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1.
Sci Total Environ ; 690: 956-964, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31302559

RESUMO

In present study, a potential bacterial isolate Acetobacter pasteurianus SKYAA25 was found to be very effective in the bioconversion of apple pomace to acetic acid. The isolated strain was tolerant to high ethanol concentrations of upto 14% and temperature of 42 °C. Fermentation of apple pomace alone in presence of brewing yeast produced 7.3% of bio-ethanol which was further used for acetic acid production. Apple pomace in combination with cane molasses produced 14% of bio-ethanol. The fermented bio-ethanol was used as medium for acetic acid production which yielded 52.4 g of acetic acid/100 g of DM (Dry Matter) of apple pomace. Hence, an ecofriendly process has been developed that is entirely based on microbial processing of apple pomace to produce acetic acid without involving commercial enzymes. The present bio-conversion will prove to be beneficial for utilizing food and beverage industrial waste in the production of acetic acid.


Assuntos
Ácido Acético/metabolismo , Acetobacter/fisiologia , Adaptação Fisiológica/fisiologia , Etanol/metabolismo , Fermentação , Malus/microbiologia , Saccharomyces cerevisiae , Água/metabolismo
2.
Pol J Microbiol ; 68(2): 203-209, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31250590

RESUMO

The composition of vagina lactic acid bacteria (LAB) differs within the different ethnic group. This study is aimed at determining the prevalence of LAB with their antimicrobial properties in Nigerian women's vagina during different stages of the menstrual cycle. Microorganisms were isolated from vaginal swabs of ten Nigerian women during different stages of the menstrual cycle and identified by partial sequencing of the 16S rRNA gene. The antimicrobial properties of the LAB were tested against the multidrug-resistant uropathogens. The prevalence of LAB was higher during ovulation period while during menstruation period, it declined. Twenty-five LAB isolates were identified as three species, namely: Lactobacillus plantarum (15), Lactobacillus fermentum (9), Lactobacillus brevis (1) and one acetic acid bacteria - Acetobacter pasteurianus. The LAB had antimicrobial activities against the three uropathogens with zones of inhibition from 8 to 22 mm. The presence of LAB inhibits the growth of Staphylococcus sp. GF01 also in the co-culture. High LAB counts were found during ovulation period with L. plantarum as a dominant species while during menstruation, there was a decrease in the LAB counts. The isolated LAB has antimicrobial properties against the urogenital pathogens tested thus exhibiting their potential protective role against uropathogens.The composition of vagina lactic acid bacteria (LAB) differs within the different ethnic group. This study is aimed at determining the prevalence of LAB with their antimicrobial properties in Nigerian women's vagina during different stages of the menstrual cycle. Microorganisms were isolated from vaginal swabs of ten Nigerian women during different stages of the menstrual cycle and identified by partial sequencing of the 16S rRNA gene. The antimicrobial properties of the LAB were tested against the multidrug-resistant uropathogens. The prevalence of LAB was higher during ovulation period while during menstruation period, it declined. Twenty-five LAB isolates were identified as three species, namely: Lactobacillus plantarum (15), Lactobacillus fermentum (9), Lactobacillus brevis (1) and one acetic acid bacteria ­ Acetobacter pasteurianus. The LAB had antimicrobial activities against the three uropathogens with zones of inhibition from 8 to 22 mm. The presence of LAB inhibits the growth of Staphylococcus sp. GF01 also in the co-culture. High LAB counts were found during ovulation period with L. plantarum as a dominant species while during menstruation, there was a decrease in the LAB counts. The isolated LAB has antimicrobial properties against the urogenital pathogens tested thus exhibiting their potential protective role against uropathogens.


Assuntos
Antibiose , Lactobacillales/isolamento & purificação , Lactobacillales/fisiologia , Ciclo Menstrual , Vagina/microbiologia , Acetobacter/classificação , Acetobacter/genética , Acetobacter/isolamento & purificação , Acetobacter/fisiologia , Adulto , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Feminino , Humanos , Lactobacillales/classificação , Lactobacillales/genética , Nigéria , Filogenia , Prevalência , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Staphylococcus/crescimento & desenvolvimento , Adulto Jovem
3.
J Econ Entomol ; 111(1): 283-292, 2018 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-29202199

RESUMO

This research aimed to more clearly describe the interactions of Drosophila suzukii (Matsumura; Diptera: Drosophilidae) with microorganisms that may contribute to spoilage or quality loss of wine grapes during harvest. Experiments were conducted in controlled laboratory experiments and under field conditions to determine these effects. Laboratory trials determined the role of insect contact and oviposition to vector spoilage bacteria onto wine grapes. In the field, the roles of key organoleptic parameters in grape fruit ripening were assessed to determine their relative contribution to oviposition potential as fruit ripened. Finally, field trials determined the relationships of egg and larval infestation to sour rot levels. Non-ovipositional trials indicated elevated levels of microbiota when D. suzukii was present. D. suzukii oviposition exponentially increased the concentration of acetic acid bacteria. Both incised and sound berries showed a significant increase in concentrations of acetic acid bacteria exposed to D. suzukii. Volatile acidity was higher in treatments infested with D. suzukii. Fruit with only eggs did not develop a significant increase of volatile acidity. Larva-infested grape berries in 9.5% of samples developed higher volatile acidity after 14 d. Sound grape berries were less susceptible to the development of microbiota associated with sour rot and spoilage. D. suzukii oviposition and larval development increase risk of spoilage bacteria vectored by D. suzukii adults. Acetic acid bacteria induced fermentation and produced several volatile compounds contributing to spoilage. Spoilage bacteria may create a positive feedback loop that attracts both D. suzukii and other drosophilids, which may contribute to additional spoilage.


Assuntos
Drosophila/fisiologia , Oviposição , Doenças das Plantas/microbiologia , Vitis/microbiologia , Acetobacter/fisiologia , Animais , Drosophila/crescimento & desenvolvimento , Fermentação , Gluconobacter/fisiologia , Larva/fisiologia , Leveduras/fisiologia
4.
PLoS Biol ; 15(4): e2000862, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28441450

RESUMO

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.


Assuntos
Acetobacter/fisiologia , Aminoácidos Essenciais/metabolismo , Drosophila melanogaster/microbiologia , Comportamento Alimentar , Microbioma Gastrointestinal , Lactobacillus/fisiologia , Simbiose , Acetobacter/genética , Acetobacter/crescimento & desenvolvimento , Acetobacteraceae/genética , Acetobacteraceae/crescimento & desenvolvimento , Acetobacteraceae/fisiologia , Aminoácidos Essenciais/administração & dosagem , Aminoácidos Essenciais/análise , Aminoácidos Essenciais/deficiência , Animais , Animais Geneticamente Modificados , Regulação do Apetite , Comportamento Animal , Misturas Complexas/administração & dosagem , Misturas Complexas/química , Proteínas de Drosophila/antagonistas & inibidores , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/fisiologia , Enterococcus faecalis/genética , Enterococcus faecalis/crescimento & desenvolvimento , Enterococcus faecalis/fisiologia , Feminino , Preferências Alimentares , Técnicas de Inativação de Genes , Interações Hospedeiro-Parasita , Lactobacillus/genética , Lactobacillus/crescimento & desenvolvimento , Oviposição , Especificidade da Espécie , Fermento Seco/química
5.
Microbes Environ ; 31(4): 395-400, 2016 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-27667143

RESUMO

Acetobacter pasteurianus SKU1108 is a typical thermotolerant acetic acid bacterium. In this study, the complete genome sequence of the SKU1108 strain was elucidated, and information on genomic modifications due to the thermal adaptation of SKU1108 was updated. In order to obtain a clearer understanding of the genetic background responsible for thermotolerance, the SKU1108 genome was compared with those of two closely related complete genome strains, thermotolerant A. pasteurianus 386B and mesophilic A. pasteurianus NBRC 3283. All 24 "thermotolerant genes" required for growth at higher temperatures in the thermotolerant Acetobacter tropicalis SKU1100 strain were conserved in all three strains. However, these thermotolerant genes accumulated amino acid mutations. Some biased mutations, particularly those that occurred in xanthine dehydrogenase XdhA, may be related to thermotolerance. By aligning whole genome sequences, we identified ten SKU1108 strain-specific regions, three of which were conserved in the genomes of the two thermotolerant A. pasteurianus strains. One of the regions contained a unique paralog of the thermotolerant gene xdhA, which may also be responsible for conferring thermotolerance. Thus, comparative genomics of complete genome sequences may provide novel insights into the phenotypes of these thermotolerant strains.


Assuntos
Acetobacter/genética , Acetobacter/fisiologia , DNA Bacteriano/química , DNA Bacteriano/genética , Genoma Bacteriano , Análise de Sequência de DNA , Termotolerância , Acetobacter/isolamento & purificação , Acetobacter/efeitos da radiação , Genes Bacterianos , Variação Genética , Temperatura Alta
6.
Food Microbiol ; 58: 68-78, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27217361

RESUMO

Acetobacter ghanensis LMG 23848(T) and Acetobacter senegalensis 108B are acetic acid bacteria that originate from a spontaneous cocoa bean heap fermentation process and that have been characterised as strains with interesting functionalities through metabolic and kinetic studies. As there is currently little genetic information available for these species, whole-genome sequencing of A. ghanensis LMG 23848(T) and A. senegalensis 108B and subsequent data analysis was performed. This approach not only revealed characteristics such as the metabolic potential and genomic architecture, but also allowed to indicate the genetic adaptations related to the cocoa bean fermentation process. Indeed, evidence was found that both species possessed the genetic ability to be involved in citrate assimilation and displayed adaptations in their respiratory chain that might improve their competitiveness during the cocoa bean fermentation process. In contrast, other properties such as the dependence on glycerol or mannitol and lactate as energy sources or a less efficient acid stress response may explain their low competitiveness. The presence of a gene coding for a proton-translocating transhydrogenase in A. ghanensis LMG 23848(T) and the genes involved in two aromatic compound degradation pathways in A. senegalensis 108B indicate that these strains have an extended functionality compared to Acetobacter species isolated from other ecosystems.


Assuntos
Acetobacter/genética , Cacau/microbiologia , Microbiologia de Alimentos , Genoma Bacteriano/genética , Genômica , Ácido Acético/metabolismo , Acetobacter/enzimologia , Acetobacter/fisiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cacau/metabolismo , Fermentação , Ácido Láctico/metabolismo , NADP Trans-Hidrogenases/genética , NADP Trans-Hidrogenases/metabolismo , Filogenia , Sementes/enzimologia , Sementes/metabolismo , Sementes/microbiologia , Sementes/fisiologia , Análise de Sequência de DNA
7.
Biosci Biotechnol Biochem ; 80(4): 655-68, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26566045

RESUMO

Environmental adaptation is considered as one of the most challenging subjects in biology to understand evolutionary or ecological diversification processes and in biotechnology to obtain useful microbial strains. Temperature is one of the important environmental stresses; however, microbial adaptation to higher temperatures has not been studied extensively. For industrial purposes, the use of thermally adapted strains is important, not only to reduce the cooling expenses of the fermentation system, but also to protect fermentation production from accidental failure of thermal management. Recent progress in next-generation sequencing provides a powerful tool to track the genomic changes of the adapted strains and allows us to compare genomic DNA sequences of conventional strains with those of their closely related thermotolerant strains. In this article, we have attempted to summarize our recent approaches to produce thermotolerant strains by thermal adaptation and comparative genomic analyses of Acetobacter pasteurianus for high-temperature acetic acid fermentations, and Zymomonas mobilis and Kluyveromyces marxianus for high-temperature ethanol fermentations. Genomic analysis of the adapted strains has found a large number of mutations and/or disruptions in highly diversified genes, which could be categorized into groups related to cell surface functions, ion or amino acid transporters, and some transcriptional factors. Furthermore, several phenotypic and genetic analyses revealed that the thermal adaptation could lead to decreased ROS generation in cells that produce higher ROS levels at higher temperatures. Thus, it is suggested that the thermally adapted cells could become robust and resistant to many stressors, and thus could be useful for high-temperature fermentations.


Assuntos
Adaptação Fisiológica , Fermentação , Genoma Bacteriano , Genoma Fúngico , Temperatura Alta , Ácido Acético/metabolismo , Acetobacter/genética , Acetobacter/metabolismo , Acetobacter/fisiologia , Elementos de DNA Transponíveis , Kluyveromyces/genética , Kluyveromyces/metabolismo , Kluyveromyces/fisiologia
8.
Commun Agric Appl Biol Sci ; 80(1): 37-43, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26630753

RESUMO

Six strains of acetic acid bacteria were isolated from Moroccan local products and their potential as industrial strains was evaluated in lab-bioreactor. Three of them, namely TAV01, AF01 and CV01, isolated from traditional apple vinegar, apple and cactus fruit, respectively were selected and their responses to high temperature were assessed. Morphological and biochemical identification confirmed that these strains belong to Acetobacter species. Their growth and acetic acid production were compared with the thermoresistant reference strain, Acetobacter senegalensis and mesophilic strains of Acetobacter pasteurianus. The two strains AF01 and CV01 showed abundant growth and noticeable acetic acid production ability at high temperatures (38 to 41°C). A thermophilic character was observed for AF01 strain. Indeed, this bacterium grew better at 38 than 30°C.


Assuntos
Acetobacter/classificação , Acetobacter/fisiologia , Microbiologia de Alimentos , Frutas/microbiologia , Temperatura Alta , Fermentação , Marrocos
9.
Curr Microbiol ; 70(5): 724-9, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25648427

RESUMO

Acetobacter pasteurianus plays an important role in the process of traditional vinegar production and is also essential for the fermentation of Zhenjiang aromatic vinegar. In this study, we utilized the proteomic approach to analyze the proteomic profile of A. pasteurianus HSZ3-21, and 258 proteins were successfully identified by MALDI-TOF-MS and database search. The hydropathy and GO analyse combined with COG results of the identified proteins revealed the molecular biological characteristics of A. pasteurianus proteins, that is, most proteins of A. pasteurianus were related to metabolic process, binding, catalytic or cellular response. Meanwhile, our results also showed that some proteins of A. pasteurianus may be responsible for acetic acid tolerance, thermotolerance, and stress response. Therefore, the identification of 258 proteins not only deciphers protein composition and functional classification of A. pasteurianus, but also provides useful information for improving quality of Zhenjiang aromatic vinegar.


Assuntos
Acetobacter/química , Proteínas de Bactérias/análise , Proteoma/análise , Ácido Acético/metabolismo , Ácido Acético/toxicidade , Acetobacter/metabolismo , Acetobacter/fisiologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Estresse Fisiológico
10.
J Microbiol Biotechnol ; 24(12): 1679-84, 2014 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-25179899

RESUMO

Acetobacter sp. strains were isolated from traditional vinegar collected in Daegu city and Gyeongbuk province. The strain KJY8 showing a high acetic acid productivity was isolated and characterized by phenotypic, chemotaxonomic, and phylogenetic inference based on 16S rRNA sequence analysis. The chemotaxonomic and phylogenetic analyses revealed the isolate to be a strain of Acetobacter pomorum. The isolate showed a G+C content of 60.8 mol%. It contained LL-diaminopimelic acid (LL-A2pm) as the cell wall amino acid and ubiquinone Q9 (H6) as the major quinone. The predominant cellular fatty acids were C18:1w9c, w12t, and w7c. Strain KJY8 grew rapidly on glucose-yeast extract (GYC) agar and formed pale white colonies with smooth to rough surfaces. The optimum cultivation conditions for acetic acid production by the KJY8 strain were 20°C and pH 3.0, with an initial ethanol concentration of 9% (w/v) to produce an acetic acid concentration of 8% (w/v).


Assuntos
Ácido Acético , Acetobacter/classificação , Acetobacter/isolamento & purificação , Microbiologia de Alimentos , Ácido Acético/metabolismo , Acetobacter/genética , Acetobacter/fisiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , Parede Celular/química , Análise por Conglomerados , Citosol/química , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácido Diaminopimélico/análise , Ácidos Graxos/análise , Humanos , Concentração de Íons de Hidrogênio , Coreia (Geográfico) , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Filogenia , Quinonas/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Temperatura Ambiente
11.
Appl Environ Microbiol ; 80(6): 1848-57, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24413595

RESUMO

Four cocoa-specific acetic acid bacterium (AAB) strains, namely, Acetobacter pasteurianus 386B, Acetobacter ghanensis LMG 23848(T), Acetobacter fabarum LMG 24244(T), and Acetobacter senegalensis 108B, were analyzed kinetically and metabolically during monoculture laboratory fermentations. A cocoa pulp simulation medium (CPSM) for AAB, containing ethanol, lactic acid, and mannitol, was used. All AAB strains differed in their ethanol and lactic acid oxidation kinetics, whereby only A. pasteurianus 386B performed a fast oxidation of ethanol and lactic acid into acetic acid and acetoin, respectively. Only A. pasteurianus 386B and A. ghanensis LMG 23848(T) oxidized mannitol into fructose. Coculture fermentations with A. pasteurianus 386B or A. ghanensis LMG 23848(T) and Lactobacillus fermentum 222 in CPSM for lactic acid bacteria (LAB) containing glucose, fructose, and citric acid revealed oxidation of lactic acid produced by the LAB strain into acetic acid and acetoin that was faster in the case of A. pasteurianus 386B. A triculture fermentation with Saccharomyces cerevisiae H5S5K23, L. fermentum 222, and A. pasteurianus 386B, using CPSM for LAB, showed oxidation of ethanol and lactic acid produced by the yeast and LAB strain, respectively, into acetic acid and acetoin. Hence, acetic acid and acetoin are the major end metabolites of cocoa bean fermentation. All data highlight that A. pasteurianus 386B displayed beneficial functional roles to be used as a starter culture, namely, a fast oxidation of ethanol and lactic acid, and that these metabolites play a key role as substrates for A. pasteurianus in its indispensable cross-feeding interactions with yeast and LAB during cocoa bean fermentation.


Assuntos
Acetobacter/fisiologia , Cacau/metabolismo , Microbiologia de Alimentos , Interações Microbianas , Acetobacter/crescimento & desenvolvimento , Acetobacter/metabolismo , Técnicas de Cocultura , Meios de Cultura/química , Etanol/metabolismo , Fermentação , Ácido Láctico/metabolismo , Lactobacillus fermentum/crescimento & desenvolvimento , Lactobacillus fermentum/metabolismo , Manitol/metabolismo , Oxirredução , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismo
12.
BMC Genomics ; 14: 526, 2013 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-23902333

RESUMO

BACKGROUND: Acetobacter pasteurianus 386B, an acetic acid bacterium originating from a spontaneous cocoa bean heap fermentation, proved to be an ideal functional starter culture for coca bean fermentations. It is able to dominate the fermentation process, thereby resisting high acetic acid concentrations and temperatures. However, the molecular mechanisms underlying its metabolic capabilities and niche adaptations are unknown. In this study, whole-genome sequencing and comparative genome analysis was used to investigate this strain's mechanisms to dominate the cocoa bean fermentation process. RESULTS: The genome sequence of A. pasteurianus 386B is composed of a 2.8-Mb chromosome and seven plasmids. The annotation of 2875 protein-coding sequences revealed important characteristics, including several metabolic pathways, the occurrence of strain-specific genes such as an endopolygalacturonase, and the presence of mechanisms involved in tolerance towards various stress conditions. Furthermore, the low number of transposases in the genome and the absence of complete phage genomes indicate that this strain might be more genetically stable compared with other A. pasteurianus strains, which is an important advantage for the use of this strain as a functional starter culture. Comparative genome analysis with other members of the Acetobacteraceae confirmed the functional properties of A. pasteurianus 386B, such as its thermotolerant nature and unique genetic composition. CONCLUSIONS: Genome analysis of A. pasteurianus 386B provided detailed insights into the underlying mechanisms of its metabolic features, niche adaptations, and tolerance towards stress conditions. Combination of these data with previous experimental knowledge enabled an integrated, global overview of the functional characteristics of this strain. This knowledge will enable improved fermentation strategies and selection of appropriate acetic acid bacteria strains as functional starter culture for cocoa bean fermentation processes.


Assuntos
Acetobacter/genética , Acetobacter/fisiologia , Adaptação Fisiológica/genética , Cacau/microbiologia , Ecossistema , Fermentação , Genômica , Acetobacter/citologia , Acetobacter/metabolismo , Metabolismo dos Carboidratos/genética , Membrana Celular/metabolismo , Transporte de Elétrons/genética , Genoma Bacteriano/genética , Concentração de Íons de Hidrogênio , Espaço Intracelular/metabolismo , Anotação de Sequência Molecular , Oxirredutases/genética , Filogenia , Análise de Sequência , Temperatura Ambiente
13.
Int J Food Microbiol ; 163(2-3): 204-13, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23562697

RESUMO

Acetic acid bacteria (AAB) are used in production of vinegars. During acetic acid fermentation, AAB encounter various aggressive conditions which may lead to a variety of cellular disorders. Previous researches mainly studied the influences of different carbon sources on tolerance of AAB to ethanol and acetic acid. In this study, different techniques were used comparatively to investigate the effects of preadaptation on the ability of A. senegalensis to tolerate ethanol and acetic acid. In general, the carbon sources used for preadaptation of A. senegalensis exhibited significant effects on the tolerance of cells to stressors. Flow-cytometric assessments of preadapted cells in ethanol showed that 87.3% of the cells perform respiration after exposure to a stress medium containing 5% (v/v) ethanol and 3% (w/v) acetic acid. However, 58.4% of these preadapted cells could keep their envelope integrity under the stress condition. They could also grow rapidly (µmax=0.39/h) in the stress medium (E5A3) with a high yield (>80%). A. senegalensis grown in glucose exhibited a low tolerance to acetic acid. Analysis of their respiration capacity, membrane integrity and culturability revealed that almost all the population were dead after exposure to 5% (v/v) ethanol and 3% (w/v) acetic acid. In contrast, exposure of A. senegalensis preadapted in a mixture of glucose and acetic acid to a stress medium containing 5% (v/v) ethanol and 3% (w/v) acetic acid, exhibited an intact respiration system and cellular membrane integrity in 80.3% and 50.01% of cells, respectively. Moreover, just 24% of these cells could keep their culturability under that stress condition. In summary, cell envelope integrity, growth and culturability are more susceptible to pH and acetic acid stresses whereas respiration system is less subjected to damages under stress condition. In addition, preadaptation of A. senegalensis in a mixture of glucose and acetic acid enables it to tolerate and grow in ethanol and acetic acid.


Assuntos
Acetobacter/fisiologia , Estresse Fisiológico , Ácido Acético/farmacologia , Acetobacter/efeitos dos fármacos , Acetobacter/crescimento & desenvolvimento , Etanol/farmacologia , Viabilidade Microbiana/efeitos dos fármacos
14.
Protein Sci ; 21(5): 686-96, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22374910

RESUMO

Bacterial formyl-CoA:oxalate CoA-transferase (FCOCT) and oxalyl-CoA decarboxylase work in tandem to perform a proton-consuming decarboxylation that has been suggested to have a role in generalized acid resistance. FCOCT is the product of uctB in the acidophilic acetic acid bacterium Acetobacter aceti. As expected for an acid-resistance factor, UctB remains folded at the low pH values encountered in the A. aceti cytoplasm. A comparison of crystal structures of FCOCTs and related proteins revealed few features in UctB that would distinguish it from nonacidophilic proteins and thereby account for its acid stability properties, other than a strikingly featureless electrostatic surface. The apparently neutral surface is a result of a "speckled" charge decoration, in which charged surface residues are surrounded by compensating charges but do not form salt bridges. A quantitative comparison among orthologs identified a pattern of residue substitution in UctB that may be a consequence of selection for protein stability by constant exposure to acetic acid. We suggest that this surface charge pattern, which is a distinctive feature of A. aceti proteins, creates a stabilizing electrostatic network without stiffening the protein or compromising protein-solvent interactions.


Assuntos
Acetobacter/fisiologia , Proteínas de Bactérias/química , Coenzima A-Transferases/química , Ácido Acético , Acetobacter/enzimologia , Proteínas de Bactérias/metabolismo , Coenzima A-Transferases/metabolismo , Etanol , Concentração de Íons de Hidrogênio , Modelos Moleculares , Estabilidade Proteica , Eletricidade Estática , Especificidade por Substrato
15.
Curr Microbiol ; 64(6): 576-80, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22441885

RESUMO

Acetobacter species are members of the α-subclass of Proteobacteria, which harbors a large number of bacteria recalcitrant to cultivation. Strain AB0220 was isolated from a superficial acetification system and preserved for 9 years by short and long time methods. Under short time preservation it was estimated that 540.54 number of generations occurred, whereas in long time preservation conditions the number of generations was 17.40. Ethanol oxidation to acetic acid was stable and confirmed, as well as acetate assimilation during long time preservation. Cultivability checks showed persistence of phenotypic traits (growth on ethanol and methanol, growth on different carbon sources and cellulose production) over the extended preservation time. 16S rRNA gene sequences analysis showed 100 % of similarity with A. pasteurianus (Accession number GQ240636). Stability of subcultures related to the culture age and subcultures frequency, tested by ERIC/PCR, confirmed the suitability of long term preservation at least over a period of 9 years.


Assuntos
Acetobacter/fisiologia , Preservação Biológica , Ácido Acético/metabolismo , Acetobacter/genética , Acetobacter/crescimento & desenvolvimento , Acetobacter/metabolismo , Carbono/metabolismo , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Etanol/metabolismo , Dados de Sequência Molecular , Oxirredução , Fenótipo , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
16.
Bioresour Technol ; 104: 388-93, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22130075

RESUMO

This study describes the cooperative effect of the two biocatalysts Acetobacter aceti and Gluconobacter roseus for biodegradation as well as current generation. The electro activity of the biofilms of these two microorganisms was investigated by the bioelectrocatalytic oxidation of ethanol and glucose using cyclic voltammetry. Two chamber microbial fuel cells (MFCs) were constructed using single culture of A. aceti (A-MFC), and G. roseus (G-MFC) and also using mixed culture (AG-MFC). Each MFC was fed with four different substrates viz., glucose, ethanol, acetate and bad wine. AG-MFC produced higher power density with glucose (1.05 W/m(3)), ethanol (1.97 W/m(3)), acetate (1.39 W/m(3)) and bad wine (3.82 W/m(3)). COD removal (94%) was maximum for acetate fed MFCs. Higher coulombic efficiency was obtained with bad wine (45%) as the fuel. This work provides the scope of using these biofuel cells in wineries for performing the dual duty of bad wine degradation along with current generation.


Assuntos
Acetobacter/fisiologia , Fontes de Energia Bioelétrica/microbiologia , Gluconobacter/fisiologia , Resíduos Industriais/prevenção & controle , Eliminação de Resíduos/métodos , Vinho/microbiologia , Biodegradação Ambiental , Catálise , Eletricidade
17.
Science ; 334(6056): 670-4, 2011 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-22053049

RESUMO

The symbiotic microbiota profoundly affect many aspects of host physiology; however, the molecular mechanisms underlying host-microbe cross-talk are largely unknown. Here, we show that the pyrroloquinoline quinone-dependent alcohol dehydrogenase (PQQ-ADH) activity of a commensal bacterium, Acetobacter pomorum, modulates insulin/insulin-like growth factor signaling (IIS) in Drosophila to regulate host homeostatic programs controlling developmental rate, body size, energy metabolism, and intestinal stem cell activity. Germ-free animals monoassociated with PQQ-ADH mutant bacteria displayed severe deregulation of developmental and metabolic homeostasis. Importantly, these defects were reversed by enhancing host IIS or by supplementing the diet with acetic acid, the metabolic product of PQQ-ADH.


Assuntos
Acetobacter/fisiologia , Desidrogenases de Carboidrato/metabolismo , Drosophila/microbiologia , Insulina/metabolismo , Metagenoma/fisiologia , Transdução de Sinais , Acetobacter/genética , Animais , Tamanho Corporal/genética , Drosophila/crescimento & desenvolvimento , Feminino , Homeostase , Intestinos/microbiologia , Somatomedinas/metabolismo
18.
Biosci Biotechnol Biochem ; 75(10): 1921-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21979075

RESUMO

Acetobacter tropicalis SKU1100 is a thermotolerant acetic acid bacterium that grows even at 42 °C, a much higher temperature than the limit for the growth of mesophilic strains. To elucidate the mechanism underlying the thermotolerance of this strain, we attempted to identify the genes essential for growth at high temperature by transposon (Tn10) mutagenesis followed by gene or genome analysis. Among the 4,000 Tn10-inserted mutants obtained, 32 exhibited a growth phenotype comparable to that of the parent strain at 30 °C but not at higher temperatures. We identified the insertion site of Tn10 on the chromosomes of all the mutant strains by TAIL (Thermal Asymmetric Interlaced)-PCR, and found 24 genes responsible for thermotolerance. The results also revealed a partial overlap between the genes required for thermotolerance and those required for acetic acid resistance. In addition, the origin and role of these thermotolerant genes are discussed.


Assuntos
Acetobacter/genética , Acetobacter/fisiologia , Adaptação Biológica/genética , Genes Bacterianos/genética , Genômica , Temperatura Ambiente , Acetobacter/crescimento & desenvolvimento , Elementos de DNA Transponíveis/genética , Mutação , Análise de Sequência
19.
Biochem Biophys Res Commun ; 409(1): 120-4, 2011 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-21554859

RESUMO

Thermotolerant acetic acid bacteria (AAB), Acetobacter tropicalis SKU1100, can grow above 40°C. To investigate the basis of its thermotolerance, we compared the genome of A. tropicalis SKU1100 with that of mesophilic AAB strain Acetobacter pasteurianus IFO3283-01. The comparative genomic study showed that amino acid substitutions from large to small residue and Lys to Arg occur in many orthologous genes. Furthermore, comparative modeling study was carried out with the orthologous proteins between SKU1100 and IFO3283-01 strains, indicating that the number of Arg-based salt bridges increased in protein models. Since it has been reported that Arg-based salt bridges are important factor for thermo-stability of protein structure, our results strongly suggest that the increased number of Arg-based salt bridges may contributes to the thermotolerance of A. tropicalis SKU1100 (the thermo-stability of proteins in A. tropicalis SKU1100).


Assuntos
Acetobacter/fisiologia , Substituição de Aminoácidos , Arginina/química , Proteínas de Bactérias/química , Temperatura Alta , Acetobacter/genética , Sequência de Aminoácidos , Arginina/genética , Proteínas de Bactérias/genética , Genoma Bacteriano , Lisina/química , Lisina/genética , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Estabilidade Proteica
20.
Appl Environ Microbiol ; 75(10): 3281-8, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19304818

RESUMO

Following cultivation-dependent and -independent techniques, we investigated the microbiota associated with Bactrocera oleae, one of the major agricultural pests in olive-producing countries. Bacterial 16S rRNA gene libraries and ultrastructural analyses revealed the presence of several bacterial taxa associated with this insect, among which Acetobacter tropicalis was predominant. The recent increased detection of acetic acid bacteria as symbionts of other insect model organisms, such as Anopheles stephensi (G. Favia et al., Proc. Natl. Acad. Sci. USA 104:9047-9051, 2007) or Drosophila melanogaster (C. R. Cox and M. S. Gilmore, Infect. Immun. 75:1565-1576, 2007), prompted us to investigate the association established between A. tropicalis and B. oleae. Using an A. tropicalis-specific PCR assay, the symbiont was detected in all insects tested originating from laboratory stocks or field-collected from different locations in Greece. This acetic acid bacterium was successfully established in cell-free medium, and typing analyses, carried out on a collection of isolates, revealed that different A. tropicalis strains are present in fly populations. The capability to colonize and lodge in the digestive system of both larvae and adults and in Malpighian tubules of adults was demonstrated by using a strain labeled with a green fluorescent protein.


Assuntos
Acetobacter/isolamento & purificação , Acetobacter/fisiologia , Trato Gastrointestinal/microbiologia , Simbiose , Tephritidae/microbiologia , Acetobacter/classificação , Acetobacter/genética , Animais , Técnicas de Tipagem Bacteriana , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Proteínas de Drosophila , Grécia , Larva/microbiologia , Túbulos de Malpighi/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Homologia de Sequência
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