Biodegradation of high concentration phenol using sugarcane bagasse immobilized Candida tropicalis PHB5 in a packed-bed column reactor.

Biodegradation of phenolic compounds in wastewater can be effectively carried out in packed bed reactors (PBRs) employing immobilized microorganisms. A low-cost, reusable immobilization matrix in PBR can provide economic advantages in large scale removal of high concentration phenol. In this study, we evaluated the efficiency and reusability of sugarcane bagasse (SCB) as a low-cost immobilization support for high strength phenol removal in recirculating upflow PBR. An isolated yeast Candida tropicalis PHB5 was immobilized onto the SCB support and packed into the reactor to assess phenol biodegradation at various influent flow rates. Scanning electron microscopy exhibited substantial cell attachment within the pith and onto the fibrous strand surface of the SCB support. The PBR showed 97% removal efficiency at the initial phenol concentration of 2400 mg L-1 and 4 mL min-1 flow rate within 54 h. Biodegradation kinetic studies revealed that the phenol biodegradation rate and biodegradation rate constant were dependent on the influent flow rate. A relatively higher rate of biodegradation (64.20 mg g-1 h-1) was found at a flow rate of 8 mL min-1, indicating rapid phenol removal in the PBR. Up to six successive batches (phenol removal >94%) were successfully applied in the PBR using an initial phenol concentration of 400-2400 mg L-1 at a flow rate of 4 mL min-1 indicating the reusability of the PBR system. The SCB-immobilized C. tropicalis could be employed as a cost-effective packing material for removal of high strength phenolic compounds in real scale PBR.

Low pH treatment of starch industry effluent with bacteria from leaf debris for methane production.

Cornstarch industry generates a huge amount of acidic effluent, that is, 5-11 M3 /Mt grinding, with a high load of chemical oxygen demand, 6000-19000 mg/L. The acidic effluent requires neutralization making the treatment process expensive. Methanogenesis under the acidic environment (pH 5-5.5) can reduce the cost of operation as well as treatment time. This research focuses on the evaluation of the optimum condition of COD reduction and methane generation simultaneously from leaf debris sludge using Box-Behnken model. Three 1 L bioreactors were seeded with 5000-10000 mg/L inoculum and operated at different pH 4.0-7.0 for 72 hr up to 10 cycles. The production of methane was found maximum 2980 ml after treating the wastewater from the starch industry at pH 5.57 and 9612.9 mg biomass load at 62.4 hr. The high reduction rate of around 97% shows there is ample opportunity for further research on low pH treatment of waste along with recovery as methane. PRACTITIONER POINTS: The low pH tolerant methanogenic bacteria are promising and are isolable from various natural resources. The low pH tolerant methanogens was able to remove 97% COD from starch industry effluent at pH 5.57. The recovery of methane was 2980 ml from 9612 mg/L COD which is at per with present treatment system thus provides cost effective alternatives.

Approaches towards the enhanced production of Rapamycin by Streptomyces hygroscopicus MTCC 4003 through mutagenesis and optimization of process parameters by Taguchi orthogonal array methodology.

The present research was conducted to define the approaches for enhanced production of rapamycin (Rap) by Streptomyces hygroscopicus microbial type culture collection (MTCC) 4003. Both physical mutagenesis by ultraviolet ray (UV) and chemical mutagenesis by N-methyl-N-nitro-N-nitrosoguanidine (NTG) have been applied successfully for the improvement of Rap production. Enhancing Rap yield by novel sequential UV mutagenesis technique followed by fermentation gives a significant difference in getting economically scalable amount of this industrially important macrolide compound. Mutant obtained through NTG mutagenesis (NTG-30-27) was found to be superior to others as it initially produced 67% higher Rap than wild type. Statistical optimization of nutritional and physiochemical parameters was carried out to find out most influential factors responsible for enhanced Rap yield by NTG-30-27 which was performed using Taguchi orthogonal array approach. Around 72% enhanced production was achieved with nutritional factors at their assigned level at 23 °C, 120 rpm and pH 7.6. Results were analysed in triplicate basis where validation and purification was carried out using high performance liquid chromatography. Stability study and potency of extracted Rap was supported by turbidimetric assay taking Candida albicans MTCC 227 as test organism.

An approach towards optimization of the extraction of polyphenolic antioxidants from ginger (Zingiber officinale).

The present study aims to maximize the extraction of polyphenols from ginger (Zingiber officinale) through the statistical optimization of three influential process parameters ethanol (EtOH) proportion (%), temperature (°C) and extraction time (min). Response Surface Methodology (RSM) was employed to design experiments and study the interaction effects of these parameters on the extraction process. Analysis of Variance (ANOVA) was used for the analysis of regression coefficient, prediction of equation and case statistics. The optimum conditions for the maximum yield of polyphenols from each gram of ginger were found to be 75 % aqueous EtOH, 40 °C temperature and extraction time of 60 min respectively. The order of relative importance of these three parameters was: EtOH > time > temperature. Antioxidant activity of the extracted polyphenols using optimized parameters was also determined by DPPH assay. DPPH radical scavenging activity of ginger extract was compared with Vitamin C and butyl hydroxy toluene (BHT). Finally, this study revealed a cost effective analytical model to maximize the extraction of polyphenols from ginger with higher antioxidant activity. It was also concluded that at lower concentration ethanolic extract of ginger possess high antioxidant activity in comparison with synthetic antioxidants like vitamin C or BHT and thus it can be applicable as potent natural antioxidant in food and pharmaceutical industries for the preparation of functional food.

Kinetics of phenol biodegradation at high concentration by a metabolically versatile isolated yeast Candida tropicalis PHB5.

A highly tolerant phenol-degrading yeast strain PHB5 was isolated from wastewater effluent of a coke oven plant and identified as Candida tropicalis based on phylogenetic analysis. Biodegradation experiments with C. tropicalis PHB5 showed that the strain was able to utilize 99.4% of 2,400 mg l(-1) phenol as sole source of carbon and energy within 48 h. Strain PHB5 was also observed to grow on 18 various aromatic hydrocarbons. Haldane model was used to fit the exponential growth data and the following kinetic parameters were obtained: µ max = 0.3407 h(-1), K S = 15.81 mg l(-1), K i = 169.0 mg l(-1) (R (2) = 0.9886). The true specific growth rate, calculated from µ max, was 0.2113. A volumetric phenol degradation rate (V max) was calculated by fitting the phenol consumption data with Gompertz model and specific degradation rate (q) was calculated from V max. The q values were fitted with Haldane model, yielding following parameters: q max = 0.2766 g g(-1) h(-1), K S ' = 2.819 mg l(-1), K i ' = 2,093 (R (2) = 0.8176). The yield factor (Y X/S ) varied between 0.185 to 0.96 g g(-1) for different initial phenol concentrations. Phenol degradation by the strain proceeded through a pathway involving production of intermediates such as catechol and cis,cis-muconic acid which were identified by enzymatic assays and HPLC analysis.

Kinetics of rapamycin production by Streptomyces hygroscopicus MTCC 4003.

Research work was carried out to describe the kinetics of cell growth, substrate consumption and product formation in batch fermentation of rapamycin using shake flask as well as laboratory-scale fermentor. Fructose was used as the sole carbon source in the fermentation media. Optimization of fermentation parameters and reliable mathematical models were used for the maximum production of rapamycin from Streptomyces hygroscopicus MTCC 4003. The experimental data for microbial production of rapamycin fitted well with the proposed mathematical models. Kinetic parameters were evaluated using best fit unstructured models, viz. Andrew's model, Monod model, Yano model, Aiba model. Andrew's model showed a comparatively better R2 value (0.9849) among all tested models. The values of maximum specific growth rate (µmax), saturation constant (KS), inhibition constant (Ki), and growth yield coefficient (YX/S) were found to be 0.008 (h-1), 2.835 (g/L), 0.0738 (g/L), and 0.1708 (g g-1), respectively. The optimum production of rapamycin was obtained at 300 rpm agitation and 1 vvm aeration rate in the fermentor. The final production of rapamycin in shake flask was 539 mg/L. Rapamycin titer found in bioreactor was 1,316 mg/L which is 52 % higher than the latest maximum value reported in the literature.

Decolorization and biodegradation of congo red dye by a novel white rot fungus Alternaria alternata CMERI F6.

A novel white rot fungus Alternaria alternata CMERI F6 decolorized 99.99% of 600 mg/L congo red within 48 h in yeast extract-glucose medium at 25 °C, pH 5 and 150 rpm. Physicochemical parameters like carbon and nitrogen sources, temperature, pH and aeration were optimized to develop faster decolorization process. Dye decolorization rate was maximal (20.21 mg/L h) at 25 °C, pH 5, 150 rpm and 800 mg/L dye, giving 78% final decolorization efficiency. Scanning electron microscopy and X-ray Diffraction analysis revealed that the fungus become amorphous after dye adsorption. HPLC and FTIR analysis of the extracted metabolites suggested that the decolorization occurred through biosorption and biodegradation. Thermogravimetric analysis (TGA), differential thermal analysis (DTA) and acid-alkali and 70% ethanol treatment revealed the efficient dye retention capability of the fungus. The foregoing results justify the applicability of the strain in removal of congo red from textile wastewaters and their safe disposal.

Enzymatic hydrolysis of water hyacinth biomass for the production of ethanol: optimization of driving parameters.

An efficient conversion of lignocellulose into fermentable sugars is a key step in producing bioethanol in a cost effective and eco-friendly manner. Alternative source like water hyacinth biomass (WHB) (Eichhornia crassipes) may be used as a supplement for the routine feedstocks. The enzyme loading for optimum yield of total reducing sugar was investigated and the enzyme-substrate interaction optimised. The maximal reducing sugar and xylose yield was obtained using cellulase and xylanase loading of 46.12 and 289.98 U/g and 2.26% (w/v) substrate loading. The efficiencies of ethanol production from the WHB hydrolysate are very less and the maximal ethanol yield was 3.4969 g/L when Pichia stiptis was used, followed by 3.4496 and 3.1349 g/L for Candida shehatae and Saccharomyces cerevisiae.

Process engineering studies to investigate the effect of temperature and pH on kinetic parameters of alkaline protease production.

An in depth process engineering study on the effect of temperature and pH on kinetic parameters of alkaline protease production by Bacillus licheniformis NCIM-2042 using starch as substrate has been reported.

Effect of pH and temperature on stability and kinetics of novel extracellular serine alkaline protease (70 kDa).

A novel extracellular serine protease (70 kDa by SDS-PAGE) was purified and characterized. This enzyme retained more than 93% of its initial activity after preincubation for 30 min at 37 °C in the presence of 25% (v/v) tested organic solvents and showed feather degradation activity. The purified enzyme was deactivated at various combinations of pH and temperature to examine the interactive effect of them on enzyme activity. The deactivation process was modeled as first-order kinetics and the deactivation rate constant (k(d)) was found to be minimum at pH 9 and 37 °C. The kinetic analysis of enzyme over a range of pH values indicated two pK values at 6.21 and at 10.92. The lower pK value was likely due to the catalytic histidine in the free enzyme and higher pK value likely reflected deprotonation of the proline moiety of the substrate but ionization of the active site serine is another possibility. Inhibition kinetic showed that enzyme is serine protease because enzyme was competitively inhibited by antipain and aprotinin as these compounds are known to be competitive inhibitors of serine protease. The organic solvent, thermal and pH tolerances of enzyme suggested that it may have potential for use as a biocatalyst in industry.

Kinetic studies of alkaline protease from Bacillus licheniformis NCIM-2042.

An extensive investigation was carried out to describe the kinetics of cell growth, substrate consumption, and product formation in the batch fermentation using starch as substrate. Evaluation of intrinsic kinetic parameters was carried out using a best-fit unstructured model. A nonlinear regression technique was applied for computational purpose. The Andrew's model showed a comparatively better R2 value among all tested models. The values of specific growth rate (micronmax), saturation constant (KS), inhibition constant (KI), and YX/S were found to be 0.109 h-1, 11.1 g/l, 0.012 g/l, and 1.003, respectively. The Leudeking- Piret model was used to study the product formation kinetics and the process was found to be growth-associated. The growth-associated constant (alpha) for protease production was sensitive to substrate concentration. Its value was fairly constant up to a substrate concentration of 30.8 g/l, and then decreased.

Application of Central Composite Design approach for removal of chromium (VI) from aqueous solution using weakly anionic resin: modeling, optimization, and study of interactive variables.

In this paper, response surface methodology (RSM) approach using Central Composite Design (CCD) is applied to develop mathematical model and optimize process parameters for Cr (VI) removal from aqueous streams using weakly anionic resin Amberlite IRA 96. The individual and combined effect of four process parameters, i.e. contact time, initial solution pH, initial Cr (VI) concentration and resin dose on Cr adsorption were studied. Analysis of variance (ANOVA) showed the relative significance of process parameters in removal process. Initial solution pH and resin dose were found to be more significant than contact time and initial Cr (VI) concentration. The second-order regression model was developed to predict the removal efficiency using Design Expert software. The optimal conditions to remove Cr from aqueous solution at constant temperature of 30°C and stirring speed of 250 rpm were found to be contact time 62.5 min, pH 1.96, initial Cr (VI) concentration 145.4 mg/L, and resin dose 8.51 g/L. At these conditions, high removal efficiency (93.26%) was achieved. FTIR and EDX analysis were conducted to interpret the functional groups involved during the Cr-resin interaction.

Sulfide oxidation in fluidized bed bioreactor using nylon support material.

A continuous fluidized bed bioreactor (FBBR) with nylon support particles was used to treat synthetic sulfide wastewater at different hydraulic retention time of 25, 50 and 75 min and upflow velocity of 14, 17 and 20 m/hr. The effects of upflow velocity, hydraulic retention time and reactor operation time on sulfide oxidation rate were studied using statistical model. Mixed culture obtained from the activated sludge, taken from tannery effluent treatment plant, was used as a source for microorganisms. The diameter and density of the nylon particles were 2-3 mm and 1140 kg/m3, respectively. Experiments were carried out in the reactor at a temperature of (30 +/- 2) degrees C, at a fixed bed height of 16 cm after the formation of biofilm on the surface of support particles. Biofilm thickness reached (42 +/- 3) microm after 15 days from reactor start-up. The sulfide oxidation, sulfate and sulfur formation is examined at all hydraulic retention times and upflow velocities. The results indicated that almost 90%-92% sulfide oxidation was achieved at all hydraulic retention times. Statistical model could explain 94% of the variability and analysis of variance showed that upflow velocity and hydraulic retention time slightly affected the sulfide oxidation rate. The highest sulfide oxidation of 92% with 70% sulfur was obtained at hydraulic retention time of 75 min and upflow velocity of 14 m/hr.

Statistical Approach for Optimization of Physiochemical Requirements on Alkaline Protease Production from Bacillus licheniformis NCIM 2042.

The optimization of physiochemical parameters for alkaline protease production using Bacillus licheniformis NCIM 2042 were carried out by Plackett-Burman design and response surface methodology (RSM). The model was validated experimentally and the maximum protease production was found 315.28 U using optimum culture conditions. The protease was purified using ammonium sulphate (60%) precipitation technique. The HPLC analysis of dialyzed sample showed that the retention time is 1.84 min with 73.5% purity. This enzyme retained more than 92% of its initial activity after preincubation for 30 min at 37°C in the presence of 25% v/v DMSO, methanol, ethanol, ACN, 2-propanol, benzene, toluene, and hexane. In addition, partially purified enzyme showed remarkable stability for 60 min at room temperature, in the presence of anionic detergent (Tween-80 and Triton X-100), surfactant (SDS), bleaching agent (sodium perborate and hydrogen peroxide), and anti-redeposition agents (Na(2)CMC, Na(2)CO(3)). Purified enzyme containing 10% w/v PEG 4000 showed better thermal, surfactant, and local detergent stability.

An integrated approach to remove Cr(VI) using immobilized Chlorella minutissima grown in nutrient rich sewage wastewater.

The potential of an integrated system for sewage wastewater treatment and biosorption of chromium(VI) was evaluated using immobilized Chlorella minutissima cells. Immobilized algal cells were grown in sewage wastewater in designed photobioreactor for 48 h and then subjected to removal of Cr(VI) from synthetic wastewater. The effect of pH, Cr(VI) concentration, biosorbent dose on Cr(VI) removal was investigated. C. minutissima showed a higher NH(4)(+)-N and PO(4)(3-)-P removal efficiency (above 99% removal) than the NO(3)(2-)-N (58% removal) in 48 h. Biosorption of Cr(VI) was found to be highly dependent on solution pH, biosorbent dose and initial Cr(VI) concentration. Maximum Cr(VI) uptake 57.33 mg Cr(VI)/g dry biosorbent/L of solution was observed at pH2 with 20% (w/v) biosorbent. Further more than 90% of total Cr adsorbed could be recovered using 0.5 M NaOH as desorption medium.

Sequence alignment and phylogenetic analysis of Human Herpes Simplex Virus (HHV) using bioinformatics tool: a review.

Bioinformatics is the application of computational techniques to analyse the wet lab information associated with biomolecules on a commercial scale. Today's it concentrate on structural biology, genomics to gene expression studies. In this review we discuss the main principles that desirable bioinformatics analyses, sequence alignment and phylogenetic analysis from biological databases that are commonly used and examine some of the studies that are being conducted, particularly with reference to Human Herpes Simplex Virus (HHV). Finally provide an introduction and overview of the bioinformatics tools and software used for sequence alignment.

MEGA biocentric software for sequence and phylogenetic analysis: a review.

Biocomputing has moved into central position in molecular biology research. Enormous improvements in genetic engineering have led to the accumulation of a vast amount of biological information. With the advent of this extensive repertoire of raw sequence information, the next major challenge for a modern researcher is to interpret this biological information. Molecular Evolutionary Genetic Analysis (MEGA) is bio-computational software to fill the vacuum between data development and analysis. In this paper, an attempt to review the evolution of MEGA software, working and application has been made. Moreover, data analysis, implementation and advantages over other bioinformatics software have been discussed systematically.