Modulating the production of xylanase by Bacillus pumilus BS131 through optimization using waste fiber sludge

In recent days, cheapest alternative carbon source for fermentation purpose is desirable to minimize production cost. Xylanases have become attractive enzymes as their potential in bio-bleaching of pulp and paper industry. The objective of the present study was to identify the potential ability on the xylanase production by locally isolated Bacillus pumilus BS131 by using waste fiber sludge and wheat bran media under submerged fermentation. Culture growth conditions were optimized to obtain significant amount of xylanase. Maximum xylanase production was recorded after 72 hours of incubation at 30 °C and 7 pH with 4.0% substrate concentration. In the nutshell, the production of xylanase using inexpensive waste fiber sludge and wheat-bran as an alternative in place of expensive xylan substrate was more cost effective and environment friendly.

Effect of Glucose on Endo-xylanase and β-xylosidase Production by Fungi Isolated in Indonesia

Xylanases are widely produced by fungi, and the production of polysaccharide-degrading enzymes, in general, are usually subjected to carbon catabolite repression. In this work, the ability of several Indonesian indigenous fungi to produce endo-xylanase and β-xylosidase and their responses to glucose as a repressor were determined. Ten fungi were grown in a liquid medium supplemented with glucose as the repressor (0, 1%, 3%, and 5%), and the endo-xylanase and β-xylosidase productions were assayed. Aspergillus aculeatus FIG1 and A. oryzae KKB4 produced 3.85 and 0.70 U/mL of endo-xylanase, respectively, compared with other strains (0.22 U/mL or less). Trichoderma asperellum PK1J2, T. virens MLT2J2, A. aculeatus FIG1, T. asperellum MLT5J1, A. oryzae KKB4, and T. asperellum MLT3J2 produced 0.021–0.065 U/mL of β-xylosidase, whereas the other strains produced 0.013 U/mL or less of β-xylosidase. Adding 1% glucose to the growth medium can partially repress endo-xylanase production in A. aculeatus FIG1, T. asperellum PK1J2, and T. virens MLT4J1 and completely repress other strains. By adding 1% glucose, strains FIG1, PK1J2, and MLT4J1 suffered almost complete repression of β-xylosidase production, although such strains exhibited partial repression of endo-xylanase production. β-Xylosidase produced by the other strains showed complete repression by adding 1% glucose, except for A. aculeatus FIG1, A. tamarii FNCC 6151, and T. asperellum MLT1J1, which showed partial repression. Therefore, adding 3% glucose to the growth medium can result in complete repression of endo-xylanase and β-xylosidase productions in all strains examined.

Artificial neural network-based modelling of optimized experimental study of xylanase production by Penicillium citrinum xym2

The industrial production of enzymes is generally optimized by one-factor-at-a-time (OFAT) approach. However, enzyme production by the method involves submerged or solid-state fermentation, which is laborious and time-consuming and it does not consider interactions among process variables. Artificial neural network (ANN) offers enormous potential for modelling biochemical processes and it allows rational prediction of process variables of enzyme production. In the present work, ANN has been used to predict the experimental values of xylanase production optimized by OFAT. This makes the reported ANN model to predict further optimal values for different input conditions. Both single hidden layered (6-3-1) and double hidden layered (6-12-12-1) were able to closely predict the actual values with MSE equals to 0.004566 and 0.002156, respectively. The study also uses multiple linear regression (MLR) analysis to calculate and compare the outcome with ANN predicted xylanase activity, and to establish a parametric sensitivity.

Statistical Optimization of Media Components for Xylanase Production by Aspergillus spp. Using Solid State Fermentation and its Application in Fruit Juice Clarification

Xylanases are enzymes that convert xylan into xylose, xylobiose, and xylotriose. The present study deals with the production and optimization of xylanase through Solid-State Fermentation (SSF) using different agricultural wastes by Aspergillus spp. The Plackett Burman (PB) design was used to screen significant media components affecting the xylanase production. The carbon sources screened were wheat bran, rice bran, sugarcane bagasse, corn cob, and orange peel. The nitrogen sources screened were yeast extract, peptone, (NH4)2SO4, Na2NO3, and urea. Also, nine different salts such as KCl, MgSO4, Na2HPO4, CaCl2, FeSO4, ZnSO4, Na2CO3, KH2PO4, and NaH2PO4 which act as trace elements were screened. The results showed that wheat bran, yeast extract, Na2NO3 and KCl are the significant factors that affect xylanase production. A 33 Full Factorial Design (FFD) was performed to optimize the significant media components (wheat bran, KCl, yeast extract) obtained from PB design using Response Surface Methodology (RSM). Statistical analysis of results showed that wheat bran, KCl, yeast extract, and interaction between wheat bran and yeast extract were found to be significant. The optimum concentration of wheat bran, KCl, yeast extract was 8 g/L, 0.1 g/L and 3 g/L. The Partial purification of xylanase was carried out using ammonium salt precipitation and dialysis. Gel filtration chromatography was performed to optimize the elution time, which was found to be 6 minutes. Application of xylanase in orange juice clarification was studied at 40 °C, 50 °C, and 60 °C. The optimum temperature obtained was 60 ºC.

Xylanase Production By Thermobacillus Xylanilyticus is Impaired By Population Diversification But Can Be Mitigated Based On the Management of Cheating Behavior

Background: The microbial production of hemicellulasic cocktails is still a challenge for the sector of biorefineries and agro-waste valorization. In this work, the production of hemicellulolytic enzymes by Thermobacillus xylanilyticus has been considered. This microorganism is of interest since it is able to produce an original set of thermostable hemicellulolytic enzymes, and notably a xylanase GH11, Tx-xyn11. However, cell-to-cell heterogeneities impairs the production capability of the whole microbial population.Results: Sequential cultivations of the strain on xylan as a carbon source has been considered in order to highlight and better understand this cell-to-cell heterogeneity. Successive cultivations pointed out a fast decrease of xylanase activity (loss of ~75%) after 23.5 generations. Accordingly, the expression of the Tx-xyn11 gene decreased drastically and followed the same trend as the xylanase activity. Flow cytometry analyses pointed out that two subpopulations, differing at the level of their light scattering properties, were potentially involved in this progressive loss of enzymatic activities. Interestingly, upon successive cultivations on xylan, the subpopulation exhibiting low forward scatter (FSC) signal. Additionally, the evolution of the ratio between the two subpopulations was correlated to the decrease in xylanase activity. Cell sorting and direct observation of the sorted subpopulations revealed that the low-FSC subpopulation was not sporulating, whereas the high-FSC subpopulation contained cells at the onset of the sporulation stage. Serial cultivations on glucose, followed by the addition of a xylan pulse led to a ~1.5-fold to ~15-fold improvement of xylanase, depending on the moment for pulse addition, , suggesting that alternating cultivation conditions could lead to an efficient population management strategy for the production of xylanase. Conclusions: Taken altogether, the data from this study point out that a cheating behaviour is responsible for the progressive reduction in xylanase activity during serial cultivations of T. xylanilyticus. Alternating cultivation condition between glucose and xylan could be used as an efficient strategy for promoting population stability and higher enzymatic productivity from this bacterium.

Xylanase Production via Aspergillus niger: Effect of Carbon Source and Composition

Xylanases are secondary metabolite product of variety organisms from various agriculture wastes. Xylanases’ demands in industrial level are increasing. Precisely, the necessity of enzyme such as xylanase to breaks down the xylan into reducing sugar for biofuel production is inevitable. However, the production of xylanases is insufficient to support the market demand. Hence, Aspergillus niger is used as the xylanase producer in this research. In this study, effect of carbon sources (corn cob-based xylan (CCX) and empty fruit bunches (EFB)) and concentrations of carbon source (2.5g/L to 4.0g/L) on xylanase production through One-factor-at-time (OFAT) experimental technique were investigated. The optimum fermentation period of 5 days determined by using mycelial dry cell mass and Bradford protein concentration growth profile is 5 days was set as the incubation period. Among these data, both carbon sources shown the maximum value at concentration of 3.5g/L. CCX showed a higher xylanase concentration (0.882±0.005μg/mL) compared to EFB (0.533 ± 0.006μg/mL). Hence, among these data analysis CCX has a better performance compared to EFB. Hence, among these data analysis CCX has a better performance compared to EFB.