Genomic and functional insights of a mucin foraging Rhodopirellula halodulae sp. nov.

Nine novel strains were obtained from various algal and seagrass samples. The analysis of the 16S rRNA gene-based phylogenetic tree revealed monophyletic placement of all novel strains within the Rhodopirellula genus. The type strain was identified as JC737T, which shared 99.1 % 16S rRNA gene sequence identity with Rhodopirellula baltica SH1T, while strain JC740 was designated as an additional strain. The genome sizes of strains JC737T and JC740 were 6.6 and 6.7 Mb, respectively, and the G + C content was 56.2 %. The strains cladded distinctly in the phylogenomic tree, and the ANI and dDDH values of the strain JC737T were 75.8-76.1 % and 20.8-21.3 %, respectively, in comparison to other Rhodopirellula members. The strain demonstrated a versatile degradation capability, exhibiting a diverse array of complex polysaccharides, including mucin which had not been previously identified within the members of the phylum Planctomycetota. The phylogenomic, pan-genomic, morphological, physiological, and genomic characterization of the strain lead to the proposal to describe the strain as Rhodopirellula halodulae sp. nov.

Metagenomic insights into the effects of cosmetics containing complex polysaccharides on the composition of skin microbiota in females.

Introduction: The use of cosmetics has become a habit for women. However, their influence on the microbial diversity of the skin has rarely been studied. Methods: Herein, the effect of cosmetics containing complex polysaccharides on the skin bacterial microbiota of female forehead and cheek areas was analyzed. Eighty volunteers were recruited and split into two groups (40 people each); one group was treated with cosmetics containing complex polysaccharides and the other with basic cream for 28 days. Skin samples were collected using sterilized cotton swabs, and 16S rDNA high-throughput sequencing was used to analyze the changes in skin bacterial microbiota composition before and after the intervention. Results and discussion: A total of twenty-four phyla were detected in the forehead and cheek skin samples of 80 volunteers, the top three of which were Proteobacteria, Firmicutes, and Actinobacteria. The main genera of the forehead skin bacterial microbiota were Cutibacterium (11.1%), Acinetobacter (10.4%), Enterococcus (8.9%), Ralstonia (8.8%), and Staphylococcus (8.7%), while those of the cheek skin bacterial microbiota were Staphylococcus (20.0%), Ralstonia (8.7%), Propionibacterium (7.9%), Acinetobacter (7.2%), and Bifidobacterium (6.0%). Compared with basic cream, the use of cosmetics containing complex polysaccharides significantly increased the relative abundance of Staphylococcus and Bacillus in the forehead and cheek and reduced the relative abundance of Propionibacterium and Bifidobacterium. Thus, cosmetics containing complex polysaccharides could modify the composition of skin bacterial microbiota, which may help to maintain stable conditions of the skin.

Marine Cellulases and their Biotechnological Significance from Industrial Perspectives.

Marine microorganisms represent virtually unlimited sources of novel biological compounds and can survive extreme conditions. Cellulases, a group of enzymes that are able to degrade cellulosic materials, are in high demand in various industrial and biotechnological applications, such as in the medical and pharmaceutical industries, food, fuel, agriculture, and single-cell protein, and as probiotics in aquaculture. The cellulosic biopolymer is a renewable resource and is a linearly arranged polysaccharide of glucose, with repeating units of disaccharide connected via ß-1,4-glycosidic bonds, which are broken down by cellulase. A great deal of biodiversity resides in the ocean, and marine systems produce a wide range of distinct, new bioactive compounds that remain available but dormant for many years. The marine environment is filled with biomass from known and unknown vertebrates and invertebrate microorganisms, with much potential for use in medicine and biotechnology. Hence, complex polysaccharides derived from marine sources are a rich resource of microorganisms equipped with enzymes for polysaccharides degradation. Marine cellulases' extracts from the isolates are tested for their functional role in degrading seaweed and modifying wastes to low molecular fragments. They purify and renew environments by eliminating possible feedstocks of pollution. This review aims to examine the various types of marine cellulase producers and assess the ability of these microorganisms to produce these enzymes and their subsequent biotechnological applications.

Synergistic immunomodulatory effect of complex polysaccharides from seven herbs and their major active fractions.

In this report, we present the strategy for the revelation of synergistic effect and elucidation of active fractions from an immunomodulatory complex polysaccharide derived from seven herbs (Lentinula edodes, Ganodorma lucidum, Tremella fuciformis, Chrysanthemum, Lycium barbarum, Codonopsis pilosula and Poria cocos), a formula used as health product in China market, using the combination of HPSEC-MALLS, immunological bioassay and saccharide mapping analysis. The effects of complex polysaccharide and their fractions on RAW 246.7 macrophages demonstrated that the fractions (CD1, CD2, CD3) with molecular weight above 10 kDa exhibited immune activity by directly stimulated NO release and phagocytosis, and induced macrophages to secrete cytokines. Especially, fraction CD2 with molecular weight of 100-1000 kDa showed the strongest bioactivity (EC50 = 0.19 µg/mL) compared with their individual corresponding herbal polysaccharides fractions due to synergistic effect, which supported the scientific use of Chinese herbal mixture. Moreover, their chemical characters were analyzed by HPSEC-MALLS and saccharide mapping, and the original herbs, including L. edodes, G. lucidum, T. fuciformis and Chrysanthemum, responsible for the immunomodulatory activity were tentatively revealed. Results are beneficial for the quality analysis and formula optimization of complex polysaccharides in both biomedical and functional food field.

Preferential use of plant glycans for growth by Bacteroides ovatus.

B. ovatus is a member of the human gut microbiota with a broad capability to degrade complex glycans. Here we show that B. ovatus degrades plant polysaccharides in a preferential order, and that glycan structural complexity plays a role in determining the prioritisation of polysaccharide usage.

Prebiotics from Seaweeds: An Ocean of Opportunity?

Seaweeds are an underexploited and potentially sustainable crop which offer a rich source of bioactive compounds, including novel complex polysaccharides, polyphenols, fatty acids, and carotenoids. The purported efficacies of these phytochemicals have led to potential functional food and nutraceutical applications which aim to protect against cardiometabolic and inflammatory risk factors associated with non-communicable diseases, such as obesity, type 2 diabetes, metabolic syndrome, cardiovascular disease, inflammatory bowel disease, and some cancers. Concurrent understanding that perturbations of gut microbial composition and metabolic function manifest throughout health and disease has led to dietary strategies, such as prebiotics, which exploit the diet-host-microbe paradigm to modulate the gut microbiota, such that host health is maintained or improved. The prebiotic definition was recently updated to "a substrate that is selectively utilised by host microorganisms conferring a health benefit", which, given that previous discussion regarding seaweed prebiotics has focused upon saccharolytic fermentation, an opportunity is presented to explore how non-complex polysaccharide components from seaweeds may be metabolised by host microbial populations to benefit host health. Thus, this review provides an innovative approach to consider how the gut microbiota may utilise seaweed phytochemicals, such as polyphenols, polyunsaturated fatty acids, and carotenoids, and provides an updated discussion regarding the catabolism of seaweed-derived complex polysaccharides with potential prebiotic activity. Additional in vitro screening studies and in vivo animal studies are needed to identify potential prebiotics from seaweeds, alongside untargeted metabolomics to decipher microbial-derived metabolites from seaweeds. Furthermore, controlled human intervention studies with health-related end points to elucidate prebiotic efficacy are required.

Autonomous cure of damaged human intestinal epithelial cells by TLR2 and TLR4-dependent production of IL-22 in response to Spirulina polysaccharides.

In order to analyze the damage of human epithelial cells, we used human quasi-normal FPCK-1-1 cells derived from a colonic polyp in a patient with familial adenomatous polyposis as a monolayer, which is co-cultured with peptidoglycan (PGN)-stimulated THP-1 cells. Co-cultured FPCK-1-1 cells showed a decreased transepithelial electrical resistance (TER) and the lower level of claudin-2. When Spirulina complex polysaccharides were added one day before the start of the co-culture, there was no decrease of TER and claudin-2 (early phase damage). In contrast, when Spirulina complex polysaccharides were added to FPCK-1-1 cells after the level of TER had decreased, there was no recovery at the level of claudin-2, though the TER level recovered (late phase damage). The mucosa reconstitution is suggested to be involved in the recovery from the damaged status. Interestingly, autonomous recovery of FPCK-1-1 cells from both the early and late phase damage requires the production of IL-22, because anti-IL-22 antibodies inhibited recovery in these cases. Antibodies against either TLR2 or TLR4 inhibited the production of IL-22 from FPCK-1-1 colon epithelial cells, suggesting that signals through TLR2 and TLR4 are necessary for autonomous recovery of FPCK-1-1 colon epithelial cells by producing IL-22. In conclusion, we have established a useful model for the study of intestinal damage and recovery using human colon epithelial cells and our data suggest that damage to human colon epithelial cells can, at least in part, be recovered by the autonomous production of IL-22 in response to Spirulina complex polysaccharides.

Plant cell wall polysaccharides as potential resources for the development of novel prebiotics.

Prebiotic oligosaccharides, with a degree of polymerization (DP) of mostly less than 10, exhibit diverse biological activities that contribute to human health. Currently available prebiotics are mostly derived from disaccharides and simple polysaccharides found in plants. Subtle differences in the structures of oligosaccharides can cause significant differences in their prebiotic proper-ties. Therefore, alternative substances supplying polysaccharides that have more diverse and complex structures are necessary for the development of novel oligosaccharides that have actions not present in existing prebiotics. In this review, we show that structural polysaccharides found in plant cell walls, such as xylans and pectins, are particularly potential resources supplying broadly diverse polysaccharides to produce new prebiotics.