Showing papers in "The Open Biotechnology Journal in 2009"
TL;DR: Departamento de Bioquimica e Microbiologia Instituto de Biociencias Universidade Estadual Paulista, UNESP, Avenida 24A, 1515, CEP 13506-900 Rio Claro, SP
Abstract: Departamento de Bioquimica e Microbiologia Instituto de Biociencias Universidade Estadual Paulista, UNESP, Avenida 24A, 1515, CEP 13506-900 Rio Claro, SP
284 citations
TL;DR: The results indicated that the composting process of EFB with partially treated POME was dominated by uncultured bacteria species, which contributed to a better understanding of mechanisms involved in co-composting process in pilot scale.
Abstract: Microbial communities and cellulolytic enzymes activities were analyzed during the co-composting of empty fruit bunch (EFB) and partially treated palm oil mill effluent (POME) in pilot scale. The physicochemical parameters were also measured during the composting. The diversity of the bacterial community was investigated using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results indicated that the composting process of EFB with partially treated POME was dominated by uncultured bacteria species. The dominant bacterial group changed from the phylum proteobacteria in the thermophilic stage to the phylum chloroflexi in the maturing stage. Scanning elec- tron microscope (SEM) analysis exhibited the significant degradation of EFB structure during the composting process. The maximum cellulase activity for carboxymethylcellulase (CMCase), filter paperase (FPase) and � -glucosidase were 13.6, 4.1 and 20.3 U/g of dry substrate, respectively at day 30 of composting. The results of this study significantly con- tributed to a better understanding of mechanisms involved in co-composting process in pilot scale.
47 citations
TL;DR: It is concluded that selected plant essential oils can act as potent inhibitors of both microorganisms in a food product and their genotoxicity potential in eukaryotic cells made them unacceptable as food preservatives, particularly at high doses.
Abstract: In this study, investigations were carried out to assess the efficiency of two plant essential oils; rosemary and oregano as natural food preservatives. The effect of the plant essential oils at concentrations of 0.1%, 0.5% and 1% was studied in the soft cheese against Salmonella enteritidis and Escherichia coli at fridge temprature over a 14-day period. The essential oils performed well in the inhibition of S. enteritidis and E. coli. It is concluded that selected plant essential oils can act as potent inhibitors of both microorganisms in a food product. At the same time, evaluation of their safety as food preservatives was undertaken via monitoring the genotoxic activity of the mentioned essential oils using Vicia faba test. Vicia faba roots were treated with the above concentrations for 3 hours. Results revealed cytotoxic and genotoxic ef- fects of the applied doses. Mitotic index decreased significantly when compared to control. Chromosomal abnormalities and micronuclei were also observed and the effects were dose-dependent. Despite the efficient role of the studied oils as antimicrobial agents, their genotoxicity potential in eukaryotic cells made them unacceptable as food preservatives, par- ticularly at high doses. Therefore, more research in the use of essential oils as food preservatives is needed.
28 citations
TL;DR: In the present study, a high-throughput microtitre plate-based col- orimetric assay for xanthine oxidase producing microorganism was developed and may be utilized for the rapid screening of a variety of xanthines producing microorganisms from the na- ture.
Abstract: Xanthine oxidase is a highly versatile and ubiquitous complex molybdoflavoprotein, which controls the rate limiting step of purine catabolism pathway. Microbial xanthine oxidase can be used to address a number of questions presently not feasible with the eukaryotic enzymes. In the present study, a high-throughput microtitre plate-based col- orimetric assay for xanthine oxidase producing microorganism was developed. Superoxides produced by microbial cul- tures, grown on xanthine rich medium interacts with nitroblue tetrazolium (NBT) solution and produces dark blue color, which facilitates the rapid screening of xanthine oxidase producing microorganisms and could be adapted for quick quan- titative assessment and distribution of xanthine oxidase in many heterogeneous microbial communities. The method de- veloped may be utilized for the rapid screening of a variety of xanthine oxidase producing microorganisms from the na- ture.
20 citations
TL;DR: In this article, palm oil mill effluent (POME) was used as the substrate for bio-hydrogen production and preliminary screening on the effects of inocula sizes, heat treatment, substrate concentration and pH of incubation were conducted under mesophilic condition (37°C) using a serum vial (160 mL).
Abstract: In this study, palm oil mill effluent (POME) was used as the substrate for biohydrogen production. Heat-treated POME sludge acclimated with POME incubated at 37°C for 24 hours was used as seed culture. Preliminary screening on the effects of inocula sizes, heat treatment, substrate concentration and pH of incubation by using a factorial design (FD) were conducted under mesophilic condition (37°C) using a serum vial (160 mL). The experimental results from two-level FD showed that pH and Chemical Oxygen Demand (COD) of POME significantly affected biohydrogen production. Op- timizations of the specific hydrogen production (Ps) and the hydrogen production rate (Rm) were achieved by using a cen- tral composite design (CCD). The maximum Ps of 272 mL H2/g carbohydrate was obtained under optimum conditions of pH 5.75 and substrate concentration of 80 g/L. The maximum Rm of 98 mL H2/h was calculated under the optimum condi- tions of pH 5.98 and substrate concentration of 80 g/L. The optimized conditions obtained were subjected to a confirma- tion run and it showed reproducible data with a Ps of 226 mL H2/g carbohydrate and Rm of 72 mL H2/h.
19 citations
TL;DR: Results indicated that DNA polymorphisms detected by RAPD analysis could be used as an investigation tool for environ- mental toxicology and as a useful biomarker assay for the detection of genotoxic effects of food dyes.
Abstract: In this study, faba bean (Vicia faba) seedlings were used as bioindicator to determine genotoxic effect of syn- thetic dyes currently used as food color additives in many countries. Novel short-term assays are required to substantiate the battery of assessment methods for evaluating the genotoxicity of candidate substances. Therefore, an attempt has been made to evaluate randomly amplified polymorphic DNA (RAPD) analysis for its potential to establish genotoxic effect of colored food. For the preliminary assessment, this study compared the effects occurring at molecular levels in Vicia faba exposed to colored food at concentrations in the range of 0.2% to 18.2%. The qualitative modifications arising in random amplified polymorphic DNA (RAPD) profiles as a measure of DNA effects were compared with control. Results sug- gested that treatments of the above test food samples reflect changes in RAPD profiles. Changes in RAPD patterns in- cluded variation in band intensity; loss of normal bands and appearance of new bands compared with control. These re- sults indicated that DNA polymorphisms detected by RAPD analysis could be used as an investigation tool for environ- mental toxicology and as a useful biomarker assay for the detection of genotoxic effects of food dyes. In conclusion, the measurement of parameters at molecular levels is valuable for investigating the specific effects of agents interacting with DNA. Ultimately, this methodology may allow the ecotoxicological examination of the link between molecular alterations and measurable adverse effects at higher levels of biological organization.
19 citations
TL;DR: It is demonstrated that transgenic plants are an efficient system for the production of a multimerized recombinant GLP-1, and may prove to be an attractive delivery system for direct oral administration of a novel stable GLp-1 analog in the treatment of patients with Type 2 diabetes.
Abstract: Glucagon-like peptide-1 (GLP-1) is a small peptide hormone with potent insulinotropic activity and represents a promising new therapeutic tool for the treatment of diabetes. Like many other therapeutic peptides, GLP-1 is commonly produced using chemical synthesis methods, but is limited by product quantity and cost. The advent of recombinant DNA technology offers the possibility of producing GLP-1 inexpensively and in vast quantities. In this study, transgenic plants were used as a recombinant expression platform for the production of GLP-1 as a large multimeric protein. A synthetic gene encoding ten sequential tandem repeats of GLP-1 sequence (GLP-1x10) was produced and introduced into tobacco plants. Transcriptional expression of the GLP1x10 gene in transgenic plants was confirmed by RT-PCR. Western blot analysis showed that the GLP-1x10 protein efficiently accumulated in transgenic plants, with an accumulation level as high as 0.15% of total soluble protein in leaves. Importantly, insulin secretion assays using a mouse pancreaticcell line (MIN6), showed that plant-derived GLP-1 in its synthetic decamer form, retained its ability to stimulate cellular insulin secretion, although with reduced efficacy. These results demonstrate that transgenic plants are an efficient system for the production of a multimerized recombinant GLP-1. Moreover, transgenic plants synthesizing high levels of GLP-1x10 may prove to be an attractive delivery system for direct oral administration of a novel stable GLP-1 analog in the treatment of patients with Type 2 diabetes.
13 citations
TL;DR: The qualitative modifications arising in random amplified polymorphic DNA (RAPD) pro- files as a measure of DNA effects were compared with control which showed many differences and the meas- urement of parameters at molecular levels is valuable for investigating the specific effects of agents interacting with DNA.
Abstract: Technological application of essential oils, as natural antimicrobial agents, to reduce the effect of pathogenic microorganisms, requires new methods of detection. The present work evaluated the parameters of antimicrobial activity of the essential oils of rosemary (Rosmarinus officinalis) on two pathogenic strains Escherichia coli and Staphylococcus aureus. The MBC and MIC values were of 2.5, 25 μl ml -1 , and values of 1.25 and 5 μl ml -1 for the two strains respectively. In this study, an attempt has been made to evaluate randomly amplified polymorphic DNA (RAPD) analysis for its poten- tial to establish antimicrobial effect of rosemary essential oil. For the preliminary assessment, this study compared the ef- fects occurring at molecular levels in E. coli and Staph. aureus exposed to rosemary essential oil at the MIC concentra- tions for the two organisms. The qualitative modifications arising in random amplified polymorphic DNA (RAPD) pro- files as a measure of DNA effects were compared with control which showed many differences. In conclusion, the meas- urement of parameters at molecular levels is valuable for investigating the specific effects of agents interacting with DNA.
12 citations
TL;DR: This bacterium was found superior in pullulanase production using sago starch and pep- tone as carbon and nitrogen sources, respectively.
Abstract: Enhancement of pullulanase production by Raoultella planticola DSMZ 4617 using optimized medium formu- lation was investigated in batch fermentation using 500-mL shake flask. The fermentations were carried out, firstly, to search for a suitable cultivation medium for enzyme production and followed by the evaluations on the influence of car- bon and nitrogen sources and also initial culture pHs on the secretion of pullulanase by this bacterium. The modified min- eral Czapek medium was found suitable to produce substantially high activity of pullulanase (320 times higher) as com- pared to 'Ohba-Ueda' medium. This bacterium was found superior in pullulanase production using sago starch and pep- tone as carbon and nitrogen sources, respectively. Using the optimized medium, the bacterium produced 0.95 U/mL of pullulanase at initial culture pH of 7 and incubation temperature of 30 o C.
11 citations
Journal Article•
TL;DR: The influence of different carbon and nitrogen sources on growth of recombinant Escherichia coli and human interferon-α2b production in periplasmic space was studied in shake flask culture and the highest yield was predicted to be obtained in optimized medium.
Abstract: The influence of different carbon and nitrogen sources on growth of recombinant Escherichia coli and human interferon-α2b (IFN-α2b) production in periplasmic space was studied in shake flask culture. A statistical method based on Plackett-Burman design was used to screen the main medium components that greatly influenced the performance of the fermentation process. The optimization of medium was performed using response surface methodology (RSM) where three critical factors (glucose, yeast extract and peptone) were optimized using central composite design. The highest yield of periplasmic recombinant human interferon-α2b (PrIFN-α2b) (335.8 µg/L) was predicted to be obtained in optimized medium containing 5.47 g/L glucose, 55.24 g/L yeast extract and 42.27 g/L peptone.. The production of IFN-α2b in perip- lasmic space in optimized medium was about 2.5, 11.7 and 124.4 times higher than Terrific broth (TB), Luria-Bertani (LB), and minimal medium (M9), respectively.
9 citations
TL;DR: PQQ-modified peptide fragments, the proteolytic products of PQZ-modified � - synuclein, prevent the amyloid formation of full-length � -synuclein and these inhibitory effects are derived from the PQQ modification of the peptide.
Abstract: The inhibition of amyloid fibril and/or oligomer formation allows a novel therapeutic approach to neurodegen- erative diseases such as Parkinson's disease. We have previously reported that pyrroloquinoline quinone (PQQ), a cofac- tor in the bacterial oxidative metabolism of alcohols, prevents the amyloid formation of � -synuclein, which is the causa- tive factor of Parkinson's disease. Moreover, PQQ-modified � -synuclein is also able to inhibit the fibrillation of intact � - synuclein. Here, we demonstrate that PQQ-modified peptide fragments, the proteolytic products of PQQ-modified � - synuclein, prevent the amyloid formation of full-length � -synuclein, and that these inhibitory effects are derived from the PQQ modification of the peptide. Moreover, these effects are likely to be peptide-sequence-dependent. Thus, the specific interaction between the full-length � -synuclein and the peptide region of the PQQ-modified peptide prevents amyloid formation.
TL;DR: It is found that this new ELISA-based assay is capable of identifying novel small molecule inhibitors that function during the initial stages of peptide assembly, and is able to discriminate between inhibitors of early-stage, low-molecular weight oligomers and later- stage, high-molescular weight fibrillar structures.
Abstract: Amyloid deposits found in Alzheimer's disease result from aggregation of peptide which leads to loss of synaptic function, chronic microglial activation and cognitive impairment. Because of this, identification of small mole- cule inhibitors of aggregation as potential therapeutics is a topic of current interest. The majority of inhibitor screening approaches rely on in vitro assays that lack the necessary sensitivity to distinguish low-molecular weight oligomers from larger, more advanced-stage fibrillar structures. Differentiating between these two structures is of vital concern since recent studies indicate that small, early-stage oligomers are the most neurotoxic form of peptide aggregate. To address this limitation, we have explored the adaptability of a recently described ELISA-based assay for discovery of small mole- cule inhibitors of oligomerization. Results show that this assay is highly sensitive as it is able to quantify oli- gomers with as little as 80 nM input peptide. In addition, data were obtained re-confirming the function of curcumin as a potent inhibitor of aggregation (IC50 = 2 μM) and defining its inhibitor:peptide functional stoichiometry. Further ex- amination of other known anti-aggregation compounds showed that this assay is able to discriminate between inhibitors of early-stage, low-molecular weight oligomers and later-stage, high-molecular weight fibrillar structures. These findings in- dicate that this new ELISA-based assay is capable of identifying novel small molecule inhibitors that function during the initial stages of peptide assembly.
TL;DR: A quaternary salt, benzalkonium chloride (BAC), was used as a chemical agent for sterilization of nonwoven polyethylene terephthalate (PET) fibers and polylactic acid nanofibers and astrocyte cells were successfully cultured in the PET scaffolds following BAC sterilization, demonstrating the suitability of BAC as a sterilization agent.
Abstract: Tissue engineering is an emerging field in biomedicine, holding enormous promise for regenerative medicine. Scaffolds, within which cells proliferate, are a controlling factor in tissue engineering applications. Upon fabrication, tis- sue scaffolds must undergo appropriate sterilization to eliminate contaminants. Current sterilization methods are either costly, time consuming, or ineffective. In this study, a quaternary salt, benzalkonium chloride (BAC), was used as a chemical agent for sterilization of nonwoven polyethylene terephthalate (PET) fibers and polylactic acid nanofibers. Treating the PET scaffolds with 0.1% (w/v) BAC for only 2 minutes was effective to eliminate bacterial contaminants in the fibrous matrices. In addition, astrocyte cells were successfully cultured in the PET scaffolds following BAC steriliza- tion, demonstrating the suitability of BAC as a sterilization agent. This chemical sterilization method is also mild and nonabrasive to nanostructured materials such as electrospun polylactic acid nanofibers.
TL;DR: The green fluorescent protein and the non-toxic subunit of cholera toxin were expressed in tobacco chloro-plasts as mentioned in this paper, and both recombinant proteins accumulated to levels greater than 20% of the total soluble protein.
Abstract: The green fluorescent protein and the non-toxic subunit of cholera toxin were expressed in tobacco chloro- plasts. Both recombinant proteins accumulated to levels greater than 20% of the total soluble protein. We did not observe light-dependent induction of gene expression despite employing the promoter and 5´-UTR from the psbA gene. Both pro- teins were stable in young and old leaves. The estimated half-life, determined by pulse-chase labeling, was greater than 48 h. Freeze-drying of pulverized leaves supplied an easy method of post-harvest handling with no significant loss of the re- combinant protein after 7 months of storage at room temperature. These data suggest that both proteins are good candi- dates for the expression of fusion proteins (e.g. with antigens) in tobacco chloroplasts.
TL;DR: It was concluded that the recombinant of pIA� 8-phytase could ex- press intracellular phytase, while the recombinant of pGAPZA-phyTase could express extracellularphytase.
Abstract: Phytase and phytase gene from Aspergillus ficuum (A. ficuum) were used in this study. The results showed that phytase activity reached the peak of 0.17 U/g after 4 d incubation in solid medium for A. ficuum; the optimum pH and temperature of phytase were 2.5 and 50 o C, respectively. A 1.4-kb DNA containing the coding region of phytase gene was isolated and inserted into the expression vectors of pIA� 8 and pGAPZA, which were transformed into E. coli (Top 10). The maximal phytase activities in the supernatant and cells were 2.31 and 9.04 U/ml for the E. coli with pIA� 8, 8.04 and 2.93 U/ml for the E. coli with pGAPZA, respectively. It was concluded that the recombinant of pIA� 8-phytase could ex- press intracellular phytase, while the recombinant of pGAPZA-phytase could express extracellular phytase. The molecu- lar weight of phytase protein was 54.61 kDa.
TL;DR: This review is concerned with the application of morphological variables to correlate with bioprocess parameters for explaining optimal production strategy.
Abstract: Various options in biotechnology have been exercised to produce industrially important metabolites from fila- mentous organisms. To select a suitable production strategy, the direct and indirect roles of morphological parameters in controlling bioprocess variables are observed. Some progress has been made in quantitation of morphology.Useful corre- lations have been reported in the literature in this avenue. Of course, some of the models, with proper modification, can be used to explain the morphological phenomena. This review is concerned with the application of morphological variables to correlate with bioprocess parameters for explaining optimal production strategy.