Three Alginate Lyases from Marine Bacterium Pseudomonas fluorescens HZJ216: Purification and Characterization

Marine Pseudomonas: diving into the waves of blue biotechnology

From marine to terrestrial environments, Pseudomonas spp. exhibit a remarkable ability not only to adapt but also thrive even amidst adverse conditions. This fact turns Pseudomonas spp. into one of the most prominent candidates for novel biotechnological solutions. Even though terrestrial isolates have been extensively studied, there is still an almost untapped source to be explored in marine Pseudomonas. Harnessing such strains offers an opportunity to discover novel bioactive compounds that could address current global challenges in healthcare and sustainable development. Therefore, this minireview aimed to provide an overview of the main recent discoveries regarding antimicrobials, antifouling, enzymes, pigments, and bioremediation strategies derived from marine isolates of Pseudomonas spp. Future research perspectives will also be discussed to foster forthcoming endeavors to explore the marine counterparts of such a prolific bacterial genus.

Biochemical characterization and degradation pattern analysis of a novel PL-6 alginate lyase from Streptomyces coelicolor A3(2)

Alginate is the main component of brown algae which contributes to a huge biomass. The alginate oligosaccharides (AOs) have been widely used in food, cosmetic and pharmaceutical industries due to their various physiological activities. In this study, we expressed and characterized a novel PL-6 alginate lyase, named OUC-ScCD6. The results indicated that OUC-ScCD6 showed highest activity at 50 °C and pH 9.0. OUC-ScCD6 prefers to degrade poly M blocks and could digest poly G blocks as well. Endolytic action mode towards polysaccharides contributes to the creation of AOs with the degrees of polymerization 2-6. Degradation towards saturated oligosaccharides showed that saturated trisaccharides (M3 and G3) were minimum identifiable substrates. Furthermore, OUC-ScCD6 shows an even-numbered glycosidic bonds preference from non-reducing end which provided clearer insights into the substrate recognition and action mode of PL-6 family alginate lyases.

Sulfated steroids of Halichondriidae family sponges - Natural inhibitors of polysaccharide-degrading enzymes of bacterium Formosa algae, inhabiting brown alga Fucus evanescens

Inhibiting effects of sulfated steroids from marine sponges of Halichondriidae family: halistanol sulfate, topsentiasterol sulfate D and chlorotopsentiasterol sulfate D were investigated on three different types of enzymes degrading polysaccharides of brown algae: endo-1,3-β-d-glucanase GFA, fucoidan hydrolase FFA2 and bifunctional alginate lyase ALFA3 from marine bacterium Formosa algae KMM 3553T, inhabiting thalli of brown alga Fucus evanescens. This is the first research, devoted to influence of a marine natural compound on three functionally related enzymes that make up the complex of enzymes, necessary to degrade unique carbohydrate components of brown algae. Alginic acid, 1,3-β-D-glucan (laminaran) and fucoidan jointly constitute practically all carbohydrate biomass of brown algae, so enzymes, able to degrade such polysaccharides, are crucial for digesting brown algae biomass as well as for organisms surviving and proliferating on brown algae thalli. Halistanol sulfate irreversibly inhibited native endo-1,3-β-D-glucanases of marine mollusks, but reversibly competitively inhibited recombinant endo-1,3-β-d-glucanase GFA. This fact indicates that there are significant structural differences between the enzymes of practically the same specificity. For alginate lyase and fucoidan hydrolase halistanol sulfate was irreversible inhibitor. Topsentiasterol sulfate D was less active inhibitor whereas chlorotopsentiasterol sulfate D was the strongest inhibitor of enzymes under the study. Chlorotopsentiasterol sulfate D caused 98% irreversible inhibition of GFA. Chlorotopsentiasterol sulfate D also caused reversible and 100% inhibition of ALFA3, which is unusual for reversible inhibitors. Inhibition of FFA2 was complete and irreversible in all cases.

The Potential of Using Bee Pollen in Cosmetics: a Review

During ancient times in China, bee pollen was used for skin whitening and beauty. Around 70% of substances in bee pollen are biologically active, such as proteins, carbohydrates, lipids and fatty acids, phenolic compounds, vitamins and bioelements.This review describes the cosmeceutical properties of bee pollen and the mechanism of its active components action, its beneficial influence on human skin. As a natural bee product, bee pollen may effectively enhance protective mechanisms against skin aging, skin dryness, ultraviolet B radiation, oxidative damage, inflammatory and melanogenesis, which are involved in a wide range of negative effects on human skin, thus they have attracted attention for health and cosmetic applications.

Marine Microbiological Enzymes: Studies with Multiple Strategies and Prospects

Marine microorganisms produce a series of promising enzymes that have been widely used or are potentially valuable for our daily life. Both classic and newly developed biochemistry technologies have been broadly used to study marine and terrestrial microbiological enzymes. In this brief review, we provide a research update and prospects regarding regulatory mechanisms and related strategies of acyl-homoserine lactones (AHL) lactonase, which is an important but largely unexplored enzyme. We also detail the status and catalytic mechanism of the main types of polysaccharide-degrading enzymes that broadly exist among marine microorganisms but have been poorly explored. In order to facilitate understanding, the regulatory and synthetic biology strategies of terrestrial microorganisms are also mentioned in comparison. We anticipate that this review will provide an outline of multiple strategies for promising marine microbial enzymes and open new avenues for the exploration, engineering and application of various enzymes.

Usefulness of Alginate Lyases Derived from Marine Organisms for the Preparation of Alginate Oligomers with Various Bioactivities

Alginate-degrading enzyme, alginate lyase, catalyzes the cleavage of glycosidic 1-4 O-linkages between uronic acid residues of alginate by a β-elimination reaction leaving a 4-deoxy-l-erythro-hex-4-ene pyranosyluronate as nonreducing terminal end. The enzymes from a wide variety of sources such as marine molluscs, seaweeds, and marine bacteria have been discovered and studied not only from a point of view of enzymological interest of enzyme itself but also for elucidation of fine chemical structure of alginate, structure-activity relationship of alginate, and biological activities and physicochemical features of the enzymatic digestion products. Based on the substrate specificities, alginate lyases are classified into three groups: poly(β-d-mannuronate) lyase, poly(α-l-guluronate) lyase, and bifunctional alginate lyase, which are specific to mannuronate, guluronate, and both uronic acid residues, respectively. We have studied enzymological aspects of these three types of alginate lyases, and bioactivities of enzymatically digested alginate oligomers. In this chapter, we described the purification and characterization of three types of alginate lyases from different marine origins and overviewed the bioactivities of alginate oligomers.

Culture medium optimization of a new bacterial extracellular polysaccharide with excellent moisture retention activity

A new kind of extracellular polysaccharide (EPS) from Pseudomonas fluorescens PGM37 was obtained and culture media was optimized using the statistical methods single factor experiments and response surface methodology (RSM) design. As a result, the optimum cultivation conditions initial pH value, medium volume, inoculum size, temperature, and rotation speed were 7.5, 100 mL/250 mL, 5%, 28 °C, and 180 rpm, respectively. The optimized media: sucrose 36.23 g L(-1), yeast extract 3.32 g L(-1), sodium chloride 1.13 g L(-1), and calcium chloride 0.20 g L(-1). The maximum predicted yield of EPS was 10.1163 g L(-1) under these conditions. The validation data was 10.012 g L(-1), which could strongly confirm the correlation between the experimental and theoretical values. Gas Chromatography analysis revealed that the polymer was made up of mannose and glucose in the ratio of 1:1. Infrared spectroscopy showed that the polysaccharide had β-D-pyranoid configuration and contained no other substituent. Graded by different multiples of alcohol after specific degradation by enzyme and then detected by LC-ESI-MS, the EPS structure was β-D-Glcp-(1, 4)-β-D-Manp-(1, 4)-β-D-Glcp-(1, 4)-β-D-Manp. The moisture retention ability of the EPS was found to be superior to glycerol and only a little inferior to hyaluronic acid (HA), which presented potential application value in cosmetics and clinical medicine fields.