17,891 research outputs found

    Penapisan Aktivitas Lipolitik Sepuluh Biakan Rhizopus Koleksiuicc (University of Indonesia Culture Collection) [Screening Lipolytic Activity of Ten Strains Rhizopus From University of Indonesia Culture Collection (Uicc)]

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    Ten Rhizopus were screened for their extracellular lipolytic activity. All strains showed lipolytic activity with diffferent activities.R. microsporus var. rhizopodiformis (Cohn) Scipper & Stalpers UICC 520 (4.52 unit/ml) and R. microsporus var. oligosporus UICC 550 (2.58 unit/ml) showed a high lipolytic activity in screening medium containing 5% pepton and 1% glucose (b/v) without a lipid substrate after 24 hours of incubation at room temperature

    Influence of temperature and culture media on growth and lipolytic activity of deep-sea Halomonas sulfidaeris LAMA 838 and Marinobacter excellens LAMA 842

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    Bacteria with lipolytic activity are widespread in the marine environment. These organisms can be usedas a source of lipases with activity in unusual conditions such as low temperatures and high salinities.These characteristics allow them to be applied to several industrial processes and products includingwastewater treatment and detergent production. In this context the lipolytic activity of bacteria isolatedfrom deep-sea sediments of the South Atlantic was evaluated. Among the collection studied, two strains,Halomonas sulfidaeris LAMA 838 and Marinobacter excellens LAMA 842, were selected for further analysisconcerning their growth and lipolytic activity in different temperatures and culture media. Both strainswere characterized as mesophiles: H. sulfidaeris LAMA 838 grew best at 30ÂșC, while M. excellens LAMA 842showed a maximum growth rate between 20 and 25ÂșC. Maximum lipolytic activity for both microorganismswas observed above 45ÂșC, but only M. excellens LAMA 842 had lipolytic activity at low temperatures (5ÂșC) aswell. Considering the culture media employed, H. sulfidaeris LAMA 838 grew better in marine broth withoutTween 40, while M. excellens LAMA 842 grew best in marine broth supplemented with Tween 40. Bothorganisms had maximum lipolytic activity in rich or minimal media supplemented with Tween 40. Theseresults demonstrate the potential of deep-sea bacteria as sources of lipases and indicate conditions thatmay be used in their cultivation and for the production of industrially relevant enzymes

    Effects of detergents on activity, thermostability and aggregation of immobilized lipases

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    Predmetom tejto diplomovej prĂĄce bolo ĆĄtĂșdium vplyvu detergentov na aktivitu, termostabilitu a agregĂĄciu voÄŸnej a imobilizovanej formy komerčnĂ©ho preparĂĄtu lipĂĄzy izolovanej z mikroskopickej huby Rhizopus arrhizus. TeoretickĂĄ časĆ„ obsahuje ucelenĂș reĆĄerĆĄ popisujĂșcu ĆĄtruktĂșru, mechanizmus Ășčinku a priemyselnĂœ vĂœznam spomĂ­nanej hydrolĂĄzy spolu s popisom chemickĂœch Ășčinkov detergentov, pričom dĂŽraz bol kladenĂœ predovĆĄetkĂœm na skupinu neionogĂ©nnych detergentov s nĂĄzvom tweeny. V experimentĂĄlnej časti bol ĆĄtudovanĂœ efekt tweenov na rozpustnej a imobilizovanej forme RA lipĂĄzy. ImobilizĂĄcia spočívala v priamej adsorpcii enzĂœmu na neupravenĂœ nosič. Ako nosič bol pouĆŸitĂœ oxidovanĂœ grafĂ©n oĆĄetrenĂœ tweenom (tween 20, 60, 80). Aktivita enzĂœmu bola stanovenĂĄ spektrofotometricky za pomoci substrĂĄtu p-nitrofenyl laurĂĄtu. ZvĂœĆĄenie aktivity voÄŸnej lipĂĄzy (104 % oproti maximĂĄlnej hodnote) bolo zaznamenanĂ© pri pouĆŸitĂ­ tweenu 20 o koncentrĂĄcii vysoko nad hodnotou kritickej micelĂĄrnej koncentrĂĄcie (10 mmol‱dm-3). Na zĂĄklade ĆĄtĂșdie imobilizačnĂœch podmienok, boli nastavenĂ© ideĂĄlne parametre pre dosiahnutie Ășčinnej imobilizĂĄcie v spojenĂ­ s čo najvyĆĄĆĄou lipolytickou aktivitou (koncentrĂĄcia enzĂœmu 0,1 mg‱ml-1, fosfĂĄtovĂœ tlmivĂœ roztok pH 7,2, koncentrĂĄcia tweenu 10,8 mmol‱dm-3, čas imobilizĂĄcie 1 hodina). Obe formy lipĂĄzy vykazovali maximĂĄlnu aktivitu pri 35 °C. OptimĂĄlne pH sa u imobilizovanej lipĂĄzy posunulo na hodnotu 8, v porovnanĂ­ s voÄŸnou formou, ktorej pH optimum bolo stanovenĂ© na 9. TepelnĂĄ stabilita vykazovala pribliĆŸne rovnakĂœ priebeh u oboch foriem skĂșmanej hydrolĂĄzy. AvĆĄak v prĂ­pade ĆĄtĂșdia stability enzĂœmu pri dlhodobej Ășschove bolo po imobilizĂĄcii zistenĂ© vĂœraznĂ© zlepĆĄenie tohto parametru.The diploma thesis deals with the issue of the effect of tweens on enzymatic activity of model hydrolase both free and immobilized on carbon-based carrier. In theoretical part, structural features, mechanism of action, and specialty applications of microbial lipases are reviewed along with detergent chemistry, with emphasize on tween family of detergents belonging into non-ionic surfactant group. In experimental part, effect of tweens on soluble as well as immobilized hydrolase was examined. Immobilization of commercial preparation of lipase was performed by non-covalent adsorption on graphene oxide as a carrier treated with different tweens (tween 20, 60, 80). The activity was determined spectrophotometrically by p-nitrophenyl laurate assay. Enhancement of soluble Rhizopus arrhizus lipase activity (activity coupling of 104 %) was observed at tween 20 concentration of 10 mmol‱dm-3, which is highly above critical micelle concentration of this detergent. On the base of screening study, immobilization protocol comprised the incubation of soluble enzyme at concentration of 0.1 mg‱ml-1 in phosphate buffer (pH 7.2) with tween 20 (10.8 mmol‱dm-3) and the carrier for one hour. Both soluble and immobilized lipase exhibited maximum activity at approx. 35 °C. Optimal pH of immobilized lipase shifted to 8 compared to soluble form for which pH optimum at 9 was determined. Thermal stability profile follows almost same trend for both soluble and immobilized enzyme samples. The interactions between carrier and enzyme are suggested to be mainly non–covalent (adsorption, electrostatic interactions). No protein leaching was observed under studied conditions, and significant improvement of storage stability of immobilized lipase was achieved (activity retention of 41 % after 110 days) in comparison with soluble lipase (activity retention of 16 % after 42 days).

    Isolation of Local Lipolytic Isolate from Domestic Compost

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    Screening of lipolytic bacteria from domestic compost resulting an isolate namely AL17. Morphological analysis shows that the isolates were rod shape and belong to negative gram bacteria. The 16S rRNAs genes of the bacteria have been sequenced, and phylogenetic analysis showed that the isolates were close to genus Pseudoxanthomonas. The enzyme production was synchronized with bacterial growth and reached a maximum level during the late-stationary phase. The optimum pH and temperature of enzyme activity were at pH 9.0 and 60°C.The isolate also showed alcohol tolerance in medium containing 3% and 5% methanol. The ability of bacterial cells to tolerate methanol is an important cell characteristic that determines their use as a biocatalyst in transesterification and other industrial process

    In preeclampsia, maternal third trimester subcutaneous adipocyte lipolysis is more resistant to suppression by insulin than in healthy pregnancy

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    Obesity increases preeclampsia risk, and maternal dyslipidemia may result from exaggerated adipocyte lipolysis. We compared adipocyte function in preeclampsia with healthy pregnancy to establish whether there is increased lipolysis. Subcutaneous and visceral adipose tissue biopsies were collected at caesarean section from healthy (n=31) and preeclampsia (n=13) mothers. Lipolysis in response to isoproterenol (200 nmol/L) and insulin (10 nmol/L) was assessed. In healthy pregnancy, subcutaneous adipocytes had higher diameter than visceral adipocytes (<i>P</i><0.001). Subcutaneous and visceral adipocyte mean diameter in preeclampsia was similar to that in healthy pregnant controls, but cell distribution was shifted toward smaller cell diameter in preeclampsia. Total lipolysis rates under all conditions were lower in healthy visceral than subcutaneous adipocytes but did not differ after normalization for cell diameter. Visceral adipocyte insulin sensitivity was lower than subcutaneous in healthy pregnancy and inversely correlated with plasma triglyceride (<i>r</i>=−0.50; <i>P</i>=0.004). Visceral adipose tissue had lower <i>ADRB3, LPL,</i> and leptin and higher insulin receptor messenger RNA expression than subcutaneous adipose tissue. There was no difference in subcutaneous adipocyte lipolysis rates between preeclampsia and healthy controls, but subcutaneous adipocytes had lower sensitivity to insulin in preeclampsia, independent of cell diameter (<i>P</i><0.05). In preeclampsia, visceral adipose tissue had higher <i>LPL</i> messenger RNA expression than subcutaneous. In conclusion, in healthy pregnancy, the larger total mass of subcutaneous adipose tissue may release more fatty acids into the circulation than visceral adipose tissue. Reduced insulin suppression of subcutaneous adipocyte lipolysis may increase the burden of plasma fatty acids that the mother has to process in preeclampsia

    Stimulation of a glycosyl-phosphatidylinositol-specific phospholipase by insulin and the sulfonylurea, glimepiride, in rat adipocytes depends on increased glucose transport

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    Abstract. Lipoprotein lipase (LPL) and glycolipidanchored cAMP-binding ectoprotein (Gcel) are modified by glycosyl-phosphatidylinositol (GPI) in rat adipocytes, however, the linkage is potentially unstable. Incubation of the cells with either insulin (0.1-30 nM) or the sulfonylurea, glimepiride (0.5-20/zM), in the presence of glucose led to conversion of up to 35 and 20%, respectively, of the total amphiphilic LPL and Gcel to their hydrophilic versions. Inositol-phosphate was retained in the residual protein-linked anchor structure. This suggests cleavage of the GPI anchors by an endogenous GPI-specific insulin- and glimepiride-inducible phospholipase (GPI-PL). Despite cleavage, hydrophilic LPL and Creel remained membrane associated and were released only if a competitor, e.g., inositol-(cyclic)monophosphate, had been added. Other constituents of the GPI anchor (glucosamine and mannose) were less efficient. This suggests reat body of information exists regarding the structural diversity as well as the biosynthesis and posttranslational attachment of glycosyl-phosphatidylinositol (GPI) ~ structures (for recent reviews see Low, 1989; McConville et al., 1993). However, the functional significance of membrane anchorage via GPI structures versus transmembrane polypeptide domains is still a matter of debate. The accessibility of GPI molecules to cleavage by phospholipase [(G)PI-PL] opens the possibility of a regu-Address all correspondence to Dr. (;tinter Miiller, Hoechst AG Frankfurt

    Isolasi dan Identifikasi Bakteri Lipolitik dari Limbah Cair Kelapa Sawit (Elaeis quineensis Jacq.)

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    This study aims to determine the ability of lipolytic bacteria to degrade lipids by obtaining isolates of lipolytic bacteria in palm oil industrial wastewater. By testing the ability of the lipolytic index, the research method used is a description method with bacterial isolation techniques using NA media (Nutrient Agar) and selective media for lipolytic agar. The results showed that there were 10 isolates of lipolytic bacteria with morphological and biochemical characteristics indicating three bacterial genera, namely, the genera Bacillus, Pseudomonas, and Klebsiella. Data analysis showed that 10 isolates of lipolytic bacteria had the potential to degrade lipids; the highest lipolytic activity index value of the isolates was found in isolate BL1 at 0.48 mm, and the lowest lipolytic index was found in isolate BL9 at 0.16 mm. In conclusion, isolating and identifying lipolytic bacteria in palm oil wastewater is one way to reduce environmental pollution that damages existing ecosystems in the environment.  Keywords: Lipolytic Bacteria, Isolation, Palm Oil Effluent, Lipi

    Technological activities of Staphylococcus carnosus and Staphylococcus simulans strains isolated from fermented sausages

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    The aim of this study was to determine the technological properties of 2 strains of Staphylococcus simulans (Ssm12, Ssm21) and 4 strains of S. carnosus (SC28, SC31, SC54 and SC55) for the selection of a potential starter cultures to employ in the processing of dry fermented sausages. The strains were studied to evaluate nitrate reductase, proteolytic, lipolytic, decarboxylase and antioxidant activities as well as growth ability at different temperatures, pH and NaCl concentrations. Nitrate reductase activity was determined at 15, 20 and 30 degrees C. By spectrophotometric method all the strains were able to reduce nitrate to nitrite at the different temperatures but these results were not confirmed by the agar plate method. Antioxidant and lipolytic activities were evaluated by spectrophotometric assay. All the strains showed antioxidative enzymes superoxide dismutase (SOD) and catalase whereas all appeared unable to hydrolyse pork fat. Proteolytic activity was determined by agar plate method, spectrophotometric assay (OPA) and sodium dodecyl sulphate gel-electrophoresis (SDS-PAGE) and all strains appeared to be able to hydrolyse sarcoplasmic proteins but not myofibrillar proteins. Finally, all the strains grew at 15 and 20 degrees C, in presence of 10%, 15% and 20% of NaCl and at pH 5.0 and 5.5 and were unable to produce histamine, cadaverine and putrescine. The results showed that all strains studied possess useful technological activities that would make them eligible as a good starter cultures for fermented sausages
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