Showing papers in "Biotechnology and Bioprocess Engineering in 2009"
TL;DR: In this article, the physico-chemical characteristics of extracellular polysaccharides (EPS) produced by Arthrospira platensis were evaluated using elemental analysis and bicinchoninic acid (BCA) reaction.
Abstract: In this study, the physico-chemical characteristics of extracellular polysaccharides (EPS) produced by Arthrospira platensis were evaluated. Elemental analysis and a bicinchoninic acid (BCA) reaction indicated that the EPS were heteropolysaccharides that contain carbohydrate (13%) and protein (55%) moieties. Analysis of the infrared spectrum and elemental analysis revealed the presence of a sulfate group (0.5%). The UV-visible spectrum showed high UV absorption at 190∼230 nm and a shoulder at 260∼280 nm. In addition, this spectrum indicated that EPS can form aggregates with mycosporine-like amino acids and/or scytonemin. Gas chromatography analysis of the carbohydrate portion of the EPS indicated that it was composed of seven neutral sugars: galactose (14.9%), xylose (14.3%), glucose (13.2%), frucose (13.2%), rhamnose (3.7%), arabinose (1%), and mannose (0.3%) and two uronic acids, galacturonic acid (13.5%) and glucuronic acid (0.9%).
128 citations
TL;DR: Hydrogen was produced from various marine macro-algae (seaweeds) through anaerobic fermentation using an undefined bacterial consortium using Laminaria japonica to be the optimum substrate for hydrogen production.
Abstract: Hydrogen was produced from various marine macro-algae (seaweeds) through anaerobic fermentation using an undefined bacterial consortium. In this study, anaerobic fermentation from various marine macro-algae for Ulva lactuca, Porphyra tenera, Undaria pinnatifida, and Laminaria japonica was studied. From this analysis Laminaria japorica was determined to be the optimum substrate for hydrogen production. When L. japornica was used as the carbon source for enhanced hydrogen production, the optimum fermentation temperature, substrate concentration, initial pH, and pretreatment condition were determined to be 35°C, 5%, 7.5, and BT120 (Ball mill and thermal treatments at 120°C for 30 min), respectively. In addition, hydrogen production was improved when the sludge was heat-treated at 65°C for 20 min. Under these conditions, about 4,164 mL of hydrogen was produced from 50 g/L of dry algae (L. japonica) for 50 h, with a hydrogen concentration around 34.4%. And the maximum hydrogen production rate and yield were found to be 70 mL/L·h and 28 mL/g dry algae, respectively.
100 citations
TL;DR: The feasibility of using mass cultivation of the adventitious roots of Echinacea purpurea in balloon type bubble (air-lift) bioreactors to produce caffeic acid derivatives, which have pharmaceutical and therapeutic values, is evaluated.
Abstract: In this study, we evaluated the feasibility of using mass cultivation of the adventitious roots of Echinacea purpurea in balloon type bubble (air-lift) bioreactors to produce caffeic acid derivatives, which have pharmaceutical and therapeutic values. An approximately 10 fold increase in biomass and secondary compounds was observed after 4 weeks of culture in balloon type bubble bioreactors (5 L capacity containing 4 L of half strength MS medium). In addition, a linear relationship was observed between the concentration of biomass and the sucrose and ion consumption rate. Furthermore, the concentration of biomass in the bioreactor culture was found to increase as the conductivity decreased. An inoculum density of 7 g/L FW and an aeration rate of 0.1 vvm were found to be suitable for inducing the accumulation of biomass and secondary metabolites. Of the three caffeic acid derivatives evaluated (caftaric acid, chlorogenic acid, and cichoric acid), the concentration of cichoric acid was the highest (26.64 mg/g DW).
75 citations
TL;DR: In this paper, the effect of biotic elicitors (yeast extract, chitosan), signaling molecule (salicylic acid), and polyamines (putrescine and spermidine) with respect to isoflavones accumulation in hairy root cultures of Psoralea corylifolia L.
Abstract: The effect of biotic elicitors (yeast extract, chitosan), signaling molecule (salicylic acid), and polyamines (putrescine and spermidine) was studied with respect to isoflavones accumulation in hairy root cultures of Psoralea corylifolia L. Untreated hairy roots (control) accumulated 1.55% dry wt of daidzein and 0.19% dry wt of genistein. In precursor feeding experiment, phenylalanine at 2 mM concentration led to 1.3 fold higher production of daidzein (1.91% dry wt) and genistein (0.27% dry wt). In biotic elicitors, chitosan (2 mg/L) was found to be the most efficient elicitor to induce daidzein (2.78% dry wt) and genistein (0.279% dry wt) levels in hairy roots. Salicylic acid at 1 mM concentration stimulated the maximum accumulation of daidzein (2.2% dry wt) and genistein (0.228% dry wt) 2 days after elicitation. In case of polyamines, putrescine (50 mM) resulted in highest accumulation of daidzein (3.01% dry wt) and genistein (0.227% dry wt) after 5 days of addition. Present results indicated the effectiveness of elicitation and precursor feeding on isoflavones accumulation in hairy roots of P. corylifolia. This is the first report of elicitation on isoflavones production by hairy roots of P. corylifolia.
75 citations
TL;DR: This study has shown that procedure 3, a one step practical procedure for lipid extraction and in situ methyl ester derivation could be used successfully for the determination of the fatty acid compositions of microalgae and cyanobacteria.
Abstract: Microalgae are a very diverse group of organisms that consist in both prokaryotic and eukaryotic forms. Some species of microalgae can be induced to overproduce particular fatty acids through simple manipulations of the physical and chemical properties of the culture medium. In this paper, the effect of different extraction techniques on the recovery of fatty acids from the freeze-dried biomass from two lipid-producing microalgal strains: Botryococcus braunii LB 572 (green algae) and Synechocystis sp. PCC 6803 (cyanobacteria) was examined. Five procedures were used: after conversion of the lipid material into the corresponding fatty acid methyl esters (FAMEs) via suitable derivatization reactions (extraction-transesterification) and direct transesterification of biomass to produce FAMEs (without the initial extraction step) that used differential types of catalysts and processing conditions. This study has shown that procedure 3, a one step practical procedure for lipid extraction and in situ methyl ester derivation could be used successfully for the determination of the fatty acid compositions of microalgae and cyanobacteria.
72 citations
TL;DR: Veratryl alcohol oxidase (VAO) enzyme from Comamonas UVS was able to decolorize textile dyes and GC-MS analysis of the metabolites suggested oxidative cleavage and desulphonation of these dyes.
Abstract: In the present work, we have purified veratryl alcohol oxidase (VAO) enzyme from Comamonas UVS to evaluate its potential to decolorize textile dyes. VAO was purified (13.9 fold) by an ion exchange followed by the size exclusion chromatography. Molecular weight of the VAO was estimated to be about 66 kDa by SDS-PAGE. The optimum pH and temperature of oxidase were 30°C and 65°C, respectively. VAO showed maximum activity with n-propanol among the various substrates (n-propanol, veratryl alcohol, L-dopa, tryptophan, etc.). Under standard assay conditions, Km value of the enzyme was 2.5 mM towards veratrole. The enzyme activity was completely inhibited by 0.5 mM sodium azide. L-cysteine, dithiothreitol, and the metal chelator, EDTA had a slight inhibitory effect. The purified enzyme was able to decolorize textile dyes, Red HE7B (57.5%) and Direct Blue GLL (51.09%) within 15 h at 40 μg/mL concentration. GC-MS analysis of the metabolites suggested oxidative cleavage and desulphonation of these dyes.
71 citations
TL;DR: SAPB demonstrated powerful dehairing capabilities of hair removal from skin with minimal damage on the collagen and a nearly complete feather-degradation and showed excellent stability and compatibility in laundry detergent.
Abstract: The newly Tunisian soil-isolated bacterium, producing the alkaline proteinase termed SAPB that was already purified and characterized [1], was assigned as Bacillus pumilus CBS strain on the basis of biochemical properties and 16S rRNA gene sequencing. The maximum protease activity recorded after 24 h of incubation in an optimized medium at 37°C was 6,500 U/mL in shaking flask culture and 25,000 U/mL in fermentor. SAPB showed excellent stability and compatibility in laundry detergent retaining more than 98% of its initial activity after pre-incubation for 1 h at 40°C with Det, followed by OMO (97%), Dinol (94%), and Dixan (93%). Examination of various stained cloth pieces exhibited a remarkable efficiency in the removal of blood and chocolate stains. More interestingly, SAPB demonstrated powerful dehairing capabilities of hair removal from skin with minimal damage on the collagen and a nearly complete feather-degradation. Likewise, Bacillus pumilus CBS effectively degraded feather-meal (98.5%), chicken feather (92%), goat hair (80%), and bovine hair (68%) whereas sheep wool under went less degradation. Keratin-degradation resulted in sulfhdryl group formation (0.95∼3.91 μM).
64 citations
TL;DR: The simplicity and effectiveness of aqueous two-phase systems (ATPS) in the purification of lipase were proven in this study.
Abstract: An aqueous two-phase purification process was employed for the recovery of Burkholderia pseudomallei lipase from fermentation broth. The partition behavior of B. pseudomallei lipase was investigated with various parameters such as phase composition, tie-line length (TLL), volume ratio (VR), sample loading, system pH, and addition of neutral salts. Optimum conditions for the purification of lipase were obtained in polyethylene glycol (PEG) 6000-potassium phosphate system using TLL of 42.2% (w/w), with VR of 2.70, and 1% (w/w) NaCl addition at pH 7 for 20% (w/w) crude load. Based on this system, the purification factor of lipase was enhanced to 12.42 fold, with a high yield of 93%. Hence, the simplicity and effectiveness of aqueous two-phase systems (ATPS) in the purification of lipase were proven in this study.
60 citations
TL;DR: Comparison with other protein hydrolysates aimed for fertilizer suggests that keratin degradation products, obtained by enzymatic hydrolysis, have potential to be used for foliar fertilization, alone or in a combination with another complementary hydrolysate of a different source, such as skin or plant proteins.
Abstract: Waste bovine hooves and horns were enzymatically hydrolysed into soluble products intended for foliar fertilizer. With the powdered keratin at 50°C and pH 8 between 34 to nearly 60% of nitrogen was solubilized in 5 h, depending on the enzyme concentration. The reaction could further be improved by steam pretreatment of the keratin, resulting in 98% solubilisation of the nitrogen. The products of hydrolysis consisted of a mixture of soluble proteins, peptides, and free amino acids. Among the latter, 18 common amino acids were detected. Several of them were previously recognized to have a positive effect on plants. Nonpolar neutral, basic, and sulphur amino acids were present in relatively large amounts, while proline and tryptophan were not found. Comparison with other protein hydrolysates aimed for fertilizer suggests that keratin degradation products, obtained by enzymatic hydrolysis, have potential to be used for foliar fertilization, alone or in a combination with another complementary hydrolysate of a different source, such as skin or plant proteins.
57 citations
TL;DR: To test the impact of commercial nanomaterials on the environment and biological species, the potential eco-toxicity of nano sized silver powder was investigated with bacteria, Gram-negative Escherichia coli and Gram-positive Bacillus subtilis and yeast, Saccharomyces cerevisiae.
Abstract: To test the impact of commercial nanomaterials on the environment and biological species, the potential eco-toxicity of nano sized silver powder was investigated with bacteria, Gram-negative Escherichia coli and Gram-positive Bacillus subtilis and yeast, Saccharomyces cerevisiae. When commercial silver nanopowder was dispersed in water, it was shown to contain both silver nanoparticles and silver ions. S. cerevisiae showed a higher survival rate than the other two species. To compare the antimicrobial activity as a quantitative parameter, the susceptibility constant was determined. The susceptibility constant of the silver ions were larger than those of the silver nanopowder. On average, the degree of susceptibility to silver decreased in the following order, E. coli > B. subtilis > S. cerevisiae.
56 citations
TL;DR: Olive-mill wastewater (OMW), an agro-industrial by-product from olive-oil milling (with the three-phase extraction method), was used experimentally as 5% of the medium to culture Scenedesmus obliquus CCAP 276/3A and indicated a nitrogen deficiency.
Abstract: Olive-mill wastewater (OMW), an agro-industrial by-product from olive-oil milling (with the three-phase extraction method), was used experimentally as 5% (v/v) of the medium to culture Scenedesmus obliquus CCAP 276/3A. The characterization of the wastewater indicated a nitrogen deficiency. The highest specific growth rate of S. obliquus μm = 0.022 h−1 was found when the medium was maintained at a constant pH value of 7.0. The biomass productivity, Pb was determined by the influence of pH on the speciation of the dissolved CO2. The greatest elimination of BOD5 occurred at extreme pH values. The protein and chlorophyll contents presented a maximum value close to pH = 7.0. The highest crude-protein content in the biomass was 25.6%. The polyunsaturated and essential fatty acids presented a clear trend to increase with the pH, at pH 9.0, representing 26.2 and 19.4%, respectively, of the total fatty-acid content of the biomass.
TL;DR: This manuscript aimed at increasing the production of α-ketoglutarate by the multi-vitamin auxotrophic yeast Torulopsis glabrata CCTCC M202019 by manipulating the specific activity of pyruvate dehydrogenase complex (PDH, PDH, PC, and PDC), resulting in an enhanced α- ketoglutamate synthesis.
Abstract: This manuscript aimed at increasing the production of α-ketoglutarate by the multi-vitamin auxotrophic yeast Torulopsis glabrata CCTCC M202019. The carbon flux was redistributed from pyruvate to α-ketoglutarate node by manipulating the specific activity of pyruvate dehydrogenase complex (PDH), pyruvate carboxylase (PC), pyruvate decarboxylase (PDC), and α-ketoglutarate dehydrogenase complex (KGDH). By proper increase of PDH, PC, and PDC activities, α-ketoglutarate in fermentation broth could be accumulated to the levels of 17.1 g/L, 21.6 g/L, and 31.2 g/L, respectively. In addition, decrease in the specific activity of KGDH also resulted in an enhanced α-ketoglutarate synthesis. With a proposed combinational enzymes regulation strategy, the highest α-ketoglutarate concentration of 37.7 g/L was achieved.
TL;DR: In this paper, the results of single-factor experiments and an orthogonal array experiment were found to be the most important factors for the acid hydrolysis of rice hulls.
Abstract: Hydrolytic conditions of rice hulls by acid and alkaline treatments before enzymatic saccharification were optimized in this study. Based on the results of single-factor experiments and an orthogonal array experiment, reaction time was found to be the most important factor for the acidic hydrolysis of rice hulls. Maximum yield of sugars from 1 g of rice hulls by acidic treatment under optimized conditions was 213.6 mg. The yield of lignin removal from acidic pretreated rice hulls by alkaline treatment increased with increase in reaction temperature and time. The amount of sugars obtained from 1 g of pretreated rice hulls by enzymatic saccharification was 307.7 mg, and the conversion rate of sugars from crude fibers in pretreated rice hulls was about 72%. Instrumental analyses with FTIR and SEM indicated that lignin in rice hulls was partially removed by alkaline treatment, and the structure of rice hulls became deformed and more fibers were exposed to cellulases after acidic treatment.
TL;DR: Six agro-industrial wastes were evaluated as a support for ligninolytic enzyme production by the white-rot fungus Lentinus polychrous Lév.
Abstract: Six agro-industrial wastes were evaluated as a support for ligninolytic enzyme production by the white-rot fungus Lentinus polychrous Lev. under solid-state fermentation. Enzyme production was markedly different according to the substrate used. Rice bran (RB) yielded the highest laccase activity of 1,449 U/L (after 21 days of culture) with specific activity of 4.4 U/g substrate. Rice bran supplemented with rice husk (RH) (2:1 by wt) showed high laccase activity of 1,425 U/L with specific activity of 10.0 U/g substrate (after 17 days of culture). The crude enzyme of the RH-RB culture also contained manganese peroxidase (MnP) and manganese-independent peroxidase (MIP) activities in relative proportions of 1.9:1.4:1 of laccase:MnP:MIP, respectively. Zymogram studies showed the same isoenzyme pattern with these ligninolytic enzymes. The high enzyme production level and low substrate cost of SSF-L. polychrous Lev. suggest that it has potential for industrial applications. Our studies showed that the crude enzyme from this culture exhibited in vitro decolorization of Indigo Carmine. The highest efficiency of dye decolorization was observed under alkaline conditions (pH 9.0) at an initial dye concentration of 10 mg/L. The rather high pH conditions and high efficiency in Indigo Carmine decolorization make the enzyme further interest for the applications in treatment of waste water from the textile industry, which contains synthetic dyes.
TL;DR: The results from N-terminal amino acid sequencing imply the purified protein is a putative beta-carbonic anhydrase with close similarities to CAs from plants, microorganisms.
Abstract: Carbonic anhydrase enzyme, one of the fastest known enzymes, remains largely unexplored in prokaryotes when compared to its mammalian counterparts despite its ubiquity. In this study, the enzyme has been purified from Bacillus subtilis SA3 using sequential Sephadex G-75 chromatography, DEAE cellulose chromatography, and sepharose-4B-L-tyrosinesulphanilamide affinity chromatography and characterized to provide additional insights into its properties. The apparent molecular mass of carbonic anhydrase obtained by SDS-PAGE was found to be approximately 37 kDa. Isoelectric focusing of the purified enzyme revealed an isoelectric point (pI) of around 6.1 when compared with marker. The presence of metal ions such as Zn2+, Co2+, Cu2+, Fe3+, Mg2+, and anion SO4− increased enzyme activity while strong inhibition was observed in the presence of Hg2+, Cl−, HCO3−, and metal chelator EDTA. The optimum pH and temperature for the enzyme were found to be 8.3 and 37°C, respectively. Enzyme kinetics with p-nitrophenyl acetate as substrate at pH 8.3 and 37°C determined the Vmax and Km values of the enzyme to be 714.28 μmol/mg protein/min and 9.09 mM, respectively. The Ki value for acetazolamide was 0.22 mM, compared to 0.099 mM for sulphanilamide. The results from N-terminal amino acid sequencing imply the purified protein is a putative beta-carbonic anhydrase with close similarities to CAs from plants, microorganisms.
TL;DR: The results indicate that P. dioscoreae is an excellent source of taxol production, which suggests that the fungus has potential to undergo genetic engineering in order to improve its production level.
Abstract: Taxol is a highly functionalized anticancer drug widely used in hospitals and clinics. The leaf spot fungus, Phyllosticta dioscoreae was isolated from diseased leaves of Hibiscus rosa-sinensis and screened for extracellular production of taxol in M1D (Modified liquid medium) and PDB (Potato dextrose broth) medium for the first time. The fungus was identified by its morphological and conidial features in the culture growth. The presence of taxol in the fungal culture filtrate was confirmed by different spectroscopic and chromatographic analyses. The amount of taxol produced was quantified by HPLC. The maximum amount of taxol produced was found to be 298 μg/L in M1D medium. Production rate was 5.96 × 103 times faster than that found in culture broth of earlier reported fungus, Taxomyces andreanae. The extracted fungal taxol also showed strong cytotoxic activity in vitro in the cultures of human cancer cells tested by apoptotic assay. The results indicate that P. dioscoreae is an excellent source of taxol production, which suggests that the fungus has potential to undergo genetic engineering in order to improve its production level.
TL;DR: Peroxidase was purified by an ion exchange chromatography followed by gel filtration chromatography from dye degrading Bacillus sp.
Abstract: Peroxidase was purified by an ion exchange chromatography followed by gel filtration chromatography from dye degrading Bacillus sp. strain VUS. The optimum pH and temperature of the enzyme activity was 3.0 and 65°C, respectively. This enzyme showed more activity with n-propanol than other substrates tested viz. xylidine, 3-(3,4-dihydroxy phenyl) Lalanine (L-DOPA), hydroxyquinone, ethanol, indole, and veratrole. Km value of the enzyme was 0.076 mM towards n-propanol under standard assay conditions. Peroxidase was more active in presence of the metal ions like Li2+, Co2+, K2+, Zn2+, and Cu2+ where as it showed less activity in the presence of Ca2+ and Mn2+. Inhibitors like ethylenediamine tetraacetic acid (EDTA), glutamine, and phenylalanine inhibited the enzyme partially, while sodium azide (NaN3) completely. The crude as well as the purified peroxidase was able to decolourize different industrial dyes. This enzyme decolourized various textile dyes and enhanced percent decolourization in the presence of redox mediators. Aniline was the most effective redox mediator than other mediators tested. Gas chromatography-Mass spectrometry (GC-MS) confirmed the formation of 7-Acetylamino-4-hydroxy-naphthalene-2-sulphonic acid as the final product of Reactive Orange 16 indicating asymmetric cleavage of the dye.
TL;DR: In this article, an anaerobic sludge from a piggery wastewater treatment plant had been acclimated to an NH+/Fe3+-rich environment to secure an enrichment culture and investigate an ammonia oxidation coupled with an iron reduction.
Abstract: The oxidation of ammonia coupled with the reduction of iron is a unique pathway mostly reported in soils and sediments. An anaerobic sludge from a piggery wastewater treatment plant had been acclimated to an NH+/Fe3+-rich environment to secure an enrichment culture and investigate an anaerobic ammonia oxidation coupled with an iron reduction. The enrichment culture showed an average pH of 6.8 and the concentration of mixed liquor volatile suspended solid was measured as 1,120 mg/L. The mol ratio of oxidized NH4
+ and reduced Fe3+ was 0.33 mol NH4
+/mol Fe3+. It was suggested that the culture acclimated to NH4
+/Fe3+ contained the anaerobic ammonia oxidizing bacteria as well and thus NH4
+ was fully oxidized to NO3
− by the bacterial consortia. In a batch experiment using the culture, the oxidation of NH4
+ was increased as the initial concentration increased. However, it was suspected from the experimental results that other iron reducing bacteria had grown under the environment applied for the enrichment culture. As a result, it was observed that heterotrophic and autotrophic iron reducers were competing for Fe3+.
TL;DR: Results have indicated that ATPS can be successfully employed as a non-organic solvent method for the isolation of PHA from hydrolyzed bacterial cells and purified protease can be recovered as a byproduct, in a single defined experiment.
Abstract: Main objective of present work was to isolate polyhydroxyalkanoate (PHA) from cell lysate of Bacillus flexus by aqueous-aqueous two-phase system (ATPS). Selected ATPS having polyethylene glycol (12%, w/v) and potassium phosphate (9.7%, pH 8.0) containing cell lysate obtained by sonication or hypochlorite treatment of B. flexus biomass (1 g%, dry weight), was held at 28°C for 30 min, which partitioned PHA into top PEG phase and residual cell materials into bottom phase. For enzymatic cell hydrolysis, Microbispora sp. culture filtrate having protease (3 U/mL) was mixed with B. flexus biomass and ATPS, incubated at 37°C for 2 h prior to phase separation. PHA recovered by centrifugation was 19∼51% of cell dry weight, depending on the mode of cell disruption. Protease was recovered along with PHA in the PEG phase and showed 7 fold increase in activity. PHA was characterized by GC, FTIR, and 1H NMR. Results indicated that ATPS can be used for the isolation of PHA from hydrolyzed bacterial cells and purified protease can be recovered as a byproduct, in a single defined experiment. Results have indicated that ATPS can be successfully employed as a non-organic solvent method for the isolation of PHA.
TL;DR: In this article, the authors evaluated 20 agro-industrial residues to check the possibility of potential utilization of substrates in SSF for milk clotting enzyme protease production by Mucor circinelloides.
Abstract: Agro-industrial residues, a cheap source of energy have high potential in the area of fermentation for the production of enzymes. Twenty agro-industrial residues were evaluated to check the possibility of potential utilization of substrates in SSF for milk clotting enzyme protease production by Mucor circinelloides. In this study, dhal husk holds the greatest promise for cost effective production of the milk clotting enzyme. The dhal husk supported maximum milk clotting protease production, and yield was improved with the supplementation of sucrose and yeast extract as carbon and nitrogen source, respectively. Among all the physico-chemical parameters tested, the best results were obtained in a medium having moisture content of 20% at pH 7.0, when inoculated with 30% of spore suspension and incubated at 30°C for 5 days. The activity was increased further on addition of Ca2+, Cu2+, and Mg2+ ions. The purified milk-clotting protease obtained from M. circinelloides was successfully applied and compared with commercial rennet in the manufacture of a cheddar cheese.
TL;DR: In this paper, the authors examined the effectiveness of ammonia percolation pretreatment of wheat straw for ethanol production and reported a total process for bioethanol production from agricultural biomass and an efficient pretreatment for lignocellulosic material.
Abstract: This study examined the effectiveness of ammonia percolation pretreatment of wheat straw for ethanol production. Ground wheat straw at a 10% (w/v) loading was pretreated with a 15% (v/v) ammonia solution. The experiments were performed at treatment temperature of 50∼170°C and residence time of 10∼150 min. The solids treated with the ammonia solution showed high lignin degradation and sugar availability. The pretreated wheat straw was hydrolyzed by a cellulase complex (NS50013) and β-glucosidase (NS50010) at 45°C. After saccharification, Saccharomyces cerevisiae was added for fermentation. The incubator was rotated at 120 rpm at 35°C. As a result of the pretreatment, the delignification efficiency was > 70% (170°C, 30 min) and temperature was found to be a significant factor in the removal of lignin than the reaction time. In addition, the saccharification results showed an enzymatic digestibility of > 90% when 40 FPU/g cellulose was used. The ethanol concentration reached 24.15 g/L in 24 h. This paper reports a total process for bioethanol production from agricultural biomass and an efficient pretreatment of lignocellulosic material.
TL;DR: Various parameters such as solvent selection, concentration, soaking time, and temperature were tested in a single bioreactor to determine optimum extraction conditions of glucoamylase, when produced simultaneously with protease by Aspergillus awamari nakazawa MTCC 6652.
Abstract: Various parameters such as solvent selection, concentration, soaking time, and temperature were tested in a single bioreactor in order to determine optimum extraction conditions of glucoamylase, when produced simultaneously with protease by Aspergillus awamari nakazawa MTCC 6652. Optimum conditions were achieved in a 10% glycerol solution soaked for 2 h at 40°C, followed by concentration of extracted glucoamylase (9,157 U/gds) by acetone precipitation (1:2, v/v), which yielded 51.9% recovery. Ion exchange chromatography and gel filtration showed specific activities of 270.5 and 337.5 U/mg, respectively, while SDS-PAGE and zymogram analysis of glucoamylase indicated the presence of three starch-hydrolyzing isoforms with molecular weights of approximately 109.6, 87.1, and 59.4 kDa, respectively
TL;DR: The results indicate that phosphorus, Zn2+, CO2, and light intensity are important factors that impact growth, biochemical composition and the activity of extracellular CA in I. galbana.
Abstract: The effects of phosphorus, Zn2+, CO2, and light intensity on growth, biochemical composition, and the activity of extracellular carbonic anhydrase (CA) in Isochrysis galbana were investigated. A significant change was observed when the concentration of phosphorus in the medium was increased from 5 μmol/L to 1000 μmol/L affecting I. galbana’s cell density, biochemical composition, and the activity of extracellular CA. Phosphorous concentration of 50 μmol/L to 500 μmol/L was optimal for this microalgae. The Zn2+ concentration at 10 μmol/L was essential to maintain optimal growth of the cells, but a higher concentration of Zn2+ (≥ 1000 μmol/L) inhibited the growth of I. galbana. High CO2 concentrations (43.75 mL/L) significantly increased the cell densities compared to low CO2 concentrations (0.35 mL/L). However, the activity of extracellular CA decreased significantly with an increasing concentration of CO2. The activity of extracellular CA at a CO2 concentration of 43.75 mL/L was approximately 1/6 of the activity when the CO2 concentration was at 0.35 mL/L CO2. Light intensity from 4.0 mW/cm2 to 5.6 mW/cm2 was beneficial for the growth, biochemical composition and the activity of extracellular CA. The lower and higher light intensity was restrictive for growth and changed its biochemical composition and the activity of extracellular CA. These results indicate that phosphorus, Zn2+, CO2, and light intensity are important factors that impact growth, biochemical composition and the activity of extracellular CA in I. galbana.
TL;DR: In this paper, a newly isolate of thermophilic PLA-degrading Actinomadura sp. T16-1 was investigated, which produced 33.9 U/mL of enzyme activity after cultivation at 50°C under shaking of 150 rpm for 96 h in a medium consisting of (w/v) 0.05% PLA film, 0.2% gelatin, 0 4% NH4 2SO4, 0.4% K2HPO4, 0 2 % KH2PO4, and 0.02% MgSO4 ·
Abstract: The fermentation process for a poly (L-lactide) (PLA)-degrading enzyme production by a newly isolate of thermophilic PLA-degrading Actinomadura sp. T16-1 was investigated. The strain produced 33.9 U/mL of enzyme activity after cultivation at 50°C under shaking of 150 rpm for 96 h in a medium consisting of (w/v) 0.05% PLA film, 0.2% gelatin, 0.4% (NH4)2SO4, 0.4% K2HPO4, 0.2 % KH2PO4, and 0.02% MgSO4 · 7H2O. The optimal concentration of PLA film and gelatin obtained by response surface methodology (RSM) for the highest production of PLA-degrading enzyme was 0.035% (w/v) and 0.238% (w/v), respectively. Under these conditions, the model predicted 40.4 U/mL of PLA-degrading activity and the verification of the optimization showed 44.6 U/mL of PLA-degrading enzymatic activity in the flasks experiment. The maximum PLA-degrading activity reached 150 U/mL within 72 h cultivation in the 3-L airlift fermenter.
TL;DR: In this article, the surface plasmon resonance peak in absorption spectra of silver nanoparticles showed an absorption maximum at 420 nm in UV-VIS spectrometry and the X-ray diffraction pattern showed the presence of sharp reflections at 111, 200, 220, and 311.17 nm.
Abstract: In the present research silver nanoparticle was fabricated by chemical reduction of silver salt (Silver nitrate, AgNO3) solution. Sodium citrate was used as a reducer. The formation of silver nanoparticle was observed visually by color change (greenish yellow). The surface plasmon resonance peak in absorption spectra of silver nanoparticle showed an absorption maximum at 420 nm in UV-VIS spectrometry. The X-ray diffraction pattern showed the presence of sharp reflections at 111, 200, 220, and 311. This would indicate the presence of silver nanoparticle. The scanning electron micrograph revealed that the average size of silver nanoparticle was 21.22 ± 5.17 nm. Silver nanoparticle exhibited better antimicrobial activity against Staphylococcus aureus than the other bacterial pathogens. The correlation coefficient between silver nanoparticles and selected bacterial pathogens revealed that there is a strong negative correlation with Escherichia coli, S. aureus and Klebsiella pneumonia (r = −0.975, −0.993, and −0.998, respectively).
TL;DR: In this article, the lignocellulosic component of the olive cake was dilute-acid pretreated at a 13.5% loading with 1.75% (w/v) sulfuric acid and heating at 160°C for 10 min.
Abstract: The inexpensive production of sugars from lignocellulose is an essential step for the use of biomass to produce fuel ethanol. Olive cake is an abundant by-product of the olive oil industry and represents a potentially significant lignocellulosic source for bioethanol production in the Mediterranean basin. Furthermore, converting olive cake to ethanol could add further value to olive production. In the present study, olive cake was evaluated as a feedstock for ethanol production. To this end, the lignocellulosic component of the olive cake was dilute-acid pretreated at a 13.5% olive-cake loading with 1.75% (w/v) sulfuric acid and heating at 160°C for 10 min. This was followed by chemical elimination of fermentation inhibitors. Soluble sugars resulting from the pretreatment process were fermented using E. coli FBR5, a strain engineered to selectively produce ethanol. 8.1 g of ethanol/L was obtained from hydrolysates containing 18.1 g of soluble sugars. Increasing the pretreatment temperature to 180°C resulted in failed fermentations, presumably due to inhibitory by-products released during pretreatment.
TL;DR: A high correlation between the Nile Red fluorescence intensity measured by flow cytometry and total lipid content assayed by the traditional lipid extraction method was found for this microalga, making this method a suitable and quick technique for the screening of microalgal strains for lipid production, optimization of biofuel production bioprocesses, and scale-up studies.
Abstract: Multi-parameter flow cytometry was used to monitor cell intrinsic light scatter, viability, and lipid content of Chlorella protothecoides cells grown in shake flasks. Changes in the right angle light scatter (RALS) and forward angle light scatter (FALS) were detected during the microalgal growth, which were attributed to the different microalgal cell cycle stages. The proportion of cells not stained with PI (cells with intact cytoplasmic membrane) was high (> 90%) during the microalgal growth, even in the latter stationary phase, suggesting that the microalgal cells built-up storage materials which allowed them to survive under nutrient starvation, maintaining their cytoplasmic membranes intact. A high correlation between the Nile Red fluorescence intensity measured by flow cytometry and total lipid content assayed by the traditional lipid extraction method was found for this microalga, making this method a suitable and quick technique for the screening of microalgal strains for lipid production, optimization of biofuel production bioprocesses, and scale-up studies. The highest oil content (∼28% w/w dry cell weight, estimated by flow cytometry) was observed in the latter stationary phase. In addition, C. protothecoides oil also depicted the adequate fatty acid methyl ester composition for biodiesel purposes at this growth phase, suggesting that the microalgal oil produced during the latter stationary phase could be an adequate substitute for diesel fuel. Medium growth optimization for enhancement of microalgal oil production is now in progress, using the multi-parameter approach.
TL;DR: An endosymbiont Halobacterium salinarum MMD047, isolated from marine sponge Fasciospongia cavernosa, collected from the peninsular coast of India, was characterized as relatively heat sensitive and alkalophilic amylase which can be developed for extensive industrial applications.
Abstract: An endosymbiont Halobacterium salinarum MMD047, which could produce high yields of amylase, was isolated from marine sponge Fasciospongia cavernosa, collected from the peninsular coast of India. Maximum production of enzyme was obtained in minimal medium supplemented with 1% sucrose. The enzyme was found to be produced constitutively even in the absence of starch. The optimum temperature and pH for the enzyme production was 40°C and 8.0, respectively. The enzyme exhibited maximum activity in pH range of 6∼10 with an optimum pH of 9.0. The enzyme was stable at 40°C and the enzyme activity decreased dramatically above 50°C. Based on the present findings, the enzyme was characterized as relatively heat sensitive and alkalophilic amylase which can be developed for extensive industrial applications.
TL;DR: The liquid culture conditions were optimized for maximal production of mycelial biomass and exo-polysaccharide (EPS) by C. militaris and the effects of medium composition, environmental factors, and C/N ratio were investigated.
Abstract: Both crude exo-biopolymers and mycelial biomass, produced by liquid culture of Cordyceps species, are believed to possess several potential health benefits As a result of its known biological activities, Cordyceps militaris has been extensively characterized in regards to potential medicinal applications However, optimized liquid culture conditions for enhanced polysaccharide productivity have yet to be developed, which is a necessary step for industrial applications Therefore, in this study, the liquid culture conditions were optimized for maximal production of mycelial biomass and exo-polysaccharide (EPS) by C militaris The effects of medium composition, environmental factors, and C/N ratio were investigated Among these variables 80 g, glucose; 10 g, yeast extract; 05 g, MgSO4·7H2O; and 05 g, KH2PO4 in 1 L distilled water were found to be the most suitable carbon, nitrogen, and mineral sources, respectively The optimal temperature, initial pH, agitation, and aeration were determined to be 24°C, uncontrolled pH, 200 rpm, and 15 vvm, respectively Under these optimal conditions, mycelial growth in shake flask cultures and 5 L jar bioreactors was 2943 and 4060 g/L, respectively, and polysaccharide production in shake flask cultures and 5 L jar bioreactors was 253 and 674 g/L, respectively
TL;DR: The production of domain III of d Dengue virus E glycoprotein (EIII) in transgenic plants demonstrates the feasibility of using plant-based vaccines to prevent infection by the dengue virus.
Abstract: Dengue virus enters into host cells by binding envelope glycoprotein (E) to a receptor and causes human disease. Domain III of dengue virus E glycoprotein (EIII) is immunogenic and capable of inducing neutralizing antibodies. A DNA fragment encoding EIII (amino acids 297–394) was introduced into tobacco plant cells (Nicotiana tabacum L. cv MD609) by Agrobacterium tumefaciens-mediated transformation methods. The integration of EIII gene was observed in the genomic DNA of transgenic plants by PCR DNA amplification methods. The transcripts of EIII gene were detected in the transgenic plant leaf tissues by Northern blot analysis. The EIII protein was detected in transgenic plant leaf extracts by Western blot analysis. Based on the results of the Western blot analysis, the expression level of plant-produced EIII protein was between 0.13 and 0.25% of the total soluble protein in transgenic plant leaf tissues. The production of domain III of dengue virus E glycoprotein (EIII) in transgenic plants demonstrates the feasibility of using plant-based vaccines to prevent infection by the dengue virus.