Effect of tweens on the lipase activity of Oospora lactis

Oospora lactis was found to use Tweens 20, 40, 60 and 80 as a source of carbon in a nutrient medium for lipase biosynthesis. The highest production of lipase was registered in the medium with Tween-80. The lipase activity of the culture increased if even small quantities of Tweens 40, 60 and, particularly, 80 (0.05--1.0%) were added to the medium containing cottonseed oil. All the tested Tweens stimulating the biosynthesis of lipase were also, at a particular concentration, the inhibitors of this enzyme.     

Thermoalkalophilic lipase-producing Bacillus selected by continuous cultivation

Abstract Several lipase-producing thermophilic bacteria were isolated by continuous culture from samples collected near Bulgarian hot springs. Most of them had lipase activity of about 0.5 U ml⁻¹ when activated in shaken flasks. Three strains, Gram-positive sporeforming rods, possess higher enzyme activity in a Tween-80 containing medium. The highest lipase activity (2.0–3.0 U ml⁻¹) was observed in the newly-isolated thermoalkalophilic Bacillus sp. strain MC7.     

Cellulase production and activity by Trichoderma sp. A-001

Trichoderma species A-001 was grown on various carbon and nitrogen sources supplemented with surfactants on shake cultures. Although the degree of growth was variable, the organism grew on all carbon substrates. Large amounts of the cellulase enzyme components were released into the growth medium during growth on filter paper. In the filter paper containing medium, the organism produced 167 U/ml of carboxymethylcellulase (CMCase), 18 U/ml of filter paper activity (FPase) and 49 U/ml of beta-glucosidase activity (BGDase). Wheat straw and grass were better carbon sources than cotton or barley husks. Nitrogen in the form of KNO₃ was better than NH₄Cl or urea in facilitating the production of cellulase. Of the surfactants used, Tween-80 at 0.2% concentration in the medium increased the production of cellulase several-fold. All the cellulase components were optimally active in the assay at pH 5.5 and 60°C. CMCase and FPase lost 20–33% of their activities when kept at 60°C for 4 h before assaying. On the other hand, BGDase was moderately stable; it lost only 37% of its activity when maintained at 70°C for 4 h.     

Production, purification, and characterization of lipase from thermophilic and alkaliphilic Bacillus coagulans BTS-3

A thermophilic isolate Bacillus coagulans BTS-3 produced an extracellular alkaline lipase, the production of which was substantially enhanced when the type of carbon source, nitrogen source, and the initial pH of culture medium were consecutively optimized. Lipase activity 1.16 U/ml of culture medium was obtained in 48 h at 55 degrees C and pH 8.5 with refined mustard oil as carbon source and a combination of peptone and yeast extract (1:1) as nitrogen sources. The enzyme was purified 40-fold to homogeneity by ammonium sulfate precipitation and DEAE-Sepharose column chromatography. Its molecular weight was 31 kDa on SDS-PAGE. The enzyme showed maximum activity at 55 degrees C and pH 8.5, and was stable between pH 8.0 and 10.5 and at temperatures up to 70 degrees C. The enzyme was found to be inhibited by Al3+, Co2+, Mn2+, and Zn2+ ions while K+, Fe3+, Hg2+, and Mg2+ ions enhanced the enzyme activity; Na+ ions have no effect on enzyme activity. The purified lipase showed a variable specificity/hydrolytic activity towards various 4-nitrophenyl esters.     

Optimized production of a thermostable lipase by recombinantPseudomonas putida 1641

A thermostable lipase gene fromPseudomonas fluorescence was cloned into a multicopy plasmid and electroporated intoP. putida. The recombinantP. putida produced soluble lipase into the broth. Using these recombinant cells, the optimum conditions for lipase production were investigated. Olive oil was the most effective carbon source, producing upto 60 unit/ml. Supplementation of the medium with a surfactant, such as Tween-80, increased the lipase productivity significantly. The optimum temperature and pH for lipase production were 26°C and 7.0, respectively.     

Lipase from Pseudomonas aeruginosa LP602: biochemical properties and application for wastewater treatment

Lipase from Pseudomonas aeruginosa LP602, a bacterial strain isolated from a domestic wastewater sample, was preliminarily characterized. The enzyme exhibited maximum lipolytic activity at pH 8.0 where it was also stably maintained. At 55°C, the lipase had the highest activity but not stability. The enzyme was insensitive to EDTA and to many ions tested except Zn²⁺. It was sensitive to SDS but not to Tween-20, Tween-80 or Triton X-100. The enzyme was active towards a number of commercial food grade fats and oils. A suitable medium formula for lipase production was MMP containing 6.25% whey as a carbon source, 1% soybean oil as inducer and 0.5% yeast extract supplement. The culture was fed with glucose to a final concentration of 0.1% at the 15th hour of incubation. Lipase production under this condition was 3.5 U ml⁻¹. Both P. aeruginosa LP602 cells and the lipase were shown to be usable for lipid-rich wastewater treatment. Received 21 April 1998/ Accepted in revised form 6 August 1998     

Effect of oleic acid and Tween-80 on lysine synthesis by the culture Corynebacterium glutamicum]

The effect of oxidized and unoxidized oleic acid and Tween-80 on the growth and lysine synthesis by the producers C. glutamicum strains 95, 8, 28 was investigated. Surface active substances like oxidized and unoxidized oleic acid and Tween-80 during cultivation of the lysine producers on the glucose medium (the synthetic medium) and the medium with molasses and corn extract either inhibited the culture growth, thus reducing lysine yield, or accelerated the culture growth, thus increasing lysine yield. Oxidized and unoxidized oleic acid produced the greatest effect when added to the nutrient medium on the 48th cultivation hour. The increment of synthesized lysine was 120-150% of the control. Tween-80 proved to be very effective when added at early stages of fermentation (20 hours).     

Strain improvement of Serratia marcescens ECU1010 and medium cost reduction for economic production of lipase

Industrial strain improvement plays a central role in the commercial development of microbial fermentation processes. The strain of Serratia marcescens ECU1010, a wild-type lipase-producer capable of stereospecific synthesis of a Diltiazem precursor, was subjected to physical mutation involving treatment by UV-irradiation for 30 s. A mutant strain, no. UV-01, showed enhanced lipase production, but lost the capability of producing red pigment (prodigiosin). The variant strain UV-01 had a 2.3-fold higher activity than the wild type and was stable in its enzyme production for ten serial transfers. For reduction of the fermentation medium cost, dried powder of corn steep liquor was used as an inexpensive substitute for beef extract in the medium. Dextrin as an organic carbon source and Tween-80 as an important element were further optimized, respectively. The high primary biodegradation of the Tween-80 by S. marcescens ECU1010 and its variant demonstrated their potential ability of degrading alkyl polyethoxylates to remove harmful nonionic surfactants from polluted effluents and streams. The optimal cultivation time for lipase biosynthesis was 24 h. These optimized compositions resulted in an economic production of lipase by S. marcescens ECU1010 var. UV-01, with a dramatically reduced cost (1/8–1/7 of the initial one) which is more suitable for industrial application.     

Investigation of lipase production by a new isolate of Aspergillus sp.

Fungi isolated from soil were screened for exogenous lipolytic activity. The highest lipase activity was found in a new soil isolate of Aspergillus sp. Some optimal cultural parameters influencing the growth and production of extracellular lipase from this Aspergillus sp. were investigated. The lipase yield was maximum on day 4 of incubation of the culture at pH 5.5 and 30 °C. When the medium was prepared using olive oil as carbon source and peptone as a nitrogen source, better lipase yields were obtained. Aeration enhanced growth and lipase production.     

Production of extracellular alkaline lipase by a new thermophilicBacillus sp

A thermophilic soil isolate—Bacillus sp. RS-12, grew optimally at 50°C and not below 40°C. Production of an extracellular lipase by this organism was substantially enhanced when the type and concentration of carbon and nitrogen sources and initial pH of the culture medium were consecutively optimized. The lipase production was found to be growth-associated with maximum secretion in the late exponential growth phase,i.e. 15h of incubation. The enzyme activity as high as 0.98 nkat/mL was obtained under optimum conditions. Tween 80 (0.5%) and yeast extract (0.5%) were found to be the best carbon and nitrogen sources inducing maximum enzyme yield with initial pH 8.0 at 50°C. The kinetic characteristics of the crude lipase indicated the highest activity at 50–55°C and pH 8.0. It had a half life of 60, 18 and 15 min at 65, 70 and 75°C, respectively.     

Isolation and characterization of a thermophilic lipase from Bacillus thermoleovorans ID-1

A thermophilic microorganism, Bacillus thermoleovorans ID-1, isolated from hot springs in Indonesia, showed extracellular lipase activity and high growth rates on lipid substrates at elevated temperatures. On olive oil (1.5%, w/v) as the sole carbon source, the isolate ID-1 grew very rapidly at 65 degrees C with its specific growth rate (2.50 h(-1)) and its lipase activity reached the maximum value of 520 U l(-1) during the late exponential phase and then decreased. In addition to this, isolate ID-1 could grow on a variety of lipid substrates such as oils (olive oil, soybean oil and mineral oil), triglycerides (triolein, tributyrin) and emulsifiers (Tween 20, 40). The excreted lipase of ID-1 was purified 223-fold to homogeneity by ammonium sulfate precipitation, DEAE-Sephacel ion-exchange chromatography and Sephacryl S-200 gel filtration chromatography. As a result, the relative molecular mass of the lipase was determined to be 34 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme showed optimal activity at 70-75 degrees C and pH 7.5 and exhibited 50% of its original activity after 1 h incubation at 60 degrees C and 30 min at 70 degrees C and its catalytic function was activated in the presence of Ca(2+) or Zn(2+).     

Fluorene biodegradation and identification of transformation products by white-rot fungus Armillaria sp. F022

A diverse surfactant, including the nonionic Tween 80 and Brij 30, the anionic sodium dodecyl sulphate, the cationic surfactant Tetradecyltrimethylammonium bromide, and biosurfactant Rhamnolipid were investigated under fluorine-enriched medium by Armilaria sp. F022. The cultures were performed at 25 °C in malt extract medium containing 1 % of surfactant and 5 mg/L of fluorene. The results showed among the tested surfactants, Tween-80 harvested the highest cell density and obtained the maximum specific growth rate. This due Tween-80 provide a suitable carbon source for fungi. Fluorane was also successfully eliminated (>95 %) from the cultures within 30 days in all flasks. During the experiment, laccase production was the highest among other enzymes and Armillaria sp. F022-enriched culture containing Non-ionic Tween 80 showed a significant result for laccase activity (1,945 U/L). The increased enzyme activity was resulted by the increased biodegradation activity as results of the addition of suitable surfactants. The biotransformation of fluorene was accelerated by Tween 80 at the concentration level of 10 mg/L. Fluorene was initially oxidized at C-2,3 positions resulting 9-fluorenone. Through oxidative decarboxylation, 9-fluorenone subjected to meta-cleavage to form salicylic acid. One metabolite detected in the end of experiment, was identified as catechol. Armillaria sp. F022 evidently posses efficient, high effective degrader and potential for further application on the enhanced bioremediation technologies for treating fluorene-contaminated soil.     

Growth of the extreme thermophile Sulfolobus acidocaldarius in a hyperbaric helium bioreactor

The relationship between pressure and temperature as it affects microbial growth and metabolism has been examined only for a limited number of bacterial species. Because many newly-discovered, extremely thermophilic bacteria have been isolated from pressurized environments, this relationship merits closer scrutiny. In this study, the extremely thermophilic bacterium, Sulfolobus acidocaldarius, was cultured successfully in a hyperbaric chamber containing helium and air enriched with 5% carbon dioxide. Over a pressure range of approximately 1-120 bar and a temperature range of 67-80 degrees C, growth was achieved in a heterotrophic medium with the air mixture at partial pressures up to 3.5 bar. Helium was used to obtain the final, desired incubation pressure. No significant growth was noted above 80 degrees C over the same range of hyperbaric pressures, or at 70 degrees C when pressure was applied hydrostatically. Growth experiments conducted under hyperbaric conditions may provide a means to study these bacteria under simulated in situ conditions and simultaneously avoid the complications associated with hydrostatic experiments. Results indicate that hyperbaric helium bioreactors will be important in the study of extremely thermophilic bacteria that are isolated from pressurized environments.     

Nutritional factors affecting lipase production byRhizopus delemar CDBB H313

Summary Some nutritional factors that affect lipase yields byRhizopus delemar were studied. Dextrin proved to be the best carbon source when used at 1% level. Yeast extract was the best nitrogen source for lipase production. The presence of a lipidic source in the growth medium, at a level not higher than 2% resulted in higher enzyme production. Tween 80 exerted a positive effect on enzyme production, used in a range that goes from 0.02% to 2.00%.     

Effect of different non-ionic surfactants on the biodegradation of PAHs by diverse aerobic bacteria

The aim of this work was to evaluate the effect of several non-ionic surfactants (Tween-80, Triton X-100 and Tergitol NP-10) on the ability of different bacteria (Enterobacter sp., Pseudomonas sp. and Stenotrophomonas sp.) to degrade polycyclic aromatic hydrocarbons (PAHs). Bacterial cultures were performed at 25 °C in an orbital shaker under dark conditions in BHB medium containing 1% of surfactant and 500 mg l⁻¹ of each PAH. Experiments performed with Tween-80 showed the highest cell density values and maximum specific growth rate because this surfactant was used as a carbon source by all bacteria. High degree of PAHs degradation (>90%) was reached in 15 days in all experiments. Toxicity increased at early times using Tween-80 but decreased to low levels in a short time after the firsts 24 h. On the other hand, Triton X-100 and Tergitol NP-10 were not biodegraded and toxicity kept constant along time. However, PAHs-degradation rate was higher, especially by the action of Enterobacter sp. with Tween-80 or Triton X-100. Control experiments performed without surfactant showed a significant decrease in biomass growth rate with a subsequent loss of biodegradation activity likely due to a reduced solubility and bioavailability of PAHs in absence of surfactant.     

S5 Lipase: an organic solvent tolerant enzyme

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 production 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 (Mg2+) 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.     

假丝酵母Candida rugosa产脂肪酶条件的优化

对假丝酵母Candidarugosa产脂肪酶的条件进行了优化.比较实验证明,碳源是影响酶产量的主要因素.其中,糖类使细胞生长良好,但酶产量较低,而脂类是较为适合的碳源.本实验首次发现长链的不饱和脂肪酸酯,三油酸甘油酯是最好的碳源.氮源的影响较小.而添加物的使用是有效提高脂肪酶产量的另一种方法.PVA可促进碳源的乳化,从而提高脂肪酶产量.吐温虽没有促进细胞生长,但却大幅度提高了酶的产量.将以上优化的结果应用于发酵罐中,分批流加操作时,脂肪酶产量高达每毫升128.2单位,为目前报道的最高值.     

Cholinesterase,acid phosphatase,and phospholipase C ofPseudomonas aeruginosa under hyperosmotic conditions in a high-phosphate medium

The presence of low choline or betaine concentrations in a culture medium containing succinate, NH₄Cl, and inorganic phosphate (Pi) as the carbon, nitrogen, and phosphate sources, respectively, permits the growth ofPseudomonas aeruginosa in a hyperosmolar medium. Dimethylglycine, acetylcholine, and phosphorylcholine were less effective as osmoprotectants than choline or betaine. Other alkylammonium compounds tested were virtually ineffective in this capacity. Bacterial growth was also observed in a hyperosmolar medium when choline was the sole carbon and nitrogen source. Choline could act as an osmoprotectant under all the conditions tested. However, the production of cholinesterase (ChE), acid phosphatase (Ac. Pase) and phospholipase C (PLC) took place only when choline was the carbon and nitrogen source. This fact confirms that the synthesis of PLC may occur even in the presence of a high Pi concentration in the medium. Inasmuch as in a high-P_i medium the synthesis of PLC and Ac. Pase (phosphorylcholine phosphatase) is dependent only on choline metabolism, it is postulated that both enzymes are involved in a set of reactions coordinated to produce the breakdown of the membrane phospholipids of the host cell in a hyperosmotic medium.     

Enhanced production of Penicillium expansum PED-03 lipase through control of culture conditions and application of the crude enzyme in kinetic resolution of racemic Allethrolone

Alkaline lipase production was performed in submerged fermentation by Penicillium expansum PED-03. It was found that the suitable carbon source and nitrogen source for lipase production were 0.5% starch and 4.0% soybean meal, respectively. The maximal lipase activity (850 U/mL) of production was achieved at initial pH 5.5-6.0, 26 degrees C, 72 h. Tween-80 was an effective enhancer for lipase production. Agitation speed of the fermentor played an important role, and the suitable agitation speed for lipase production was 500 r/min. The lipase was stable within the range of pH 7.0-10.0 and 20-40 degrees C, and the optimum conditions for the enzymatic reaction were 35 degrees C and pH 9.5. The enzymatic resolution of racemic allethrolone (4-hydroxy-3-methyl-2-(2-propenyl)-2- cyclopenten-1-one) was carried out by the lipase from P. expansum PED-03, and the conversion reached 48% with excellent enantioselectivity (E > 100), which showed a good application potential in the production of optically pure allethrolone.