Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
1.
J Phycol ; 59(6): 1339-1346, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37795780

RESUMEN

Novel CRISPR systems capable of cleaving both DNA and RNA are progressively emerging as attractive tools for genome manipulation of prokaryotic and eukaryotic organisms. We report specific characteristics of CRISPR systems present in Oxynema aestuarii AP17, a halotolerant, filamentous cyanobacterium and the second known member of the Oxynema genus. In-silico analyses of its whole-genome sequence revealed the presence of multiple Type I and Type III CRISPR loci with one Type I-G system previously unreported in cyanobacteria. We further identified the leader sequences at the 5' end of multiple CRISPR loci, many of which were distinct from previously reported cyanobacterial CRISPR leaders. Phylogenetic analyses of the O. aestuarii AP17 Cas1 proteins revealed two protein sequences that were unique and distantly related to other cyanobacterial Cas1 protein sequences. Our findings are significant because novel Class 1 CRISPR systems possess multi-subunit effectors and are highly flexible for repurposing by protein domain fusions made to the effector complex. Additionally, Type III CRISPRs are particularly useful for genome editing in certain extremophiles for which mesophilic Type II CRISPRs are ineffective.


Asunto(s)
Sistemas CRISPR-Cas , Cianobacterias , Filogenia , Cianobacterias/genética , Genoma , Análisis de Secuencia
2.
Int J Biol Macromol ; 253(Pt 6): 127317, 2023 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-37820911

RESUMEN

Purified calcium serine metalloprotease from Stenotrophomonas maltophilia strain SMPB12 exhibits highest enzyme activity at pH 9 and temperature range between 15 °C-25 °C. Enzyme supplemented with 40 µM Ca-Hap-NP (NP-protease) showed maximum elevated activity of 17.29 µmole/min/ml (1.9-fold of original protease activity). The thermostability of the enzyme was maintained for 1 h at 60 °C over an alkaline pH range 7.5-10, as compared to the NP untreated enzyme whose activity was of 8.97 µmole/min/ml. A significant loss of activity with EDTA (1.05 µmole/min/ml, 11.75 %), PMSF (0.93 µmole/min/ml, 10.46 %) and Hg2+ (3.81 µmole/min/ml, 42.49 %) was also observed. Kinetics study of NP-protease showed maximum decreases in Km (28.11 %) from 0.28 mM (NP untreated enzyme) to 0.22 mM (NP-protease) along with maximum increase in Vmax (42.88 %) from 1.25 µmole/min/ml to 1.79 µmole/min/ml at varying temperatures. The enhanced activity of NP-protease was able to efficiently degrade recalcitrant solid wastes like feather to produce value-added products like amino acids and helps in declogging recalcitrant solid wastes. The nano-enabled protease may be utilized in a smaller amount for degrading in bulk recalcitrant solid proteinaceous waste at 15 °C temperature as declogging agents providing an eco-friendly efficient process.


Asunto(s)
Durapatita , Plumas , Animales , Plumas/metabolismo , Durapatita/metabolismo , Residuos Sólidos , Péptido Hidrolasas/metabolismo , Bacterias/metabolismo , Temperatura , Bosques , Concentración de Iones de Hidrógeno , Estabilidad de Enzimas
3.
Heliyon ; 6(9): e05053, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33015393

RESUMEN

Non-enzymatic glycation of proteins is believed to be the root cause of high dietary sugar associated pathophysiological maladies. We investigated the structural changes in protein during progression of glycation using ribosylated Bovine Serum Albumin (BSA). Non enzymatic attachment of about 45 ribose molecules to BSA resulted in gradual reduction of hydrophobicity and aggregation as indicated by red-shifted tryptophan fluorescence, reduced ANS binding and lower anisotropy of FITC-conjugated protein. Parallely, there was a significant decrease of alpha helicity as revealed by Circular Dichroism (CD) and Fourier transformed-Infra Red (FT-IR) spectra. The glycated proteins assumed compact globular structures with enhanced Thioflavin-T binding resembling amyloids. The gross structural transition affected by ribosylation led to enhanced thermostability as indicated by melting temperature and Transmission Electron Microscopy. At a later stage of glycation, the glycated proteins developed non-specific aggregates with increase in size and loss of amyloidogenic behaviour. A parallel non-glycated control incubated under similar conditions indicated that amyloid formation and associated changes were specific for ribosylation and not driven by thermal denaturation due to incubation at 37 °C. Functionality of the glycated protein was significantly altered as probed by Isothermal Titration Calorimetry using polyphenols as substrates. The studies demonstrated that glycation driven globular amyloids form and persist as transient intermediates during formation of misfolded glycated adducts. To the best of our knowledge, the present study is the first systematic attempt to understand glycation associated changes in a protein and provides important insights towards designing therapeutics for arresting dietary sugar induced amyloid formation.

4.
Microbiol Resour Announc ; 9(44)2020 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-33122408

RESUMEN

Oxynema sp. AP17 is the second distinct species of the Oxynema genus, and it differs from the first (Oxynema thaianum) in 16S-23S internal transcribed spacer (ITS) sequence, morphology, and optimal salinity. The genome size is 6.37 Mbp; 4,801 protein-coding genes, 74 tRNAs, and 5 each of the 16S, 23S, and 5S rRNAs constitute the genome.

5.
Chem Biol Interact ; 308: 120-129, 2019 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-31129132

RESUMEN

A preclinical study using DEN-induced HCC rat model was attempted to evaluate the antitumor potential of zolmitriptan (ZOL). The molecular insights were investigated using ELISA, qRT-PCR and Western blot techniques. The result confirmed that the HCC condition was developed in response to lower expressions of caspase 3 and 9 which, in turn, was due to the upstream regulation of iNOS, Bcl-xl and Bcl-2, and downstream regulation of eNOS, BAX, BAD and Cyt C. The treatment with ZOL caused the significant activation of caspase mediated apoptotic signals that could be responsible for its anti-HCC potential. Later, 1H NMR based serum metabolomics study confirmed that ZOL restored the perturbed metabolites associated with DEN-induced HCC. The antineoplastic potential of ZOL was found comparable or to some degree better than the marketed chemotherapeutics, 5-flurouracil.


Asunto(s)
Apoptosis/efectos de los fármacos , Caspasa 3/metabolismo , Caspasa 9/metabolismo , Oxazolidinonas/farmacología , Triptaminas/farmacología , Animales , Carcinoma Hepatocelular/inducido químicamente , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/patología , Citocinas/análisis , Modelos Animales de Enfermedad , Glutatión/metabolismo , Lípidos/sangre , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Neoplasias Hepáticas/inducido químicamente , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/patología , Masculino , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/metabolismo , Oxazolidinonas/uso terapéutico , Estrés Oxidativo/efectos de los fármacos , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Ratas , Ratas Wistar , Triptaminas/uso terapéutico , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismo
6.
Environ Sci Pollut Res Int ; 25(31): 31326-31345, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30194579

RESUMEN

Metal pollution is a subject of growing concern as it affects the whole food chain of an ecosystem by bioaccumulation. Growing industrialization and anthropogenic intervention have put tremendous pressure on self-sustaining ecosystems worldwide. Sundarbans mangrove estuary, being a UNESCO World Heritage site, suffers severely from anthropogenic stress, urbanization, ecotourism, overexploitation of natural resources and discharges of industrial as well as municipal waste products. Our study unfolds the extent of metal pollution in the sediment of this estuarine mangrove ecosystem and also investigates the source and distribution of these metals. Extensive samplings were performed during three major seasons, namely pre-monsoon, monsoon, and post-monsoon for two consecutive years at ten sampling stations along the major river networks of the mangrove estuary. Seasonal variations of these metals, physicochemical properties, and soil texture studies were performed to explore the sediment quality of the study area. Positive correlation was observed between the pollutants and siltation. Several environmental indices were investigated to explore the degree of metal pollution which revealed contamination of Cd, Cr, and Pb to cross the permitted safe index in the study area. Pollution load index indicates the spatial as well as seasonal variation of eco toxic metal load along the course of the rivers. Statistical analyses such as principal component analysis and correlation matrix identified different sources for metal contamination. Almost 700 tannery industries are located in the upstream region of the rivers, and several small- and large-scale battery industries seem to be the main possible source for Cd, Cr, and Pb pollution. Analysis of the results indicates the alarming condition of this heritage site. The metal concentrations beyond toxicity thresholds are responsible for gradual deterioration of this estuarine mangrove which may only be protected by developing sustainable management planning.


Asunto(s)
Monitoreo del Ambiente , Metales Pesados/análisis , Ríos/química , Contaminantes Químicos del Agua/análisis , Ecosistema , Monitoreo del Ambiente/métodos , Estuarios , Sedimentos Geológicos/química , Estaciones del Año , Suelo/química
7.
Genome Announc ; 6(27)2018 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-29976609

RESUMEN

Streptomyces sp. SMS_SU21 possesses strong antimicrobial activity and antioxidant potential. This strain was isolated from the Sundarbans mangrove ecosystem, and its draft genome comprises 7,449,420 bp with 6,680 open reading frames. Genome analysis of strain SMS_SU21 provides insight into its secondary metabolite arsenal and reveals the gene clusters putatively responsible for its bioactive potential.

8.
Environ Sci Pollut Res Int ; 25(3): 2331-2349, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29124636

RESUMEN

Microbial synthesis of gold nanoparticles (GNPs) has attracted considerable attention in recent times due to their exceptional capability for the bioremediation of industrial wastes and also for the treatment of wastewater. A bacterial strain Staphylococcus warneri, isolated from the estuarine mangroves of Sundarbans region produced highly stable GNPs by reducing hydrogen auric chloride (HAucl4) salt using intracellular protein extract. The nanoparticles were characterized utilizing ultraviolet-visible spectrophotometry, transmission electron microscopy, scanning electron microscopy, atomic force microscopy, X-ray diffraction, and surface enhanced Raman scattering. Highly dispersed, spherically shaped GNPs varied around 15-25 nm in size and were highly crystalline with face-centered cubic structures. Recyclable catalytic activity of as-synthesized GNPs was evidenced by complete degradation of nitro aromatic pollutants like 2-nitroaniline, 4-nitroaniline, 2-nitrophenol and 4-nitrophenol. Our GNPs show excellent and efficient catalytic activity with significantly high rate constant (10-1 order) and high turnover frequency (103 order) in recyclable manner up to three times. To our knowledge, this is the first report of Staphylococcus warneri in the production of gold nanoparticles. This green technology for bioremediation of toxic nitro aromatic pollutants is safe and economically beneficial to challenge the development and sustainability issue.


Asunto(s)
Oro/química , Tecnología Química Verde/métodos , Hidrocarburos Aromáticos/análisis , Nanopartículas del Metal/química , Nitrocompuestos/análisis , Staphylococcus/metabolismo , Catálisis , Restauración y Remediación Ambiental , Equipo Reutilizado , Estuarios , Staphylococcus/aislamiento & purificación
9.
Genom Data ; 7: 76-8, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26981367

RESUMEN

The global knowledge of microbial diversity and function in Sundarbans ecosystem is still scarce, despite global advancement in understanding the microbial diversity. In the present study, we have analyzed the diversity and distribution of bacteria in the tropical mangrove sediments of Sundarbans using 16S rRNA gene amplicon sequencing. Metagenome is comprised of 1,53,926 sequences with 108.8 Mbp data and with 55 ± 2% G + C content. Metagenome sequence data are available at NCBI under the Bioproject database with accession no. PRJNA245459. Bacterial community metagenome sequences were analyzed by MG-RAST software representing the presence of 56,547 species belonging to 44 different phyla. The taxonomic analysis revealed the dominance of phyla Proteobacteria within our dataset. Further taxonomic analysis revealed abundance of Bacteroidetes, Acidobactreia, Firmicutes, Actinobacteria, Nitrospirae, Cyanobacteria, Planctomycetes and Fusobacteria group as the predominant bacterial assemblages in this largely pristine mangrove habitat. The distribution of different community datasets obtained from four sediment samples originated from one sampling station at two different depths providing better understanding of the sediment bacterial diversity and its relationship to the ecosystem dynamics of this pristine mangrove sediment of Dhulibhashani in, Sundarbans.

10.
Genom Data ; 7: 94-6, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26981374

RESUMEN

This is a pioneering report on the metagenomic exploration of the bacterial diversity from a busy sea port in Paradip, Odisha, India. In our study, high-throughput sequencing of community 16S rRNA gene amplicon was performed using 454 GS Junior platform. Metagenome contain 34,121 sequences with 16,677,333 bp and 56.3% G + C content. Metagenome sequences data are now available at NCBI under the Sequence Read Archive (SRA) database with accession no. SRX897055. Community metagenome sequence revealed the presence of 11,705 species belonging to 40 different phyla. Bacteroidetes (23%), Firmicutes (19%), Proteobacteria (17%), Spirochaetes (10%), Nitrospirae (8%), Actinobacteria (7%) and Acidobacteria (3%) are the predominant bacterial phyla in this port soil. Analysis of metagenomic sequences unfolded the interesting distribution of several phyla which pointed to the significant anthropogenic intervention influencing the bacterial community character of this port.

11.
Genom Data ; 4: 90-2, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26484187

RESUMEN

In this present study we report the profile of bacterial community at variable depth of soil sediment in the world's largest tropical mangrove sediments of Sundarbans, India using 16S rRNA gene amplicon sequencing. Metagenome of three samples consisted of 61301 sequences with 32.0 Mbp and 55.6% G + C content. Metagenome data of this study are available at NCBI under the Biosample data base accession no. SRX883521. The taxonomic analysis of 2746 species belonged to 33 different phyla revealing the dominance of Proteobacteria, Firmicutes, Chloroflexi, Bacteroidetes, Acidobacteria, Nitrospirae and Actinobacteria respectively. Remarkably less than 5.0% sequences belong to a poorly characterized group. Our pyrosequencing data report unfolds the bacterial community profile at different depth of soil sediment indicating the changing community pattern, in the light of specific chronology.

12.
Genom Data ; 4: 112-4, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26484193

RESUMEN

Brackish water lake is the most extraordinary reservoir for bacterial community with an adaptability of tolerance to saline stress. In the present study, metagenomic approach was implemented utilising 454-pyrosequencing platform to gain deeper insights into the bacterial diversity profile of the soil sediment of Chilika Lake, Odisha, India. Metagenome contained 68,150 sequences with 31,896,430 bp and 56.79% G + C content. Metagenome sequences data are now available at NCBI under the Sequence Read Archive (SRA) database with accession no. SRX753382. Bacterial community metagenome sequences were analysed by MG-RAST server representing the presence of 16,212 species belonging to 45 different phyla. The dominating phyla were Proteobacteria, Chloroflexi, Firmicutes, Acidobacteria, Actinobacteria, Bacteroidetes and Planctomycetes. The analysis of bacterial community datasets obtained from two different saline soil sediments revealed significant differences in bacterial community composition and diversity value providing better understanding of the ecosystem dynamics of Chilika Lake.

13.
BMC Microbiol ; 15: 170, 2015 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-26293487

RESUMEN

BACKGROUND: New broad spectrum antimicrobial agents are urgently needed to combat frequently emerging multi drug resistant pathogens. Actinomycetes, the most talented group of microorganisms isolated from unexplored regions of the world may be the ultimate solution to this problem. Thus the aim of this study was to isolate several bioactive actinomycetes strains capable of producing antimicrobial secondary metabolite from Sundarbans, the only mangrove tiger land of the world. RESULTS: Fifty four actinomycetes were isolated and analyzed for antimicrobial activity against fifteen test organisms including three phytopathogens. Nine morphologically distinct and biologically active isolates were subjected to polyphasic identification study.16 s rDNA sequencing indicated eight isolates to reveal maximum similarity to the genus streptomyces, whereas one isolate presented only 93.57% similarity with Streptomyces albogriseolus NRRL B-1305(T). Seventy-one carbon sources and twenty-three chemical sources utilization assay revealed their metabolic relatedness. Among these nine isolates three specific strains were found to have notably higher degree of antimicrobial potential effective in a broader range including phyto-pathogenic fungus. Finally the strain SMS_SU21, which showed antimicrobial activity with MIC value of 0.05 mg ml(-1) and antioxidant activity with IC50 value of 0.242 ± 0.33 mg ml(-1) was detected to be the most potential one. True prospective of this strain was evaluated utilizing GC-MS and the bioactive compound responsible for antimicrobial activity was purified. CONCLUSION: Rare bioactive actinomycetes were isolated from unexplored heritage site. Antimicrobial compound has also been identified and purified which is active against a broad range of pathogens.


Asunto(s)
Actinobacteria/aislamiento & purificación , Actinobacteria/metabolismo , Antiinfecciosos/metabolismo , Microbiología Ambiental , Actinobacteria/clasificación , Actinobacteria/genética , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , Bacterias/efectos de los fármacos , Técnicas de Tipificación Bacteriana , Bangladesh , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Hongos/efectos de los fármacos , Cromatografía de Gases y Espectrometría de Masas , India , Concentración 50 Inhibidora , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
14.
Mar Biotechnol (NY) ; 17(4): 463-78, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25837832

RESUMEN

Sponge diseases have increased dramatically, yet the causative agents of disease outbreaks have eluded identification. We undertook a polyphasic taxonomic analysis of the only confirmed sponge pathogen and identified it as a novel strain of Pseudoalteromonas agarivorans. 16S ribosomal RNA (rRNA) and gyraseB (gyrB) gene sequences along with phenotypic characteristics demonstrated that strain NW4327 was most closely related to P. agarivorans. DNA-DNA hybridization and in silico genome comparisons established NW4327 as a novel strain of P. agarivorans. Genes associated with type IV pili, mannose-sensitive hemagglutinin pili, and curli formation were identified in NW4327. One gene cluster encoding ATP-binding cassette (ABC) transporter, HlyD and TolC, and two clusters related to the general secretion pathway indicated the presence of type I secretion system (T1SS) and type II secretion system (T2SS), respectively. A contiguous gene cluster of at least 19 genes related to type VI secretion system (T6SS) which included all 13 core genes was found. The absence of T1SS and T6SS in nonpathogenic P. agarivorans S816 established NW4327 as the virulent strain. Serine proteases and metalloproteases of the classes S8, S9, M4, M6, M48, and U32 were identified in NW4327, many of which can degrade collagen. Collagenase activity in NW4327 and its absence in the nonpathogenic P. agarivorans KMM 255(T) reinforced the invasiveness of NW4327. This is the first report unambiguously identifying a sponge pathogen and providing the first insights into the virulence genes present in any pathogenic Pseudoalteromonas genome. The investigation supports a theoretical study predicting high abundance of terrestrial virulence gene homologues in marine bacteria.


Asunto(s)
Arrecifes de Coral , Fenotipo , Poríferos/microbiología , Pseudoalteromonas/genética , Pseudoalteromonas/patogenicidad , Animales , Sistemas de Secreción Bacterianos/genética , Secuencia de Bases , Análisis por Conglomerados , Colagenasas/genética , Biología Computacional , Girasa de ADN/genética , Metaloproteasas/genética , Microscopía Electrónica de Transmisión , Datos de Secuencia Molecular , Familia de Multigenes/genética , Hibridación de Ácido Nucleico , Océano Pacífico , Filogenia , Pseudoalteromonas/citología , Queensland , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Serina Proteasas/genética , Especificidad de la Especie , Virulencia
15.
Biomed Res Int ; 2014: 436056, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24991552

RESUMEN

A heterotrophic carbon utilizing microbe (R31) capable of simultaneous nitrification and denitrification (SND) was isolated from wastewater of an Indian slaughterhouse. From an initial COD value of 583.0 mg/L, 95.54% was removed whilst, from a starting NH4 (+)-N concentration of 55.7 mg/L, 95.87% was removed after 48 h contact. The concentrations of the intermediates hydroxylamine, nitrite, and nitrate were low, thus ensuring nitrogen removal. Aerobic denitrification occurring during ammonium removal by R31 was confirmed by utilization of both nitrate and nitrite as nitrogen substrates. Glucose and succinate were superior while acetate and citrate were poor substrates for nitrogen removal. Molecular phylogenetic identification, supported by chemotaxonomic and physiological properties, assigned R31 as a close relative of Chryseobacterium haifense. The NH4 (+)-N utilization rate and growth of strain R31 were found to be higher at C/N = 10 in comparison to those achieved with C/N ratios of 5 and 20. Monod kinetic coefficients, half saturation concentration (K s ), maximum rate of substrate utilization (k), yield coefficient, (Y) and endogenous decay coefficient (K d ) indicated potential application of R31 in large-scale SND process. This is the first report on concomitant carbon oxidation, nitrification, and denitrification in the genus Chryseobacterium and the associated kinetic coefficients.


Asunto(s)
Carbono/metabolismo , Chryseobacterium/crecimiento & desarrollo , Procesos Heterotróficos/genética , Nitrificación/genética , Mataderos , Aerobiosis/genética , Carbono/química , Chryseobacterium/genética , Chryseobacterium/aislamiento & purificación , Humanos , Aguas Residuales/microbiología
16.
Genome Announc ; 2(1)2014 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-24482504

RESUMEN

To date, only one marine sponge pathogen (Pseudoalteromonas sp. strain NW 4327) has fulfilled Koch's postulates. We report the 4.48-Mbp draft genome sequence of this strain, which is pathogenic to the Great Barrier Reef sponge Rhopaloeides odorabile. The sequence provides valuable information on sponge-pathogen interactions, including the mode of transmission and associated virulence factors.

17.
Appl Environ Microbiol ; 79(24): 7922-30, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24038685

RESUMEN

The aims of the investigation were to ascertain if surface attachment of Cunninghamella elegans and niche intertidal conditions provided in a bioreactor influenced biotransformation of fluoranthene by C. elegans. A newly designed polymethylmethacrylate (PMMA) conico-cylindrical flask (CCF) holding eight equidistantly spaced rectangular strips mounted radially on a circular disc allowed comparison of fluoranthene biotransformation between CCFs with a hydrophobic surface (PMMA-CCF) and a hydrophilic glass surface (GS-CCF) and a 500-ml Erlenmeyer flask (EF). Fluoranthene biotransformation was higher by 22-fold, biofilm growth was higher by 3-fold, and cytochrome P450 gene expression was higher by 2.1-fold when C. elegans was cultivated with 2% inoculum as biofilm culture in PMMA-CCF compared to planktonic culture in EF. Biotransformation was enhanced by 7-fold with 10% inoculum. The temporal pattern of biofilm progression based on three-channel fluorescence detection by confocal laser scanning microscopy demonstrated well-developed, stable biofilm with greater colocalization of fluoranthene within extracellular polymeric substances and filaments of the biofilm grown on PMMA in contrast to a glass surface. A bioreactor with discs rotating at 2 revolutions per day affording 6-hourly emersion and immersion mimicked the niche intertidal habitat of C. elegans and supported biofilm formation and transformation of fluoranthene. The amount of transformed metabolite was 3.5-fold, biofilm growth was 3-fold, and cytochrome P450 gene expression was 1.9-fold higher in the process mimicking the intertidal conditions than in a submerged process without disc rotation. In the CCF and reactor, where biofilm formation was comparatively greater, higher concentration of exopolysaccharides allowed increased mobilization of fluoranthene within the biofilm with consequential higher gene expression leading to enhanced volumetric productivity.


Asunto(s)
Biopelículas/crecimiento & desarrollo , Cunninghamella/metabolismo , Fluorenos/metabolismo , Reactores Biológicos , Biotransformación , Cunninghamella/enzimología , Cunninghamella/aislamiento & purificación , Cunninghamella/fisiología , Sistema Enzimático del Citocromo P-450/metabolismo
18.
AMB Express ; 2(1): 34, 2012 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-22776040

RESUMEN

Vinasse, a highly polluting waste of the ethanol industry was utilized for the production of polyhydroxyalkanoate (PHA) by the extremely halophilic archaeon, Haloferax mediterranei in shake-flasks. Following pre-treatment through adsorption on activated carbon, 25%-50% (v/v) pre-treated vinasse was utilized leading to 70% maximum accumulation of PHA. Maximum PHA concentration of 19.7 g/l, product yield coefficient (based on total carbohydrates) of 0.87 and 0.21 g/l h volumetric productivity were achieved. Concomitant lowering of BOD5 of pre-treated vinasse by at least 78% and COD by at least 80% was attained at the end of this process. The PHA was recovered by osmotic lysis of the cells and purification by sodium hypochlorite and organic solvents. Through UV-vis spectroscopy, gas chromatography, differential scanning calorimetry and nuclear magnetic resonance spectroscopy, the PHA was identified as poly-3-(hydroxybutyrate-co-hydroxyvalerate). The 3-hydroxyvalerate content was 12.36 mol % (utilizing 25% pre-treated vinasse) and 14.09 mol % (utilizing 50% pre-treated vinasse). High salt concentration in the medium allowed this process without sterile conditions and thus reduction in costs of sterilization can be envisaged. Activated charcoal pre-treatment of vinasse is economical than competing processes such as ultrafiltration of whey, extrusion and enzymatic treatment of rice and corn starch. Without impacting sugar prices, this process can easily be integrated into a distillery that has fermentation equipment and trained personnel. High PHA content, productivity, zero-cost carbon source, low-cost isolation of a high-purity product and potential integration into ethanol manufacturing unit with concomitant wastewater treatment should merit further development of this process to higher scales.

19.
Folia Microbiol (Praha) ; 57(1): 71-9, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22258750

RESUMEN

Vinasse, a recalcitrant waste of the ethanol industry was employed for the production of polyhydroxyalkanoate (PHA) by the extremely halophilic archaeon, Haloarcula marismortui in shake flasks. The PHA was recovered by osmotic lysis of the cells and subsequent purification by sodium hypochlorite and organic solvents. Through UV-vis spectroscopy, differential scanning calorimetry, Fourier transform infrared, and nuclear magnetic resonance spectroscopy, the PHA was found to have characteristics very similar to that of the standard polyhydroxybutyrate (PHB) from Sigma. Inhibitory effect of polyphenols contained in vinasse was assessed by a quick and reliable cup-plate agar-diffusion method. Raw vinasse (10%) was utilized leading to accumulation of 23% PHA (of cell dry weight) and following an efficacious pre-treatment process through adsorption on activated carbon, 100% pre-treated vinasse could be utilized leading to 30% accumulation of PHB by H. marismortui. Maximum specific growth rate, specific production rate, and volumetric productivity attained using 10% raw vinasse were comparable to that obtained using a previously reported nutrient deficient medium (NDM), while the values with 100% pre-treated vinasse were higher than that determined using NDM medium. This is the first report of polyhydroxybutyrate production by a halophilic microorganism utilizing vinasse.


Asunto(s)
Haloarcula marismortui/metabolismo , Residuos Industriales/análisis , Polihidroxialcanoatos/metabolismo , Proteínas Arqueales/genética , Proteínas Arqueales/metabolismo , Regulación de la Expresión Génica Arqueal , Haloarcula marismortui/genética , Haloarcula marismortui/crecimiento & desarrollo , Eliminación de Residuos
20.
Bioprocess Biosyst Eng ; 35(5): 721-8, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22130566

RESUMEN

Heterotrophic carbon utilizing microbes were acclimatized in the laboratory by inoculating sludge collected from the waste discharge pond of a small-scale rural abattoir in India in a nutrient solution intermittently fed with glucose and ammonium chloride. Cultures of 10 well-developed isolates were selected and grown in a basal medium containing glucose and ammonium chloride. Culture supernatants were periodically analyzed for ammonium nitrogen (NH(4)(+)-N) and chemical oxygen demand (COD). Polyphasic taxonomic study of the most active nitrifier (S18) was done. Half saturation concentration (K(s)), maximum rate of substrate utilization (k), yield coefficient (Y) and decay coefficient (K(d)) were determined from the Lineweaver-Burk plot using the modified Monod equation. S18 was able to remove 97 ± 2% of (NH(4)(+)-N) and 88 ± 3% of COD. Molecular phylogenetic study supported by physiological and biochemical characteristics assigned S18 as Achromobacter xylosoxidans. Nitrification activity of A. xylosoxidans was demonstrated for the first time, while interestingly, the distinctive anaerobic denitrification property was preserved in S18. K (s) values were determined as 232.13 ± 1.5 mg/l for COD reduction and 2.131 ± 1.9 mg/l for NH(4)(+)-N utilization. Yield coefficients obtained were 0.4423 ± 0.1134 mg of MLVSS/mg of COD and 0.2461 ± 0.0793 mg of MLVSS/mg of NH(4)(+)-N while the decay coefficients were 0.0627 ± 0.0013 per day and 0.0514 ± 0.0008 per day, respectively. After a contact period of 24 h, 650 ± 5 mg/l solids were produced when the initial concentration of COD and NH(4)(+)-N were 1820 ± 10 mg/l and 120 ± 5.5 mg/l, respectively. This is the first report on the kinetic coefficients for carbon oxidation and nitrification by a single bacterium isolated from slaughterhouse wastewater.


Asunto(s)
Mataderos , Achromobacter denitrificans/aislamiento & purificación , Achromobacter denitrificans/fisiología , Residuos Industriales , Nitrificación/fisiología , Microbiología del Agua , Amoníaco/análisis , Amoníaco/metabolismo , Oxígeno/metabolismo , Consumo de Oxígeno/fisiología , Filogenia
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA