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1.
A novel bacterial strain, designated SGD-1123T was isolated from Chorao Island, in Goa Province, India. The strain was found to be able to grow at 15–42 °C, pH 5–12 and 0–12 % (w/v) NaCl. The whole cell hydrolysates were found to contain meso-diaminopimelic acid, galactose and arabinose. The major fatty acids were identified as iso-C15:0 and anteiso-C15:0, MK-7 was identified as the predominant menaquinone and the predominant polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified aminolipid. The genomic DNA G+C content was determined to be 44.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences placed the isolate within the genus Bacillus and further revealed that strain SGD-1123T had highest sequence similarity with Bacillus aquimaris, and forms a separate clade with its closest relatives i.e. B. aquimaris, Bacillus vietnamensis and Bacillus marisflavi, with which it shares 94.5, 94.1 and 94.1 % similarity respectively. The phylogenetic, chemotaxonomic and phenotypic analyses indicated that strain SGD-1123T represents a novel species within the genus Bacillus, for which the name Bacillus enclensis is proposed. The type strain is SGD-1123T (NCIM 5450T=CCTCC AB 2011125T).  相似文献   

2.
A New Alkali-Thermostable Azoreductase from Bacillus sp. Strain SF   总被引:3,自引:0,他引:3       下载免费PDF全文
A screening for dye-decolorizing alkali-thermophilic microorganisms resulted in a Bacillus sp. strain isolated out of the wastewater drain of a textile finishing company. An NADH-dependent azoreductase of this strain, Bacillus sp. strain SF, was found to be responsible for the decolorization of azo dyes. This enzyme was purified by a combination of ammonium sulfate precipitation and anion-exchange and affinity chromatography and had a molecular mass of 61.6 kDa and an isoelectric point at pH 5.3. The pH optimum of the azoreductase depended on the substrate and was within the range of pHs 8 to 9, while the temperature maximum was reached at 80°C. Decolorization only took place in the absence of oxygen and was enhanced by FAD, which was not consumed during the reaction. A 26% similarity of this azoreductase to chaperonin Cpn60 from a Bacillus sp. was found by peptide mass mapping experiments. Substrate specificities of the azoreductase were studied by using synthesized model substrates based on di-sodium-(R)-benzyl-azo-2,7-dihydroxy-3,6-disulfonyl-naphthaline. Those dyes with NO2 substituents, especially in the ortho position, were degraded fastest, while analogues with a methyl substitution showed the lowest degradation rates.  相似文献   

3.
A thermophilic Bacillus sp. strain AN-7, isolated from a soil in India, produced an extracellular pullulanase upon growth on starch–peptone medium. The enzyme was purified to homogeneity by ammonium sulfate precipitation, anion exchange and gel filtration chromatography. The optimum temperature and pH for activity was 90 °C and 6.0. With half-life time longer than one day at 80 °C the enzyme proves to be thermostable in the pH range 4.5–7.0. The pullulanase from Bacillus strain lost activity rapidly when incubated at temperature higher than 105 °C or at pH lower than 4.5. Pullulanase was completely inhibited by the Hg2+ ions. Ca2+, dithiothreitol, and Mn2+ stimulated the pullulanase activity. Kinetic experiments at 80 °C and pH 6.0 gave Vmax and Km values of 154 U mg−1 and 1.3 mg ml−1. The products of pullulan were maltotriose and maltose. This proved that the purified pullulanase (pullulan-6-glucanohydrolase, EC 3.2.1.41) from Bacillus sp. AN-7 is classified under pullulanase type I. To our knowledge, this Bacillus pullulanase is the most highly thermostable type I pullulanase known to date.  相似文献   

4.
A Gram-stain positive, facultative aerobic bacterium, designated as strain GSS03T, was isolated from a paddy field soil. The cells were observed to be endospore forming, rod-shaped and motile with flagella. The organism was found to grow optimally at 35 °C at pH 7.0 and in the presence of 1 % NaCl. The strain was classified as a novel taxon within the genus Bacillus on the basis of phenotypic and phylogenetic analyses. The closest phylogenetic relatives were identified as Bacillus psychrosaccharolyticus DSM 6T (97.61 %), Bacillus muralis DSM 16288T (97.55 %), Bacillus asahii JCM 12112T (97.48 %), Bacillus simplex DSM 1321T (97.48 %) and “Bacillus frigoritolerans” DSM 8801T (97.38 %). The menaquinone was identified as MK-7, the major cellular fatty acid was identified as anteiso-C15:0 and the major cellular polar lipids as phosphatidylethanolamine, phosphatidylmonomethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and three unknown polar lipids. The DNA G+C content was determined to be 40.2 mol%. The DNA–DNA relatedness with the closest relatives was below 48 %. Therefore, on the basis of all the results, strain GSS03T is considered to represent a novel species within the genus Bacillus, for which the name Bacillus huizhouensis sp. nov. is proposed. The type strain is GSS03T (=KCTC 33172T =CCTCC AB 2013237T).  相似文献   

5.
A Gram-positive, facultative anaerobic, motile, endospore-forming rod strain, designated DX-4T, was isolated from an electrochemically active biofilm. Growth occurred at 30–65 °C (optimum 55 °C), at pH 6.0–8.5 (optimum pH 7.0–7.5) and with <6 % (w/v) NaCl. Cells were catalase- and oxidase-positive. The main respiratory quinone was MK-7, the predominant polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol mannoside, and unidentified aminophospholipid, the DNA G+C content was 38.6 mol% and the major fatty acids (>5 %) were iso-C15:0 (38.9 %), iso-C17:0 (30.5 %), iso-C16:0 (5.6 %), and anteiso-C17:0 (5.2 %). The phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain DX-4T is a member of the genus Bacillus. The results of phenotypic, chemotaxonomic, and genotypic analyses clearly indicated that strain DX-4T represents a novel species, for which the name Bacillus borbori sp. nov. is proposed. The type strain is DX-4T (= CCTCC AB2012196T = KCTC 33103T).  相似文献   

6.
An alkaliphilic, moderately halophilic, bacterium, designated strain X10-1T, was isolated from saline-alkaline soil inDaqing, Heilongjiang Province, China. Strain X10-1T was determined to be a Gram-positive aerobe with rod-shaped cells. The isolate was catalase-positive, oxidase-negative, non-motile, and capable of growth at salinities of 0–16% (w/v) NaCl (optimum, 3%). The pHrange for growth was 7.5–11.0 (optimum, pH 10.0). The genomic DNA G+C content was 47.7 mol%. Itsmajor isoprenoid quinone was MK-7 and its cellular fatty acid profile mainly consisted of anteiso-C15:0, anteiso-C17:0, iso-C15:0, C16:0, and iso-C16:0. The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. The predominant polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylglycerol. Phylogenetic analysis based on 16S rRNA gene sequences showed that X10-1T is a member of the genus Bacillus, being most closely related to B. saliphilus DSM15402T (97.8% similarity) and B. agaradhaerens DSM 8721T (96.2%). DNA-DNA relatedness to the type strains of these species was less than 40%. On the basis of the phylogenetic, physiological, and biochemical data, strain X10-1T represents a novel species of the genus Bacillus, for which the name Bacillus daqingensis sp. nov. is proposed. The type strain is X10-1T (=NBRC 109404T = CGMCC 1.12295T).  相似文献   

7.
The present study was conducted to identify and characterize the thermophilic bacteria isolated from various hot springs in Turkey by using phenotypic and genotypic methods including fatty acid methyl ester and rep-PCR profilings, and 16S rRNA sequencing. The data of fatty acid analysis showed the presence of 17 different fatty acids in 15 bacterial strains examined in this study. Six fatty acids, 15:0 iso, 15:0 anteiso, 16:0, 16:0 iso, 17:0 iso, and 17:0 anteiso, were present in all strains. The bacterial strains were classified into three phenotypic groups based on fatty acid profiles which were confirmed by genotypic methods such as 16S rRNA sequence analysis and rep-PCR genomic fingerprint profiles. After evaluating several primer sets targeting the repetitive DNA elements of REP, ERIC, BOX and (GTG)5, the (GTG)5 and BOXA1R primers were found to be the most reliable technique for identification and taxonomic characterization of thermophilic bacteria in the genera of Geobacillus, Anoxybacillus and Bacillus spp. Therefore, rep-PCR fingerprinting using the (GTG)5 and BOXA1R primers can be considered as a promising genotypic tool for the identification and characterization of thermophilic bacteria from species to strain level.  相似文献   

8.
A Gram-positive, alkaliphilic bacterium, designated strain Zby6T, was isolated from Zhabuye Lake in Tibet, China. The strain was able to grow at pH 8.0–11.0 (optimum at pH 10.0), in 0–8 % (w/v) NaCl (optimum at 3 %, w/v) and at 10–45 °C (optimum at 37 °C). Cells of the isolate were facultatively anaerobic and spore-forming rods with polar flagellum. The predominant isoprenoid quinone was MK-7, and its cell wall peptidoglycan contained meso-diaminopimelic acid. The major cellular fatty acids were iso-C15:0, C16:0 and anteiso-C15:0. The major polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, and phosphatidylethanolamine. The genomic DNA G+C content of the isolate was 38.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain Zby6T was a member of the genus Bacillus and most closely related to Bacillus cellulosilyticus DSM 2522T (97.7 % similarity). The DNA–DNA relatedness value between strain Zby6T and B. cellulosilyticus DSM 2522T was 59.2 ± 1.8 %. Comparative analysis of genotypic and phenotypic features indicated that strain Zby6T represents a novel species of the genus Bacillus, for which the name Bacillus alkalicola sp. nov. is proposed; the type strain is Zby6T (=CGMCC 1.10368T = JCM 17098T = NBRC 107743T).  相似文献   

9.
Previously, a di-D-fructofuranose 1,2’:2,3’ dianhydride (DFA III)-producing strain, Arthrobacter aurescens SK8.001, was isolated from soil, and the gene cloning and characterization of the DFA III-forming enzyme was studied. In this study, a DFA III hydrolysis enzyme (DFA IIIase)-encoding gene was obtained from the same strain, and the DFA IIIase gene was cloned and expressed in Escherichia coli. The SDS-PAGE and gel filtration results indicated that the purified enzyme was a homotrimer holoenzyme of 145 kDa composed of subunits of 49 kDa. The enzyme displayed the highest catalytic activity for DFA III at pH 5.5 and 55°C, with specific activity of 232 U mg-1. K m and V max for DFA III were 30.7 ± 4.3 mM and 1.2 ± 0.1 mM min-1, respectively. Interestingly, DFA III-forming enzymes and DFA IIIases are highly homologous in amino acid sequence. The molecular modeling and docking of DFA IIIase were first studied, using DFA III-forming enzyme from Bacillus sp. snu-7 as a template. It was suggested that A. aurescens DFA IIIase shared a similar three-dimensional structure with the reported DFA III-forming enzyme from Bacillus sp. snu-7. Furthermore, their catalytic sites may occupy the same position on the proteins. Based on molecular docking analysis and site-directed mutagenesis, it was shown that D207 and E218 were two potential critical residues for the catalysis of A. aurescens DFA IIIase.  相似文献   

10.
A Gram-reaction-positive, strictly aerobic, motile, endospore- forming, and rod-shaped bacterial strain designated 135PIL107-10T was isolated from a sponge on Jeju Island, and its taxonomic position was investigated using a polyphasic approach. Strain 135PIL107-10T grew at 20–37°C (optimum temperature, 25°C) and pH 6.0–10.0 (optimum pH, 6.0) on marine and R2A agars. Based on 16S rRNA gene phylogeny analysis, the novel strain formed a new branch within the genus Bacillus of the family Bacillaceae, and formed clusters with Bacillus thaohiensis NHI-38T (96.8%), Bacillus fengqiuensis NPK15T (96.7%), and Bacillus songklensis CAU 1033T (96.7%). Lower sequence similarities (97.0%) were found with the type strains of all other recognized members of the genus Bacillus (95.6–96.8% similarity). The G + C content of the genomic DNA was 43.6 mol%. The predominant respiratory quinone was menaquinone-7 and the major fatty acids were iso-C15:0 and iso-C17:1ω10c. The overall polar lipid patterns were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The isolate therefore represents a novel species, for which the name Bacillus spongiae sp. nov. is proposed, with the type strain 135PIL107-10T (= KACC 19275T = LMG 30080T).  相似文献   

11.
《Carbohydrate polymers》1987,7(4):277-290
The inulinase of the thermophilic bacterial strain LCB41 (Bacillus sp.) was produced in fermentor using a mineral medium containing inulin as carbon source. The enzyme content was as high as the known inulinase producers and most of the activity was found in the culture medium. The enzyme was stable at high temperature and active at neutral and slightly basic pH. Fructose is liberated as the sole reaction product of inulin hydrolysis, classifying the enzyme as an exoinulinase. Inulin and sucrose were both hydrolyzed at appreciable rates with an (I/S) ratio of 0·40 and (Vm/Km)1/(Vm/Km)S = 9·9. The enzyme was less inhibited than yeast invertase or Kluyveromyces fragilis inulinase at high sucrose concentrations. The inulinase of strain LCB41 is a good candidate for industrial hydrolysis of inulin or sucrose.  相似文献   

12.
The potential of Bacillus SF spore laccase for coupling aromatic amines to lignin model molecules as a way of creating a stable reactive surface was investigated. The Bacillus spore laccase was shown to be active within the neutral to alkaline conditions (pH 7–8.5) and was more resistant to common laccase inhibitors than fungal laccases. Using this enzyme, tyramine was successfully covalently coupled onto syringylglycerol β-guaiacylether via a 4-O-5 bond, leaving the –NH2 group free for further attachment of functional molecules. This study demonstrates the potential of Bacillus SF spore laccase for application in lignocellulose surface functionalization and other coupling reactions which can be carried out at neutral to alkaline pH under extreme conditions which normally inhibit fungal laccases.  相似文献   

13.
A Gram-positive bacterium, designated SCSIO 15042T, was isolated from a sediment of the South China Sea and was subjected to a polyphasic taxonomic study. The isolate grew at 20–60 °C, pH 6.0–10.0 and it could grow with up to 10 % (w/v) NaCl. The cell-wall diamino acid was found to be meso-diaminopimelic acid. Polar lipids were found to be diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine and an unknown polar lipid. The only menaquinone was determined to be MK-7. The major fatty acids were identified as C16:1 ω7c/C16:1 ω6c, C16:0, iso-C15:0, anteiso-C15:0, and iso-C16:0. The DNA G+C content of strain SCSIO 15042T was determined to be 43.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain SCSIO 15042T to the genus Bacillus. Levels of 16S rRNA gene sequence similarities between strain SCSIO 15042T and Bacillus herbersteinensis D-1-5aT, Bacillus infantis SMC 4352-1T, Bacillus novalis LMG 21837T and Bacillus drentensis LMG 21831T were 96.2, 96.2, 96.1 and 96.1 %, respectively. Based on the evidence of the present polyphasic study, strain SCSIO 15042T is considered to represent a novel species of the genus Bacillus, for which the name Bacillus abyssalis sp. nov. is proposed. The type strain is SCSIO 15042T (=DSM 25875T = CCTCC AB 2012074T = NBRC 109102T).  相似文献   

14.
A rod shaped, non-motile, endospore forming, Gram-stain positive and moderately halotolerant strain, designated as NCCP-168T, was isolated from salt mines sampled in the Karak district of Khyber Pakhtunkhwa Province in Pakistan. To delineate its taxonomic position, the strain was subjected to polyphasic characterization. Cells of strain NCCP-168T can grow at 10–40 C (optimum at 30–35 C), in a pH range of 5.0–9.0 (optimum at pH 8.0) and in 0–17 % (w/v) NaCl on agar medium. The phylogenetic analysis based on the 16S rRNA gene sequence showed that strain NCCP-168T belongs to the genus Bacillus with the highest similarity to Bacillus seohaeanensis BH724T (97.1 %), and less than 97 % similarity with other closely related taxa (95.6 % with B. subtilis subsp. subtilis NCIB3610T). DNA–DNA relatedness between strain NCCP-168T and the type strains of closely related species was lower than 30 %. Chemotaxonomic data (major menaquinone, MK-7; cell wall peptidoglycan type, A1γ [meso-diaminopimelic acid]; major fatty acids, iso-C15:0 29.9 %, anteiso-C15:0 29.3 %, iso-C16:0 11.4 %, iso-C14:0 8.9 % and anteiso-C17:0 7.0 %; major polar lipids, diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine) support the affiliation of strain NCCP-168T with genus Bacillus. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain NCCP-168T can be distinguished from the closely related taxa and thus represents a novel species in the genus Bacillus, for which the name Bacillus pakistanensis sp. nov. is proposed, with the type strain NCCP-168T (= KCTC 13786T = DSM 24834T = JCM 18975T).  相似文献   

15.
The role of carboxyl group in the catalytic action of xylanase (Mr 35 000) from an alkalothermophilic Bacillus sp. was delineated through iinetic and chemical modification studies using Woodward's Reagent K. The kinetics of inactivation indicated that one carboxyl residue was essential for the xylanase activity with a second order rate constant of 3300 M−1 min−1. The spectrophotometric analysis at 340 nm revealed that the inhibition was correlated with modification of 24 carboxyl residues. In the presence of protecting ligand, modification of one carboxyl group was prevented. The pH profile showed apparent pK values of 5.2 and 6.4 for the free enzyme and 4.9 and 6.9 for enzyme-substrate complex. The pH dependence of inactivation was consistent with the modification of carboxyl group. The kinetic analysis of the modified enzyme showed similar Km and lower kcat values than the native enzyme indicating that catalytic hydrolysis and not the substrate binding was affected by chemical modification. The chemical modification of xylanase from alkalothermophilic Bacillus revealed the presence of tryptophans in the active site (Dehspande, V, Hinge, J. and Rao, M. (1990) Biochim. Biophys. Acta 1041, 172–177). This finding and present studies demonstrated the experimental evidence for the participation of carboxyl as well as tryptophan groups as essential residues of xylanase from alkalothermophilic Bacillus sp.  相似文献   

16.
We have structurally characterized the c-ring from the thermoalkaliphilic Bacillus sp. strain TA2.A1 F1Fo-ATP synthase. Atomic force microscopy imaging and cryo-electron microscopy analyses confirm previous mass spectrometric data indicating that this c-ring contains 13 c-subunits. The cryo-electron microscopy map obtained from two-dimensional crystals shows less closely packed helices in the inner ring compared to those of Na+-binding c11 rings. The inner ring of α-helices in c11 rings harbors a conserved GxGxGxGxG motif, with glycines located at the interface between c-subunits, which is responsible for the close packing of these helices. This glycine motif is altered in the c13 ring of Bacillus sp. strain TA2.A1 to AxGxSxGxS, leading to a change in c-c subunit contacts and thereby enlarging the c-ring diameter to host a greater number of c-subunits. An altered glycine motif is a typical feature of c-subunit sequences in alkaliphilic Bacillus species. We propose that enlarged c-rings in proton-dependent F-ATP synthases may represent an adaptation to facilitate ATP synthesis at low overall proton-motive force, as occurs in bacteria that grow at alkaline pH.  相似文献   

17.
A novel Gram-stain-positive, slightly halophilic, catalase- and oxidase-positive, endospore-forming, motile, aerobic, rod-shaped bacterium, designated strain JSM 081003T, was isolated from non-saline forest soil in Hunan Province, China. Growth occurred with 0.5?C15% (w/v) NaCl (optimum 2?C4%) at pH 6.5?C10.5 (optimum pH 7.5?C8.5) and at 5?C40°C (optimum 30°C). meso-Diaminopimelic acid was present in the cell-wall peptidoglycan. The major cellular fatty acids were iso-C15:0, anteiso-C15:0 and iso-C14:0. Strain JSM 081003T contained MK-7 as the predominant respiratory quinone, and diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol as the major polar lipids. The genomic DNA G + C content of strain JSM 081003T was 40.9 mol%. A phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain JSM 081003T should be assigned to the genus Bacillus, and was related most closely to the type strains of Bacillus lehensis (sequence similarity 99.6%), Bacillus oshimensis (99.4%) and Bacillus patagoniensis (96.6%); lower than 96.0% sequence similarity was observed with other Bacillus species. The combination of phylogenetic analysis, DNA?CDNA relatedness values, phenotypic characteristics and chemotaxonomic data supports the view that strain JSM 081003T represents a new species of the genus Bacillus, for which the name Bacillus hunanensis sp. nov. is proposed. The type strain is JSM 081003T (= DSM 23008T = KCTC 13711T).  相似文献   

18.
An orange-colored bacterial strain, ICM 1–15T, was isolated from greenhouse soil. The 16S rRNA gene sequence of this strain showed the highest sequence similarity with Niabella ginsengisoli GR10-1T (95.2%) and Niabella yanshanensis CCBAU 05354T (95.0%) among the type strains. The strain ICM 1–15T was a strictly aerobic, Gram-negative, non-spore-forming, non-motile, flexirubin pigment-producing, short rod-shaped bacterium. The strain grew at 15–35°C (optimum, 25°C), at a pH of 5.0–8.5 (optimum, pH 6.5), and in the presence of 0–3% NaCl (optimum, 1%). The DNA G+C content of strain ICM 1–15T was 43.6 mol%. It contained MK-7 as the major isoprenoid quinone and iso-C15:0 (38.9%), iso-C15:1 G (20.3%), and iso-C17:0 3-OH (12.9%) as the major fatty acids. On the basis of evidence from our polyphasic taxonomic study, we concluded that strain ICM 1–15T should be classified within a novel species of the genus Niabella, for which the name Niabella terrae sp. nov. is proposed. The type strain is ICM 1–15T (=KACC 17443T =JCM 19502T).  相似文献   

19.
A Gram-positive, moderately halotolerant, rod-shaped, spore forming bacterium, designated strain FJAT-14515T was isolated from a soil sample in Cihu area, Taoyuan County, Taiwan. The strain grew at 10–35 °C (optimum at 30 °C), pH 5.7–9.0 (optimum at pH 7.0) and at salinities of 0–5 % (w/v) NaCl (optimum at 1 % w/v). The diagnostic diamino acid of the peptidoglycan of the isolated strain was meso-diaminopimelic acid and major respiratory isoprenoid quinone was MK-7. Major cellular fatty acids were anteiso-C15:0 (40.6 %), iso-C15:0 (20.7 %) and the DNA G+C content of strain FJAT-14515T was 37.1 mol %. A phylogenetic analysis based on 16S rRNA gene sequences indicated that strain FJAT-14515T belongs to the genus Bacillus, and was most closely related to the reference strains of Bacillus muralis DSM 16288T (97.6 %) and Bacillus simplex DSM 1321T (97.5 %). Levels of DNA–DNA relatedness between strain FJAT-14515T and the reference strains of B. muralis DSM 16288T and B. simplex DSM 1321T were 27.9 % ± 3.32 and 44.1 % ± 0.57, respectively. Therefore, on the basis of phenotypic, chemotaxonomic and genotypic properties, strain FJAT-14515T represents a novel species of the genus Bacillus, for which the name Bacillus cihuensis sp. nov. is proposed. The type strain is FJAT-14515T (=DSM 25969T = CGMCC 1.12697T).  相似文献   

20.
A thermophilic bacterium was isolated from a hot spring area of Yellowstone National Park. The organism grew optimally at 60–65°C and in the pH range of 6–9. It was characterized as Bacillus sp. In the presence of corn or olive oil (1.0%) as the growth substrate, this Bacillus produced an extracellular lipolytic activity (EC 3.1.1.3). The enzyme activity could be efficiently recovered by ultrafiltration of cell-free culture supernatant. The partially purified lipase preparation had an optimum temperature of 60°C, at an optimum pH of 9.5. It retained 100% of the original activity after being heated at 75°C for half an hour. The half life of the enzyme was 8 h at 75°C. The enzyme retained at least 90% of the original activity after it was incubated at 60°C for 15 h at pH's in the range of 5 to 10.5. The enzyme was active on triglycerides containing fatty acids having a carbon chain length of C16 : 0 to C22 : 0 as well as on natural fats and oils. The enzyme activity was stable to both hydrogen peroxide and alkaline protease which are detergent ingredients. The purified enzyme had an isoelectric point of 5.15 and an approximate molecular weight of 65,000.  相似文献   

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