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ACS Applied Materials & Interfaces Nov 2021Actuated structures are becoming relevant in medical fields; however, they call for flexible/soft-base materials that comply with biological tissues and can be...
Actuated structures are becoming relevant in medical fields; however, they call for flexible/soft-base materials that comply with biological tissues and can be synthesized in simple fabrication steps. In this work, we extend the palette of techniques to afford soft, actuable spherical structures taking advantage of the biosynthesis process of bacterial cellulose. Bacterial cellulose spheres (BCS) with localized magnetic nanoparticles (NPs) have been biosynthesized using two different one-pot processes: in agitation and on hydrophobic surface-supported static culture, achieving core-shell or hollow spheres, respectively. Magnetic actuability is conferred by superparamagnetic iron oxide NPs (SPIONs), and their location within the structure was finely tuned with high precision. The size, structure, flexibility and magnetic response of the spheres have been characterized. In addition, the versatility of the methodology allows us to produce actuated spherical structures adding other NPs (Au and Pt) in specific locations, creating Janus structures. The combination of Pt NPs and SPIONs provides moving composite structures driven both by a magnetic field and a HO oxidation reaction. Janus Pt/SPIONs increased by five times the directionality and movement of these structures in comparison to the controls.
Topics: Acetobacteraceae; Cellulose; Hydrogen Peroxide; Hydrophobic and Hydrophilic Interactions; Magnetic Fields; Magnetite Nanoparticles; Oxidation-Reduction; Particle Size; Surface Properties
PubMed: 34766498
DOI: 10.1021/acsami.1c17752 -
Genome Biology and Evolution Jan 2019Symbiosis is now recognized as a driving force in evolution, a role that finds its ultimate expression in the variety of associations bonding insects with microbial... (Comparative Study)
Comparative Study
Symbiosis is now recognized as a driving force in evolution, a role that finds its ultimate expression in the variety of associations bonding insects with microbial symbionts. These associations have contributed to the evolutionary success of insects, with the hosts acquiring the capacity to exploit novel ecological niches, and the symbionts passing from facultative associations to obligate, mutualistic symbioses. In bacterial symbiont of insects, the transition from the free-living life style to mutualistic symbiosis often resulted in a reduction in the genome size, with the generation of the smallest bacterial genomes thus far described. Here, we show that the process of genome reduction is still occurring in Asaia, a group of bacterial symbionts associated with a variety of insects. Indeed, comparative genomics of Asaia isolated from different mosquito species revealed a substantial genome size and gene content reduction in Asaia from Anopheles darlingi, a South-American malaria vector. We thus propose Asaia as a novel model to study genome reduction dynamics, within a single bacterial taxon, evolving in a common biological niche.
Topics: Acetobacteraceae; Animals; Culicidae; Female; Genome Size; Genome, Bacterial; Symbiosis
PubMed: 30476071
DOI: 10.1093/gbe/evy255 -
Applied Microbiology and Biotechnology Aug 2020The strains of the Komagataeibacter genus have been shown to be the most efficient bacterial nanocellulose producers. Although exploited for many decades, the studies of... (Review)
Review
The strains of the Komagataeibacter genus have been shown to be the most efficient bacterial nanocellulose producers. Although exploited for many decades, the studies of these species focused mainly on the optimisation of cellulose synthesis process through modification of culturing conditions in the industrially relevant settings. Molecular physiology of Komagataeibacter was poorly understood and only a few studies explored genetic engineering as a strategy for strain improvement. Only since recently the systemic information of the Komagataeibacter species has been accumulating in the form of omics datasets representing sequenced genomes, transcriptomes, proteomes and metabolomes. Genetic analyses of the mutants generated in the untargeted strain modification studies have drawn attention to other important proteins, beyond those of the core catalytic machinery of the cellulose synthase complex. Recently, modern molecular and synthetic biology tools have been developed which showed the potential for improving targeted strain engineering. Taking the advantage of the gathered knowledge should allow for better understanding of the genotype-phenotype relationship which is necessary for robust modelling of metabolism as well as selection and testing of new molecular engineering targets. In this review, we discuss the current progress in the area of Komagataeibacter systems biology and its impact on the research aimed at scaled-up cellulose synthesis as well as BNC functionalisation. Key points • The accumulated omics datasets advanced the systemic understanding of Komagataeibacter physiology at the molecular level. • Untargeted and targeted strain modification approaches have been applied to improve nanocellulose yield and properties. • The development of modern molecular and synthetic biology tools presents a potential for enhancing targeted strain engineering. • The accumulating omic information should improve modelling of Komagataeibacter's metabolism as well as selection and testing of new molecular engineering targets.
Topics: Acetobacteraceae; Carbohydrate Metabolism; Cellulose; Genetic Engineering; Genotype; Phenotype; Systems Biology
PubMed: 32529377
DOI: 10.1007/s00253-020-10671-3 -
Biotechnology Progress 2023Bacterial cellulose (BC) is a biopolymer with applications in numerous industries such as food and pharmaceutical sectors. In this study, various hydrocolloids including...
Modification of microstructure and selected physicochemical properties of bacterial cellulose produced by bacterial isolate using hydrocolloid-fortified Hestrin-Schramm medium.
Bacterial cellulose (BC) is a biopolymer with applications in numerous industries such as food and pharmaceutical sectors. In this study, various hydrocolloids including modified starches (oxidized starch-1404 and hydroxypropyl starch-1440), locust bean gum, xanthan gum (XG), guar gum, and carboxymethyl cellulose were added to the Hestrin-Schramm medium to improve the production performance and microstructure of BC by Gluconacetobacter entanii isolated from coconut water. After 14-day fermentation, medium supplemented with 0.1% carboxymethyl cellulose and 0.1% XG resulted in the highest BC yield with dry BC content of 9.82 and 6.06 g/L, respectively. In addition, scanning electron microscopy showed that all modified films have the characteristic three-dimensional network of cellulose nanofibers with dense structure and low porosity as well as larger fiber size compared to control. X-ray diffraction indicated that BC fortified with carboxymethyl cellulose exhibited lower crystallinity while Fourier infrared spectroscopy showed characteristic peaks of both control and modified BC films.
Topics: Gluconacetobacter xylinus; Carboxymethylcellulose Sodium; Cellulose; Carbohydrates; Starch
PubMed: 37025043
DOI: 10.1002/btpr.3344 -
Genome Biology and Evolution Oct 2020Recent declines in the health of the honey bee have startled researchers and lay people alike as honey bees are agriculture's most important pollinator. Honey bees are... (Comparative Study)
Comparative Study
Recent declines in the health of the honey bee have startled researchers and lay people alike as honey bees are agriculture's most important pollinator. Honey bees are important pollinators of many major crops and add billions of dollars annually to the US economy through their services. One factor that may influence colony health is the microbial community. Indeed, the honey bee worker digestive tract harbors a characteristic community of bee-specific microbes, and the composition of this community is known to impact honey bee health. However, the honey bee is a superorganism, a colony of eusocial insects with overlapping generations where nestmates cooperate, building a hive, gathering and storing food, and raising brood. In contrast to what is known regarding the honey bee worker gut microbiome, less is known of the microbes associated with developing brood, with food stores, and with the rest of the built hive environment. More recently, the microbe Bombella apis was identified as associated with nectar, with developing larvae, and with honey bee queens. This bacterium is related to flower-associated microbes such as Saccharibacter floricola and other species in the genus Saccharibacter, and initial phylogenetic analyses placed it as sister to these environmental bacteria. Here, we used comparative genomics of multiple honey bee-associated strains and the nectar-associated Saccharibacter to identify genomic changes that may be associated with the ecological transition to honey bee association. We identified several genomic differences in the honey bee-associated strains, including a complete CRISPR/Cas system. Many of the changes we note here are predicted to confer upon Bombella the ability to survive in royal jelly and defend themselves against mobile elements, including phages. Our results are a first step toward identifying potential function of this microbe in the honey bee superorganism.
Topics: Acetic Acid; Acetobacteraceae; Animals; Bees; Gene Transfer, Horizontal; Genome, Bacterial; Phylogeny; Symbiosis
PubMed: 32870981
DOI: 10.1093/gbe/evaa183 -
PLoS Biology Apr 2017Choosing the right nutrients to consume is essential to health and wellbeing across species. However, the factors that influence these decisions are poorly understood.... (Comparative Study)
Comparative Study
Choosing the right nutrients to consume is essential to health and wellbeing across species. However, the factors that influence these decisions are poorly understood. This is particularly true for dietary proteins, which are important determinants of lifespan and reproduction. We show that in Drosophila melanogaster, essential amino acids (eAAs) and the concerted action of the commensal bacteria Acetobacter pomorum and Lactobacilli are critical modulators of food choice. Using a chemically defined diet, we show that the absence of any single eAA from the diet is sufficient to elicit specific appetites for amino acid (AA)-rich food. Furthermore, commensal bacteria buffer the animal from the lack of dietary eAAs: both increased yeast appetite and decreased reproduction induced by eAA deprivation are rescued by the presence of commensals. Surprisingly, these effects do not seem to be due to changes in AA titers, suggesting that gut bacteria act through a different mechanism to change behavior and reproduction. Thus, eAAs and commensal bacteria are potent modulators of feeding decisions and reproductive output. This demonstrates how the interaction of specific nutrients with the microbiome can shape behavioral decisions and life history traits.
Topics: Acetobacter; Acetobacteraceae; Amino Acids, Essential; Animals; Animals, Genetically Modified; Appetite Regulation; Behavior, Animal; Complex Mixtures; Drosophila Proteins; Drosophila melanogaster; Enterococcus faecalis; Feeding Behavior; Female; Food Preferences; Gastrointestinal Microbiome; Gene Knockout Techniques; Host-Parasite Interactions; Lactobacillus; Oviposition; Species Specificity; Symbiosis; Yeast, Dried
PubMed: 28441450
DOI: 10.1371/journal.pbio.2000862 -
Preparative Biochemistry & Biotechnology 2022Vinegar is a common food additive produced by acetic acid bacteria (AAB) during fermentation process. Low yield and long incubation time in conventional vinegar...
Vinegar is a common food additive produced by acetic acid bacteria (AAB) during fermentation process. Low yield and long incubation time in conventional vinegar fermentation processes has inspired research in developing efficient fermentation techniques by the activation of AAB for acetic acid production. The present study intends to enhance vinegar production using acetic acid bacteria and light emitting diode (LED). A total of eight acetic acid bacteria were isolated from Korean traditional vinegar and assessed for vinegar production. Isolate AP01 exhibited maximum vinegar production and was identified as based on the 16S rRNA sequences. The optimum fermentation conditions for the isolate AP01 was incubation under static condition at 30 °C for 10 days with 6% initial ethanol concentration. Fermentation under red LED light exhibited maximum vinegar production (3.6%) compared to green (3.5%), blue (3.2%), white (2.2%), and non-LED lights (3.0%). Vinegar produced using red LED showed less toxicity to mouse macrophage cell line (RAW 264.7) and high inhibitory effects on nitric oxide and IL-6 production. The results confirmed that red LED light could be used to increase the yield and decrease incubation time in vinegar fermentation process.
Topics: Acetic Acid; Acetobacter; Fermentation; Industrial Microbiology; Light; RNA, Ribosomal, 16S
PubMed: 33904376
DOI: 10.1080/10826068.2021.1907406 -
BMC Biotechnology Aug 2020Cellulose, the most versatile biomolecule on earth, is available in large quantities from plants. However, cellulose in plants is accompanied by other polymers like...
BACKGROUND
Cellulose, the most versatile biomolecule on earth, is available in large quantities from plants. However, cellulose in plants is accompanied by other polymers like hemicellulose, lignin, and pectin. On the other hand, pure cellulose can be produced by some microorganisms, with the most active producer being Acetobacter xylinum. A. senengalensis is a gram-negative, obligate aerobic, motile coccus, isolated from Mango fruits in Senegal, capable of utilizing a variety of sugars and produce cellulose. Besides, the production is also influenced by other culture conditions. Previously, we isolated and identified A. senengalensis MA1, and characterized the bacterial cellulose (BC) produced.
RESULTS
The maximum cellulose production by A. senengalensis MA1 was pre-optimized for different parameters like carbon, nitrogen, precursor, polymer additive, pH, temperature, inoculum concentration, and incubation time. Further, the pre-optimized parameters were pooled, and the best combination was analyzed by using Central Composite Design (CCD) of Response Surface Methodology (RSM). Maximum BC production was achieved with glycerol, yeast extract, and PEG 6000 as the best carbon and nitrogen sources, and polymer additive, respectively, at 4.5 pH and an incubation temperature of 33.5 °C. Around 20% of inoculum concentration gave a high yield after 30 days of inoculation. The interactions between culture conditions optimized by CCD included alterations in the composition of the HS medium with 50 mL L of glycerol, 7.50 g L of yeast extract at pH 6.0 by incubating at a temperature of 33.5 °C along with 7.76 g L of PEG 6000. This gave a BC yield of wet weight as 469.83 g L.
CONCLUSION
The optimized conditions of growth medium resulted in enhanced production of bacterial cellulose by A. senegalensis MA1, which is around 20 times higher than that produced using an unoptimized HS medium. Further, the cellulose produced can be used in food and pharmaceuticals, for producing high-quality paper, wound dressing material, and nanocomposite films for food packaging.
Topics: Acetobacter; Carbon; Cell Culture Techniques; Cellulose; Culture Media; Gluconacetobacter xylinus; Glycerol; Hydrogen-Ion Concentration; Nitrogen; Temperature
PubMed: 32843009
DOI: 10.1186/s12896-020-00639-6 -
Microbial Cell Factories Oct 2016Acetic acid bacteria (AAB) are well known producers of commercially used exopolysaccharides, such as cellulose and levan. Kozakia (K.) baliensis is a relatively new...
BACKGROUND
Acetic acid bacteria (AAB) are well known producers of commercially used exopolysaccharides, such as cellulose and levan. Kozakia (K.) baliensis is a relatively new member of AAB, which produces ultra-high molecular weight levan from sucrose. Throughout cultivation of two K. baliensis strains (DSM 14400, NBRC 16680) on sucrose-deficient media, we found that both strains still produce high amounts of mucous, water-soluble substances from mannitol and glycerol as (main) carbon sources. This indicated that both Kozakia strains additionally produce new classes of so far not characterized EPS.
RESULTS
By whole genome sequencing of both strains, circularized genomes could be established and typical EPS forming clusters were identified. As expected, complete ORFs coding for levansucrases could be detected in both Kozakia strains. In K. baliensis DSM 14400 plasmid encoded cellulose synthase genes and fragments of truncated levansucrase operons could be assigned in contrast to K. baliensis NBRC 16680. Additionally, both K. baliensis strains harbor identical gum-like clusters, which are related to the well characterized gum cluster coding for xanthan synthesis in Xanthomanas campestris and show highest similarity with gum-like heteropolysaccharide (HePS) clusters from other acetic acid bacteria such as Gluconacetobacter diazotrophicus and Komagataeibacter xylinus. A mutant strain of K. baliensis NBRC 16680 lacking EPS production on sucrose-deficient media exhibited a transposon insertion in front of the gumD gene of its gum-like cluster in contrast to the wildtype strain, which indicated the essential role of gumD and of the associated gum genes for production of these new EPS. The EPS secreted by K. baliensis are composed of glucose, galactose and mannose, respectively, which is in agreement with the predicted sugar monomer composition derived from in silico genome analysis of the respective gum-like clusters.
CONCLUSIONS
By comparative sugar monomer and genome analysis, the polymeric substances secreted by K. baliensis can be considered as unique HePS. Via genome sequencing of K. baliensis DSM 14400 + NBRC 16680 we got first insights into the biosynthesis of these novel HePS, which is related to xanthan and acetan biosynthesis. Consequently, the present study provides the basis for establishment of K. baliensis strains as novel microbial cell factories for biotechnologically relevant, unique polysaccharides.
Topics: Acetic Acid; Acetobacteraceae; Bacterial Proteins; Base Sequence; Cellulose; Computer Simulation; DNA Transposable Elements; Fructans; Genome, Bacterial; Gluconacetobacter xylinus; Glycerol; Mannitol; Operon; Polysaccharides, Bacterial; Sequence Analysis, DNA; Sucrose
PubMed: 27716345
DOI: 10.1186/s12934-016-0572-x -
Carbohydrate Polymers Jan 2016This study was aimed to characterize the structural and physico-mechanical properties of bio-cellulose produced through cell-free system. Fourier transform-infrared...
This study was aimed to characterize the structural and physico-mechanical properties of bio-cellulose produced through cell-free system. Fourier transform-infrared spectrum illustrated exact matching of structural peaks with microbial cellulose, used as reference. Field-emission scanning electron microscopy revealed that fibrils of bio-cellulose were thicker and more compact than microbial cellulose. The specific positions of peaks in the X-ray diffraction and nuclear magnetic resonance spectra indicated that bio-cellulose possessed cellulose II polymorphic structure. Bio-cellulose presented superior physico-mechanical properties than microbial cellulose. The water holding capacity of bio-cellulose and microbial cellulose were found to be 188.6 ± 5.41 and 167.4 ± 4.32 times their dry-weights, respectively. Tensile strengths and degradation temperature of bio-cellulose were 17.63 MPa and 352 °C, respectively compared to 14.71 MPa and 327 °C of microbial cellulose. Overall, the results indicated successful synthesis and superior properties of bio-cellulose that advocate its effectiveness for various applications.
Topics: Cell-Free System; Cellulose; Gluconobacter; Hydrolysis; Hydrophobic and Hydrophilic Interactions; Industrial Microbiology; Polysaccharides, Bacterial; Tensile Strength
PubMed: 26572428
DOI: 10.1016/j.carbpol.2015.10.010