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Human milk enriches members of the genus Bifidobacterium in the infant gut. One species, Bifidobacterium pseudocatenulatum, is found in the gastrointestinal tracts of adults and breastfed infants. In this study, B. pseudocatenulatum strains were isolated and characterized to identify genetic adaptations to the breastfed infant gut. During growth on pooled human milk oligosaccharides (HMOs), we observed two distinct groups of B. pseudocatenulatum, isolates that readily consumed HMOs and those that did not, a difference driven by variable catabolism of fucosylated HMOs. A conserved gene cluster for fucosylated HMO utilization was identified in several sequenced B. pseudocatenulatum strains. One isolate, B. pseudocatenulatum MP80, which uniquely possessed GH95 and GH29 α-fucosidases, consumed the majority of fucosylated HMOs tested. Furthermore, B. pseudocatenulatum SC585, which possesses only a single GH95 α-fucosidase, lacked the ability to consume the complete repertoire of linkages within the fucosylated HMO pool. Analysis of the purified GH29 and GH95 fucosidase activities directly on HMOs revealed complementing enzyme specificities with the GH95 enzyme preferring 1-2 fucosyl linkages and the GH29 enzyme favoring 1-3 and 1-4 linkages. The HMO-binding specificities of the family 1 solute-binding protein component linked to the fucosylated HMO gene cluster in both SC585 and MP80 are similar, suggesting differential transport of fucosylated HMO is not a driving factor in each strain's distinct HMO consumption pattern. Taken together, these data indicate the presence or absence of specific α-fucosidases directs the strain-specific fucosylated HMO utilization pattern among bifidobacteria and likely influences competitive behavior for HMO foraging in situ. IMPORTANCE Often isolated from the human gut, microbes from the bacterial family Bifidobacteriaceae commonly possess genes enabling carbohydrate utilization. Isolates from breastfed infants often grow on and possess genes for the catabolism of human milk oligosaccharides (HMOs), glycans found in human breast milk. However, catabolism of structurally diverse HMOs differs between bifidobacterial strains. This study identifies key gene differences between Bifidobacterium pseudocatenulatum isolates that may impact whether a microbe successfully colonizes an infant gut. In this case, the presence of complementary α-fucosidases may provide an advantage to microbes seeking residence in the infant gut. Such knowledge furthers our understanding of how diet drives bacterial colonization of the infant gut.

Regular intake of fucosylated oligosaccharides has been associated with several benefits for human health, particularly for new-borns. Since these biologically active molecules can be found naturally in human milk, research efforts have been focused on the alternative synthetic routes leading to their production. In particular, utilization of fucosidases to perform stereoselective transglycosylation reactions has been widely investigated. Other reasons that bring these enzymes to the spotlight are their role in viral infections and cancer proliferation. Since their involvement in the pathogenesis of these diseases have been widely described, fucosidases have become a target in newly developed therapies. Finally, activity disorders of biologically important fucosidases can lead to health problems such as fucosidosis. What is common for both mechanisms is the interaction between the enzyme and substrates in and around the active site. Therefore, this review will analyse different substrate structures that have been tested in terms of their interaction with fucosidases active sites, either in synthesis or inhibition reactions. The published results will be compared from this perspective. [ABSTRACT FROM AUTHOR]

Context • Hepatitis B can develop into cirrhosis, and most liver cancers evolve on the basis of chronic hepatitis and cirrhosis. Many patients are already at an advanced stage when diagnosed. In recent years, clinicians have advocated detection of liver cancer using multiple markers in combination to improve the sensitivity and specificity of testing. Objective • The study aimed to evaluate the clinical value of using four tumor indicators—urea, alpha L-fucosidase (AFU), carbohydrate antigen 153 (CA153), carbohydrate antigen 125 (CA125), and alpha fetoprotein (AFP) and comparing the use of combined indicators to use of a single indicator for the diagnosis of liver cancer. Design • The research team performed a prospective study. Setting • The study took place at Clinical Laboratory, Baoding People’s Hospital, Baoding City, Hebei Province, China. Participants • Participants were 98 patients with chronic hepatitis B, who became the CHB group; 102 patients with liver cirrhosis, who became the cirrhosis group, and 100 patients with liver cancer, who became the liver cancer group. They all had been admitted to the hospital between March 2019 and March 2021. Outcome Measures • The research team measured the urea, AFU, CA153, CA125, and AFP levels of the three groups, constructed an ROC curve, and analyzed the diagnostic values of the indicators singly and in combination for liver cancer. Results • For the levels of urea, AFU, CA153, CA125, and AFP, the CHB group’s levels were significantly lower than those of the cirrhosis and liver cancer groups (both P < .001), and the cirrhosis group’s levels were significantly lower than those of the liver cancer group (P < .001). In the CHB group, the compensatory group’s levels were significantly lower than those of the decompensated group (P < .05). In the cirrhosis group, no significant differences existed between the levels of the grade A and grade B groups (P < .001), between those of the grade A and grade C groups (P < .001), or between those of the grade B and grade C groups (P < .001). In the cirrhosis group, the levels of the no ascites group were significantly lower than those of the ascites group (P < .05). In the liver cancer group, the levels of the stage I-II group were significantly lower than those of the stage III and stage IV groups (both P < .05), and those of the stage III group were significantly lower than those of the stage IV group (P < .05). The levels of the <5cm group were significantly lower than those of the ≥5cm group (P < .001). The value of using a combination of indicators for diagnosis was significantly higher than that of a single indicator (P < .001). Conclusions • Urea, AFU, CA153, CA125, and AFP all have diagnostic value in the evaluation of chronic hepatitis B-cirrhosis and liver cancer, with the highest efficacy, sensitivity and specificity from a combined test and diagnosis. [ABSTRACT FROM AUTHOR]

Protein crystals grown in microfluidic droplets have been shown to be an effective and robust platform for storage, transport and serial crystallography data collection with a minimal impact on diffraction quality. Single macromolecular microcrystals grown in nanolitre‐sized droplets allow the very efficient use of protein samples and can produce large quantities of high‐quality samples for data collection. However, there are challenges not only in growing crystals in microfluidic droplets, but also in delivering the droplets into X‐ray beams, including the physical arrangement, beamline and timing constraints and ease of use. Here, the crystallization of two human gut microbial hydrolases in microfluidic droplets is described: a sample‐transport and data‐collection approach that is inexpensive, is convenient, requires small amounts of protein and is forgiving. It is shown that crystals can be grown in 50–500 pl droplets when the crystallization conditions are compatible with the droplet environment. Local and remote data‐collection methods are described and it is shown that crystals grown in microfluidics droplets and housed as an emulsion in an Eppendorf tube can be shipped from the US to the UK using a FedEx envelope, and data can be collected successfully. Details of how crystals were delivered to the X‐ray beam by depositing an emulsion of droplets onto a silicon fixed‐target serial device are provided. After three months of storage at 4°C, the crystals endured and diffracted well, showing only a slight decrease in diffracting power, demonstrating a suitable way to grow crystals, and to store and collect the droplets with crystals for data collection. This sample‐delivery and data‐collection strategy allows crystal droplets to be shipped and set aside until beamtime is available. [ABSTRACT FROM AUTHOR]

Fucose is a monosaccharide commonly found in mammalian, insect, microbial and plant glycans. The removal of terminal α-l-fucosyl residues from oligosaccharides and glycoconjugates is catalysed by α-l-fucosidases. To date, glycoside hydrolases (GHs) with exo-fucosidase activity on α-l-fucosylated substrates (EC 3.2.1.51, EC 3.2.1.-) have been reported in the GH29, GH95, GH139, GH141 and GH151 families of the Carbohydrate Active Enzymes (CAZy) database. Microbes generally encode several fucosidases in their genomes, often from more than one GH family, reflecting the high diversity of naturally occuring fucosylated structures they encounter. Functionally characterised microbial α-l-fucosidases have been shown to act on a range of substrates with α-1,2, α-1,3, α-1,4 or α-1,6 fucosylated linkages depending on the GH family and microorganism. Fucosidases show a modular organisation with catalytic domains of GH29 and GH151 displaying a (β/α)8-barrel fold while GH95 and GH141 show a (α/α)6 barrel and parallel β-helix fold, respectively. A number of crystal structures have been solved in complex with ligands, providing structural basis for their substrate specificity. Fucosidases can also be used in transglycosylation reactions to synthesise oligosaccharides. This mini review provides an overview of the enzymatic and structural properties of microbial α-l-fucosidases and some insights into their biological function and biotechnological applications., (© 2023 The Author(s).)