{"content"=>"Effect of polysaccharide admixtures on expression of multiple polysaccharide-degrading enzymes instrain CMC-5.", "i"=>{"content"=>"Microbulbifer"}} (original) (raw)
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Biotechnology Reports, 2018
Microbulbifer strain CMC-5 produces agarase, alginate lyase, xylanase, carboxymethyl cellulase and carrageenase. The extracellular production of the above carbohydrases was investigated by growing Microbulbifer strain CMC-5 in a sea water based medium containing homologous/heterologous polysaccharides as a single substrate or as a combination of mixed assorted substrate. Presence of singular homologous polysaccharides in the growth medium induces respective carbohydrase at high levels. Any two polysaccharides in various combinations produced high level of homologous carbohydrase and low level of other heterologous carbohydrase. All five carbohydrases were consistently produced by strain CMC-5, when carboxymethyl cellulose was included as one of the substrate in dual substrate combination, or in presence of mix blends of all five polysaccharides. Interestingly, thalli of Gracilaria sp. that contain agar and cellulose predominantly in their cell wall induces only agarase expression in strain CMC-5.
Saccharification of macroalgal polysaccharides through prioritized cellulase producing bacteria
Heliyon, 2019
Marine macroalgal cell wall is predominantly comprised of cellulose (polysaccharide) with the complex chain of glycosidic linkages. Bioethanol production from macroalgae entails breaking this complex chain into simple glucose molecule, which has been the major challenge faced by the industries. Cellulases have been preferred for hydrolysis of cellulose due to the absence of inhibitors affecting the subsequent fermentation process. Cellulose degrading bacteria were isolated from wide-ranging sources from marine habitats to herbivore residues and gastrointestinal region. The investigation reveals that Vibrio parahaemolyticus bacteria has higher hydrolytic capacity with salt tolerance up to 14% and 3.5% salinity is optimum for growth. Higher hydrolytic activity of 2.45 was recorded on carboxymethyl cellulose medium at 48 h and hydrolytic activity of 2.46 on Ulva intestinalis hydrolysate, 3.06 on Ulva lactuca hydrolysate at 72 h of incubation. Total activity of enzyme of 2.11 U/ml and specific activity of 6.05 U/mg were recorded at 24 h. Enzyme hydrolysis of macroalgal biomass; U. intestinalis and U. lactuca produced
Carbohydrase Systems of Saccharophagus degradans Degrading Marine Complex Polysaccharides
Marine Drugs, 2011
Saccharophagus degradans 2-40 is a γ-subgroup proteobacterium capable of using many of the complex polysaccharides found in the marine environment for growth. To utilize these complex polysaccharides, this bacterium produces a plethora of carbohydrases dedicated to the processing of a carbohydrate class. Aiding in the identification of the contributing genes and enzymes is the known genome sequence for this bacterium. This review catalogs the genes and enzymes of the S. degradans genome that are likely to function in the systems for the utilization of agar, alginate, αand β-glucans, chitin, mannans, pectins, and xylans and discusses the cell biology and genetics of each system as it functions to transfer carbon back to the bacterium.
Enzymatic hydrolysis of delignified bagasse polysaccharides
Carbohydrate Polymers, 2005
Sugarcane bagasse, consisting of cellulose, xylan, and lignin, was chemically treated to generate bagasse samples with continuously decreasing content of lignin. These bagasse samples were hydrolyzed by cellulase and xylanase enzymes, produced earlier by Penicillium janthinellum NCIM 1171 in the same bagasse polysaccharides production medium. The hydrolysis was carried out by using different concentrations of the enzymes at two different temperatures, 30 and 50 8C, taking hydrolysis of Avicel as control. It was found that while the maximum hydrolysis for Avicel was 70% that of some of the bagasse polysaccharides was as high as 95%. The products of hydrolysis were glucose, xylose, and arabinose, as confirmed by high pressure ion chromatography (HPIC). It is interesting to note that arabinose, which constitutes about 10% of the weight of bagasse xylan, could also be released easily by the enzymes. Also, the initial rates of hydrolysis was found to be much higher for the bagasse polysaccharides, and in some cases about 90% of the hydrolysis occurred within 20 h. Amongst all bagasse samples, the sample with (Kappa no. 1.2, lignin content 0.18%) gave the highest degree of hydrolysis at 50 8C. Even the bagasse polysaccharide with Kappa no. 16.8 (lignin content 2.5%) underwent greater extent of hydrolysis than Avicel. Apparently, the delignified bagasse medium appears to be a facile medium for the combined hydrolytic action of the cellulase and xylanase enzymes. Considering that sugarcane bagasse is a waste biomass material available in abundance annually, this methodology can be used to value-add to this biomass to produce sugars, which can be fermented to produce biofuels like ethanol. q
Biotechnology Letters, 1986
Since accumulation of agricultural wastes represents a huge problem, it was important to explore the available methods to help eliminate agricultural wastes safely, and simultaneously produce functional enzyme like cellulase. Six native Egyptian fungal strains were isolated, morphologically identified and screened for cellulose biodegradation potential, which was determined as endoglucanase or as carboximethylcellulase (CMCase). The most promising isolate (Aspergillus terreus) was selected for molecular characterizations based on sequencing of internal transcribed spacer (ITS). Further optimization experiments were accomplished on the selected strain. The strain with cellulolytic activity, 2.26 IU mL-1 was identified using ITS nucleotides (genes) sequences and the result confirmed that the strain is 99.8% homology with A. terreus. Then, it was submitted to GeneBank and given an accession number. Further optimization experiments revealed that 35ºC is the optimum temperature for cellulase production and raised the enzyme activity (EA) up to 3.19 IU mL-1. Out of two organic nitrogen sources; peptone at concentration 6 gL-1 was found to be the optimum nitrogen source for cellulase production with the highest activity 4 IU mL-1. Whereas, the different four carbon sources: microcellulose, corn stalks, wheat straw and rice straw showed significant differences in EA with values 11.07, 9.68, 7.87 and 3.71 IU mL-1 , respectively at pH 3. The maximum EA was recorded to be within 5-7 days of incubation, dependent on type of carbon sources. The optimization of different incubation conditions raised cellulolytic activity from 2.26 IU mL-1 up to 11.18 IU mL-1 .
Carbohydrates from Biomass: Sources and Transformation by Microbial Enzymes
Carbohydrates - Comprehensive Studies on Glycobiology and Glycotechnology, 2012
Carbohydrates-Comprehensive Studies on Glycobiology and Glycotechnology 442 is involved in the removal of O-(ester) and N-Acetyl moieties from carbohydrates. The polysaccharide lyase catalyzes the β-elimination reaction on uronic acid glucosides while the glycosyltransferase acts forming glycosidic bonds using activated sugar donors. Figure 1. Classes of carbohydrate-active enzymes. Microorganisms Enzymes Cellulase* Xylanase Invertase Inulinase Amylase Bacteria Acremonium cellulolyticus ◆ ◆ Arthrobacter sp.
Applied Biochemistry and Biotechnology
We evaluated various agricultural lignocellulosic biomass and variety of fungi to produce cellulolytic enzymes cocktail to yield high amount of reducing sugars. Solid-state fermentation was performed using water hyacinth, paddy straw, corn straw, soybean husk/tops, wheat straw, and sugarcane bagasse using fungi like Nocardiopsis sp. KNU, Trichoderma reesei, Trichoderma viride, Aspergillus flavus, and Phanerochaete chrysosporium alone and in combination to produce cellulolytic enzymes. Water hyacinth produced (U ml −1) endoglucanase (51.13) and filter paperase (0.55), and corn straw produced (U ml −1) β-glucosidase (4.65), xylanase (113.32), and glucoamylase (41.27) after 7-day incubation using Nocardiopsis sp. KNU. Production of cellulolytic enzymes was altered due to addition of various nitrogen sources, metal ions, vitamins, and amino acids. The maximum cellulolytic enzymes were produced by P. chrysosporium (endoglucanase; 166.32 U ml −1 and exoglucanase; 12.20 U ml −1), and by T. viride (filter paperase; 1.57 U ml −1). Among all, co-culture of T. reesei, T. viride, A. flavus, and P. chrysosporium showed highest β-glucosidase (17.05 U ml −1). The highest xylanase (1129 U ml −1) was observed in T. viride + P. chrysosporium co-culture. This study revealed the dependency on substrate and microorganism to produce good quality enzyme cocktail to obtain maximum reducing sugars.
Waste and Biomass …, 2012
Bacillus stearothermophilus secretes ,-mannanase and oa-galactosidase enzymatic activities capable of hydrolyzing galactomannan substrates. Expression of the hemicellulase activities in the presence of locust bean gum was sequential, with mannanase activity preceding expression of aL-galactosidase activity. The hemicellulase activities were purified to homogeneity by a combination of ammonium sulfate fractionation, gel filtration, hydrophobic interaction chromatography, and ion-exchange and chromatofocusing techniques. The purified P-D-mannanase is a dimeric enzyme (162 kilodaltons) composed of subunits having identical molecular weight (73,000). Maximal activity did not vary between pH 5.5 and 7.5. The P-D-mannanase activity exhibited thermostabiity, retaining nearly full activity after incubation for 24 h at 70°C and pH 6.5. The enzyme displayed high specificity for galactomannan substrates, with no secondary xylanase or cellulase activity detected. Hydrolysis of locust bean gum yielded short oligosaccharides compatible with an endo mode of substrate depolymerization. Initial rate velocities of the mannanase activity displayed substrate inhibition and * Corresponding author. nents . This article describes the purification and characterization of two thermostable hemicellulases from Bacillus stearothermophilus. In the presence of galactomannan, B. stearothermophilus produces both a P-D-mannanase and an a-D-galactosidase activity. Both enzymes retain activity for more than 24 h at temperatures in excess of 60°C.