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Bioengineered Apr 2022Agricultural residues are constantly increasing with increased farming processes, and improper disposal is detrimental to the environment. Majority of these waste...
Agricultural residues are constantly increasing with increased farming processes, and improper disposal is detrimental to the environment. Majority of these waste residues are rich in lignocellulose, which makes them suitable substrate for bacterial fermentation in the production of value-added products. In this study, bacterial cellulose (BC), a purer and better form of cellulose, was produced by two sp. isolated from rotten banana and kombucha drink using corncob (CC) and sugarcane bagasse (SCB) enzymatic hydrolyzate, under different fermentation conditions, that is, static, continuous, and intermittent agitation. The physicochemical and mechanical properties of the BC films were then investigated by Fourier Transformed Infrared Spectroscopy (FTIR), Thermogravimetry analysis, Field Emission Scanning Electron Microscopy (FE-SEM), and Dynamic mechanical analysis. Agitation gave a higher BC yield, with sp. CCUG73629 producing BC from CC with a dry weight of 1.6 g/L and 1.4 g/L under continuous and intermittent agitation, respectively, compared with that of 0.9 g/L in HS medium. While BC yield of dry weight up to 1.2 g/L was obtained from SCB by sp. CCUG73630 under continuous agitation compared to that of 0.3 g/L in HS medium. FTIR analysis showed BC bands associated with cellulose I, with high thermal stability. The FE-SEM analysis showed that BC fibers were highly ordered and densely packed. Although the BC produced by both strains showed similar physicochemical and morphological properties, the BC produced by the sp. CCUG73630 in CC under intermittent agitation had the best modulus of elasticity, 10.8 GPa and tensile strength, 70.9 MPa.
Topics: Acetobacteraceae; Agriculture; Cellulose; Culture Media; Fermentation; Saccharum
PubMed: 35416127
DOI: 10.1080/21655979.2022.2062970 -
Applied Microbiology and Biotechnology Jun 2021Acetic acid bacteria (AAB) are a group of Gram-negative and strictly aerobic microorganisms widely used in vinegar industry, especially the species belonging to the... (Review)
Review
Acetic acid bacteria (AAB) are a group of Gram-negative and strictly aerobic microorganisms widely used in vinegar industry, especially the species belonging to the genera Acetobacter and Komagataeibacter. The environments inhabited by AAB during the vinegar fermentation, in particular those natural traditional bioprocesses, are complex and dynamically changed, usually accompanied by diverse microorganisms, bacteriophages, and the increasing acetic acid concentration. For this reason, how AAB survive to such harsh niches has always been an interesting research field. Previous omic analyses (e.g., genomics, proteomics, and transcriptomics) have provided abundant clues for the metabolic pathways and bioprocesses indispensable for the acid stress adaptation of AAB. Nevertheless, it is far from fully understanding what factors regulate these modular mechanisms overtly and covertly upon shifting environments. Bacterial toxin-antitoxin systems (TAS), usually consisting of a pair of genes encoding a stable toxin and an unstable antitoxin that is capable of counteracting the toxin, have been uncovered to have a variety of biological functions. Recent studies focusing on the role of TAS in Acetobacter pasteurianus suggest that TAS contribute substantially to the acid stress resistance. In this mini review, we discuss the biological functions of type II TAS in the context of AAB with regard to the acid stress resistance, persister formation and resuscitation, genome stability, and phage immunity. KEY POINTS: • Type II TAS act as regulators in the acid stress resistance of AAB. • Type II TAS are implicated in the formation of acid-tolerant persister cells in AAB. • Type II TAS are potential factors responsible for phage immunity and genome stability.
Topics: Acetic Acid; Acetobacter; Cell Physiological Phenomena; Fermentation; Toxin-Antitoxin Systems
PubMed: 34021811
DOI: 10.1007/s00253-021-11357-0 -
Antonie Van Leeuwenhoek Aug 2022In this study, a novel bacterium designated F3b2 was isolated from the gut sample of weaver ant Oecophylla smaragdina and characterised. Strain F3b2 was a Gram-negative,...
In this study, a novel bacterium designated F3b2 was isolated from the gut sample of weaver ant Oecophylla smaragdina and characterised. Strain F3b2 was a Gram-negative, aerobic, non-motile, ovoid-shaped bacterium and grows optimally at 28-30 °C. Its major respiratory quinone is ubiquinone 10 (Q-10) and the major fatty acids are C ω7c, C cyclo ω8c and C, representing 85% of the total fatty acids. The 16S rRNA gene sequence of strain F3b2 was highest in similarity to that of Oecophyllibacter saccharovorans DSM106907 and Swingsia samuieinsis NBRC 107927 at 94.35% and 91.96%, respectively. A 16S rRNA gene-based phylogenetic analysis and a core genes-based phylogenomic analysis placed strain F3b2 in a distinct lineage in the family Acetobacteraceae. The phylogenetic placement was supported by lower than species delineation threshold average nucleotide identity (ANI) (≤ 70.2%), in silico DNA-DNA hybridization (DDH) (≤ 39.5%) and average amino acid identity (AAI) (≤ 63.5%) values between strain F3b2 and closest neighbours. These overall genome relatedness indices also supported the assignment of strain F3b2 to a novel genus within Acetobacteraceae. The genome of strain F3b2 was 1.96 Mb with 60.4% G + C DNA content. Based on these results, strain F3b2 represented a novel taxon of Acetobacteraceae, for which we proposed the name Formicincola oecophyllae gen. nov. sp. nov., and strain F3b2 (= LMG 30590 = DSM 106908 = NBRC 113640 = KCTC 62951) as the type strain.
Topics: Acetobacteraceae; Animals; Ants; Bacterial Typing Techniques; DNA, Bacterial; Fatty Acids; Phospholipids; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Ubiquinone
PubMed: 35674967
DOI: 10.1007/s10482-022-01750-8 -
International Journal of Environmental... Jan 2022Biorefineries are attracting attention as an alternative to the petroleum industry to reduce carbon emissions and achieve sustainable development. In particular, because...
Biorefineries are attracting attention as an alternative to the petroleum industry to reduce carbon emissions and achieve sustainable development. In particular, because forests play an important role in potentially reducing greenhouse gas emissions to net zero, alternatives to cellulose produced by plants are required. Bacterial cellulose (BC) can prevent deforestation and has a high potential for use as a biomaterial in various industries such as food, cosmetics, and pharmaceuticals. This study aimed to improve BC production from lignocellulose, a sustainable feedstock, and to optimize the culture conditions for using hydrolysates as a medium. The productivity of BC was improved using statistical optimization of the major culture parameters which were as follows: temperature, 29 °C; initial pH, 5.1; and sodium alginate concentration, 0.09% (/). The predicted and actual values of BC production in the optimal conditions were 14.07 g/L and 14.88 g/L, respectively, confirming that our prediction model was statistically significant. Additionally, BC production using hydrolysates was 1.12-fold higher than in the control group (commercial glucose). Our result indicate that lignocellulose can be used in the BC production processes in the near future.
Topics: Carbon; Cellulose; Culture Media; Gluconacetobacter xylinus; Glucose
PubMed: 35055692
DOI: 10.3390/ijerph19020866 -
Microbial Biotechnology Sep 2019The recent interest in plant pigment betalains as bioactive compounds and chemopreventive agents has led to the search for a reliable and scalable process to obtain...
The recent interest in plant pigment betalains as bioactive compounds and chemopreventive agents has led to the search for a reliable and scalable process to obtain them. The cloning of the novel and efficient enzyme 4,5-DOPA-extradiol dioxygenase from Gluconacetobacter diazotrophicus in an expression vector, and the subsequent heterologous expression in Escherichia coli cultures has led to the start-up of a biotechnological production system of individual pigments. The aim of this study was to search for the optimal conditions for the production of betalamic acid in microbial factories and the scaled-up obtention of the derived pigments. Four different betaxanthins and two betacyanins were obtained after the addition of non-transformable amines and amino acids and their condensation with the betalamic acid produced by the dioxygenase. The scaled-up obtention and purification of betalains improved the yields of the previous methodologies reaching quantities by up to 150 mg of pure compounds.
Topics: Betalains; Biotechnology; Biotransformation; Cloning, Molecular; Coloring Agents; Dioxygenases; Escherichia coli; Gene Expression; Gluconacetobacter; Metabolic Engineering; Pyridines
PubMed: 31270958
DOI: 10.1111/1751-7915.13452 -
International Journal of Systematic and... Oct 2019A heterotrophic and acidophilic bacterial strain, G45-3, was isolated from acidic mine drainage sampled in Fujian Province, PR China. Cells of strain G45-3 were...
A heterotrophic and acidophilic bacterial strain, G45-3, was isolated from acidic mine drainage sampled in Fujian Province, PR China. Cells of strain G45-3 were Gram-stain-negative, non-spore-forming, non-motile and rod-shaped. Catalase and oxidase activities were positive. Strain G45-3 grew aerobically at 20-45 °C (optimum, 37 °C) and at pH 2.5-5.0 (optimum, pH 4.0). Photosynthetic pigments were not produced. Analysis of 16S rRNA gene sequences showed that strain G45-3 was phylogenetically related to different members of the family , and the sequence identities to JCM 10600, G2-11 and ATCC 35887 were 95.9 , 95.3 and 95.3 %, respectively. Strain G45-3 contained ubiquinone-10 as its respiratory quinone. The major polar lipids were determined to be diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified aminophospholipid and an unidentified aminolipid. The predominant fatty acids were cyclo-Cω8, Cω7, C and C. The genome of G45-3 consists of one chromosome (3 907 406 bp) and three plasmids (68 344, 45 771 and 16 090 bp), with an average G+C content of 65.9 mol%. Based on the results of phenotypic and genomic analyses, it is concluded that strain G45-3 represents a novel species of a new genus, for which the name gen. nov., sp. nov. is proposed. is nominated as type species and its type strain is G45-3 (=CGMCC 1.16069=KCTC 62275).
Topics: Acetobacteraceae; Acids; Bacterial Typing Techniques; Base Composition; China; DNA, Bacterial; Fatty Acids; Mining; Phospholipids; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Ubiquinone
PubMed: 31355740
DOI: 10.1099/ijsem.0.003618 -
Journal of Bacteriology Jul 2022species are a major component of the gut microbiome of the fruit fly Drosophila melanogaster, a widely used model organism. While a range of studies have illuminated...
species are a major component of the gut microbiome of the fruit fly Drosophila melanogaster, a widely used model organism. While a range of studies have illuminated impacts of on their hosts, less is known about how association with the host impacts bacteria. A previous study identified that a purine salvage locus was commonly found in associated with . In this study, we sought to verify the functions of predicted purine salvage genes in Acetobacter fabarum DsW_054 and to test the hypothesis that these bacteria can utilize host metabolites as a sole source of nitrogen. Targeted gene deletion and complementation experiments confirmed that genes encoding xanthine dehydrogenase (), urate hydroxylase (), and allantoinase () were required for growth on their respective substrates as the sole source of nitrogen. Utilization of urate by is significant because this substrate is the major nitrogenous waste product of , and its accumulation in the excretory system is detrimental to both flies and humans. The potential significance of our findings for host purine homeostasis and health are discussed, as are the implications for interactions among microbiota members, which differ in their capacity to utilize host metabolites for nitrogen. are commonly found in the gut microbiota of fruit flies, including Drosophila melanogaster. We evaluated the function of purine salvage genes in Acetobacter fabarum to test the hypothesis that this bacterium can utilize host metabolites as a source of nitrogen. Our results identify functions for three genes required for growth on urate, a major host waste product. The utilization of this and other metabolites by gut bacteria may play a role in their survival in the host environment. Future research into how microbial metabolism impacts host purine homeostasis may lead to therapies because urate accumulation in the excretory system is detrimental to flies and humans.
Topics: Acetobacter; Animals; Bacteria; Drosophila melanogaster; Humans; Nitrogen; Uric Acid; Waste Products
PubMed: 35695500
DOI: 10.1128/jb.00041-22 -
Applied Microbiology and Biotechnology Mar 2021There is an increasing public awareness about the danger of dietary sugars with respect to their caloric contribution to the diet and the rise of overweight throughout...
There is an increasing public awareness about the danger of dietary sugars with respect to their caloric contribution to the diet and the rise of overweight throughout the world. Therefore, low-calorie sugar substitutes are of high interest to replace sugar in foods and beverages. A promising alternative to natural sugars and artificial sweeteners is the fructose derivative 5-keto-D-fructose (5-KF), which is produced by several Gluconobacter species. A prerequisite before 5-KF can be used as a sweetener is to test whether the compound is degradable by microorganisms and whether it is metabolized by the human microbiota. We identified different environmental bacteria (Tatumella morbirosei, Gluconobacter japonicus LMG 26773, Gluconobacter japonicus LMG 1281, and Clostridium pasteurianum) that were able to grow with 5-KF as a substrate. Furthermore, Gluconobacter oxydans 621H could use 5-KF as a carbon and energy source in the stationary growth phase. The enzymes involved in the utilization of 5-KF were heterologously overproduced in Escherichia coli, purified and characterized. The enzymes were referred to as 5-KF reductases and belong to three unrelated enzymatic classes with highly different amino acid sequences, activities, and structural properties. Furthermore, we could show that 15 members of the most common and abundant intestinal bacteria cannot degrade 5-KF, indicating that this sugar derivative is not a suitable growth substrate for prokaryotes in the human intestine. KEY POINTS: • Some environmental bacteria are able to use 5-KF as an energy and carbon source. • Four 5-KF reductases were identified, belonging to three different protein families. • Many gut bacteria cannot degrade 5-KF.
Topics: Bacteria; Clostridium; Fructose; Gammaproteobacteria; Gluconobacter; Humans; Sweetening Agents
PubMed: 33616697
DOI: 10.1007/s00253-021-11168-3 -
Journal of Food Science May 2024It is crucial to clarify the stability of Kombucha in the manufacture and storage stages due to the extensive study on the fermented products of Kombucha and the...
It is crucial to clarify the stability of Kombucha in the manufacture and storage stages due to the extensive study on the fermented products of Kombucha and the increase in the use of bacterial cellulose (BC). This study aimed to evaluate the stability of Kombucha in different manufacturing and storage temperatures within a certain time period. The stability of microorganisms and BC in Kombucha was investigated through regular replacement with the tea media at 28 and 25°C for manufacture, and the storage temperature of Kombucha was at 25, 4, and -20°C. Morphological observations of the BC in Kombucha ended at 28 and 25°C for manufacture and storage were performed using atomic force microscopy (AFM) before inoculation. The viable cell counts and AFM results showed that the stability of Kombucha during manufacture was better at 28°C than at 25°C, with higher microbial viability and BC productivity in the former at the time of manufacture, whereas 25°C was more favorable for the stability of Kombucha during storage. At the same temperature of 25°C, the manufacturing practice improved the microbial viability and BC stability compared with storage; the pH value of Kombucha was lower, and the dry weight of BC was higher during storage compared with manufacture. The maximum BC water holding capacity (97.16%) was maintained by storage at 4°C on day 63, and the maximum BC swelling rate (56.92%) was observed after storage at -20°C on day 7. The research was conducted to provide reference information for applying Kombucha and its BC in food and development in other industries.
Topics: Cellulose; Temperature; Fermentation; Food Storage; Food Microbiology; Kombucha Tea; Hydrogen-Ion Concentration; Microbial Viability; Acetobacteraceae; Food Handling
PubMed: 38591324
DOI: 10.1111/1750-3841.16975 -
International Journal of Systematic and... Sep 2021Honey bees are important pollinators of many major crops and add billions of dollars annually to the US economy through their services. Recent declines in the health of...
Honey bees are important pollinators of many major crops and add billions of dollars annually to the US economy through their services. 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. One factor that may influence colony health is the microbial community. Although honey bee worker guts have a characteristic community of bee-specific microbes, the honey bee queen digestive tracts are colonized predominantly by a single acetic acid bacterium tentatively named ''. This bacterium is related to flower-associated microbes such as , and initial phylogenetic analyses placed it as sister to these environmental bacteria. We used a combination of phylogenetic and sequence identity methods to better resolve evolutionary relationships among '', strains in the genus , and strains in the closely related genus . Interestingly, measures of genome-wide average nucleotide identity and aligned fraction, coupled with phylogenetic placement, indicate that many strains labelled as '' and species are all the same species as . We propose reclassifying these strains as and outline the data supporting that classification below.
Topics: Acetobacteraceae; Animals; Bacterial Typing Techniques; Base Composition; Bees; DNA, Bacterial; Fatty Acids; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA
PubMed: 34546865
DOI: 10.1099/ijsem.0.004950