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Squid pen chitin chitooligomers as food colorants absorbers.

Liang TW, Huang CT, Dzung NA, Wang SL - Mar Drugs (2015)

Bottom Line: In the culture medium, the fermented SPP was recovered, and it displayed a better adsorption rate (up to 96%) for the disperse dyes than the water-soluble food colorants, Allura Red AC (R40) and Tartrazne (Y4).Fourier transform-infrared spectroscopic (FT-IR) analysis proved that the adsorption of the dyes onto fermented SPP was a physical adsorption.Results also showed that fermented SPP was a favorable adsorber and could be employed as low-cost alternative for dye removal in wastewater treatment.

View Article: PubMed Central - PubMed

Affiliation: Life Science Development Center, Tamkang University, No. 151, Yingchuan Rd., Tamsui, New Taipei City 25137, Taiwan. QQ1987pp@hotmail.com.

ABSTRACT
One of the most promising applications of chitosanase is the conversion of chitinous biowaste into bioactive chitooligomers (COS). TKU033 chitosanase was induced from squid pen powder (SPP)-containing Bacillus cereus TKU033 medium and purified by ammonium sulfate precipitation and column chromatography. The enzyme was relatively more thermostable in the presence of the substrate and had an activity of 93% at 50 °C in a pH 5 buffer solution for 60 min. Furthermore, the enzyme used for the COS preparation was also studied. The enzyme products revealed various mixtures of COS that with different degrees of polymerization (DP), ranging from three to nine. In the culture medium, the fermented SPP was recovered, and it displayed a better adsorption rate (up to 96%) for the disperse dyes than the water-soluble food colorants, Allura Red AC (R40) and Tartrazne (Y4). Fourier transform-infrared spectroscopic (FT-IR) analysis proved that the adsorption of the dyes onto fermented SPP was a physical adsorption. Results also showed that fermented SPP was a favorable adsorber and could be employed as low-cost alternative for dye removal in wastewater treatment.

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Related in: MedlinePlus

Matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) of the chitooligomers (COS) mixtures obtained during the water-soluble chitosan hydrolysis for 48 h with the TKU033 crude enzyme. The proportion of low molecular weight oligomers was reduced by precipitation in the 90% methanol soluble/90% acetone insoluble fraction. The identified peaks are labeled with DP, in which DP indicates the degree of polymerisation.
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marinedrugs-13-00681-f004: Matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) of the chitooligomers (COS) mixtures obtained during the water-soluble chitosan hydrolysis for 48 h with the TKU033 crude enzyme. The proportion of low molecular weight oligomers was reduced by precipitation in the 90% methanol soluble/90% acetone insoluble fraction. The identified peaks are labeled with DP, in which DP indicates the degree of polymerisation.

Mentions: To determine the applicability of the TKU033 chitosanase for the bioconversion of chitosan into oligosaccharides, the crude enzyme from B. cereus TKU033 was used in the experiments. The COS was produced from the water-soluble chitosan with the TKU033 chitosanase. The course of chitosan sample degradation was conveniently studied by measurement of the total and reducing sugars. The results revealed the total sugar and the reducing sugar of the sample as a function of reaction time. The chitosan sample total and reducing sugar values produced a similar pattern (data not shown). The total and reducing sugars increased, and the chitosan sample recovery decreased dramatically in the early reaction stage, which can be attributed to an endo-type degradation process. The TKU033 chitosanase was added into the reaction solution after 24 h and continued hydrolyzing until 48 h, but it did not improve the increase in total and reducing sugar levels (data not shown). Selective precipitation in 90% methanol and acetone solutions was performed to obtain low DP oligomers, as described earlier [13]. A product analysis of the 90% acetone solution precipitation by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF) revealed that various COS had DP values up to nine. The higher DP chitooligomers were precipitated as a light yellow powder in the methanol solution. The MALDI-TOF MS of the low DP oligomer fraction revealed pronounced differences among the crude enzyme-generated chitooligomers, as demonstrated for chitosan depolymerization in Figure 4. The hydrolysate ions present in the mass spectra were identified as sodium adducts [M + Na]+. Due to the signal interference of matrix (2,5-dihydroxybenzoic acid), DP < 2 oligomers could not be determined by this method. More information about the assigned structure of each signal at different hydrolysis times is given in Table 2. When the hydrolysis time was at 2 h, the hydrolysis products contained (GlcN)4; however, (GlcN)4 could not be observed during 4–48 h, indicating that the TKU033 chitosanase could cleave the GlcN-GlcN links of (GlcN)4 to (GlcN)2 or GlcN. The hydrolysates contained chitooligomers (GlcN-oligomers) and several partial N-acetylated forms (Table 2). The TKU033 chitosanase reaction product is a mixture of DP 3–9 hetero-chitooligomers (Table 2). These products were generated by hydrolysis of the water-soluble chitosan with the TKU033 chitosanase and are not a series of fully deacetylated GlcN oligomers. During hydrolysis, the O-glycosidic and the N-acetyl linkages between the residues can be hydrolyzed. These results indicate that the TKU031 chitosanase might hydrolyze chitosan in an endo-type fashion. From these results, chitosan hydrolysis by the TKU033 chitosanase, combined with a selective methanol precipitation, is a quick and simple method to obtain good chitooligosaccharide yields with DPs up to nine and low molecular weight oligomers.


Squid pen chitin chitooligomers as food colorants absorbers.

Liang TW, Huang CT, Dzung NA, Wang SL - Mar Drugs (2015)

Matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) of the chitooligomers (COS) mixtures obtained during the water-soluble chitosan hydrolysis for 48 h with the TKU033 crude enzyme. The proportion of low molecular weight oligomers was reduced by precipitation in the 90% methanol soluble/90% acetone insoluble fraction. The identified peaks are labeled with DP, in which DP indicates the degree of polymerisation.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4306958&req=5

marinedrugs-13-00681-f004: Matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) of the chitooligomers (COS) mixtures obtained during the water-soluble chitosan hydrolysis for 48 h with the TKU033 crude enzyme. The proportion of low molecular weight oligomers was reduced by precipitation in the 90% methanol soluble/90% acetone insoluble fraction. The identified peaks are labeled with DP, in which DP indicates the degree of polymerisation.
Mentions: To determine the applicability of the TKU033 chitosanase for the bioconversion of chitosan into oligosaccharides, the crude enzyme from B. cereus TKU033 was used in the experiments. The COS was produced from the water-soluble chitosan with the TKU033 chitosanase. The course of chitosan sample degradation was conveniently studied by measurement of the total and reducing sugars. The results revealed the total sugar and the reducing sugar of the sample as a function of reaction time. The chitosan sample total and reducing sugar values produced a similar pattern (data not shown). The total and reducing sugars increased, and the chitosan sample recovery decreased dramatically in the early reaction stage, which can be attributed to an endo-type degradation process. The TKU033 chitosanase was added into the reaction solution after 24 h and continued hydrolyzing until 48 h, but it did not improve the increase in total and reducing sugar levels (data not shown). Selective precipitation in 90% methanol and acetone solutions was performed to obtain low DP oligomers, as described earlier [13]. A product analysis of the 90% acetone solution precipitation by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF) revealed that various COS had DP values up to nine. The higher DP chitooligomers were precipitated as a light yellow powder in the methanol solution. The MALDI-TOF MS of the low DP oligomer fraction revealed pronounced differences among the crude enzyme-generated chitooligomers, as demonstrated for chitosan depolymerization in Figure 4. The hydrolysate ions present in the mass spectra were identified as sodium adducts [M + Na]+. Due to the signal interference of matrix (2,5-dihydroxybenzoic acid), DP < 2 oligomers could not be determined by this method. More information about the assigned structure of each signal at different hydrolysis times is given in Table 2. When the hydrolysis time was at 2 h, the hydrolysis products contained (GlcN)4; however, (GlcN)4 could not be observed during 4–48 h, indicating that the TKU033 chitosanase could cleave the GlcN-GlcN links of (GlcN)4 to (GlcN)2 or GlcN. The hydrolysates contained chitooligomers (GlcN-oligomers) and several partial N-acetylated forms (Table 2). The TKU033 chitosanase reaction product is a mixture of DP 3–9 hetero-chitooligomers (Table 2). These products were generated by hydrolysis of the water-soluble chitosan with the TKU033 chitosanase and are not a series of fully deacetylated GlcN oligomers. During hydrolysis, the O-glycosidic and the N-acetyl linkages between the residues can be hydrolyzed. These results indicate that the TKU031 chitosanase might hydrolyze chitosan in an endo-type fashion. From these results, chitosan hydrolysis by the TKU033 chitosanase, combined with a selective methanol precipitation, is a quick and simple method to obtain good chitooligosaccharide yields with DPs up to nine and low molecular weight oligomers.

Bottom Line: In the culture medium, the fermented SPP was recovered, and it displayed a better adsorption rate (up to 96%) for the disperse dyes than the water-soluble food colorants, Allura Red AC (R40) and Tartrazne (Y4).Fourier transform-infrared spectroscopic (FT-IR) analysis proved that the adsorption of the dyes onto fermented SPP was a physical adsorption.Results also showed that fermented SPP was a favorable adsorber and could be employed as low-cost alternative for dye removal in wastewater treatment.

View Article: PubMed Central - PubMed

Affiliation: Life Science Development Center, Tamkang University, No. 151, Yingchuan Rd., Tamsui, New Taipei City 25137, Taiwan. QQ1987pp@hotmail.com.

ABSTRACT
One of the most promising applications of chitosanase is the conversion of chitinous biowaste into bioactive chitooligomers (COS). TKU033 chitosanase was induced from squid pen powder (SPP)-containing Bacillus cereus TKU033 medium and purified by ammonium sulfate precipitation and column chromatography. The enzyme was relatively more thermostable in the presence of the substrate and had an activity of 93% at 50 °C in a pH 5 buffer solution for 60 min. Furthermore, the enzyme used for the COS preparation was also studied. The enzyme products revealed various mixtures of COS that with different degrees of polymerization (DP), ranging from three to nine. In the culture medium, the fermented SPP was recovered, and it displayed a better adsorption rate (up to 96%) for the disperse dyes than the water-soluble food colorants, Allura Red AC (R40) and Tartrazne (Y4). Fourier transform-infrared spectroscopic (FT-IR) analysis proved that the adsorption of the dyes onto fermented SPP was a physical adsorption. Results also showed that fermented SPP was a favorable adsorber and could be employed as low-cost alternative for dye removal in wastewater treatment.

Show MeSH
Related in: MedlinePlus