scholarly journals Isolation and Screening of Pectinase Producing Bacteria from Soil Sample

Author(s):  
Shilpa ◽  
Mandheer Kaur ◽  
Yogita Jadon

The vast majority of the industrial use of enzymes is covered from microorganisms. Microorganisms are favoured in industry because of their several advantages for example rapid growth, short life expectancy and simplicity in doing genetic alterations. Microbial enzymes are thus amply provided, very much standardized and promoted by many companies. Among various enzymes, Pectinases hold an exceptional place because of its different uses in various sectors like food, textile and biofuel industries.A total of 25% of total enzyme market is being shared by Pectinase alone.The current study was carried out to evaluate the pectinase activity of the pectinolytic bacteria. 40 Bacterial strains were isolated from different soil samples and screened for Pectinase production. Primary and Secondary screening showed 3 potential isolates I38 , I39 and I40 showing pectin degradation on Vincent’s media. Further, extracellular pectinase was partially purified by ammonium sulphate precipitation and dialysis. Sequential ammonium sulphate saturations from 20-80% i.e. (20, 40, 60 and 80%) showed 60% ammonium sulphate was optimum for precipitation of intracellular enzyme whereas 80% was optimum for extracellular enzyme.

2013 ◽  
Vol 48 (1) ◽  
pp. 25-32 ◽  
Author(s):  
S Islam ◽  
B Feroza ◽  
AKMR Alam ◽  
S Begum

Pectinase activity among twelve different fungal strains, Aspergillus niger IM09 was identified as a potential one to produce maximal level 831 U/g at pH 4.0. Media composition, incubation temperature, incubation time, substrate concentration, aeration, inoculum size, assay temperature and nitrogen sources were found to effect pectinase activity. Moisture content did not affect the activity significantly. Media composition was varied to optimize the enzyme production in solid state fermentation. It was observed that the highest pectinase activity of 831.0 U/g was found to produce in presence of yeast extract as a nitrogen source in combination with ammonium sulfate in assay media. Aeration showed positive significant effects on pectinase production 755 U/g at 1000 ml flasks. The highest pectinase production was found at 2 g pectin (521 U/g) used as a substrate. Pectinolytic activity was found to have undergone catabolite repression with higher pectin concentration (205 U/g at 5 g pectin). The incubation period to achieve maximum pectinase activity by the isolated strain Aspergillus niger IM09 was 3 days, which is suitable from the commercial point of view. DOI: http://dx.doi.org/10.3329/bjsir.v48i1.15410 Bangladesh J. Sci. Ind. Res. 48(1), 25-32, 2013


2021 ◽  
Author(s):  
Adetunji Alex Adekanmbi ◽  
Laurence Dale ◽  
Liz Shaw ◽  
Tom Sizmur

<p>Predicting the pattern of soil organic matter (SOM) decomposition as a feedback to climate change, via release of CO<sub>2</sub>, is extremely complex and has received much attention. However, investigations often do not differentiate between the extracellular and intracellular processes involved and work is needed to identify their relative temperature sensitivities. Samples were collected from a grassland soil at Sonning, UK with average daily maximum and minimum soil temperature of 15 °C and 5 °C. We measured potential activities of β-glucosidase (BG) and chitinase (NAG) (extracellular enzymes) and glucose-induced CO<sub>2 </sub>respiration (intracellular enzymes) at a range of assay temperatures (5 °C, 15 °C, 26 °C, 37<sup>  </sup>°C, and 45 °C). The temperature coefficient Q<sub>10</sub> (the increase in enzyme activity that occurs after a 10 °C increase in soil temperature) was calculated to assess the temperature sensitivity of intracellular and extracellular enzymes activities. Between 5 °C and 15 °C intracellular and extracellular enzyme activities had equal temperature sensitivity, but between 15 °C and 26°C intracellular enzyme activity was more temperature sensitive than extracellular enzyme activity and between 26 °C and 37 °C extracellular enzyme activity was more temperature sensitive than intracellular enzyme activity. This result implies that extracellular depolymerisation of higher molecular weight organic compounds is more sensitive to temperature changes at higher temperatures (e.g. changes to daily maximum summer temperature) but the intracellular respiration of the generated monomers is more sensitive to temperature changes at moderate temperatures (e.g. changes to daily mean summer temperature). We therefore conclude that the extracellular and intracellular steps of SOM mineralisation are not equally sensitive to changes in soil temperature. The finding is important because we have observed greater increases in average daily minimum temperatures than average daily mean or maximum temperatures due to increased cloud cover and sulphate aerosol emission. Accounting for this asymmetrical global warming may reduce the importance of extracellular depolymerisation and increase the importance of intracellular catalytic activities as the rate limiting step of SOM decomposition.</p>


2011 ◽  
Vol 879 (23) ◽  
pp. 2213-2219 ◽  
Author(s):  
Ivana Stojićević ◽  
Ljiljana Dimitrijević ◽  
Nebojša Dovezenski ◽  
Irena Živković ◽  
Vladimir Petrušić ◽  
...  

1972 ◽  
Vol 27 (8) ◽  
pp. 981-988
Author(s):  
Kunhard Pollow ◽  
Barbara Pollow

The cytoplasmatic fraction of rat liver contains both 17 β-hydroxysteroid-oxidoreductase and a “transhydrogenase-activity”, which catalyses the transfer of hydrogen from the 17 β-position of estradiol-17 β to the 17-position of 4-androstene-3,17-dione. The 17 β-hydroxysteroid-oxidoreductase was purified 718-fold and the “transhydrogenase-activity” 264-fold by ammonium sulphate precipitation, gel chromatography with Sephadex G-200, column chromatography on DEAE-Sephadex and isoelectric focusing. The two enzymic activities could not be separated. The characteristics of the two enzymatic activities give some evidence that the “transhydrogenase-activity” is identical with the already known 17 β-hydroxysteroid-oxidoreductase.Isoelectric focusing of the chromatographycally enriched 17 β-enzyme gave an isoelectric point at 5,2. The 17 β-enzyme has a molecular weight of 62 — 65 000 as determined by mobility on Sephadex G-200 superfine.The kinetic constants for both the 17 β-enzyme and the “transhydrogenase-activity” were determined.


1973 ◽  
Vol 19 (1) ◽  
pp. 113-117 ◽  
Author(s):  
R. A. Holley ◽  
D. K. Kidby

Preliminary evidence has been obtained which suggests that the intracellular invertase of Saccharomyces cerevisiae may not be localized in the vacuole per se. Alkaline phosphatase, an intracellular enzyme, and acid protease, a typically lysosomal enzyme, both showed high specific activity in the vacuole fraction prepared by equilibrium centrifugation of lysed sphaeroplasts in Ficoll gradients. Invertase activity has been found to be associated with vacuoles only when glucose-repressed cells are derepressed. Cells derepressed for invertase biosynthesis contained a population of vesicles which were virtually absent from the repressed cells. Evidence is presented which strongly suggests that these vesicles rather than the vacuoles are the vehicle by which invertase is secreted from the cell.


Author(s):  
Swapnali S Gujarathi ◽  
Sandip B. Bankar ◽  
Laxmi A. Ananthanarayan

Bacteriocins are bactericidal or bacteriostatic in action and active against closely related species. Nisin is the bacteriocin produced by the lactic acid bacteria (LAB). Nisin is a small (3353 Da), cationic, hydrophobic, and 34-amino acid peptide. It is used in products such as pasteurized processed cheese, salad dressing, and liquid whole eggs to inhibit the growth of Gram-positive microorganisms including Listeria monocytogenes. The objective of the present work was to study production, purification and characterization of nisin. The production of nisin was carried out using Lactococcus lactis subsp lactis MTCC 440 by one-factor-at-a-time method and statistical design (Orthogonal array). Purification was carried out using ammonium sulphate precipitation followed by hydrophobic interaction and gel chromatography. Characterization was done for pH and temperature stability. The activity of nisin after one factor at a time optimization was found to be 5120 AU/ml. The activity of the nisin increased to 6800 AU/ml after optimization by Orthogonal Array design. Ammonium sulphate precipitation gives good yield of nisin with 60 to 80% saturation with 2.52 fold purity. The overall purification by hydrophobic interaction and gel filtration chromatography was 10.87 fold with 50.84% yield and 8.8 fold with 49.65% yield as compared to crude broth respectively.


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