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1.
Int J Mol Sci ; 23(6)2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35328811

RESUMO

This article presents a comparative analysis of bacterial cellulose membranes synthesized by several strains of the Komagataeibacter genus in terms of their specific physical, physico-chemical, and mechanical properties. Herein, the aim was to choose the most suitable microorganisms producing cellulosic materials with the greatest potential for the fabrication of bio-inspired nanocomposites. The selection was based on three main steps, starting from the evaluation of BNC biosynthetic efficiency with and without the addition of ethanol, followed by the assessment of mechanical breaking strength, and the physical parameters (compactness, structural integrity, appearance, and thickness) of the obtained biological materials. Ultimately, based on the performed screening procedure, three efficiently growing strains (K. hansenii H3 (6Et), K. rhaeticus K4 (8Et), and Komagataeibacter sp. isolated from balsamic vinegar (12Et)) were chosen for further modifications, enabling additional cellulose functionalization. Here, supplementation of the growth medium with five representative polymeric compounds (citrus/apple pectin, wheat starch, polyvinyl alcohol, polyethylene glycol) led to significant changes in BNC properties, especially dye loading abilities, mechanical strength, and water adsorption/retention capacities. The resulting nanocomposites can be potentially useful in various fields of medicine and industry, and in the future, they may become a practical and cost-effective competitor against commercial biomaterials currently available on the market.


Assuntos
Acetobacteraceae , Celulose , Ácido Acético , Celulose/química , Meios de Cultura/química
2.
Adv Sci (Weinh) ; 8(11): 2004699, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34141524

RESUMO

Bacterial cellulose (BC) has excellent material properties and can be produced sustainably through simple bacterial culture, but BC-producing bacteria lack the extensive genetic toolkits of model organisms such as Escherichia coli (E. coli). Here, a simple approach is reported for producing highly programmable BC materials through incorporation of engineered E. coli. The acetic acid bacterium Gluconacetobacter hansenii is cocultured with engineered E. coli in droplets of glucose-rich media to produce robust cellulose capsules, which are then colonized by the E. coli upon transfer to selective lysogeny broth media. It is shown that the encapsulated E. coli can produce engineered protein nanofibers within the cellulose matrix, yielding hybrid capsules capable of sequestering specific biomolecules from the environment and enzymatic catalysis. Furthermore, capsules are produced which can alter their own bulk physical properties through enzyme-induced biomineralization. This novel system uses a simple fabrication process, based on the autonomous activity of two bacteria, to significantly expand the functionality of BC-based living materials.


Assuntos
Celulose/biossíntese , Escherichia coli/metabolismo , Bioengenharia , Cápsulas , Técnicas de Cocultura , Meios de Cultura , Gluconacetobacter/metabolismo , Nanofibras/química
3.
J Microbiol Biotechnol ; 31(3): 429-438, 2021 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-33323677

RESUMO

Bacterial cellulose (BC) is widely used in the food industry for products such as nata de coco. The mechanical properties of BC hydrogels, including stiffness and viscoelasticity, are determined by the hydrated fibril network. Generally, Komagataeibacter bacteria produce gluconic acids in a glucose medium, which may affect the pH, structure and mechanical properties of BC. In this work, the effect of pH buffer on the yields of Komagataeibacter hansenii strain ATCC 53582 was studied. The bacterium in a phosphate and phthalate buffer with low ionic strength produced a good BC yield (5.16 and 4.63 g/l respectively), but there was a substantial reduction in pH due to the accumulation of gluconic acid. However, the addition of gluconic acid enhanced the polymer density and mechanical properties of BC hydrogels. The effect was similar to that of the bacteria using glycerol in another carbon metabolism circuit, which provided good pH stability and a higher conversion rate of carbon. This study may broaden the understanding of how carbon sources affect BC biosynthesis.


Assuntos
Acetobacteraceae/metabolismo , Carbono/metabolismo , Celulose/biossíntese , Concentração de Íons de Hidrogênio , Celulose/química , Meios de Cultura , Gluconatos/metabolismo , Glicerol/metabolismo , Microscopia Eletrônica de Varredura , Difração de Raios X
4.
Int J Biol Macromol ; 162: 1597-1604, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32777420

RESUMO

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.


Assuntos
Acetobacteraceae/metabolismo , Celulose/biossíntese , Meios de Cultura , Fermentação , Frutas/química , Verduras/química
5.
Int J Mycobacteriol ; 9(1): 34-38, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32474486

RESUMO

Background: Fluoroquinolones (FQs) are being used as second-line agents in the treatment of tuberculosis caused by multidrug-resistant strains. Ofloxacin (OFX) is being tried as a part of modified multidrug therapy regimens for leprosy. A preliminary study was carried out to evaluate the accumulation of FQs - OFX, levofloxacin (LFX), norfloxacin (NFX), and ciprofloxacin (CIF) in Mycobacterium smegmatis. Methods: M. smegmatis were grown in Sauton's medium till log phase, harvested and resuspended in phosphate buffer (0.1 M, pH 7.2, Optical Density (OD) of 0.4-0.5) The suspensions were incubated with OFX, LFX, NFX, and CIF (10 µg/ml) at 37°C. The drugs were estimated in the supernatants using spectrofluorimeteric methods. The experiments were also conducted with the addition of carbonyl cyanide m-chlorophenyl hydrazone (CCCP), a proton motive force inhibitor, at 100 µM, 10 min before and/or immediately after the addition of the drugs. Results: The time taken to achieve a Steady State Concentration (SSC) of OFX in M. smegmatis was 3 min and the level of accumulation was 102 ng/mg dry weight of the bacilli; with LFX the time for SSC was 5 min and the level of accumulation was 90 ng/mg; in case of NFX the accumulation to SSC was 87 ng/mg in 3 min. CIF accumulation attained a steady state (SSC level of 79 ng/mg) in 4 min. The accumulation kinetics for NFX in M. smegmatis using the spectrofluorimetric method is comparable with radioactive assays. Dose-related accumulation was observed with 10 µg/ml exposure concentrations. The addition of CCCP failed to influence the accumulation of each of these quinolones. Conclusion: The findings of dose-related accumulation of OFX, LFX NFX, and CIF suggest simple diffusion as the possible mechanism of transport of these drugs.


Assuntos
Fluorometria/métodos , Fluoroquinolonas/farmacocinética , Hansenostáticos/farmacocinética , Mycobacterium smegmatis/metabolismo , Permeabilidade da Membrana Celular , Meios de Cultura/química , Testes de Sensibilidade Microbiana
6.
Int J Biol Macromol ; 144: 198-207, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31843613

RESUMO

Optimization of the culture parameters used for biocellulose (BC) production by a previously isolated bacterial strain (Komagataeibacter hansenii AS.5) was carried out. The effect of nine culture parameters on BC production was evaluated by implementing the Plackett-Burman design, and the results revealed that, the most significant variables affecting BC production were MgSO4, ethanol, pH and yeast extract. A three-level and four-factor Box-Behnken design was applied to determine the optimum level of each significant variable. According to the results of the Plackett-Burman (PBD) and Box-Behnken designs (BBD), the following medium composition and parameters were calculated to be optimum (g/l): glucose 25, yeast extract 13, MgSO4 0.15, KH2PO4 2, ethanol 7.18 ml/l, pH 5.5, inoclume size 7%, cultivation temperature 20 °C and incubation time 9 days. Characterization of purified BC was performed to determine the network morphology by scanning electron microscopy, crystallinity by X-ray diffraction, chemical structure and functional groups by Fourier-transform infrared spectroscopy, thermal stability by thermogravimetric analysis and mechanical properties such as Young's modulus, tensile strength and elongation at beak % of BC.


Assuntos
Acetobacteraceae/metabolismo , Celulose/biossíntese , Celulose/isolamento & purificação , Celulose/ultraestrutura , Meios de Cultura , Glucose/metabolismo , Fenômenos Mecânicos , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Resistência à Tração , Termogravimetria , Difração de Raios X
7.
Int J Mycobacteriol ; 8(4): 381-389, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31793510

RESUMO

Background: The aim of the present study was to isolate and characterize nontuberculous mycobacteria (NTM) on Lowenstein-Jensen media supplemented with glycerol or pyruvate on two different temperatures from soil samples from leprosy endemic tribal areas of Purulia. Methods: Mycobacterium leprae DNA was isolated from these samples followed by polymerase chain reaction (PCR) amplification using RLEP gene target specific to M. leprae. DNA was extracted from NTM cultures by lysis method. The presence of Mycobacterial DNA was confirmed by PCR using universal mycobacterial primer as 16S rRNA. NCBI nBlast was used for the authentication of NTMs, and phylogenetic tree was constructed using M. leprae and NTM species. Statistical Analysis Used: The percentile method and phylogenetic tree were used as stastical tool in this research article. Results: The rapid-growing mycobacteria (RGM) species, 4 (80%) was obtained more than that of slow growing mycobacteria (SGM) 1 (20%) supplemented on glycerol at 30°C followed by SGM species 8 (62%) were recovered more than RGM at 37°C. Similarly, SGM species 2 (100%) were recovered on supplemented with pyruvate at 30°C and no RGM growth when supplemented with pyruvate. Further, the recovery of RGM species 3 (60%) was better on supplemented with pyruvate than SGM species at 37°C. Mycobacterium timonense was first time isolated from Indian soil samples. Highest numbers of NTM were isolated from bathing place than washing and sitting places along with M. leprae PCR positivity. Phylogenetic tree showed a close genetic evolutionary association between Mycobacterium simiae and M. leprae in the leprosy endemic environment. Conclusion: Several NTM was isolated from soil of leprosy endemic area which might have role in susceptibility of leprosy. Phylogenetic tree revealed a closed association of M. simiae with M. leprae in the environment and might be maintaining the leprosy endemicity in north block of Purulia.


Assuntos
Microbiologia Ambiental , Hanseníase/microbiologia , Micobactérias não Tuberculosas/genética , Micobactérias não Tuberculosas/isolamento & purificação , Filogenia , Microbiologia do Solo , Meios de Cultura , DNA Bacteriano/genética , Doenças Endêmicas , Humanos , Índia , Complexo Mycobacterium avium/genética , Micobactérias não Tuberculosas/crescimento & desenvolvimento , RNA Ribossômico 16S/genética
8.
Food Funct ; 10(8): 4924-4931, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31342038

RESUMO

This work allowed the evaluation of the gastrointestinal resistance of five yeasts (Saccharomyces and non-Saccharomyces) in order to assess some biotechnological characteristics linked to the potential probiotics, using a dynamic gastrointestinal simulator (simgi®). The best results obtained were for strains Saccharomyces cerevisiae 3 and Hanseniaspora osmophila 1056. Having optimised the method, the yeasts were subsequently lyophilised, and the one that showed the least loss of viability, S. cerevisiae 3, was used in a freeze-dried form to obtain a new functional food. On the other hand, some characteristics of the product were compared with those of probiotic supplements and other commercial probiotic foods. The obtained functional product showed better parameters than the rest of the samples containing yeasts which, together with the great acceptance shown after the consumer tests, means that it can be presented as a possible commercial functional product.


Assuntos
Hanseniaspora/crescimento & desenvolvimento , Probióticos/química , Saccharomyces cerevisiae/crescimento & desenvolvimento , Adolescente , Adulto , Meios de Cultura/química , Meios de Cultura/metabolismo , Feminino , Fermentação , Alimento Funcional/análise , Alimento Funcional/economia , Trato Gastrointestinal/microbiologia , Hanseniaspora/química , Hanseniaspora/metabolismo , Humanos , Microbiologia Industrial , Masculino , Viabilidade Microbiana , Pessoa de Meia-Idade , Probióticos/economia , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/metabolismo , Adulto Jovem
9.
Carbohydr Polym ; 207: 684-693, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30600054

RESUMO

Bacterial cellulose (BC) has been gaining importance over the past decades as a versatile material that finds applications in diverse industries. However, a secured supply is hindered by the slow production rate and batch-to-batch variability of the yield. Here, we report a rational approach for characterising the BC production process using Design of Experiment (DoE) methodology to study the impact of different parameters on desired process attributes. Notably, we found that the carbon source used for bacterial growth significantly impacts the interplay between the process variables and affects the desired outcomes. We therefore, propose that the highest priority process outcome in this study, the yield, is a function of the carbon source and optimal reactor design. Our systematic approach has achieved projected BC yields as high as ∼40 g/L for Gluconacetobacter hansenii 53582 grown on sucrose as the carbon source compared to the widely reported yields of ∼10 g/L.


Assuntos
Celulose/biossíntese , Acetobacteraceae/química , Acetobacteraceae/metabolismo , Celulose/química , Meios de Cultura , Fermentação , Gluconacetobacter/química , Gluconacetobacter/metabolismo , Glucose/metabolismo , Sacarose/metabolismo
10.
World J Microbiol Biotechnol ; 34(11): 161, 2018 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-30357477

RESUMO

In this study, the effect of sequential inoculation with non-Saccharomyces (Hanseniaspora guilliermondii) and Saccharomyces cerevisiae yeast on the distinctive characteristics of the Campanino white wine was investigated. For this purpose, three independent winemaking experiments were carried out on an industrial scale (batches A, B and C). In detail, the first one was carried out using the sequential inoculation technique while the other two, using a S. cerevisiae single-strain starter or no inoculation representing the control batches. Microbiological and chemical parameters and sensorial profiles of the wines were defined. Interestingly, the results showed that when sequential cultures (H. guilliermondii in a sequential mixture with S. cerevisiae) were used, a better wine aroma and quality was observed. More specifically, the wine obtained by sequential inoculation showed lower acetic acid values and enhanced volatile profiles than the wine from the control batches. Finally, sensorial analysis confirmed that the sequential cultures led to an improvement in wine flavour. Therefore, results suggest that the sequential inoculation using non-Saccharomyces and Saccharomyces yeast represents a biotechnological practice that can improve the quality features of traditional white wine. It has been shown for the first time that on an industrial scale H. guilliermondii could be used in sequential inoculum with S. cerevisiae in making white Campanino wine.


Assuntos
Hanseniaspora/crescimento & desenvolvimento , Microbiologia Industrial/métodos , Saccharomyces cerevisiae/crescimento & desenvolvimento , Vinho/microbiologia , Ácido Acético , Técnicas de Cultura Celular por Lotes , Reatores Biológicos , Meios de Cultura/metabolismo , Fermentação , Hanseniaspora/metabolismo , Cinética , Odorantes , Saccharomyces cerevisiae/metabolismo , Compostos Orgânicos Voláteis/análise
11.
Folia Microbiol (Praha) ; 63(6): 677-684, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29736893

RESUMO

Identification of yeasts isolated from apple juices of two cider houses (one located in a plain area and one in an alpine area) was carried out by culture-based method. Wallerstein Laboratory Nutrient Agar was used as medium for isolation and preliminary yeasts identification. A total of 20 species of yeasts belonging to ten different genera were identified using both BLAST algorithm for pairwise sequence comparison and phylogenetic approaches. A wide variety of non-Saccharomyces species was found. Interestingly, Candida railenensis, Candida cylindracea, Hanseniaspora meyeri, Hanseniaspora pseudoguilliermondii, and Metschnikowia sinensis were recovered for the first time in the yeast community of an apple environment. Phylogenetic analysis revealed a better resolution in identifying Metschnikowia and Moesziomyces isolates than comparative analysis using the GenBank or YeastIP gene databases. This study provides important data on yeast microbiota of apple juice and evidenced differences between two geographical cider production areas in terms of species composition.


Assuntos
Biodiversidade , Sucos de Frutas e Vegetais/microbiologia , Malus/microbiologia , Leveduras/isolamento & purificação , Leveduras/metabolismo , Meios de Cultura/metabolismo , Fermentação , Microbiologia de Alimentos , Frutas/metabolismo , Frutas/microbiologia , Malus/metabolismo , Filogenia , Leveduras/classificação , Leveduras/genética
12.
Fontilles, Rev. leprol ; 31(4): 291-311, ene.-abr. 2018. tab, maps, graf
Artigo em Espanhol | IBECS | ID: ibc-173250

RESUMO

Antecedentes: Después de tres décadas de implementación de la multiterapia (MDT), consistente en una combinación de rifampicina, dapsona y clofazimina, en Malasia la aparición de resistencia farmacológica del Mycobacterium leprae constituye una preocupación, ya que puede llevar al fracaso del tratamiento y la recidiva de la enfermedad. Objetivos: Determinar el modelo de resistencia farmacológica del M. leprae en Malasia. Métodos: Se analizaron los cultivos en almohadilla plantar de ratón (MFP) de todas las biopsias cutáneas de pacientes con lepra borderline lepromatosa y lepra lepromatosa enviados a la Unidad de la Lepra, Laboratorio Nacional de Salud Publica, Sungai Buloh, Malasia, entre 1997-2013. Resultados: Se realizaron 651 cultivos MFP. La edad media de los pacientes fue de 41 anos (rango: 6-88). La proporción varón/hembra era de 3·8:1. Cuatrocientos cuarenta y cuatro pacientes (69·1%) eran malayos. La proporción de M. leprae positivo en cultivo era del 66·6% (433 of 651). El Índice Bacteriologico (IB) y el Índice Morfológico (IM) promedios para los cultivos positivos fue de 3·7 and 2·8 respectivamente. El IB y el IM de los que no crecieron en la MFP eran significativamente menores que los que presentaban cultivos positivos (P < 0·001). La dapsona presento el mayor índice de resistencia del 55% (238 of 433). Sin embargo, el elevado grado de resistencia a la dapsona (0·01%) fue de 6·24%. Hubo 407 MFP con rifampicina 0·003% y 12 (2·9%) resultaron resistentes a la misma. La clofazimina presento el menor grado de resistencia intermedia (0·001%) que fue del 0·2% (1 of 429). No había diferencias significativas entre el patrón de resistencia y género o nacionalidad de los pacientes. Conclusiones: Mas de la mitad de los cultivos MFP presentaron resistencia de baja intensidad a la dapsona; menos del 3% eran resistentes a la rifampicina y la resistencia a la clofazimina resulto muy baja


Background: After three decades of implementing multidrug therapy (MDT) consisting of rifampicin, dapsone and clofazimine in Malaysia, the drug resistance pattern of Mycobacterium leprae is a growing concern as it may lead to failure of treatment and relapse of disease. Objective: To determine the drug resistance patterns of M. leprae in Malaysia. Methods: Mouse footpad (MFP) culture of all skin biopsy samples from patients with borderline lepromatous and lepromatous leprosy sent to the Leprosy Unit, National Public Health Laboratory, Sungai Buloh, Malaysia between 1997-2013 were retrospectively studied. Results: There were 651 MFP cultures performed. The mean age of patients was 41 years old (range: 6-88). The male: female ratio was 3·8:1. Four hundred and forty four patients (69·1%) were Malaysian. The rate of positive M. leprae culture was 66·6% (433 of 651). The mean Bacteriological Index (BI) and median Morphological Index (MI) for those with positive culture were 3·7 and 2·8 respectively. The mean BI and MI of those which failed to grow in the MFP were significantly lower than those with positive cultures (P < 0·001). Dapsone has the highest resistance rate of 55% (238 of 433). Nevertheless, high degree dapsone resistance (0·01%) was 6·24%. There were 407 MFP tests using rifampicin 0·003% and 12 (2·9%) were resistant to it. Clofazimine has the lowest intermediate degree (0·001%) resistance rate of 0·2% (1 of 429). There were no significant differences between the drug resistance pattern and the gender or the nationality of the patients. Conclusion: More than half of our positive MFP cultures showed low-level resistance to dapsone; less than 3% were resistant to rifampicin, and clofazimine resistance remained very low


Assuntos
Animais , Camundongos , Mycobacterium leprae , Mycobacterium leprae/isolamento & purificação , Resistência a Medicamentos , Resistência Microbiana a Medicamentos , Meios de Cultura/farmacologia , Cultura de Vírus/veterinária , Malásia/epidemiologia , Dapsona , Rifampina , Estudos Retrospectivos , Estudos Transversais
13.
Appl Microbiol Biotechnol ; 102(2): 641-653, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29150708

RESUMO

Arabitol is a low-calorie sugar alcohol with anti-cariogenic properties. Enzymatic hydrolysate of soybean flour is a new renewable biorefinery feedstock containing hexose, pentose, and organic nitrogen sources. Arabitol production by Debaryomyces hansenii using soybean flour hydrolysate was investigated. Effects of medium composition, operating conditions, and culture stage (growing or stationary phase) were studied. Production was also compared at different culture volumes to understand the effect of dissolved oxygen concentration (DO). Main factors examined for medium composition effects were the carbon to nitrogen concentration ratio (C/N), inorganic (ammonium) to organic nitrogen ratio (I/O-N), and sugar composition. Arabitol yield increased with increasing C/N ratio and a high I/O-N (0.8-1.0), suggesting higher yield at stationary phase of low pH (3.5-4.5). Catabolite repression was observed, with the following order of consumption: glucose > fructose > galactose > xylose > arabinose. Arabitol production also favored hexoses and, among hexoses, glucose. DO condition was of critical importance to arabitol production and cell metabolism. The yeast consumed pentoses (xylose and arabinose) only at more favorable DO conditions. Finally, arabitol was produced in fermentors using mixed hydrolysates of soy flour and hulls. The process gave an arabitol yield of 54%, volumetric productivity of 0.90 g/L-h, and specific productivity of 0.031 g/g-h.


Assuntos
Fermentação , Farinha , Saccharomycetales/metabolismo , Soja/química , Álcoois Açúcares/metabolismo , Reatores Biológicos , Repressão Catabólica , Meios de Cultura/química , Glucose/metabolismo , Hidrólise , Lignina/metabolismo , Nitrogênio/metabolismo , Pentoses/metabolismo , Xilose/metabolismo
14.
Biotechnol J ; 12(10)2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29034577

RESUMO

An industrial scale biomass production using batch or fed-batch fermentations usually optimized by selection of bacterial strains, tuning fermentation media, feeding strategy, and temperature. However, in-depth investigation of the biomass metabolome during the production may reveal new knowledge for better optimization. In this study, for the first time, the authors investigated seven fermentation batches performed on five Streptoccoccus thermophilus strains during the biomass production at Chr. Hansen (Denmark) in a real life large scale fermentation process. The study is designed to investigate effects of batch fermentation, fermentation time, production line, and yeast extract brands on the biomass metabolome using untargeted GC-MS metabolomics. Processing of the raw GC-MS data using PARAFAC2 revealed a total of 90 metabolites out of which 64 are identified. Partitioning of the data variance according to the experimental design was performed using ASCA and revealed that batch and fermentation time effects and their interaction term were the most significant effects. The yeast extract brand had a smaller impact on the biomass metabolome, while the production line showed no effect. This study shows that in-depth metabolic analysis of fermentation broth provides a new tool for advanced optimization of high-volume-low-cost biomass production by lowering the cost, increase the yield, and augment the product quality.


Assuntos
Técnicas de Cultura Celular por Lotes/métodos , Fermentação , Cromatografia Gasosa-Espectrometria de Massas/métodos , Microbiologia Industrial/métodos , Metabolômica , Streptococcus/metabolismo , Análise de Variância , Biomassa , Meios de Cultura/química , Meios de Cultura/farmacologia , Metaboloma , Streptococcus/efeitos dos fármacos , Streptococcus/crescimento & desenvolvimento , Fatores de Tempo , Leveduras/química
15.
Appl Microbiol Biotechnol ; 101(3): 1003-1012, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27678116

RESUMO

Isolate B17 from Kombucha was estimated to be an efficient producer of bacterial cellulose (BC). The isolate was deposited under the number P 1463 and identified as Komagataeibacter rhaeticus by comparing a generated amplified fragment length polymorphism (AFLP™) DNA fingerprint against a reference database. Static cultivation of the K. rhaeticus strain P 1463 in Hestrin and Schramm (HS) medium resulted in 4.40 ± 0.22 g/L BC being produced, corresponding to a BC yield from glucose of 25.30 ± 1.78 %, when the inoculum was made with a modified HS medium containing 10 g/L glucose. Fermentations for 5 days using media containing apple juice with analogous carbon source concentrations resulted in 4.77 ± 0.24 g/L BC being synthesised, corresponding to a yield from the consumed sugars (glucose, fructose and sucrose) of 37.00 ± 2.61 %. The capacity of K. rhaeticus strain P 1463 to synthesise BC was found to be much higher than that of two reference strains for cellulose production, Komagataeibacter xylinus DSM 46604 and Komagataeibacter hansenii DSM 5602T, and was also considerably higher than that of K. hansenii strain B22, isolated from another Kombucha sample. The BC synthesised by K. rhaeticus strain P 1463 after 40 days of cultivation in HS medium with additional glucose supplemented to the cell culture during cultivation was shown to have a degree of polymerization of 3300.0 ± 122.1 glucose units, a tensile strength of 65.50 ± 3.27 MPa and a length at break of 16.50 ± 0.83 km. For the other strains, these properties did not exceed 25.60 ± 1.28 MPa and 15.20 ± 0.76 km.


Assuntos
Celulose/biossíntese , Fermentação , Gluconacetobacter/metabolismo , Chá de Kombucha/microbiologia , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Carbono/metabolismo , Celulose/metabolismo , Meios de Cultura/química , Gluconacetobacter/classificação , Gluconacetobacter/crescimento & desenvolvimento , Gluconacetobacter/isolamento & purificação , Glucose/metabolismo
16.
Environ Sci Pollut Res Int ; 24(12): 11154-11162, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27312900

RESUMO

Bacterial cellulose (BC) is a homopolymer and it is distinguished from plant-based cellulose by its unique properties such as high purity, high crystallinity, high water-holding capacity, and good biocompatibility. Microalgae are unicellular, photosynthetic microorganisms and are known to have high protein, starch, and oil content. In this study, Chlorella vulgaris was evaluated as source of glucose for the production of BC. To increase the starch content of algae the effect of nutrient starvation (nitrogen and sulfur) and light deficiency were tested in a batch assay. The starch contents (%) were 5.27 ± 0.04, 7.14 ± 0.18, 5.00 ± 0.08, and 1.35 ± 0.04 for normal cultivation, nitrogen starvation, sulfur starvation, and dark cultivation conditions, respectively. The performance of enzymatic and acidic methods was compared for the starch hydrolysis. This study demonstrated for the first time that acid hydrolysate of algal starch can be used to substitute glucose in the fermentation medium of Komagataeibacter hansenii for BC production. Glucose was used as a control for BC production. BC production yields on dry weight basis were 1.104 ± 0.002 g/L and 1.202 ± 0.005 g/L from algae-based glucose and glucose, respectively. The characterization of both BCs produced from glucose and algae-based glucose was investigated by scanning electron microscopy and Fourier transform infrared spectroscopy. The results have shown that the structural characteristics of algae-based BC were comparable to those of glucose-based BC.


Assuntos
Celulose/biossíntese , Chlorella vulgaris/química , Gluconacetobacter/metabolismo , Glucose/química , Meios de Cultura/química
17.
Microbiol Immunol ; 60(12): 817-823, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27925336

RESUMO

In this study, attempts were made to culture this bacterium in media supplemented with a variety of biological materials to determine why cultivation of Mycobacterium leprae in vitro has not this far been successful. A slight increase in the number of cells in medium supplemented with human blood plasma and an extract of nude mouse tissue as observed after more than 3 months of cultivation at 30 °C. To ascertain whether this increase was real growth, the growth was analyzed by droplet digital PCR, which showed a slow increase in the copy number of cell-associated DNA and the release of a large amount of DNA into the culture medium from bacterial cells during cultivation. These results were supported by electron microscopic examination of M. leprae in infected mouse tissues, which showed that most of the replicated bacteria had degenerated and only a few cells survived. Based on these results, it was postulated that many of the replicated cells degenerate during M. leprae growth and that only a few cells remain to participate in the next growth stage. This means that, unlike other cultivable bacteria, the growth of M. leprae is not exponential and the number of cells therefore increase extremely slowly. Thus, accurate judging of the success of M. leprae cultivation requires observation of growth over a long period of time and careful measurement of the increase in number of viable cells.


Assuntos
Técnicas Bacteriológicas/métodos , Meios de Cultura/química , Mycobacterium leprae/crescimento & desenvolvimento , Animais , Sangue/metabolismo , DNA Bacteriano/análise , Humanos , Camundongos Nus , Viabilidade Microbiana , Microscopia Eletrônica , Mycobacterium leprae/fisiologia , Mycobacterium leprae/ultraestrutura , Temperatura , Extratos de Tecidos/metabolismo
18.
World J Microbiol Biotechnol ; 32(12): 207, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27807756

RESUMO

This study assessed the efficiency of Scheffersomyces amazonensis UFMG-CM-Y493T, cultured in xylose-supplemented medium (YPX) and rice hull hydrolysate (RHH), to convert xylose to xylitol under moderate and severe oxygen limitation. The highest xylitol yields of 0.75 and 1.04 g g-1 in YPX and RHH, respectively, were obtained under severe oxygen limitation. However, volumetric productivity in RHH was ninefold decrease than that in YPX medium. The xylose reductase (XR) and xylitol dehydrogenase (XDH) activities in the YPX cultures were strictly dependent on NADPH and NAD+ respectively, and were approximately 10% higher under severe oxygen limitation than under moderate oxygen limitation. This higher xylitol production observed under severe oxygen limitation can be attributed to the higher XR activity and shortage of the NAD+ needed by XDH. These results suggest that Sc. amazonensis UFMG-CM-Y493T is one of the greatest xylitol producers described to date and reveal its potential use in the biotechnological production of xylitol.


Assuntos
Debaryomyces/crescimento & desenvolvimento , Xilitol/biossíntese , Aldeído Redutase/metabolismo , Meios de Cultura/química , D-Xilulose Redutase/metabolismo , Debaryomyces/classificação , Debaryomyces/enzimologia , Fermentação , Proteínas Fúngicas/metabolismo , Microbiologia Industrial , NAD/metabolismo , NADP/metabolismo , Xilitol/metabolismo , Xilose/metabolismo
19.
Appl Environ Microbiol ; 82(14): 4320-4329, 2016 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-27208141

RESUMO

UNLABELLED: This study aimed to isolate nontuberculous mycobacterial species from environmental samples obtained from some selected communities in Ghana. To optimize decontamination, spiked environmental samples were used to evaluate four decontamination solutions and supplemented media, after which the best decontamination solution and media were used for the actual analysis. The isolates obtained were identified on the basis of specific genetic sequences, including heat shock protein 65, IS2404, IS2606, rpoB, and the ketoreductase gene, as needed. Among the methods evaluated, decontamination with 1 M NaOH followed by 5% oxalic acid gave the highest rate of recovery of mycobacteria (50.0%) and the lowest rate of contamination (15.6%). The cultivation medium that supported the highest rate of recovery of mycobacteria was polymyxin B-amphotericin B-nalidixic acid-trimethoprim-azlocillin-supplemented medium (34.4%), followed by isoniazid-supplemented medium (28.1%). Among the 139 samples cultivated in the main analysis, 58 (41.7%) yielded mycobacterial growth, 70 (50.4%) had no growth, and 11 (7.9%) had all inoculated tubes contaminated. A total of 25 different mycobacterial species were identified. Fifteen species (60%) were slowly growing (e.g., Mycobacterium ulcerans, Mycobacterium avium, Mycobacterium mantenii, and Mycobacterium malmoense), and 10 (40%) were rapidly growing (e.g., Mycobacterium chelonae, Mycobacterium fortuitum, and Mycobacterium abscessus). The occurrence of mycobacterial species in the various environmental samples analyzed was as follows: soil, 16 species (43.2%); vegetation, 14 species (38.0%); water, 3 species (8.0%); moss, 2 species (5.4%); snail, 1 species (2.7%); fungi, 1 species (2.7%). This study is the first to report on the isolation of M. ulcerans and other medically relevant nontuberculous mycobacteria from different environmental sources in Ghana. IMPORTANCE: Diseases caused by mycobacterial species other than those that cause tuberculosis and leprosy are increasing. Control is difficult because the current understanding of how the organisms are spread and where they live in the environment is limited, although this information is needed to design preventive measures. Growing these organisms from the environment is also difficult, because the culture medium becomes overgrown with other bacteria that also live in the environment, such as in soil and water. We aimed to improve the methods for growing these organisms from environmental sources, such as soil and water samples, for better understanding of important mycobacterial ecology.


Assuntos
Úlcera de Buruli/epidemiologia , Doenças Endêmicas , Microbiologia Ambiental , Micobactérias não Tuberculosas/classificação , Micobactérias não Tuberculosas/isolamento & purificação , Proteínas de Bactérias/genética , Técnicas Bacteriológicas/métodos , Meios de Cultura/química , Elementos de DNA Transponíveis , Descontaminação/métodos , Gana/epidemiologia , Humanos , Micobactérias não Tuberculosas/genética , Manejo de Espécimes/métodos
20.
Appl Microbiol Biotechnol ; 100(4): 1883-1890, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26610801

RESUMO

Phenol is one of the most common pollutants in many kinds of industrial wastewater, some of which are in high salinity, resulting in more difficulties of biodegradation. In this work, a halophilic strain capable of utilizing phenol as sole source of carbon and energy in both hypersaline and no-salt media was isolated and identified as genus Debaryomyces. The optimization of environmental parameters including phenol concentration, pH, dissolved oxygen as well as salinity was carried out and tolerance of heavy metals by the strain was evaluated. The strain Debaryomyces sp. was able to grow in culture when initial phenol concentration, pH, agitation and salinity were at wide ranges (0-1200 mg L(-1), 4.0-10.0, 50-200 rpm, 0 %-15 %, respectively). High removal efficiency was hardly affected in the presence of 5 mM of Zn (II) and Mn (II). Under optimal conditions (pH 6.0, 200 rpm, 1 % of salinity without heavy metals), 500 mg L(-1) of phenol could be completely degraded within 32 h. The high removal efficiency of phenol by the strain with significant variations of process parameters might contribute to the bioremediation of phenol-polluted environments under hypersaline or no-salt conditions.


Assuntos
Debaryomyces/efeitos dos fármacos , Debaryomyces/metabolismo , Tolerância a Medicamentos , Metais Pesados/toxicidade , Fenol/metabolismo , Biotransformação , Carbono/metabolismo , Meios de Cultura/química , Metabolismo Energético , Concentração de Íons de Hidrogênio , Oxigênio , Salinidade
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