Determination of the chemical composition of ulvan, a cell wall polysaccharide from Ulva spp. (Ulvales, Chlorophyta) by FT-IR and chemometrics

Abstract

The water-soluble cell wall polysaccharides from green seaweeds of Ulva spp. (Ulvales, Chlorophyta), referred to as ulvan, demonstrate composition-and structure-related functional properties. Mid-infrared spectroscopy combined with chemometric techniques was investigated as a means to rapidly predict the chemical composition of ulvan extracts. A calibration was realized with 41 ulvan extracts from two Ulva species. The variables studied included the constituent sugars (rhamnose, xylose, glucose, galactose, glucuronic acid, iduronic acid), protein, and sulfate contents. The correlation between Fourier transform infrared and chemical data was developed using partial least squares (PLS) regression with full cross-validation (leave one out). The coefficients of determination in cross-validation (R 2 CAL ) and the standard error in cross-validation were determined for each variable. The PLS model validation resulted in a coefficient of determination (R 2 VAL ) and a standard error in prediction. Good predictions were obtained for rhamnose (R 2 VAL = 0.9244), xylose (R 2 VAL =0.8758), glucuronic acid (R 2 VAL =0.9415), and sulfate (R 2 VAL =0.9218), which are the main ulvan constituents. However, minor components such as proteins, glucose, galactose, and iduronic acid were not correctly predicted. This study showed that mid-infrared spectroscopy combined with PLS regression is a reliable and fast method for the quantification of the main chemical constituents of ulvan extracts.

Morphological and ultrastructural studies on Ulva flexuosa subsp. pilifera (Chlorophyta) from Poland

“…Matsuo et al [39] isolated, (from an epiphytic marine bacterium), and characterized a causative factor for the induction of normal thallus germination and morphogenesis. Lahaye and Ray [40] found the sugar sequences in the water soluble polysaccharides from Ulvaceae, also Ray and Lahaye [41] as well as Robic et al [42] studied the cell wall polysaccharides of this group using mid-infrared spectroscopy combined with chemometric techniques.…”

The Marine Macroalgae of the Genus Ulva: Chemistry, Biological Activities and Potential Applications

“…It is important to mention also that ulvan, a major Sulfated Polysaccharide (SP) found in the cell wall of green algae, composed mainly of rhamnose, glucuronic acid, iduronic acid, xylose, glucose, sulphate with small amounts of iduronic acid and traces of galactose and represents 8-29% of the algae dry weight [25,26,[44][45][46][47][48][49][50][51]. The presence of the sulfate groups and the unusual chemical composition and structure of ulvan render it different biological properties [26,52,53].…”

“…In the recent years, ulvan has been extensively investigated for development of novel drugs and functional foods [26,49,53]. Because of its peculiar composition and structure [50], it represents a potential source of new functional biopolymer and it is widely used as biomaterial for tissue engineering in regenerative medicine. Furthermore, studies showed that sulfated polysaccharides can also exhibit beneficial biological activities such as anticoagulant, antiviral, antioxidant, antiinflammatory [54] and antiproliferative [27].…”

Carbohydrate-based phenotyping of the green macroalga Ulva fasciata using near-infrared spectrometry: potential implications for marine biorefinery

“…The method was based on the binding of a dye to algal polysaccharides that causes the absorption maximum at 664 nm to decrease linearly over the range of 0-30 μg. In a previous NIRS work, Robic et al (2009) developed a partial least squares (PLS) model to characterise the chemical composition of ulvan, a major polymer of Ulva, with functional properties making it interesting for industrial production. That work focused on determining the chemical composition of the extracted ulvan (Robic et al 2009).…”

“…In a previous NIRS work, Robic et al (2009) developed a partial least squares (PLS) model to characterise the chemical composition of ulvan, a major polymer of Ulva, with functional properties making it interesting for industrial production. That work focused on determining the chemical composition of the extracted ulvan (Robic et al 2009). However, to the best of our knowledge, NIRS has not been used for complete Ulva biomass phenotyping based on its content of major monosaccharides, which are critically important for the rapid selection of macroalgal feedstock for biofuel and biorefinery applications (Golberg et al 2014, Korzen et al 2015a,b, Vitkin et al 2015.…”