Production Of Lipolytic Enzymes Research Articles

Lipolytic enzyme production in batch and fed-batch cultures ofOphiostoma piceae andFusarium oxysporum

Lipase and esterase production by Ophiostoma piceae and Fusarium oxysporum were enhanced and extended by developing a fed-batch process in stirred tank reactors. Fed-batch strategy improved lipolytic enzyme production from Ophiostoma piceae in both 2 and 20 dm3 stirred tank reactors. However, fed-batch fermentation of Fusarium oxysporum in the 2 dm3 reactor was more effective than both batch and fed-batch fermentations in the 20 dm3 reactor. When a medium composed of only carbon and nitrogen source was intermittently fed to the cultures, the maximum specific lipase activity was improved by more than 80% and 35% in Ophiostoma piceae and Fusarium oxysporum cultures respectively. The maximum specific esterase activity was improved by 20% and 15% in Ophiostoma piceae and Fusarium oxysporum cultures respectively. The duration of production for both fungi extended from 144 to 216 h compared with a batch culture under the same condition. © 2000 Society of Chemical Industry

Bacterial contaminants in liquid packaging boards: assessment of potential for food spoilage.

Liquid packaging boards and blanks were examined for microbial contaminants. A total of 218 strains were identified and representatives of the most frequent species were characterized for their potential for food spoilage. Contaminants found were aerobic spore-forming bacteria, mostly Bacillus megaterium, B. licheniformis, B. cereus group, B. pumilus, Paenibacillus macerans, P. polymyxa, P. pabuli and B. flexus. Production of amylolytic, proteolytic, lipolytic and phospholipolytic enzymes was common. Approximately 50% of the B. cereus group strains were positive in the diarrhoeal enterotoxin immunoassay test or in the enterotoxin reversed passive latex agglutination test. Strains capable of growth at 6 degrees C were found among B. cereus group, P. pabuli, P. validus, B. megaterium and P. polymyxa. All b. licheniformis strains grew at 55 degrees C. The spores of B. licheniformis were most resistant to hydrogen peroxide. The B. cereus group strains were recognizable by fatty acid components not present in any of the other paperboard strains, 11-methyldodecanoic acid (13:0 iso) and trans-9-hexadecenoic acid (16:1 omega 7 trans), each contributing 7% or more to the total cellular fatty acids.

The occurrence and growth of yeasts in Camembert and Blue-veined cheeses

Yeast populations greater than 10 6 cfu g were found in approximately 54% and 36%, respectively in surface samples of retail Camembert (85 samples) and Blue-veined (45 samples) cheeses. The most predominant species isolated were Debaryomyces hansenii, Candida catenulata, C. lipolytica, C. kefyr, C. intermedia, Saccharomyces cerevisiae, Cryptococcus albidus and Kluyveromyces marxianus. The salt concentration of the surface samples of the cheeses varied between 2.5–5.5% ( w w ) (Camembert) and 7.5–8.3 (Blue-veined), depending upon brand, and influenced the yeast ecology, especially the presence of S. cerevisiae. Yeasts grew to populations of 10 6–10 8 cfu g when cheeses were stored at either 25 °C or 10 °C. These populations decreased on continued storage at 25 °C, but such decreases were not so evident on storage at 10 °C. The properties of yeasts influencing their occurrence and growth in cheeses were: fermentation/assimilation of lactose; production of extracellular lipolytic and proteolytic enzymes, utilisation of lactic and citric acids; and growth at 10 °C.

Effect of culture conditions on lipolytic enzyme production by Penicillium candidum in a solid state fermentation

Lipolytic enzymes were produced using wheat bran as substrate in a solid state fermentation with Penicillium candidum. The best production of lipolytic activity occurred at 29°C. One hundred micromoles of free butyric acid (FBA) was released from tributyrin by 1 mL of cell free supernatant in the absence of control of environmental relative humidity. When a closed chamber saturated with water vapour was used the lipolytic activity increased to 320 μmoles of free butyric acid. The best initial reaction pH was 7.0. The highest activity, 480 μmoles of FBA, was obtained at a moisture content of 67.5 % of saturation.

Lipolytic activities of two strains of Aspergillus aculeatus associated with the spoilage of two food sources

AbstractThe production of extracellular lipolytic enzymes by 2 strains of Aspergillus aculearus associated with the deterioration of peanuts and a marketed margarine in Nigeria and the effects of temperature and pH on the activities of the enzymes were investigated. Lipolytic enzymes were detected within 2 days of incubation at 35 °C in 4 out of 6 natural oils and in 3 out of 4 synthetic glycerides used irrespective of strain type. The lipolytic enzymes of both strains hydrolysed both natural oils and synthetic glycerides to free fatty acids. There was correlation between the mycelium produced to the quantity of free fatty acids produced in medium within the first 8 days of incubation. There was a general increase in mycelium production with increase in incubation period. The enzyme activities were at peak at 30‐35 °C and at pH 6‐7.

Effect of undecanoic acid on the production of exocellular lipolytic and keratinolytic enzymes by undecanoic acid-sensitive and -resistant strains of Trichophyton rubrum.

Effects of undecanoic acid on exocellular lipase, phospholipase A and keratinase activities of wild type undecanoic acid-sensitive (udas) and an undecanoic acid-resistant mutant (udar) of Trichophyton rubrum (derived from the udas strain) were determined. Undecanoic acid inhibited the production of exocellular lipase and keratinase but stimulated the production of exocellular phospholipase A in T. rubrum udas. Undecanoic acid did not affect exocellular lipase production by T. rubrum udar. Lipase production by the udar mutant was lower than that of the udas parent. No exocellular keratinase could be detected in the udar strain which had very low capacity for invasion of keratinized tissue.

A study of the Moraxella group. II. Oxidative-negative species (genus Acinetobacter).

A number of nutritional and biochemical properties of more than 100 strains of the oxidase-negative moraxellas (the Mima-Herellea-Acinetobacter group of bacteria) were studied. These properties included the range of carbon sources that can support growth, the utilization of nitrate, the production of proteolytic and lipolytic enzymes, and the reactions involved in the oxidation of sugars and of aromatic compounds. No evidence could be obtained for the accumulation of either poly-beta-hydroxybutyrate or polysaccharide as intracellular reserve materials. Of 158 different compounds tested, the group as a whole could use 85 as sole carbon sources for growth. The nutritional spectra of the individual strains, however, differed widely, with a range of from 17 to 74 alternative substrates. On the basis of 56 selected nutritional and physiological characters used for a numerical analysis, the collection could be divided into two major groups of strains comprising at least seven less clearly defined clusters. Neither the hydrolysis of gelatin nor acid production from aldose sugars was found to be a reliable index of strain affinities indicated by the phenotypic analysis, although both properties were of some use in distinguishing between the subgroups. For reasons that are discussed, we propose that the oxidase-negative moraxellas be placed in the genus Acinetobacter Brisou and Prévot, for which a modified description is presented. A. calco-aceticus (Beijerinck) is proposed as the type species, of which anitratum is regarded as a synonym or variety. On the basis of the present studies and unpublished supporting evidence provided by M. Mandel on deoxyribonucleic acid (DNA) composition and by J. Johnson on DNA homologies, it is proposed that two other species in the genus, A. lwoffi (Audureau) and A. hemolysans (Henriksen), as well as one subspecies, A. hemolysans haemolyticus (Stenzel and Mannheim), be recognized provisionally.

Purification and properties of lipase from Torulopsis.

THE production of lipolytic enzymes by micro-organisms is widely recognized, and several have been partially purified from certain bacteria1–4 and fungi5–8. Recently, Baskys et al.9 have obtained pancreatic lipase purified with calcium phosphate, which was homogeneous on ultracentrifugation and free-boundary electrophoresis at pH 8.6, but they observed at least two components on starch-gel electrophoresis at pH 8.0 and DEAE-cellulose chromatography. The milk lipase prepared by ‘Sephadex G-50’ was found to be homogeneous on ultracentrifugation and starch-gel electrophoresis at pH 8.5 by Chanden et al.10. We have isolated from soil a strain of Torulopsis which produces high lipolytic activity in the culture broth. The extracellular lipase was also obtained in a highly purified state from the culture broth by the use of ammonium sulphate fractionation, DEAE-cellulose chromatography and ‘Sephadex G-100’ gel nitration. The highly purified enzyme preparation was found to be essentially homogeneous by such criteria as sedimentation in the ultracentrifuge and free electrophoresis.