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International Journal of Biological... Jul 2023The microbial production of cellulose using different bacterial species has been extensively examined for various industrial applications. However, the...
Production efficiency and properties of bacterial cellulose membranes in a novel grape pomace hydrolysate by Komagataeibacter melomenusus AV436 and Komagataeibacter xylinus LMG 1518.
The microbial production of cellulose using different bacterial species has been extensively examined for various industrial applications. However, the cost-effectiveness of all these biotechnological processes is strongly related to the culture medium for bacterial cellulose (BC) production. Herein, we examined a simple and modified procedure for preparing grape pomace (GP) hydrolysate, without enzymatic treatment, as a sole growth medium for BC production by acetic acid bacteria (AAB). The central composite design (CCD) was used to optimise the GP hydrolysate preparation toward the highest reducing sugar contents (10.4 g/L) and minimal phenolic contents (4.8 g/L). The experimental screening of 4 differently prepared hydrolysates and 20 AAB strains identified the recently described species Komagataeibacter melomenusus AV436 as the most efficient BC producer (up to 1.24 g/L dry BC membrane), followed by Komagataeibacter xylinus LMG 1518 (up to 0.98 g/L dry BC membrane). The membranes were synthesized in only 4 days of bacteria culturing, 1 st day with shaking, followed by 3 days of static incubation. The produced BC membranes in GP-hydrolysates showed, in comparison to the membranes made in a complex RAE medium 34 % reduction of crystallinity index with the presence of diverse cellulose allomorphs, presence of GP-related components within the BC network responsible for the increase of hydrophobicity, the reduction of thermal stability and 48.75 %, 13.6 % and 43 % lower tensile strength, tensile modulus, and elongation, respectively. Here presented study is the first report on utilising a GP-hydrolysate without enzymatic treatment as a sole culture medium for efficient BC production by AAB, with recently described species Komagataeibacter melomenusus AV436 as the most efficient producer in this type of food-waste material. The scale-up protocol of the scheme presented here will be needed for the cost-optimisation of BC production at the industrial levels.
Topics: Vitis; Cellulose; Gluconacetobacter xylinus; Acetobacteraceae; Biotechnology; Acetic Acid
PubMed: 37330080
DOI: 10.1016/j.ijbiomac.2023.125368 -
Frontiers in Microbiology 2023Interest for bee microbiota has recently been rising, alleviating the gap in knowledge in regard to drivers of solitary bee gut microbiota. However, no study has...
INTRODUCTION
Interest for bee microbiota has recently been rising, alleviating the gap in knowledge in regard to drivers of solitary bee gut microbiota. However, no study has addressed the microbial acquisition routes of tropical solitary bees. For both social and solitary bees, the gut microbiota has several essential roles such as food processing and immune responses. While social bees such as honeybees maintain a constant gut microbiota by direct transmission from individuals of the same hive, solitary bees do not have direct contact between generations. They thus acquire their gut microbiota from the environment and/or the provision of their brood cell. To establish the role of life history in structuring the gut microbiota of solitary bees, we characterized the gut microbiota of from a beach population in Mayagüez, Puerto Rico. Females provide the initial brood cell provision for the larvae, while males patrol the nest without any contact with it. We hypothesized that this behavior influences their gut microbiota, and that the origin of larval microbiota is from brood cell provisions.
METHODS
We collected samples from adult females and males of ( = 10 each, = 20), larvae ( = 4), and brood cell provisions ( = 10). For comparison purposes, we also sampled co-occurring female foragers of social ( = 6). The samples were dissected, their DNA extracted, and gut microbiota sequenced using 16S rRNA genes. Pollen loads of and were analyzed and interactions between bee species and their plant resources were visualized using a pollination network.
RESULTS
While we found the gut of contained the same phylotypes previously reported in the literature, we noted that the variability in the gut microbiota of solitary was significantly higher than that of social . Furthermore, the microbiota of adult mostly consisted of acetic acid bacteria whereas that of mostly had lactic acid bacteria. Among , we found significant differences in alpha and beta diversity between adults and their brood cell provisions (Shannon and Chao1 < 0.05), due to the higher abundance of families such as Rhizobiaceae and Chitinophagaceae in the brood cells, and of Acetobacteraceae in adults. In addition, the pollination network analysis indicated that had a stronger interaction with sp. and a weaker interaction with while interactions between and its plant resources were constant with the null model.
CONCLUSION
Our data are consistent with the hypothesis that behavioral differences in brood provisioning between solitary and social bees is a factor leading to relatively high variation in the microbiota of the solitary bee.
PubMed: 37266018
DOI: 10.3389/fmicb.2023.1122489 -
Scientific Reports May 2023Several raw materials have been used as partial supplements or entire replacements for the main ingredients of kombucha to improve the biological properties of the...
Several raw materials have been used as partial supplements or entire replacements for the main ingredients of kombucha to improve the biological properties of the resulting kombucha beverage. This study used pineapple peels and cores (PPC), byproducts of pineapple processing, as alternative raw materials instead of sugar for kombucha production. Kombuchas were produced from fusions of black tea and PPC at different ratios, and their chemical profiles and biological properties, including antioxidant and antimicrobial activities, were determined and compared with the control kombucha without PPC supplementation. The results showed that PPC contained high amounts of beneficial substances, including sugars, polyphenols, organic acids, vitamins, and minerals. An analysis of the microbial community in a kombucha SCOBY (Symbiotic Cultures of Bacteria and Yeasts) using next-generation sequencing revealed that Acetobacter and Komagataeibacter were the most predominant acetic acid bacteria. Furthermore, Dekkera and Bacillus were also the prominent yeast and bacteria in the kombucha SCOBY. A comparative analysis was performed for kombucha products fermented using black tea and a fusion of black tea and PPC, and the results revealed that the kombucha made from the black tea and PPC infusion exhibited a higher total phenolic content and antioxidant activity than the control kombucha. The antimicrobial properties of the kombucha products made from black tea and the PPC infusion were also greater than those of the control. Several volatile compounds that contributed to the flavor, aroma, and beneficial health properties, such as esters, carboxylic acids, phenols, alcohols, aldehydes, and ketones, were detected in kombucha products made from a fusion of black tea and PPC. This study shows that PPC exhibits high potential as a supplement to the raw material infusion used with black tea for functional kombucha production.
Topics: Tea; Ananas; Beverages; Yeasts; Antioxidants; Camellia sinensis; Phenols; Anti-Infective Agents; Acetobacteraceae; Fermentation
PubMed: 37188725
DOI: 10.1038/s41598-023-34954-7 -
New Biotechnology Sep 2023The development of bacterial cellulose (BC) industrialization has been seriously affected by its production. Mannose/mannan is an essential component in many biomass...
The development of bacterial cellulose (BC) industrialization has been seriously affected by its production. Mannose/mannan is an essential component in many biomass resources, but Komagataeibacter xylinus uses mannose in an ineffective way, resulting in waste. The aim of this study was to construct recombinant bacteria to use mannose-rich biomass efficiently as an alternative and inexpensive carbon source in place of the more commonly used glucose. This strategy aimed at modification of the mannose catabolic pathway via genetic engineering of K. xylinus ATCC 23770 strain through expression of mannose kinase and phosphomannose isomerase genes from the Escherichia coli K-12 strain. Recombinant and wild-type strains were cultured under conditions of glucose and mannose respectively as sole carbon sources. The fermentation process and physicochemical properties of BC were investigated in detail in the strains cultured in mannose media. The comparison showed that with mannose as the sole carbon source, the BC yield from the recombinant strain increased by 84%, and its tensile strength and elongation were increased 1.7 fold, while Young's modulus was increased 1.3 fold. The results demonstrated a successful improvement in BC yield and properties on mannose-based medium compared with the wild-type strain. Thus, the strategy of modifying the mannose catabolic pathway of K. xylinus is feasible and has significant potential in reducing the production costs for industrial production of BC from mannose-rich biomass.
Topics: Mannose; Cellulose; Escherichia coli K12; Gluconacetobacter xylinus; Glucose; Carbon
PubMed: 37182820
DOI: 10.1016/j.nbt.2023.05.002 -
Microbial Ecology Oct 2023Bacteria residing in the guts of pollinating insects play a key role in nutrient acquisition, digestion, and resistance to pests and diseases. Imbalances in microbial...
Bacteria residing in the guts of pollinating insects play a key role in nutrient acquisition, digestion, and resistance to pests and diseases. Imbalances in microbial flora in response to environmental change and stress can therefore impact insect health and resilience. This study is aimed at defining the core gut microbiome of the Australian native stingless bee, Tetragonula carbonaria, and exploring the impact of colony transplantation on gut health. The gut microbiomes of nine forager bees from natural (log) and manufactured (box) hives were examined via 16S rRNA gene amplicon sequencing. Some differences were observed at the ASV level between the microbiomes of log and box hive bees. However, a core microbiome, dominated by Lactobacillus spp., unclassified Acetobacteraceae spp., and Bombella spp., was maintained. Further, the inferred functional potential of the microbiomes was consistent across all individuals. This study highlights that although hive transplantation has an impact on the overall diversity of stingless bee gut microbiomes, it is unlikely to have a significant negative impact on the overall health and resilience of the colony.
Topics: Bees; Animals; Gastrointestinal Microbiome; Australia; RNA, Ribosomal, 16S; Microbiota; Urticaria
PubMed: 37088849
DOI: 10.1007/s00248-023-02222-w -
Frontiers in Bioengineering and... 2023Exopolysaccharides formation against harmful biotic and abiotic environmental influences is common among bacteria. By using renewable resources as a substrate,... (Review)
Review
Exopolysaccharides formation against harmful biotic and abiotic environmental influences is common among bacteria. By using renewable resources as a substrate, exopolysaccharides represent a sustainable alternative to fossil-based polymers as rheological modifiers in food, cosmetics, and pharmaceutical applications. The family of traditionally associated with fermented food products, has demonstrated their ability to produce a wide range of structural and functional different polymers with interesting physicochemical properties. Several strains are well known for their production of homopolysaccharides of high industrial importance, such as levan and bacterial cellulose. Moreover, some are able to form acetan-like heteropolysaccharides with a high structural resemblance to xanthan. This mini review summarizes the current knowledge and recent trends in both homo- and heteropolysaccharide production by .
PubMed: 37064223
DOI: 10.3389/fbioe.2023.1166618 -
Analysis of cellulose synthesis in a high-producing acetic acid bacterium Komagataeibacter hansenii.Applied Microbiology and Biotechnology May 2023Bacterial cellulose (BC) represents a renewable biomaterial with unique properties promising for biotechnology and biomedicine. Komagataeibacter hansenii ATCC 53,582 is...
Bacterial cellulose (BC) represents a renewable biomaterial with unique properties promising for biotechnology and biomedicine. Komagataeibacter hansenii ATCC 53,582 is a well-characterized high-yield producer of BC used in the industry. Its genome encodes three distinct cellulose synthases (CS), bcsAB1, bcsAB2, and bcsAB3, which together with genes for accessory proteins are organized in operons of different complexity. The genetic foundation of its high cellulose-producing phenotype was investigated by constructing chromosomal in-frame deletions of the CSs and of two predicted regulatory diguanylate cyclases (DGC), dgcA and dgcB. Proteomic characterization suggested that BcsAB1 was the decisive CS because of its high expression and its exclusive contribution to the formation of microcrystalline cellulose. BcsAB2 showed a lower expression level but contributes significantly to the tensile strength of BC and alters fiber diameter significantly as judged by scanning electron microscopy. Nevertheless, no distinct extracellular polymeric substance (EPS) from this operon was identified after static cultivation. Although transcription of bcsAB3 was observed, expression of the protein was below the detection limit of proteome analysis. Alike BcsAB2, deletion of BcsAB3 resulted in a visible reduction of the cellulose fiber diameter. The high abundance of BcsD and the accessory proteins CmcAx, CcpAx, and BglxA emphasizes their importance for the proper formation of the cellulosic network. Characterization of deletion mutants lacking the DGC genes dgcA and dgcB suggests a new regulatory mechanism of cellulose synthesis and cell motility in K. hansenii ATCC 53,582. Our findings form the basis for rational tailoring of the characteristics of BC. KEY POINTS: • BcsAB1 induces formation of microcrystalline cellulose fibers. • Modifications by BcsAB2 and BcsAB3 alter diameter of cellulose fibers. • Complex regulatory network of DGCs on cellulose pellicle formation and motility.
Topics: Acetic Acid; Extracellular Polymeric Substance Matrix; Proteomics; Acetobacteraceae; Cellulose
PubMed: 36930278
DOI: 10.1007/s00253-023-12461-z -
Biomaterials Advances May 2023Bacterial cellulose (BC) exhibits beneficial properties for use in biomedical applications but is limited by its lack of tunable transparency capabilities. To overcome...
Bacterial cellulose (BC) exhibits beneficial properties for use in biomedical applications but is limited by its lack of tunable transparency capabilities. To overcome this deficiency, a novel method to synthesize transparent BC materials using an alternative carbon source, namely arabitol, was developed. Characterization of the BC pellicles was performed for yield, transparency, surface morphology, and molecular assembly. Transparent BC was produced using mixtures of glucose and arabitol. Zero percent arabitol pellicles exhibited 25% light transmittance, which increased with increasing arabitol concentration through to 75% light transmittance. While transparency increased, overall BC yield was maintained indicating that the altered transparency may be induced on a micro-scale rather than a macro-scale. Significant differences in fiber diameter and the presence of aromatic signatures were observed. Overall, this research outlines methods for producing BC with tunable optical transparency, while also bringing new insight to insoluble components of exopolymers produced by Komagataeibacter hansenii.
Topics: Cellulose; Acetobacteraceae; Sugar Alcohols
PubMed: 36889229
DOI: 10.1016/j.bioadv.2023.213345 -
Brazilian Journal of Microbiology :... Jun 2023Bacterial cellulose (BC) is a biopolymer principally synthetized by strains of the genus Komagataeibacter. However, high costs and low production yield make large-scale...
Bacterial cellulose (BC) is a biopolymer principally synthetized by strains of the genus Komagataeibacter. However, high costs and low production yield make large-scale application difficult. The aim of this work was to evaluate the effects of successive batch culture before fermentation on the ability to increase the capacity of bacterial cellulose biosynthesis by a low-producing strain. The Komagataeibacter hansenii strain ATCC 23,769 was initially cultivated in fermentation broth for two periods of 35 or 56 days under static conditions. At the end of each period of time, they were transferred to new broth to be cultivated again (new batch culture cycle) for 35 or 56 days and carried out in parallel with a 10-day fermentation to determine the quantity of BC produced. As a result, a greater increase was observed after the end of the second and third batch cultures of 56 days (increases of 137% and 187% in relation to the nonbatch cultured strain, respectively). The produced samples presented higher crystallinity and thermal properties but lower water holding capacity. Through this work, it was concluded that the longer the batch culture time was, the greater the increase in the capacity of cellulose biosynthesis, which also depended on the number of successive batch culture cycles carried out.
Topics: Cellulose; Batch Cell Culture Techniques; Acetobacteraceae; Biopolymers
PubMed: 36800074
DOI: 10.1007/s42770-023-00910-w -
PLoS Neglected Tropical Diseases Feb 2023Opisthorchis felineus, Opisthorchis viverrini and Clonorchis sinensis are epidemiologically significant food-borne trematodes endemic to diverse climatic areas. O....
BACKGROUND
Opisthorchis felineus, Opisthorchis viverrini and Clonorchis sinensis are epidemiologically significant food-borne trematodes endemic to diverse climatic areas. O. viverrini and C. sinensis are both recognized to be 1A group of biological carcinogens to human, whereas O. felineus is not. The mechanisms of carcinogenesis by the liver flukes are studied fragmentarily, the role of host and parasite microbiome is an unexplored aspect.
METHODOLOGY/PRINCIPAL FINDINGS
Specific pathogen free Mesocricetus auratus hamsters were infected with C. sinensis, O. viverrini and O. felineus. The microbiota of the adult worms, colon feces and bile from the hamsters was investigated using Illumina-based sequencing targeting the prokaryotic 16S rRNA gene. The analysis of 43 libraries revealed 18,830,015 sequences, the bacterial super-kingdom, 16 different phyla, 39 classes, 63 orders, 107 families, 187 genera-level phylotypes. O. viverrini, a fluke with the most pronounced carcinogenic potential, has the strongest impact on the host bile microbiome, changing the abundance of 92 features, including Bifidobacteriaceae, Erysipelotrichaceae, [Paraprevotellaceae], Acetobacteraceae, Coriobacteraceae and Corynebacteriaceae bacterial species. All three infections significantly increased Enterobacteriaceae abundance in host bile, reduced the level of commensal bacteria in the gut microbiome (Parabacteroides, Roseburia, and AF12).
CONCLUSIONS/SIGNIFICANCE
O. felineus, O. viverrini, and C. sinensis infections cause both general and species-specific qualitative and quantitative changes in the composition of microbiota of bile and colon feces of experimental animals infected with these trematodes. The alterations primarily concern the abundance of individual features and the phylogenetic diversity of microbiomes of infected hamsters.
Topics: Humans; Cricetinae; Animals; Opisthorchis; Clonorchis sinensis; Fasciola hepatica; Opisthorchiasis; Phylogeny; RNA, Ribosomal, 16S; Mesocricetus; Fascioliasis; Microbiota
PubMed: 36780567
DOI: 10.1371/journal.pntd.0011111