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

2021 ◽  
Vol 2080 (1) ◽  
pp. 012001
Author(s):  
C.Z. Tan ◽  
W. T. Chang ◽  
M. Tarrsini ◽  
Y. P. Teoh ◽  
K. C. Lee ◽  
...  

Abstract 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.

Author(s):  
Eka Metreveli ◽  
Tamar Khardziani ◽  
Vladimir Elisashvili

In the present study, the polysaccharide-hydrolyzing secretomes of Irpex lacteus BCC104, Pycnoporus coccineus BCC310, and Schizophyllum commune BCC632 were analyzed in submerged fermentation conditions to elucidate the effect of chemically and structurally different carbon sources on the expression of cellulases and xylanase. Among polymeric substrates, crystalline cellulose appeared to be the best carbon source providing the highest endoglucanase, total cellulase, and xylanase activities. Mandarin pomace as a growth substrate for S. commune allowed to achieve comparatively high volumetric activities of all target enzymes while wheat straw induced a significant secretion of cellulase and xylanase activities of I. lacteus and P. coccineus. A synergistic effect on the secretion of cellulases and xylanases by the tested fungi was observed when crystalline cellulose was combined with mandarin pomace. In I. lacteus the cellulase and xylanase production is inducible in the presence of cellulose-rich substrates but is suppressed in the presence of an excess of easily metabolizable carbon source. These enzymes are expressed in a coordinated manner under all conditions studied. It was shown that the substitution of glucose in the inoculum medium with Avicel provides accelerated enzyme production by I. lacteus and higher cellulase and xylanase activities of the fungus. These results add new knowledge to the physiology of basidiomycetes to improve cellulase production.


2021 ◽  
Author(s):  
Chen Zhang ◽  
Gangqin Shu ◽  
Hui Wang ◽  
Daojie Li ◽  
Yuan Xü ◽  
...  

Abstract Background The gossypol, as an antinutritional factor or natural plant toxin, has antifertility effects on humans and animals, exists in cottonseed oil and meal, and is a typical food or feed contaminant. It is the classic screening method to using acetate gossypol as the sole carbon sources to prepare selective medium and screening gossypol-degrading microorganisms. By the classic screening strategy, many researchers have discovered that some microorganisms, and Aspergillus niger is the most reported microorganism. A strain of A. niger which can grow in an agar solid medium with gossypol as the sole carbon source is isolated from cattle rumen liquid was obtained by classic screening strategy. The effectiveness of the classic screening strategy was verified, by duplicating and verifying the degradation of gossypol by the A. niger. Results the A. niger can reduce the free gossypol (FG) content through biosorption but has no effect on the total gossypol (TG) content. And it can secrete agarase, utilise agar as carbon source. Conclusions The A. niger can secrete agarase, but cannot effectively degrade gossypol, In this case, it will mislead researchers and lead them to make wrong judgments. The usual methods of previous screening strategies are not rigorous enough, the classic screening method has defect in screening toxin-degrading strain, so agar control group should be added.


Biomolecules ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1341
Author(s):  
Eka Metreveli ◽  
Tamar Khardziani ◽  
Vladimir Elisashvili

In the present study, the polysaccharide-hydrolyzing secretomes of Irpex lacteus (Fr.) Fr. (1828) BCC104, Pycnoporus coccineus (Fr.) Bondartsev and Singer (1941) BCC310, and Schizophyllum commune Fr. (1815) BCC632 were analyzed in submerged fermentation conditions to elucidate the effect of chemically and structurally different carbon sources on the expression of cellulases and xylanase. Among polymeric substrates, crystalline cellulose appeared to be the best carbon source providing the highest endoglucanase, total cellulase, and xylanase activities. Mandarin pomace as a growth substrate for S. commune allowed to achieve comparatively high volumetric activities of all target enzymes while wheat straw induced a significant secretion of cellulase and xylanase activities of I. lacteus and P. coccineus. An additive effect on the secretion of cellulases and xylanases by the tested fungi was observed when crystalline cellulose was combined with mandarin pomace. In I. lacteus the cellulase and xylanase production is inducible in the presence of cellulose-rich substrates but is suppressed in the presence of an excess of easily metabolizable carbon source. These enzymes are expressed in a coordinated manner under all conditions studied. It was shown that the substitution of glucose in the inoculum medium with Avicel provides accelerated enzyme production by I. lacteus and higher cellulase and xylanase activities of the fungus. These results add new knowledge to the physiology of basidiomycetes to improve cellulase production.


2011 ◽  
Vol 233-235 ◽  
pp. 1442-1446
Author(s):  
Shi Chang Li ◽  
Dong Dong Wang ◽  
Zhao Yang Zhu ◽  
Hong Xia Liu

With ion implantation, a high xylanase-producing strainAspergillus nigerBU99 was selected. Different late acting carbon sources (wheat bran, wheat straw, corncob and bagasse) had an effect on enzymatic production. Additionally, it was found that fast acting carbon sources (lactose, galactose, sucrose, glucose and maltose) put into the media affected on xylanase production too. Severe catabolic repression was observed in the media with lactose, but other sugars (galactose, sucrose, glucose and maltose) could increase the production of xylanase compared with the control. The production of xylanase was improved too when corncob flour was hydrolyzed by α-amylase, cellulase or/and glucoamylase. Additionally, it was found that the production of xylanase would be almost higher at 60h when the media contained glucose or were hydrolyzed by enzymes.


2009 ◽  
Vol 76 (3) ◽  
pp. 359-364
Author(s):  
S.M. Tauk-Tornisiel ◽  
M.C. Vallejo ◽  
J.C. Govone

ABSTRACT Six Penicillium strains were isolated from soil at a depth of 0 15 cm in the Juréia-Itatins Ecology Station (JIES), in the São Paulo State, Brazil. They were evaluated for xylanase production under different temperatures and carbon sources. The best carbon source and temperature were first determined in an automated Bioscreen C system, verifying the growth of microorganisms. Liquid media containing tap water with 2% carbohydrate and/or 1% nitrogen sources were used. Afterwards, Penicillium citrinum, P. fellutanum, P. rugulosum and P. decumbens were cultivated in 250 mL Erlenmeyer flasks with 50 mL of culture medium containing tap water sole 2% carbon source (fructose, glucose, mannitol, sucrose or xylose) and 1% yeast extract as a nitrogen source at pH 5.0 and 28o C, with agitation of 150 rpm for 72 hours. These same strains, except P. decumbens, and P. purpurogenum were cultivated in solid substrate with wheat bran under the same environmental conditions to study the potential of xylanase activity. Maximum xylanase activity was observed in cultures with wheat bran, without the addition of any other carbon source, using inocula containing 1 x 107 spores.mL-1 (28o C, pH 5.0, 72 h). It can be concluded that P. fellutanum and P. citrinumare a good xylanase producers under the conditions of 28º C. The results of xylanase activity were 54% less at 28º C in liquid cultures media cultures than in solid substrate.


1983 ◽  
Vol 29 (9) ◽  
pp. 1213-1217 ◽  
Author(s):  
Amaresh Das ◽  
Ajit K. Mishra

Optimum growth and acetylene reduction in Azospirillum brasilense which are comparable to those observed with organic acids, e.g., malate, succinate, pyruvate, and lactate, were obtained using fructose as the carbon source. Best yields of cell mass had been obtained with fructose and malate, while the yields were poor with other carbon sources tried. Acetylene reduction occurred at optimum levels only between pH 7.0 and 7.5. Efficiency of N2 fixation and the efficiency of the utilization of combined nitrogen were high with fructose but low with malate. Fructose as well as malate, succinate, pyruvate, and lactate were actively oxidized both in cell suspensions and cell-free extracts, while glucose, galactose, sucrose, and citrate were oxidized only in cell-free extracts.


Author(s):  
Kavitha K ◽  
Asha S ◽  
Hima Bindu T.V.L ◽  
Vidyavathi M

The safety and efficacy of a drug is based on its metabolism or metabolite formed. The metabolism of drugs can be studied by different in vitro models, among which microbial model became popular. In the present study, eight microbes were screened for their ability to metabolize phenobarbital in a manner comparable to humans with a model to develop alternative systems to study human drug metabolism. Among the different microbes screened, a filamentous fungi Rhizopus stolonifer metabolized phenobarbital to its metabolite which is used for further pharmacological and toxicological studies. The transformation of phenobarbital was identified by high- performance liquid chromatography (HPLC). Interestingly, Rhizopus stolonifer sample showed an extra metabolite peak at 3.11min. compared to its controls. The influence of different carbon sources in media used for growth of fungus, on metabolite production was studied, to find its effect in production of metabolite as the carbon source may influence the growth of the cell.


Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1306
Author(s):  
Pedro Almeida ◽  
Laurent Dewasme ◽  
Alain Vande Wouwer

The recirculating aquaculture system (RAS) is a land-based water treatment technology, which allows for farming aquatic organisms, such as fish, by reusing the water in the production (often less than 5%). This technology is based on the use of filters, either mechanical or biological, and can, in principle, be used for any species grown in aquaculture. Due to the low recirculation rate, ammonia accumulates in the system and must be converted into nitrate using nitrification reactors. Although less toxic for fish, nitrate can also be further reduced into nitrogen gas by the use of denitrification biofilters which may create several issues, such as incomplete denitrification, resulting in toxic substances, such as nitrite and nitric oxide, or a waste of carbon source in excess. Control of the added quantity of carbon source in the denitrification biofilter is then mandatory to keep nitrate/nitrite concentrations under toxic levels for fish and in accordance with local effluent regulations, and to reduce costs related to wasted organic carbon sources. This study therefore investigates the application of different control methodologies to a denitrification reactor in a RAS. To this end, a numerical simulator is built to predict the RAS behavior and to allow for the comparison of different control approaches, in the presence of changes in the operating conditions, such as fish density and biofilter removal efficiency. First, a classical proportional-integral-derivative (PID) controller was designed, based on an SIMC tuning method depending on the amount of ammonia excreted by fish. Then, linearizing and cascade controllers were considered as possible alternatives.


Sign in / Sign up

Export Citation Format

Share Document