“Algae’s sulfated polysaccharides modifications: Potential use of microbial enzymes”

Cyanobacterial and microalgae polymers: antiviral activity and applications

At the end of 2019, the world witnessed the beginning of the COVID-19 pandemic. As an aggressive viral infection, the entire world remained attentive to new discoveries about the SARS-CoV-2 virus and its effects in the human body. The search for new antivirals capable of preventing and/or controlling the infection became one of the main goals of research during this time. New biocompounds from marine sources, especially microalgae and cyanobacteria, with pharmacological benefits, such as anticoagulant, anti-inflammatory and antiviral attracted particular interest. Polysaccharides (PS) and extracellular polymeric substances (EPS), especially those containing sulfated groups in their structure, have potential antiviral activity against several types of viruses including HIV-1, herpes simplex virus type 1, and SARS-CoV-2. We review the main characteristics of PS and EPS with antiviral activity, the mechanisms of action, and the different extraction methodologies from microalgae and cyanobacteria biomass.

Statistical optimization of process variables for agarase production using Microbacterium sp. SS5 strain from non-marine sources

Agar oligosaccharides are thought to be valuable biomolecules with high bioactivity potential, along with a wide range of applications and advantages. The current study aimed to optimize the culture parameters required to produce agarase enzyme and agar oligosaccharides from industrial waste agar. Microbacterium spp. strain SS5 was isolated from a non-marine source and could synthesize oligo derivatives for use in a variety of industries ranging from food to pharmaceuticals. In addition, the strain and culture conditions were optimized to maximize extracellular agarase production. The bacterium grew best at pH 5.0 - 9.0, with an optimal pH of 7.5 - 8.0; temperatures ranging from 25 to 45 °C, with an optimal of 35 °C; and carbon and nitrogen concentrations of 0.5% each. Plackett-Burman experimental design and response surface methods were used to optimize various process parameters for agarase production by Microbacterium spp. strain SS5. Using the Plackett-Burman experimental design, eleven process factors were screened, and agar, beef extract, CaCl2, and beginning pH were found as the most significant independent variables affecting agarase production with confidence levels above 90%. To determine the optimal concentrations of the identified process factors on agarase production, the Box- Behnken design was used. Agarase production by Microbacterium spp. strain SS5 after optimization was 0.272 U/mL, which was determined to be greater than the result obtained from the basal medium (0.132 U/mL) before screening using Plackett-Burman and BBD with a fold increase of 2.06.

Application of logistic regression, support vector machine and random forest on the effects of titanium dioxide nanoparticles using macroalgae in treatment of certain risk factors associated with kidney injuries

The use of titanium dioxide (TiO₂) nanoparticles in many biological and technical domains is on the rise. There hasn't been much research on the toxicity of titanium dioxide nanoparticles in biological systems, despite their ubiquitous usage. In the current investigation, samples were exposed to various dosages of TiO₂ nanoparticles for 4 days, 1 month, and 2 months following treatment. ICP-AES was used to dose TiO₂ into the tissues, and the results showed that the kidney had a significant TiO₂ buildup. On the other hand, apoptosis of renal tubular cells is one of the most frequent cellular processes contributing to kidney disease (KD). Nevertheless, the impact of macroalgal seaweed extract on KD remains undetermined. In this work, machine learning (ML) approaches have been applied to develop prediction algorithms for acute kidney injury (AKI) by use of titanium dioxide and macroalgae in hospitalized patients. Fifty patients with (AKI) and 50 patients (non-AKI group) have been admitted and considered. Regarding demographic data, and laboratory test data as input parameters, support vector machine (SVM), and random forest (RF) are utilized to build models of AKI prediction and compared to the predictive performance of logistic regression (LR). Due to its strong antioxidant and anti-inflammatory powers, the current research ruled out the potential of using G. oblongata red macro algae as a source for a variety of products for medicinal uses. Despite a high and fast processing of algorithms, logistic regression showed lower overfitting in comparison to SVM, and Random Forest. The dataset is subjected to algorithms, and the categorization of potential risk variables yields the best results. AKI samples showed significant organ defects than non-AKI ones. Multivariate LR indicated that lymphocyte, and myoglobin (MB) ≥ 1000 ng/ml were independent risk parameters for AKI samples. Also, GCS score (95% CI 1.4-8.3 P = 0.014) were the risk parameters for 60-day mortality in samples with AKI. Also, 90-day mortality in AKI patients was significantly high (P < 0.0001). In compared to the control group, there were no appreciable changes in the kidney/body weight ratio or body weight increases. Total thiol levels in kidney homogenate significantly decreased, and histopathological analysis confirmed these biochemical alterations. According to the results, oral TiO₂ NP treatment may cause kidney damage in experimental samples.

Sulfated Polysaccharides from Macroalgae-A Simple Roadmap for Chemical Characterization

The marine environment presents itself as a treasure chest, full of a vast diversity of organisms yet to be explored. Among these organisms, macroalgae stand out as a major source of natural products due to their nature as primary producers and relevance in the sustainability of marine ecosystems. Sulfated polysaccharides (SPs) are a group of polymers biosynthesized by macroalgae, making up part of their cell wall composition. Such compounds are characterized by the presence of sulfate groups and a great structural diversity among the different classes of macroalgae, providing interesting biotechnological and therapeutical applications. However, due to the high complexity of these macromolecules, their chemical characterization is a huge challenge, driving the use of complementary physicochemical techniques to achieve an accurate structural elucidation. This review compiles the reports (2016-2021) of state-of-the-art methodologies used in the chemical characterization of macroalgae SPs aiming to provide, in a simple way, a key tool for researchers focused on the structural elucidation of these important marine macromolecules.

Prebiotic potential of enzymatically produced ulvan oligosaccharides using ulvan lyase of Bacillus subtilis, NIOA181, a macroalgae-associated bacteria

AIMS

To characterize the polysaccharide hydrolyzing potential of macroalgae-associated bacteria (MABs) for enzymatic production of oligosaccharides and determining their prebiotic potential.

METHODS AND RESULTS

Approximately 400 MABs were qualitatively characterised for polysaccharide hydrolyzing activity. Only about 5 to 15% of the isolates were found to have the potential for producing porphyranase, alginate lyase and ulvan lyase enzymes which were quantified in specific substrate broths. One potential MAB, Bacillus subtilis, NIOA181, isolated from green macroalgae, showed the highest ulvan lyase activity. This enzyme was partially purified and used to hydrolyse ulvan into ulvan oligosaccharides. Structural characterization of ulvan oligosaccharides showed that they are predominantly composed of di-, tri-, and tetrasaccharide units. Results showed that the enzymatically produced ulvan oligosaccharides exhibited prebiotic activity by promoting the growth of probiotic bacteria and suppressing the enteric pathogens, which were higher than the ulvan polysaccharide and equivalent to commercial fructooligosaccharides.

CONCLUSIONS

A potential MAB, NIOA181, producing ulvan lyase was isolated and used for the production of ulvan oligosaccharides with prebiotic activity.

SIGNIFICANCE AND IMPACT OF STUDY

Rarely studied ulvan oligosaccharides with prebiotic activity can be widely used as an active pharmaceutical ingredient in nutraceutical and other healthcare applications.

Substrate degradation pathways, conserved functions and community composition of the hindgut microbiota in the herbivorous marine fish Kyphosus sydneyanus

Symbiotic gut microbiota in the herbivorous marine fish Kyphosus sydneyanus play an important role in digestion by converting refractory algal carbohydrate into short-chain fatty acids. Here we characterised community composition using both 16S rRNA gene amplicon sequencing and shotgun-metagenome sequencing. Sequencing was carried out on lumen and mucosa samples (radial sections) from three axial sections taken from the hindgut of wild-caught fish. Both lumen and mucosa communities displayed distinct distributions along the hindgut, likely an effect of the differing selection pressures within these hindgut locations, as well as considerable variation among individual fish. In contrast, metagenomic sequences displayed a high level of functional similarity between individual fish and gut sections in the relative abundance of genes (based on sequencing depth) that encoded enzymes involved in algal-derived substrate degradation. These results suggest that the host gut environment selects for functional capacity in symbionts rather than taxonomic identity. Functional annotation of the enzymes encoded by the gut microbiota was carried out to infer the metabolic pathways used by the gut microbiota for the degradation of important dietary substrates: mannitol, alginate, laminarin, fucoidan and galactan (e.g. agar and carrageenan). This work provides the first evidence of the genomic potential of K. sydneyanus hindgut microbiota to convert highly refractory algal carbohydrates into metabolically useful short-chain fatty acids.

Catalase Activity in Keratinocytes, Stratum Corneum, and Defatted Algae Biomass as a Potential Skin Care Ingredient

The generation of reactive oxygen species presents a destructive challenge for the skin organ and there is a clear need to advance skin care formulations aiming at alleviating oxidative stress. The aim of this work was to characterize the activity of the antioxidative enzyme catalase in keratinocytes and in the skin barrier (i.e., the stratum corneum). Further, the goal was to compare the activity levels with the corresponding catalase activity found in defatted algae biomass, which may serve as a source of antioxidative enzymes, as well as other beneficial algae-derived molecules, to be employed in skin care products. For this, an oxygen electrode-based method was employed to determine the catalase activity and the apparent kinetic parameters for purified catalase, as well as catalase naturally present in HaCaT keratinocytes, excised stratum corneum samples collected from pig ears with various amounts of melanin, and defatted algae biomass from the diatom Phaeodactylum tricornutum. Taken together, this work illustrates the versatility of the oxygen electrode-based method for characterizing catalase function in samples with a high degree of complexity and enables the assessment of sample treatment protocols and comparisons between different biological systems related to the skin organ or algae-derived materials as a potential source of skin care ingredients for combating oxidative stress.

Red algae natural products for prevention of lipopolysaccharides (LPS)-induced liver and kidney inflammation and injuries

BACKGROUND

The liver and kidney inflammation due to bacterial infection is one of the most common pathological problems leading to tissue damage or disease. In many liver and kidney disorders, which represent serious global health burden with a high economic cost, oxidative stress-related inflammation and apoptosis are important pathogenic components, finally resulting in acute liver and/or kidney failure. Erythropoietin and its analogues are well known to influence the interaction between apoptosis and inflammation in liver and kidney.

OBJECTIVE

The aim of the present study is to investigate and clarify the effect of Gromphadorhina oblongata red algae on lipopolysaccharides (LPS)-induced acute liver and kidney injury of mice with endotoxemia and associated molecular mechanism from inflammation, apoptosis and oxidative stress levels.

RESULTS

The current study cleared out that treatment of rats with the G. oblongata extract prior to LPS injection significantly lowered serum cytokines, including NF-κB, MPO and LPO, and improved liver apoptosis through suppressing protein tyrosine kinase signaling pathway, and that may be due to antibacterial activity as well antioxidant capacity of G. oblongata extract.

CONCLUSION

The present study was cleared out the possibility of administration of G.oblongata red algae as a multi products source for biotechnological, medical, nutraceutical and pharmaceutical applications due to highly antioxidant and anti-inflammatory capacities even although more investigations are required for separating, purifying and characterizing these bioactive compounds.

Antibacterial Use of Macroalgae Compounds against Foodborne Pathogens

The search for food resources is a constant in human history. Nowadays, the search for natural and safe food supplies is of foremost importance. Accordingly, there is a renewed interest in eco-friendly and natural products for substitution of synthetic additives. In addition, microbial contamination of food products during their obtaining and distribution processes is still a sanitary issue, and an important target for the food industry is to avoid food contamination and its related foodborne illnesses. These diseases are fundamentally caused by certain microorganisms listed in this review and classified according to their Gram negative or positive character. Algae have proven to possess high nutritional value and a wide variety of biological properties due to their content in active compounds. Among these capabilities, macroalgae are recognized for having antimicrobial properties. Thus, the present paper revises the actual knowledge of microbial contaminants in the food industry and proposes antimicrobial algal compounds against those pathogenic bacteria responsible for food contamination as valuable molecules for its growth inhibition. The capacity of algae extracts to inhibit some major food pathogen growth was assessed. Moreover, the main applications of these compounds in the food industry were discussed while considering their favorable effects in terms of food safety and quality control.

A new integrated HPTLC - ATR/FTIR approach in marine algae bioprofiling

The aim of this study was to evaluate marine algae extracts in terms of their anti-inflammatory activity using a combination of chromatographic separation and chemical detection with subsequent infrared vibrational spectroscopy identification. Extraction parameters, chemical fingerprint, and the activity levels were considered for the method optimization. High-performance thin-layer chromatography (HPTLC) combined with microchemical derivatization, was used to separate and detect bioactive compounds with antioxidant activity and anti-inflammatory activities, and to detect different classes of terpenoids. Infrared attenuated total reflectance (ATR) spectral analysis of the bands with bioactive compounds, identified sulfated polysaccharides to be responsible for the anti-inflammatory activity in extracts of brown algae Carpoglossum confluens and Phyllospora comosa. Steroids as unique antioxidants with significant free radical scavenging activities were observed in extracts of brown algae Cystophora platylobium, Cystophora retorta, Carpoglossum confluens and Phyllospora comosa. HPTLC combined with biochemical assays and FTIR-ATR spectrometry was demonstrated to be a straightforward strategy for bioprofiling marine algae extracts.

Marine-polysaccharide degrading enzymes: Status and prospects

Marine-polysaccharide degrading enzymes have recently been studied extensively. They are particularly interesting as they catalyze the cleavage of glycosidic bonds in polysaccharide macromolecules and produce oligosaccharides with low degrees of polymerization. Numerous findings have demonstrated that marine polysaccharides and their biotransformed products possess beneficial properties including antitumor, antiviral, anticoagulant, and anti-inflammatory activities, and they have great value in healthcare, cosmetics, the food industry, and agriculture. Exploitation of enzymes that can degrade marine polysaccharides is in the ascendant, and is important for high-value use of marine biomass resources. In this review, we describe research and prospects regarding the classification, biochemical properties, and catalytic mechanisms of the main types of marine-polysaccharide degrading enzymes, focusing on chitinase, chitosanase, alginate lyase, agarase, and carrageenase, and their product oligosaccharides. The state-of-the-art discussion of marine-polysaccharide degrading enzymes and their properties offers information that might enable more efficient production of marine oligosaccharides. We also highlight current problems in the field of marine-polysaccharide degrading enzymes and trends in their development. Understanding the properties, catalytic mechanisms, and modification of known enzymes will aid the identification of novel enzymes to degrade marine polysaccharides and facilitation of their use in various biotechnological processes.

Antifungal Properties of Fucus vesiculosus L. Supercritical Fluid Extract Against Fusarium culmorum and Fusarium oxysporum

In this study, potential antifungal properties of a brown alga Fucus vesiculosus were evaluated. The algal extract was obtained with the use of supercritical fluid extraction (scCO2) at a temperature of 50 °C under a pressure of 300 bar. The aqueous solution of the extract at the concentration of 0.05%, 0.2%, 0.5% and 1.0% was studied against pathogenic fungi on a liquid RB medium. This study is the first report on antifungal properties of the brown algae F. vesiculosus scCO2 extract against Fusarium culmorum and Fusarium oxysporum phytopathogens. The concentrations of the studied extract (0.5% and 1.0%) were demonstrated to have an ability to inhibit 100% growth of macroconidia within 144 h, as well as an ability to cause their total degradation. As a result of the study, the antifungal effect of fucosterol against F. culmorum was also indicated. The total macroconidia growth was inhibited by 1.0% fucosterol. Moreover, at lower concentrations (0.05-0.2%) of fucosterol, macroconidia were characterized by shorter length and structural degradation was observed. The mycelial growth of Fusarium oxysporum (Fo38) by 1% scCO2 F. vesiculosus extract was analyzed at the level of 48% after 168 h of incubation, whereas 100% extract was found to be effective in F. culmorum (CBS122) and F. oxysporum (Fo38) growth inhibition by 72% and 75%, respectively after 168 h of incubation.

Marine prebiotics: Polysaccharides and oligosaccharides obtained by using microbial enzymes

Utilization of marine algae has increased considerably over the past decades, since biodiversity within brown, red and green marine algae offers possibilities of finding a variety of bioactive compounds. Marine algae are rich sources of dietary fibre. The remarkable positive effects of seaweed dietary fibre on human body are related to their prebiotic activity over the gastrointestinal tract (GIT) microbiota. However, dietary modulation of microorganisms present in GIT can be influenced by different factors such as type and source of the dietary fibre, their molecular weight, type of extraction and purification methods employed, composition and modification of polysaccharide and oligosaccharide. This review will demonstrate evidence that polysaccharides and oligosaccharides from marine algae can be used as prebiotics, emphasizing their use in human health, their application as food and other possible applications. Furthermore, an important approach of microbial enzymes employment during extraction, modification or production of those prebiotics is highlighted.

Applications of Algal Polysaccharides and Derivatives in Therapeutic and Agricultural Fields

BACKGROUND

Recently, researchers have given more and more consideration to natural polysaccharides thanks to their huge properties such as stability, biodegradability and biocompatibility for food and therapeutics applications.

METHODS

a number of enzymatic and chemical processes were performed to generate bioactive molecules, such as low molecular weight fractions and oligosaccharides derivatives from algal polysaccharides.

RESULTS

These considerable characteristics allow algal polysaccharides and their derivatives such as low molecular weight polymers and oligosaccharides structures to have great potential to be used in lots of domains, such as pharmaceutics and agriculture etc. Conclusion: The present review describes the mains polysaccharides structures from Algae and focuses on the currents agricultural (fertilizer, bio-elicitor, stimulators, signaling molecules and activators) and pharmaceutical (wound dressing, tissues engineering and drugs delivery) applications by using polysaccharides and/or their oligosaccharides derivatives obtained by chemical, physical and enzymatic processes.

Update on Marine Carbohydrate Hydrolyzing Enzymes: Biotechnological Applications

After generating much interest in the past as an aid in solving structural problems for complex molecules such as polysaccharides, carbohydrate-hydrolyzing enzymes of marine origin still appear as interesting biocatalysts for a range of useful applications in strong interdisciplinary fields such as green chemistry and similar domains. The multifaceted fields in which these enzymes are of interest and the scarce number of original articles in literature prompted us to provide the specialized analysis here reported. General considerations from modern (2016-2017 interval time) review articles are at start of this manuscript; then it is subsequently organized in sections according to particular biopolymers and original research articles are discussed. Literature sources like the Science Direct database with an optimized W/in search, and the Espacenet patent database were used.