Optimization of alkali-thermostable and cellulase-free eylanase production from Bacillus Sp (original) (raw)
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Production of alkali tolerant cellulase free xylanase in high levels by Bacillus pumilus SV-205
International Journal of Biological Macromolecules, 2012
The fermentation conditions were optimized for hyper production of xylanase from Bacillus pumilus SV-205. The bacterium secretes high levels (7382.7 ± 1200 IU/mL) of cellulase-free xylanase using wheat bran led to 21.63 fold increase in activity. A combination of yeast extract and peptone stimulated highest xylanase production (2448.0 IU/mL) as compared to other combinations. The most important characteristic of the enzyme is its high pH stability (100%) over a broad pH range of 6-11 for 24 h. Thermostability studies revealed that enzyme retained 65% activity after an incubation of 2 h at 60 • C. The level of production is remarkable as compared to earlier reports.
Production and characterization of xylanases of a Bacillus strain isolated from soil
World Journal of Microbiology & Biotechnology, 2005
Xylanase production was performed by growing a Bacillus isolate on agricultural by-products, wheat straw, wheat bran, corn cobs and cotton bagasse. A maximum xylanase activity of 180 U/ml was obtained together with a cellulase activity of 0.03 U/ml on 4 (w/v) corn cobs. Electrophoretic analysis showed the presence of three endo-β-1, 4-xylanases having molecular weights of about 22, 23 and 40 kDa. Xylanolytic activity was stable up to 50 °C in the pH range of 4.5–10 and the highest activity was observed at 70 °C and pH 6.5.
2015
The present study was aimed at isolation and characterization of a new xylan degrading strain of Bacillus from soil for production of xylanase. Different soil samples from Punjab state were used to isolate xylan degrading strains. We isolated a highly active xylanolytic strain and performed genetic characterisation using 16S r-RNA analysis. DNA sequencing and phylogenetic analysis using MEGA4 software showed our strain to be a novel strain (accession number JQ916900) which was named Bacillus lpuarvinder st. lpu002. Biochemical characterization of the enzyme showed optimum activity at 60 o C and pH 8.6. The enzyme was stable at 70 o C for up to 6 hours. The xylanase activity seems to be alleviated by divalent Ca 2+ , Mn 2+ and Mg 2+ ions. The best enzyme activity was obtained when the cells were grown in Bushnell-Haas medium supplemented with 0.5% xylan and beef extract. The process optimization was done using solid state fermentation (SSF) using wheat straw as substrate. The enzyme ...
World Journal of Microbiology & Biotechnology, 2010
A xylanase producer, Bacillus pumilus SB-M13, was isolated from soil and identified using various tests based on carbohydrate fermentation preferences and fatty acid analysis. Xylanase gene, isolated using PCR amplification, was partially sequenced and it showed 89–94% sequence similarity to the xylanase genes of other B. pumilus strains. Xylanase with very low level of cellulase was produced on agricultural byproducts. The enzyme has been purified 186-fold by hydrophobic interaction chromatography and biochemically characterized. It has a molecular weight of 24.8 kDa and pI of 9.2. Xylanolytic activity is stable at alkaline pH and highest activity is observed at 60 °C and pH 7.5. Enzyme K m and k cat values were determined as 1.9 mg/mL and 42,600 U/mg, respectively. In aqueous-two-phase system, xylanase always partitioned to the top phase. Basic pH, low PEG concentration, salt addition, and presence of microbial cells enhanced xylanase partitioning. A maximum sevenfold purification, 10-fold concentration and 100% xylanase recovery were obtained, separately, by adjusting system parameters. A fourfold concentrated xylanase was obtained with 70% enzyme recovery only in one step ATPS process without cell harvesting.
MIcrobiology Indonesia, 2009
Bacillus sp. AQ-1 was isolated from household aquarium sediment. The isolate produced extracellular xylanolytic enzymes on xylan containing agar medium. Based on morphological, and physiological analysis, the isolate was identified as Bacillus sp. AQ1. The effect of temperature and pH on isolate growth and xylanase production were observed. The best condition observed for the enzyme production in Luria Broth supplemented with 0.5% oat spelt xylan medium was at 40 °C pH 7. The maximum enzyme production was 0.23 U mL -1 after 20 h of fermentation. Two different medium compositions (A and B) were examined for xylanase production. The maximum growth of the isolate and the xylanase production was better in A medium. Replacing oat spelt xylan in medium A with fruitless oil palm bunch in the medium caused the growth slightly slower than that of in the original formula. However, the xylanase production was 3 times higher in fruitless oil palm bunch medium. Optimum activity of the crude enzyme was observed at 60 °C and pH 7. Each ml of the crude enzyme contained 55.21 U xylanase, 8.12 U amylase and 0.50 U carboxymethylcellulase.
Xylanase production by a new alkali-tolerant isolate of Bacillus
Biotechnology Letters, 1998
The xylanolytic system of an alkali-tolerant Bacillus sp. consists of several xylanases ranging from 22 to 120 kDa and pI values from 7.0 to 9.0. Crude xylanase retained 72% of initial activity after 5 h at pH 9.0 and 45°C. Xylanase production was induced by xylose and xylan and was maximum at 42°C and pH 7.8. Crude xylanase released xylotriose and xylotetraose as main products of xylan hydrolysis. Xylose was not detected. © Rapid Science Ltd. 1998
2017
Bacillus flexus, an alkalophilic bacterial strain, was isolated from tea rhizosphere of Golaghat District of Assam by culture enrichment method. During the study the strain was found to produce cellulose-free xylanase of molecular weight 25 kDa which was determined using SDS-PAGE analysis. The enzyme had high hydrolytic activity against birchwood xylan, oat spelt xylan and beech wood xylan; and exhibited relatively low activity against cellobiose, starch, carboxy methyl cellulose and avicel. Optimum PH and temperature in which enzyme was found active at pH 8.0 ± 0.2 and at 70°C ± 2°C respectively. The Km and Vmax values were found to be 0.9 mg/ml and 3633 U/ml, respectively. Hydrolytic activity of the enzyme with metal ions were also determined and interestingly it was found that Co, Zn, Mg, Fe and Ca elevated the enzyme activity while Hg and metal chelator EDTA reduced its activity.
Applied Ecology and Environmental Sciences, 2021
Xylanases are extensively applied in paper and pulp industries as well as during preparation of baked products to improve their quality. Additionally, it is also used in coffee, oil and starch industries in order to increase their nutritional values. Soil samples were collected near saw mills in various localities of Bangalore urban to isolate organisms for the production of xylanase using solid state fermentation. Six organisms were isolated using selective media based on their morphological characters. Among them one organism showed maximum production of xylanase enzyme identified as Bacillus sp based on their biochemical test and 16s RNA sequencing. Solid substrate fermentation was carried out using various agro wastes such as sugar cane bagasse, saw dust, paddy husk, wheat straw and orange peel powder. Sugarcane bagasse showed maximum production of enzyme compared to other substrates with different physical parameters such as pH 8, temperature at 35 °C after 72 hrs of incubation. Trace element such as Mg ++ enhances the production of enzyme more than 22 % compared with other metal ions like Ca ++ , Mn ++ and Fe ++. After production, enzyme purified by using three step methods such ammonium sulphate precipitation, dialysis, ion exchange and gel filtration. Fold purification was increased up to 12 fold, yield 36 % and molecular weight of enzyme was 62 KDa determined using SDS PAGE.
A novel Bacillus pumilus strain for alkaline xylanase production at and above 40°C
Ceylon Journal of Science (Biological Sciences), 2010
The objective of the study was to select a bacterial strain which can produce xylanase at alkaline pH and temperatures above 40 o C and to characterize the strain. Among the 45 bacterial strains, isolated from different sources, five strains, which were expected to produce alkaline xylanase, above 40 o C, isolated from open media containing xylan as carbon source (GS 7 , GS 15 , GS 17 , GS 20 & GS*), were selected for the study. Xylanase production by the strains GS 17 and GS*, was less affected by pH changes between pH 8.0 and 9.5 than the strains GS 7 , GS 15 and GS 20 . Strains GS 17 and GS* produced xylanase at pH 10.0 while the others did not produce. Therefore strains GS 17 and GS* were selected. Xylanase production, by GS 17 at 39 hours was 1.2, 1.3, 1.2 and 3.2 times higher at 40, 45, 50 and 55 o C than by GS*. At 60 o C, GS 17 produced 4.25 UmL -1 (30h) of xylanase activity while GS* did not. As GS 17 produced xylanase at and above pH 9.0 and 40 to 60 o C, it was selected. The xylanase of GS 17 showed activity in the temperature range from 40 to 95 o C showing highest activity at 60 o C. Strain GS 17 is non-branching, gram-positive, sporulating, motile, aerobic, catalase positive, β hemolytic, oxidase positive long rods. Hence, it belongs to the genus Bacillus. Slightly oval shaped terminal and subterminal endospores were observed in 24h old cultures. When the culture became old, formation of spores was very much reduced. Further, based on the shape and arrangement of spores, ability to produce acid from glucose, xylose & mannose; growth temperature; inability to hydrolyze starch and tyrosine; inability to produce urease and indole; inability to reduce nitrate; ability to grow in NaCl and ability to grow in different carbohydrate sources, the strain, GS 17 was identified as Bacillus pumilus. Thus, Bacillus pumilus which was locally isolated can grow and produce xylanase at and above 40 o C and pH 9.0.