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ACS Biomaterials Science & Engineering Apr 2021The bacterial skin studied here is a several centimeter-wide colony of living on a cellulose-based hydrogel. We demonstrate that the colony exhibits trains of spikes of...
The bacterial skin studied here is a several centimeter-wide colony of living on a cellulose-based hydrogel. We demonstrate that the colony exhibits trains of spikes of extracellular electrical potential, with amplitudes of the spikes varying from 1 to 17 mV. The bacterial pad responds to mechanical stimulation with distinctive changes in its electrical activity. While studying the passive electrical properties of the bacterial pad, we found that the pad provides an open-circuit voltage drop (between 7 and 25 mV) and a small short-circuit current (1.5-4 nA). We also observed by pulsed tomography and spatially resolved impedance spectroscopy that the conduction occurs along preferential paths, with the peculiar side-effect of having a higher resistance between closer electrodes. We speculate that the Acetobacter biofilms could be utilized in the development of living skin for soft robots: such skin will act as an electrochemical battery and a reactive tactile sensor. It could even be used for wearable devices.
Topics: Acetobacter; Biofilms; Electronics; Wearable Electronic Devices
PubMed: 33780232
DOI: 10.1021/acsbiomaterials.0c01804 -
International Journal of Biological... Oct 2018The morphology and structure of the biosynthesized cellulose are related to the culture methods and conditions. In order to investigate the detail culture conditions,...
The morphology and structure of the biosynthesized cellulose are related to the culture methods and conditions. In order to investigate the detail culture conditions, the Gluconacetbacter xylinum 1.1812 (ATCC 23767) strains were cultivated in static culture at 12 and 30 °C, and agitated culture at 12 °C. The cellulose samples were analyzed by FESEM, FTIR, CP/MAS C NMR, WAXRD and TGA. The cellulose membrane produced in static medium at 30 °C is made up of the microfibrils with a width of 60-90 nm, which has highest crystallinity index and the most content of cellulose I. The cellulose membrane produced in static medium at 12 °C is accumulated by the pellicles with a thickness of ~10 nm and a width of 700-3000 nm, which is cellulose I crystalline structure. The macroscopic sphere-like cellulose produced in agitated culture at 12 °C is composed of flat, strongly twisted cellulose bands with a width of 700-1200 nm, and reveals completely amorphous structure which exhibits only the diffuse X-ray diffraction pattern, lack of characteristic crystalline peaks. This work provides a new method to prepare amorphous cellulose.
Topics: Bioreactors; Cellulose; Culture Techniques; Gluconacetobacter xylinus; Temperature
PubMed: 29883701
DOI: 10.1016/j.ijbiomac.2018.06.013 -
International Journal of Biological... Nov 2020This study focused on the investigation of bacterial cellulose production potency of some fruit and vegetable peels (cucumber, melon, kiwifruit, tomato, apple, quince...
This study focused on the investigation of bacterial cellulose production potency of some fruit and vegetable peels (cucumber, melon, kiwifruit, tomato, apple, quince and pomegranate) with Komagataeibacter hansenii GA2016. Fruit and vegetable peels were hydrolyzed, used for bacterial cellulose (BC) production and their chemical, physical, thermal and structural features were compared to BC from Hestrin-Schramm medium (HSBC) and plant cellulose (CP). Except for pomegranate peel hydrolysate, all the fruit and vegetable peel hydrolysates supplied to K. hansenii GA2016 supported the BC production. Among the fruit and vegetable peel hydrolysates, the highest BC production was observed in kiwifruit peel hydrolysate (11.53%), while the lowest production was observed in apple peel hydrolysate (1.54%). Water-holding capacities of the BCs were ranged from 627.50% to 928.79% and higher than HSBC (609.30%), average fiber diameters were ranged from 47.64 nm to 61.11 nm and thinner than HSBC (74.29) and CP (10,420 nm), crystallinities were ranged from 80.27% to 92.96%, thermal capacities BCs were higher than HSBC and CP. For the BC productions, utilization of the fruit and vegetable peels as the sole nutrient source could reduce the production costs and among the polysaccharides, increase the use of BC in industry.
Topics: Acetobacteraceae; Cellulose; Culture Media; Fermentation; Fruit; Vegetables
PubMed: 32777420
DOI: 10.1016/j.ijbiomac.2020.08.049 -
Carbohydrate Polymers Aug 2023Bacterial cellulose (BC) is a bio-produced nanostructure material widely used in biomedical, food, and paper-manufacturing industries. However, low production efficiency...
Bacterial cellulose (BC) is a bio-produced nanostructure material widely used in biomedical, food, and paper-manufacturing industries. However, low production efficiency and high-cost have limited its industrial applications. This study aimed to examine the level of improvement in BC production by co-culturing Bacillus cereus and Komagataeibacter xylinus. The BC yield in corn stover enzymatic hydrolysate was found to be obviously enhanced from 1.2 to 4.4 g/L after the aforementioned co-culturing. The evidence indicated that acetoin (AC) and 2,3-butanediol (2,3-BD) produced by B. cereus were the key factors dominating BC increment. The mechanism underlying BC increment was that AC and 2,3-BD increased the specific activity of AC dehydrogenase and the contents of adenosine triphosphate (ATP) and acetyl coenzyme A (acetyl-CoA), thus promoting the growth and energy level of K. xylinus. Meanwhile, the immobilization of BC could also facilitate oxygen acquisition in B. cereus under static conditions. This study was novel in reporting that the co-culture could effectively enhance BC production from the lignocellulosic enzymatic hydrolysate.
Topics: Bacillus cereus; Cellulose; Coculture Techniques; Nanostructures; Gluconacetobacter xylinus
PubMed: 37182977
DOI: 10.1016/j.carbpol.2023.120892 -
International Journal of Systematic and... Mar 2019A Gram-stain-negative, strictly aerobic, catalase-positive and oxidase-positive bacterium, designated strain HR-AS, was isolated from a water sample of the Han River...
A Gram-stain-negative, strictly aerobic, catalase-positive and oxidase-positive bacterium, designated strain HR-AS, was isolated from a water sample of the Han River located in the Republic of Korea. Cells were motile rods with a polar flagellum. Growth was observed at 5-35 °C (optimum of 25 °C) and pH 6-8 (optimum of pH 7) and in the presence of 0-2 % (w/v) NaCl (optimum of 0 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HR-AS formed a tight phylogenic lineage with Zavarzinia compransoris LMG 5821. Strain HR-AS was most closely related to Z. compransoris LMG 5821 with a 98.7 % 16S rRNA gene sequence similarity and had very low similarities (below 91.0 %) to other type strains with validly published names. Average nucleotide identity and in silico DNA-DNA hybridization values between strain HR-AS and Z. compransoris DSM 1231 were 80.4 and 23.1 %, respectively. Strain HR-AS contained ubiquinone-10 as the major quinone and homospermidine and putrescine as the major polyamines. The major fatty acids were summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c), C16 : 0 and C18 : 1 2-OH. Strain HR-AS contained diphosphatidylglycerol, an unidentified aminolipid and two unidentified phospholipids as major polar lipids. The DNA G+C content of strain HR-AS was 67.2 mol%. Based on the genotypic, chemotaxonomic and phenotypic analyses, strain HR-AS represents a novel species of the genus Zavarzinia, for which the name Zavarziniaaquatilis sp. nov. is proposed. The type strain is HR-AS (=KACC 19412=JCM 32263).
Topics: Acetobacteraceae; Bacterial Typing Techniques; Base Composition; DNA, Bacterial; Fatty Acids; Nucleic Acid Hybridization; Phospholipids; Phylogeny; Putrescine; RNA, Ribosomal, 16S; Republic of Korea; Rivers; Sequence Analysis, DNA; Spermidine; Ubiquinone
PubMed: 30605080
DOI: 10.1099/ijsem.0.003214 -
Microbial Cell Factories Jun 2017Acetic acid bacteria (AAB) are widely applied in food, bioengineering and medicine fields. However, the acid stress at low pH conditions limits acetic acid fermentation...
BACKGROUND
Acetic acid bacteria (AAB) are widely applied in food, bioengineering and medicine fields. However, the acid stress at low pH conditions limits acetic acid fermentation efficiency and high concentration of vinegar production with AAB. Therefore, how to enhance resistance ability of the AAB remains as the major challenge. Amino acids play an important role in cell growth and cell survival under severe environment. However, until now the effects of amino acids on acetic fermentation and acid stress resistance of AAB have not been fully studied.
RESULTS
In the present work the effects of amino acids on metabolism and acid stress resistance of Acetobacter pasteurianus were investigated. Cell growth, culturable cell counts, acetic acid production, acetic acid production rate and specific production rate of acetic acid of A. pasteurianus revealed an increase of 1.04, 5.43, 1.45, 3.30 and 0.79-folds by adding aspartic acid (Asp), and cell growth, culturable cell counts, acetic acid production and acetic acid production rate revealed an increase of 0.51, 0.72, 0.60 and 0.94-folds by adding glutamate (Glu), respectively. For a fully understanding of the biological mechanism, proteomic technology was carried out. The results showed that the strengthening mechanism mainly came from the following four aspects: (1) Enhancing the generation of pentose phosphates and NADPH for the synthesis of nucleic acid, fatty acids and glutathione (GSH) throughout pentose phosphate pathway. And GSH could protect bacteria from low pH, halide, oxidative stress and osmotic stress by maintaining the viability of cells through intracellular redox equilibrium; (2) Reinforcing deamination of amino acids to increase intracellular ammonia concentration to maintain stability of intracellular pH; (3) Enhancing nucleic acid synthesis and reparation of impaired DNA caused by acid stress damage; (4) Promoting unsaturated fatty acids synthesis and lipid transport, which resulted in the improvement of cytomembrane fluidity, stability and integrity.
CONCLUSIONS
The present work is the study to show the effectiveness of Asp and Glu on metabolism and acid stress resistance of A. pasteurianus as well as their working mechanism. The research results will be helpful for development of nutrient salts, the optimization and regulation of high concentration of cider vinegar production process.
Topics: Acetic Acid; Acetobacter; Aspartic Acid; Fatty Acids; Fermentation; Glutamic Acid; Glutathione; NADP; Oxidation-Reduction; Pentose Phosphate Pathway; Proteomics; Stress, Physiological
PubMed: 28619110
DOI: 10.1186/s12934-017-0717-6 -
PloS One 2022Mosquitoes transmit many pathogens responsible for human diseases, such as malaria which is caused by parasites in the genus Plasmodium. Current strategies to control...
Mosquitoes transmit many pathogens responsible for human diseases, such as malaria which is caused by parasites in the genus Plasmodium. Current strategies to control vector-transmitted diseases are increasingly undermined by mosquito and pathogen resistance, so additional methods of control are required. Paratransgenesis is a method whereby symbiotic bacteria are genetically modified to affect the mosquito's phenotype by engineering them to deliver effector molecules into the midgut to kill parasites. One paratransgenesis candidate is Asaia bogorensis, a Gram-negative bacterium colonizing the midgut, ovaries, and salivary glands of Anopheles sp. mosquitoes. Previously, engineered Asaia strains using native signals to drive the release of the antimicrobial peptide, scorpine, fused to alkaline phosphatase were successful in significantly suppressing the number of oocysts formed after a blood meal containing P. berghei. However, these strains saw high fitness costs associated with the production of the recombinant protein. Here, we report evaluation of five different partner proteins fused to scorpine that were evaluated for effects on the growth and fitness of the transgenic bacteria. Three of the new partner proteins resulted in significant levels of protein released from the Asaia bacterium while also significantly reducing the prevalence of mosquitoes infected with P. berghei. Two partners performed as well as the previously tested Asaia strain that used alkaline phosphatase in the fitness analyses, but neither exceeded it. It may be that there is a maximum level of fitness and parasite inhibition that can be achieved with scorpine being driven constitutively, and that use of a Plasmodium specific effector molecule in place of scorpine would help to mitigate the stress on the symbionts.
Topics: Acetobacteraceae; Alkaline Phosphatase; Animals; Biological Control Agents; Defensins; Malaria; Mosquito Vectors; Plasmodium; Recombinant Proteins
PubMed: 36048823
DOI: 10.1371/journal.pone.0273568 -
International Journal of Systematic and... Feb 2023Acetic acid bacteria (family ) are found in the gut of most insects. Two clades are currently recognized: and a-. The latter group is only found in hymenopteran insects...
Acetic acid bacteria (family ) are found in the gut of most insects. Two clades are currently recognized: and a-. The latter group is only found in hymenopteran insects and the described species have been isolated from bees and ants. In this study, two new strains DDB2-T1 (=KACC 21507=LMG 31759) and DM15PD (=CCM 9165=DSM 112731=KACC 22353=LMG 32454) were isolated from wasps collected in the Republic of Korea and Germany, respectively. Molecular and phenotypic analysis revealed that the strains are closely related, with 16S rRNA gene sequences showing 100 % identity and genomic average nucleotide identity (ANI) values ≥99 %. The closest related species based on type strain 16S rRNA gene sequences are , , and (94.8-94.7% identity), whereas the closest related species based on type strain genome analysis are and (ANI values of 68.8 and 68.2 %, respectively). The reconstruction of a phylogenomic tree based on 107 core proteins revealed that the branch leading to DDB2-T1 and DM15PD is localized between and . Further genomic distance metrics such as ANI, percentage of conserved proteins and alignment fraction values were consistent with these strains belonging to a new genus. The key phenotypic characteristics were one MALDI-TOF-MS peak (m/z=4601.9±2.0) and the ability to produce acid from d-arabinose. Based on this polyphasic approach, including phylogenetics, phylogenomics, genome distance calculations, ecology and phenotypic characteristics, we propose to name the novel strains gen. nov., sp. nov., with the type strain DDB2-T1 (=KACC 21507=LMG 31759).
Topics: Bees; Animals; Ants; Wasps; Fatty Acids; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Phylogeny; Base Composition; DNA, Bacterial; Bacterial Typing Techniques; Acetobacteraceae
PubMed: 36749681
DOI: 10.1099/ijsem.0.005699 -
Applied Microbiology and Biotechnology May 2019Only a few cobalamin-producing bacterial species are known which are suitable for food fermentations. The strain of Acetobacter pasteurianus DSM 3509 was found to have...
Only a few cobalamin-producing bacterial species are known which are suitable for food fermentations. The strain of Acetobacter pasteurianus DSM 3509 was found to have the capability to synthesize cobalamin. A survival test and a preliminary genetic study of the gene of uroporphyrinogen-III synthase indicated the ability to synthesize cobalamin. By a modified microbiological assay based on Lactobacillus delbrueckii ssp. lactis DSM 20355, 4.57 ng/mL of cyanocorrinoids and 0.75 ng/mL of noncorrinoid growth factors were detected. The product extracted and isolated by immunoaffinity chromatography in its cyanide form had the similar UV spectrum as standard cyanocobalamin and Coα-[α-(7-adenyl)]-(Coβ-cyano) cobamide also known as pseudovitamin B produced by Lactobacillus reuteri DSM 20016. The chromatographically separated product of A. pasteurianus was subjected to mass spectrometrical analysis. There, its fragmentation pattern turned out to be equivalent to that of cyanocobalamin also produced by Propionibacterium freudenreichii ssp. freudenreichii DSM 20271 and clearly differs from pseudovitamin B. Due to the presence of this species in several food applications, there might be cobalamin residues in food fermented with these bacteria.
Topics: Acetobacter; Cobamides; Limosilactobacillus reuteri; Mass Spectrometry; Propionibacterium; Vitamin B 12
PubMed: 30911787
DOI: 10.1007/s00253-019-09704-3 -
Molecular Ecology Feb 2019Acacia-ant mutualists in the genus Pseudomyrmex nest obligately in acacia plants and, as we show through stable isotope analysis, feed at a remarkably low trophic level....
Acacia-ant mutualists in the genus Pseudomyrmex nest obligately in acacia plants and, as we show through stable isotope analysis, feed at a remarkably low trophic level. Insects with diets such as these sometimes depend on bacterial symbionts for nutritional enrichment. We, therefore, examine the bacterial communities associated with acacia-ants in order to determine whether they host bacterial partners likely to contribute to their nutrition. Despite large differences in trophic position, acacia-ants and related species with generalized diets do not host distinct bacterial taxa. However, we find that a small number of previously undescribed bacterial taxa do differ in relative abundance between acacia-ants and generalists, including several Acetobacteraceae and Nocardiaceae lineages related to common insect associates. Comparisons with an herbivorous generalist, a parasite that feeds on acacias and a mutualistic species with a generalized diet show that trophic level is likely responsible for these small differences in bacterial community structure. While we did not experimentally test for a nutritional benefit to hosts of these bacterial lineages, metagenomic analysis reveals a Bartonella relative with an intact nitrogen-recycling pathway widespread across Pseudomyrmex mutualists and generalists. This taxon may be contributing to nitrogen enrichment of its ant hosts through urease activity and, concordant with an obligately host-associated lifestyle, appears to be experiencing genomewide relaxed selection. The lack of distinctiveness in bacterial communities across trophic level in this group of ants shows a remarkable ability to adjust to varied diets, possibly with assistance from these diverse ant-specific bacterial lineages.
Topics: Acacia; Acetobacteraceae; Animals; Ants; Bartonella; Herbivory; Metagenomics; Microbiota; Nocardiaceae; Symbiosis
PubMed: 30106217
DOI: 10.1111/mec.14834