.78 U/ml upon the addition of 3% soybean oil to the modified GYP medium. In a jar fermentor culture, 30 U/ml lipase activity was obtained after 72 h at 28°C under appropriate conditions. Lipase production was greatly influenced by the culture temperature, and the optimum temperature for lipase production was about 24°C with a narrow temperature range, which was 10 degrees lower than that for the growth. In the submerged cultures, two kinds of lipase at least exhibiting different substrate specificities were also suggested.     

Optimizing production of extracellular lipase fromRhodotorula glutinis

Production of extracellular lipase byRhodotorula glutinis was substantially enhanced when the type and concentration of carbon and nitrogen source, the initial pH of culture medium and the growth temperature were consecutively optimized. Lipase activity as high as 30.4 U/ml of culture medium was obtained at optimum conditions, comparing favourably with most of the activities reported for other lipase hyperproducing microorganisms. The enzyme was optimally active at pH 7.5 and 35°C and had, at optimum pH, half-lives of 45 and 11.8 min at 45 and 55°C respectively. The high activity and kinetic characteristics of the enzyme make this process worthy of further investigation.     

Lipase and esterase formation by psychrophilic and mesophilic Acinetobacter species.

Acinetobacter O16, a psychrophilic species, produced extracellular lipase (measured by hydrolysis of olive oil, tributyrin, or beta-naphthyl laurate) when grown on a complex medium (peptone plus yeast extract). Most lipase was produced during the logarithmic phase of growth. Very little cell-bound lipase was formed. These cells also produced an esterase (measured by the hydrolysis of beta-naphthyl acetate). At first, all esterase was cell bound; significant amounts appeared in the external medium late in growth. Breaking the cells did not increase cell-bound lipase activity. After breaking of the cells, most of the cell-bound lipase and esterase activity was solubilized, even after very high speed centrifugation. No appreciable amounts of these enzymes were released by osmotic shock. Lipase formation was greatly affected by nutrient conditions. Lowering either the yeast extract of the peptone content of the normal complex medium lowered or abolished lipase formation. Esterase activity was lowered to a lesser extent. Cells growing in synthetic amino acid plus vitamin medium or in acid-hydrolyzed casein produced substantial amounts of esterase but no cell-free or cell-bound lipase. However, if sodium taurocholate was added to these media, lipase was produced. Greatest production occurred if a mixture of di- and poly-peptides was also present. Taurocholate also stimulated lipase production in the normal complex medium. Adding Tween 80 or ethanol to the normal complex medium inhibited lipase production. Sodium acetate, oleic acid, olive oil, or Tween 20 added to synthetic media did not affect lipase production. The psychrophile grew more quickly at 30 degrees C than at 15 or 20 degrees C but produced more lipase at the lower temperatures. Esterase production was about the same at 20 and 30 degrees C. A mesophilic Acinetobacter species produced the same amount of lipase and esterase at 20 and 30 degrees C. The best production of lipase by the psychrophile occurred in standing cultures.     

Oil/mineral-salts medium designed for easy recovery of extracellular lipase from Fusarium oxysporum AM3

Lipase production by the potato pathogen Fusarium oxysporum AM3 was investigated in a mineral medium using triolein and sodium nitrate as carbon and nitrogen sources, respectively. Medium design by factorial analysis of the medium components increased enzyme activity 9.4-folds over the standard medium. The simple medium composition promoted easy enzyme recovery to its homogeneity in a single step. The lipase showed optimum activity at pH 9.0 and 35 °C, with a K _M value of 7.5 mM for triolein and apparent molecular weight of 29.0 kDa. When assayed with different solvents, FoxAM3 lipase showed an increase on its activity by isooctane, isopropanol and acetone.     

Partial purification and characterization of the organic solvent-tolerant lipase produced by Pseudomonas fluorescens RB02-3 isolated from milk

Eighty-five putative Pseudomonas isolates were obtained from various raw milk and pasteurized milk samples using Pseudomonas CFC agar. Among them, 36 isolates were identified as Pseudomonas fluorescens, and one isolate was identified as Pseudomonas putida. Lipase activity of the strains was quantitatively measured by the spectrophotometric method using p-nitrophenyl palmitate (p-NPP) as substrate. Detected lipase activity of the strains was between 10.03 U/mL and 22.16 U/mL. Pseudomonas fluorescens RB02-3 possessed the highest lipase activity. The extracellular lipase of P. fluorescens RB02-3 strain was homogeneously purified using a combination of ammonium sulfate precipitation, dialysis, and gel filtration column chromatography. This purification procedure resulted in 2.97-fold purification with 20.3% recovery. The enzyme was characterized, and exhibited maximum activity at pH 7.0 and 50 °C; after it was incubated for 1 h it was activated in the presence of hexane, ethyl acetate, isopropanol, and ethanol and remained stable after the incubation was extended for 2 hr. The lipase was slightly inhibited in the presence of Zn2+, Co2+, Cu2+, Ni2+ salts, and ethylenediamine tetraacetic acid (EDTA), whereas Cd2+, sodium dodecyl sulfate (SDS), and Tween-80 had no effect on its activity.     

Intensification of lipase biosynthesis as a result of electrofusion of Rhizopus cohnii protoplasts

Our objective was to obtain products of fusion of the filamentous fungus Rhizopus cohnii Rh.c./1 with an increased capacity for lipase biosynthesis in comparison with the original strain. Protoplasts of auxotrophic mutants of the parent strain Rh.c./1 obtained after UV irradiation of the spores were subjected to electrofusion. We found that the largest number of electrofusion products could be obtained with the use of the following process parameters: 1 or 2 impulses immediately following one another with a field intensity of 200 V/cm and an exposition time of 1000 ms at the stage of dielectrophoresis, 1 impulse with a field intensity of 500 V/cm and an exposition time of 10 ms or 20 ms at the stage of fusion, regulated temperature of 4 degrees C before and after the process, rounding time of ca 20 min. Electrofusion of protoplasts of auxotrophic mutants of the Rh.c./1 strain produced 19 fusion products whose lipase biosynthesis capacity in a liquid medium culture was higher than that of the parent strains. The fusion product labelled XIII-21 was selected as the best strain. Lipase activity obtained after its culture in the liquid medium was ca 3.5 times higher than that obtained after the culture of the original strain Rh.c./1.     

Lipase Activity from Strains of Pasteurella multocida

Thirteen clinical isolates of Pasteurella multocida from a variety of different animals and humans were examined for their ability to produce lipase. Lipase substrates used included Tween 20, Tween 40, Tween 80, and Tween 85. Lipase activity was detected in the filtrates of organisms grown to the exponential phase in Roswell Park Memorial Institute-1640 defined media (RPMI-1640), but activity increased in the filtrates when the cultures were allowed to proceed to the stationary phase. All strains examined (except for serotype 2) showed lipase activity against at least one of the Tweens. Tween 40 was the best substrate to demonstrate lipase activity. Pasteurella multocida serotype 8 produced the most active lipase against Tween 40 (3,561.7 units of activity/μg of protein). This activity continued to increase after P. multocida entered a stationary growth phase. P. multocida lipase activity was optimal at pH 8.0. Lipase activity of P. multocida serotype 8 was eluted from a Sepharose 2B column at several points, indicating that several lipases may be produced in vitro by this organism. These data demonstrate that clinical isolates of P. multocida produce lipase; therefore, this enzyme should be considered a potential virulence factors for this organism. Received: 16 September 1999 / Accepted: 22 November 1999     

奶牛瘤胃微生物元基因组文库中脂肪酶的筛选与酶学性质

利用含有三油酸甘油酯的脂肪酶选择性筛选培养基,从奶牛瘤胃微生物元基因组文库15360个克隆中,筛选得到了18个脂肪酶阳性克隆,其插入片段大约为60kb,并且各个克隆的插入片段各不一样。利用p-NPP法对脂肪酶克隆的脂肪酶活性分析,表明均具有大小不等的脂肪酶活性。底物特异性分析表明Lipase6、Lipase7和Lipase8分别对C16底物(对硝基苯棕榈酸酯)、C12底物(对硝基苯月桂酸酯)和C16底物(对硝基苯棕榈酸酯)水解能力最强。Lipase6、Lipase7、Lipase8的脂肪酶最适pH为7.5;Lipase8的脂肪酶活性半衰期随反应温度的升高而缩短,70oC时能达到30min。本研究所筛选的脂肪酶具有不同的底物特异性和较好的热稳定性,这对于工业化生产具有一定的应用潜力。     

Studies on the enhanced production of extracellular lipase by Staphylococcus epidermidis

Staphylococcus epidermidis isolated from spoiled frozen marine fish samples exhibited optimum lipase activity of 8.1 U within 72 h in batch fermentation. Inducible effect of different sugars, nitrogen sources, salts and metal ions were studied on enzyme production. Trybutyrin induced the enzyme production by twofold. Addition of lactose in the production medium further improved lipase production. Sodium chloride increased lipase production whereas the presence of metals in the media had an inhibitory effect. Cells of immobilized S. epidermidis in agar beads (3%) increased lipase production compared with free cells. The optimum temperature and pH for enzyme activity was 20 degrees C and 7.0 respectively. Lipase retained its 85% stability at pH 6.0 and at 40 degrees C. Immobilized cells with high lipolytic activity and stability may provide commercial advantages over conventional methods of lipase production.     

Regioselectivity of New Bacterial Lipases Determined by Hydrolysis of Triolein

The newly identified lipases of 67 bacterial strains, primarily Bacillus and Pseudomonas, from the ARS Culture Collection have been characterized on the basis of their positional specificity for triglycerides (triolein). Lipase was produced by growing the cultures in tryptone–glucose–yeast extract medium for 24 h at 30°C before addition of triglyceride. The lipase was allowed to act on the triglyceride for 3 days before analysis by thin-layer chromatography. Of the bacterial lipases tested, 55 displayed random specificity, 9 were 1,3-specific, and 3 showed no apparent lipase activity under these conditions. Received: 25 July 2001 / Accepted: 27 August 2001     

Biochemical characterization of a lipase from olive fruit (Olea europaea L.)

Lipase (triacylglycerol acylhydrolase; EC 3.1.1.3) is the first enzyme of the degradation path of stored triacylglycerols (TAGs). In olive fruits, lipase may determine the increase of free fatty acids (FFAs) which level is an important index of virgin olive oil quality. However, despite the importance of virgin olive oil for nutrition and human health, few studies have been realized on lipase activity in Olea europaea fruits. In order to characterize olive lipase, fruits of the cv. Ogliarola, widely diffused in Salento area (Puglia, Italy), were harvested at four stages of ripening according to their skin colour (green, spotted I, spotted II, purple). Lipase activity was detected in the fatty layer obtained after centrifugation of the olive mesocarp homogenate. The enzyme exhibited a maximum activity at pH 5.0. The addition of calcium in the lipase assay medium leads to an increment of activity, whereas in the presence of copper the activity was reduced by 75%. Furthermore, mesocarp lipase activity increases during olive development but declined at maturity (purple stage). The data represent the first contribution to the biochemical characterization of an olive fruit lipase associated to oil bodies.     

Extracellular cold-active lipase of Microbacterium luteolum isolated from Gangotri glacier,western Himalaya: Isolation,partial purification and characterization

A psychrophilic bacterium producing cold-active lipase upon growth at low temperature was isolated from the soil samples of Gangotri glacier and identified as Microbacterium luteolum. The bacterial strain produced maximum lipase at 15 °C, at a pH of 8.0. Beef extract served as the best organic nitrogen source and ammonium nitrate as inorganic for maximum lipase production. Castor oil served as an inducer and glucose served as an additional carbon source for production of cold-active lipase. Ferric chloride as additional mineral salt in the medium, highly influenced the lipase production with an activity of 8.01 U ml^?1. The cold-active lipase was purified to 35.64-fold by DEAE-cellulose column chromatography. It showed maximum activity at 5 °C and thermostability up to 35 °C. The purified lipase was stable between pH 5 and 9 and the optimal pH for enzymatic hydrolysis was 8.0. Lipase activity was stimulated in presence of all the solvents (5%) tested except with acetonitrile. Lipase activity was inhibited in presence of Mn²⁺, Cu²⁺, and Hg²⁺; whereas Fe⁺, Na⁺ did not have any inhibitory effect on the enzyme activity. The purified lipase was stable in the presence of SDS; however, EDTA and dithiothreitol inhibited enzyme activity. Presence of Ca²⁺ along with inhibitors stabilized lipase activity. The cold active lipase thus exhibiting activity and stability at a low temperature and alkaline pH appears to be practically useful in industrial applications especially in detergent formulations.