Activity enhancement of ligninolytic enzymes of Trametes versicolor with bagasse powder

Suspended cultures of white-rot fungus, Trametes versicolor, supplemented with bagasse powder showed a concentration dependent enhancement in the ligninolytic enzymes activity in liquid shake cultures. 2% (w/v) bagasse powder improved greater stability to the enzymes. The optimum pH is 3.5 and the optimum temperature is 40°C for maximum lignonolytic enzymatic activity. The optimum shaking speed is 60 rpm for maximum enzymatic activity. The maximum enzymatic activity showed by T. versicolor is 495, 440 and 410 mmol/ml.min for LiP, MnP and laccase with bagasse powder at optimum conditions, respectively. Without bagasse powder at optimum conditions, the maximum enzymatic activity for LiP, MnP and laccase is 195, 150 and 170 mmol/ml.min, respectively.Keywords: Bagasse, enhancement, enzymes, optimum, white-rot fungu

Activity enhancement of ligninolytic enzymes of Trametes versicolor with bagasse powder

Suspended cultures of white-rot fungus, Trametes versicolor   , supplemented with bagasse powder showed a concentration dependent enhancement in the ligninolytic enzymes activity in liquid shake cultures. 2% (w/v) bagasse powder improved greater stability to the enzymes. The optimum pH is 3.5 and the optimum temperature is 40°C for maximum lignonolytic enzymatic activity. The optimum shaking speed is 60 rpm for maximum enzymatic activity. The maximum enzymatic activity showed by T. versicolor is 495, 440 and 410 μmol/ml.min for LiP, MnP and laccase with bagasse powder at optimum conditions, respectively. Without bagasse powder at optimum conditions, the maximum enzymatic activity for LiP, MnP and laccase is 195, 150 and 170 μmol/ml.min, respectively

Studies on bacterial growth and lead(IV) biosorption using <i style="">Bacillus subtilis</i>

591-596Gram-positive bacterium Bacillus subtilis biosorbs lead(IV) ion from its aqueous solution. The maximum biosorption of lead is 97.68% (w/w) within 48 h of incubation time with optimum pH 4.5 and optimum temperature 40°C for 700 ppm initial loading of lead in a shake flask (optimum rpm 60). 7 days old and 30% (v/v) of suspension inoculum culture is used in the studies. Lead is measured by using atomic absorption spectrophotometer (AAS) into an air-acetylene flame and absorbance is measured at 283.3 nm. The maximum bacterial growth is noticed as 4.90108 cells/mL at optimum bioprocess conditions

Bioethanol fermentation from untreated and pretreated lignocellulosic wheat straw using fungi <i style="">Fusarium oxysporum</i>

63-70A comparison has been made among untreated, lime pretreated and dilute alkaline peroxide pretreated wheat straw for bioethanol production by simultaneous saccharification and fermentation (SSF) process in a continuous stirred batch bioreactor (CSBR) using fungi Fusarium oxysporum. The optimum parameters used for the bioethanol fermentation are: time 48 h, pH 6, temperature 50, stirring speed 35, and wheat straw loading 35 g/L. Maximum yield of ethanol is found to be 0.756 , 0.796 and 0.810 g/g of wheat straw under optimum conditions for untreated, lime pretreated and dilute alkaline peroxide pretreated wheat straw. The sp. fungal growth rate is found to be 5.26 , 5.40, and 5.88 s−1 and maximum sp. fungal growth rate is 10.52, 10.80 and 11.76 s−1 using the Monod model for the fermentation of untreated, lime pretreated and dilute alkaline peroxide pretreated wheat straw under optimum conditions respectively. The fungal growth kinetic parameters are 33.6 , 33.9 and 34.7 g/L respectively for fermentation of the three samples under the optimum conditions. The sp. carboxy methyl cellulase ( CMCase) activity are 1185 , 1455 and 1545 min−1 and maximum sp. CMCase activity are 2370, 2910 and 1545 min−1 using Michaelis-Menten enzyme kinetic model for the fermentation of three samples respectively under optimum conditions. The CMCase enzyme kinetic parameters are 34.3, 34.5 and 34.7 g/L for the three samples respectively under optimum fermentation conditions. Fungi Aspergillus oryzae show the better conversion of ethanol than fungi Fusarium oxysporum. The fermentation process follows the first order rate equation in CSBR

Anaerobic biogas generation from sugar industry wastewaters in three-phase fluidized-bed bioreactor

58-64The studies are undertaken to develop an effective anaerobic continuous digestion process for biogas generation from sugar industry wastewaters using actively digested sludge from a sewage plant, in three-phase fluidized bed bioreactor. Attempts are made to optimize hydraulic retention time (HRT), initial feed pH, feed temperature and flow rate of feed (organic loading rate) for maximum production of methane gas and maximum removal of chemical oxygen demand (COD) and biological oxygen demand (BOD) of sugar industry wastewaters. The optimum conditions for the system are: digestion time, 8 h; initial pH of feed, 7.5; feed temperature, 40ºC; feed flow rate, 14 L/ min with maximum organic loading rate (OLR), 39.513 kg COD m⁻³ h⁻¹. The organic loading rates (OLR) are calculated on the basis of COD inlet in the bioreactor at different flow rates. The maximum expansion of the bed is observed as 23.67 m at optimum feed flow rate of 14 L/ min. The maximum methane gas concentration is 63.56% (v/v) of the total biogas generation at optimum process parameters. The maximum biogas yield rate is 0.835 m³ /kg COD m⁻³ h⁻¹ with maximum methane gas yield rate of 0.530 m³ /kg COD m⁻³ h⁻¹ (63.56% v/v) at optimum process parameters. The values for maximum reduction of COD and BOD are 76.82% (w/w) and 81.65% (w/w) with maximum OLR of 39.513 kg COD m⁻³ h⁻¹ at optimum conditions

Scale-up and optimization studies on lignin biodegradation of rice straw using <i>Phanerochaete chrysosporium</i>

227-234An effective batch aerobic study on lignin biodegradation with Phanerochaete chrysosporium is performed and process parameters are optimized. The optimum time is 14 days for lignin biodegradation of rice straw. At the optimum time, 2 percent glucose (carbon source) and 0.20 percent L-asparagine (nitrogen source) calculated on raw material, can degrade maximum lignin. The percent of lignin degradation at optimum GNC dose is 47.38 with lowest kappa number (k) value 23.58 with optimum inoculum concentration 20 percent (v/v) and optimum age of inoculums 7 days with pH 4.5. The minimum COD and BOD values for optimum GNC Dose treated effluents after 14 days digestion are 1,050 mg/L and 625 mg/L respectively. The optimum GNC Dose treated effluents having colour (OD at 465 nm) is 0.20 which is minimum. </span

Biodesulphurization of natural gas in a three-phase fluidized bed bioreactor using Thiobacillus dentrificans

406-411Natural gas from well head contain a number of undesirable components including hydrogen sulphide (H2S), which can be removed by anaerobic desulphurization process using three-phase fluidized bed bioreactor. Optimum H2S removal (90.89%, w/w) was obtained at following parameters: H2S conc., 0. 55 ì M /l; loading rate, 6.05 ì M /min; contact time, 12 h; pH, 7.0; temperature, 45°C and feed and culture flow rate, 11 l/ min. Methane (CH4) gas of natural gas acts as a sole carbon source to bacteria and maximum bacterial growth is observed as 9.93 ´ 108 numbers of cells/ml

Studies on biobleaching of kraft pulp using <i>Phanerochaete chrysosporium</i>

166-174White-rot fungi Phanerochaete chrysosporium can degrade residual lignin (bleach) of kraft pulp maximum 69.59 percent within 7 days (optimum digestion time) with 20 percent inoculum concentration (optimum) of 7 days old aged (optimum) fungus with 1.0 percent (wlw percent of pulp) (optimum) of glucose and 0.10 percent (w/w percent of pulp) (optimum) of l-asparagine at pH 4.5 and temperature 35°C. COD, BOD and colour of the effluents (filtrate after digestion with microbe) at optimum conditions are very lower. Average COD, BOD and colour values of effluents after bleaching for optimum dose are 320 mg/L, 545 mg and 0.23 (OD at 465 nm) respectively. The increase percentage of brightness, tear index, urst index, tensile index and breaking length of bleached pulp for optimum dose are 89.35, 38.93, 47.46 , 68.17 and 66.97 respectively

Studies on biohydrometallurgical leaching of iron sulphide ore using <i style="">Thiobacillus ferrooxidans</i>

116-120Biohydrometallurgical leaching of iron sulphide ore in an aerobic batch system using bacteria Thiobacillus ferrooxidans has been studied for process parameters optimization. The maximum bioleaching of Fe2+ is 79.88 and 79.10 per cent (w/w) for 25 and 30 kg/m3 initial ferrous iron loading at optimum conditions. The optimum parameters are—time 172 h, pH 2.5 and temperature 35°C. The optimum glucose and nitrogen (as ammonium sulphate) concentration for maximum bacterial bioleaching is 3.0 and 0.30 per cent (w/w) respectively. The optimum shaking speed (rpm) is 60. 20 percent (v/v) and 7 days age-old suspension culture was used for the studies. The bacteria can tolerate upto 35 kg/m3 initial ferrous iron concentration

A Comparative Analysis of Peak Load Shaving Strategies for Isolated Microgrid Using Actual Data

Peak load reduction is one of the most essential obligations and cost-effective tasks for electrical energy consumers. An isolated microgrid (IMG) system is an independent limited capacity power system where the peak shaving application can perform a vital role in the economic operation. This paper presents a comparative analysis of a categorical variable decision tree algorithm (CVDTA) with the most common peak shaving technique, namely, the general capacity addition technique, to evaluate the peak shaving performance for an IMG system. The CVDTA algorithm deals with the hybrid photovoltaic (PV)—battery energy storage system (BESS) to provide the peak shaving service where the capacity addition technique uses a peaking generator to minimize the peak demand. An actual IMG system model is developed in MATLAB/Simulink software to analyze the peak shaving performance. The model consists of four major components such as, PV, BESS, variable load, and gas turbine generator (GTG) dispatch models for the proposed algorithm, where the BESS and PV models are not applicable for the capacity addition technique. Actual variable load data and PV generation data are considered to conduct the simulation case studies which are collected from a real IMG system. The simulation result exhibits the effectiveness of the CVDTA algorithm which can minimize the peak demand better than the capacity addition technique. By ensuring the peak shaving operation and handling the economic generation dispatch, the CVDTA algorithm can ensure more energy savings, fewer system losses, less operation and maintenance (O&M) cost, etc., where the general capacity addition technique is limited