Effect of pH, Temperature and Medium Composition on Xylanase Production by Bacillus sp. AQ-1 and Partial Characterization of the Crude Enzyme

A Bacillus strain with xylanase activity has been isolated. Maximum xylanase production was obtained when the strain was cultured in media supplemented with birchwood xylan or rice straw; production was repressed by glucose and xylose. The optimal temperature and pH for xylanase activity were 45–50 °C and 5.5–7.5, respectively. Crude xylanase was highly stable at a wide range of pH values, retaining 100% of the activity after 24 h of incubation at 37 °C in buffer at pH 10.0. Analysis by polyacrylamide gel electrophoresis and zymogram techniques showed four xylanase activity bands with apparent molecular masses of 32, 48, 61, and 66 kDa. The most active of them (molecular mass 32 kDa) apparently corresponded to a xylanase with an isoelectric point (pI) of 9.3 in isoelectrofocusing gels developed as zymograms. Four other bands with xylanase activity were detected at pIs of 7.7, 5.6, 5.0, and 4.5. Analysis for carboxymethylcellulase activity revealed that only the band of 48 kDa and the band with a pI of 7.7 showed hydrolytic activity against the cellulosic substrate.Key words: Bacillus sp., xylanase, isolation.

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PRODUCTION AND PARTIAL CHARACTERIZATION OF A MILK-CLOTTING PROTEINASE PRODUCED BY BACILLUS SUBTILIS SMDFS-2B MN715837 IN SUBMERGED CULTURES

Bacterial Empire ◽

10.36547/be.257 ◽

2021 ◽

Vol 4 (2) ◽

pp. e257

Author(s):

Jermen Mamo ◽

Martin Kangwa ◽

Hector-Marcelo Fernandez-Lahore ◽

Fassil Assefa

Keyword(s):

Bacillus Subtilis ◽

Crude Enzyme ◽

Partial Characterization ◽

Effect Of Temperature ◽

Submerged Cultures ◽

Milk Clotting ◽

Milk Clotting Protease ◽

Pepstatin A ◽

Milk Clotting Activity

This study focused on the production and partial characterization of a milk-clotting protease produced by Bacillus subtilis SMDFS 2B in submerged cultures, under partially optimized conditions. The crude enzyme was recovered in the culture supernatant and concentrate was produced after cell removal and subsequent dialysis. Inhibition studies were conducted employing four distinct protease inhibitors: Pepstatin-A, Phenylmethane-sulphonyl-fluoride (PMSF), Ethylenediaminetetraacetic acid (EDTA), and iodoacetamide (IA). The effect of temperature, pH, metal ions and substrate concentration on milk-clotting activity were also evaluated. The thermal stability of the enzyme was determined by incubating the crude enzyme at a temperature value ranging from 35 oC to 60 oC. Similarly, pH stability was determined at pH values ranging between 4.5 and 8.0. The highest milk-clotting activity was observed at a temperature of 55 oC and pH 5.5. The crude enzyme preparation remained stable on incubation at 35 oC and 40 oC for 15 min and at pH 5.5. The enzyme also showed the lowest residual milk-clotting activity in the presence of EDTA (7.94%) and Pepstatin-A (26.71%). The addition of Mg2+ and Mn2+ significantly increased milk-clotting activity. The enzyme also showed an elevation in its apparent milk-clotting activity upon increasing the substrate (skim-milk) concentration. Thus, the milk-clotting protease produced by B. subtilis SMDFS 2B by submerged fermentation revealed some interesting milk-clotting characteristics. This may open the way for applications in the food and dairy industries.

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Statistical Approach for the Production and Partial Characterization of Alkaline Stable Protease from a Newly Isolated Bacillus sp. IND6 for Silver Recovery

Research Journal of Microbiology ◽

10.3923/jm.2015.83.99 ◽

2015 ◽

Vol 10 (3) ◽

pp. 83-99

Author(s):

Ponnuswamy Vijayaragh ◽

M. Kalaiyaras ◽

Samuel Gnana Prakash Vi

Keyword(s):

Statistical Approach ◽

Partial Characterization ◽

Bacillus Sp ◽

Silver Recovery

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Purification and partial characterization of an exo-β-glucanase from the yeast Kluyveromyces aestuarii

Canadian Journal of Biochemistry ◽

10.1139/o77-149 ◽

1977 ◽

Vol 55 (9) ◽

pp. 1001-1006 ◽

Cited By ~ 17

Author(s):

Marc-André Lachance ◽

Tomas G. Villa ◽

Herman J. Phaff

Keyword(s):

Molecular Weight ◽

Ion Exchange ◽

Polypeptide Chain ◽

Activation Energies ◽

Partial Characterization ◽

Effect Of Ph ◽

Single Polypeptide Chain ◽

Exclusion Chromatography ◽

Single Polypeptide

The intracellular–periplasmic exo-1,3-β-glucanase (EC 3.2.1.58) has been extracted from the yeast Kluyveromyces aestuarii and purified to immunoelectrophoretic homogeneity by ion-exchange and gel-exclusion chromatography. The kinetic constants and activation energies for laminarin, p-nitrophenyl-β-D-glucoside, and pustulan have been determined, along with the effect of pH. Evidence is presented indicating that the enzyme is composed of a single polypeptide chain, about 24% carbohydrates, and its molecular weight was estimated to be 43 000.

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Agave syrup as a substrate for inulinase production by Kluyveromyces marxianus NRRL Y-7571

Acta Scientiarum Biological Sciences ◽

10.4025/actascibiolsci.v38i3.31489 ◽

2016 ◽

Vol 38 (3) ◽

pp. 283

Author(s):

Luana Paula de Azevedo de Oliveira ◽

Tiago Felipe Oliveira ◽

Jonas Contiero ◽

Márcia Luciana Cazetta

Keyword(s):

Thermal Stability ◽

Central Composite Design ◽

Yeast Extract ◽

Kluyveromyces Marxianus ◽

Crude Enzyme ◽

Partial Characterization ◽

Central Composite ◽

Optimal Ph

The factorial planning was used to plan and optimize inulinase production by the yeast Kluyveromyces marxianus NRRL Y-7571. The experiments were conducted using a Central Composite Design (CCD) 22, at different concentrations of agave syrup (3.6 to 6.4%) and yeast extract (2.2 to 3.0%). After 96 hours of fermentation, the best condition for the inulinase production was 5% agave syrup and 2.5% yeast extract, which yielded an average of 129.21 U mL-1 of inulinase. Partial characterization of the crude enzyme showed that the optimal pH and temperature were 4.0 and 60°C, respectively. The enzyme showed thermal stability at 55°C for 4 hours.

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