This study was conducted to evaluate the effect of an eminent decay fungus, Phanerocheate chrysosporium of organic residues on wastewater sludge for its improvement through decomposition and separation of waste particles by Liquid State Bioconversion (LSB). The effect of fungal treatment was compared to uninoculated (Control) at three different harvests 7, 14 and 21 days after inoculation (DAI). The observed results showed that the weight loss and solid content of wastewater sludge were significantly influenced by Phanerocheate chrysosporium. Both parameters were highly influenced at 7 DAI. The COD and pH of wastewater sludge were also highly influenced by fungal treatment.
Abstract Urokinase was produced in a hollow fiber reactor using HT‐1080 human fibrosarcoma cells. External modulation comprised replenishing of the medium in the extracapillary space, reducing the serum concentration in the extracapillary space from 10% to 2% and increasing flow rate of the circulating medium in the intracapillary space from 20 to 80 mL/min, each according to a specific protocol. More than sixfold increase was observed in the cumulative urokinase production for two and three medium replenishing modulations of the extracapillary space. After 15 days of continuous operation, the highest cumulative urokinase obtained was 1.63 × 10 6 PU/mL. SDS‐PAGE and zymogram study established that the urokinase obtained was in the high molecular weight range of 54 kDa. The effect of external modulation on cumulative urokinase production was visualized as trajectories with respect to the ratio of lactic acid production rate (LPR) to the glucose uptake rate (GUR). The collective external modulation data showed two separate physiological regions in the cumulative urokinase vs. LPR/GUR plane. The HT‐1080 cells exhibited two distinct morphologies in these regions that may be related to acidosis and metastasis. These regions also correspond to low and high urokinase productivity.
An integrated product recovery system was developed to separate urokinase from the cell culture broth of human kidney cells HT1080. Supermacroporous monolithic cryogels provided ideal matrices with respect to surface and flow properties for use as cell culture scaffold as well as for affinity chromatographic capture step of the enzyme in the integrated system. The urokinase was produced continuously in the reactor running for 4 weeks with continuous circulation of 500 ml of culture medium. The enzyme activity in the culture medium reached to 280 Plough units (PU)/mg protein. Cu(II)-iminodiacetic acid (IDA)-polyacrylamide (pAAm) cryogel column was used to capture urokinase by integrating with the gelatin-coupled pAAm-cryogel bioreactor for HT1080 cell culture. After removing the urokinase capture column from the integrated system the bound protein was eluted. The metal affinity capture step gave 4.5-fold purification of the enzyme thus achieving a specific activity of 1300 PU/mg protein. The enzyme eluate from Cu(II)-IDA-pAAm cryogel capture column was further purified on benzamidine-Sepharose affinity column. This step finally led to a homogeneous preparation of different forms of urokinase in two different elution peaks with a best urokinase activity of 13 550 PU/mg of protein. As compared to initial activity in the cell culture broth, about 26.2- and 48.4-fold increase in specific activity was achieved with enzyme yields corresponding to 32% and 35% in two different peak fractions, respectively. Native electrophoresis and SDS-PAGE showed multiple protein bands corresponding to different forms of the urokinase, which were confirmed by Western blotting and zymography.
Abstract The data on ethanol‐water vapor‐liquid equilibrium in the presence of cellulase enzyme, nutrients, yeast, and rice straw indicated a substantial increase in ethanol concentration in vapor phase at reduced pressures. Maximum relative volatility of ethanol in the presence of added components is approximately twice that of a pure ethanol‐water system. The equation correlating the activity coefficient and ethanol concentration in the liquid phase adequately represents the equilibrium behavior.
The pyrite sulphur removal from coal by Thiobacillus ferrooxidans was studied in batch reactor. A combination of SEM, IR and XRD was used to study the presence of superficial phases and the changes in solid surface during biodesulphurization. Biodesulphurization was found to be a three-step process. In the first step (0-4 days), direct oxidation of pyrite by bacteria brought about 28% pyritic sulphur removal. Both direct and indirect oxidation contributed to the second step (4-10 days) resulting in 51% pyrite removal. The deposition of elemental sulphur, jarosite and ferric sulphate precipitates in the third step reduced the pyrite availability and ferric iron concentration in the leachate and brought the process of biodesulphurization to an end.
The commercial production of lactic acid through fermentation process has always been in competition with its chemical synthesis process (Kirk Othmer, 1995). Lactic acid produced through the fermentation process has to cope with the problems of purification to meet the required quality standards. An attempt to improve the fermentative production is possible by proper design of an industrial process involving low capital cost for the plant. Also, the low energy costs both in its fermentation and purification, are required. In the commercial interest, the investment cost should be minimised, which is possible only when the cell density in fermenter is high. It means that the inhibitory effect of the product on process kinetics must be minimised. Based on these requirements, the extractive bioconversion technique is one of the approaches to achieve the commercially viable lactic acid production. Extractive lactic acid bioconversion using ion-exchange resin process has already been described in our earlier publications (Srivastava e al., 1992: Roychoudhury et al., 1995) It is always an advantage to develop a process model, thus opening an area of biotechnological improvements to the process. In the present paper, an empirical mathematical model has been described to explain this extractive bioconversion using ion-exchange resin process. It was based on generalised Monod's growth model and Leudeking and Piret equation. The system was defined with the assumption that the microbial growth can be represented as a single reaction; only a very little part of the substrate is utilised for the maintenance of the cells. The effect of end product inhibition on growth and product formation kinetics has also been considered in this model. A non-linear regression technique was used for evaluation of bioconversion kinetic parameters. The fourth order Runge Kutta method was used for solving the differential equations. The results of this process simulation are also discussed in the present paper. It indicates that the use of present technique has minimised the effect of lactic acid inhibition on process kinetics and hence higher productivity and least substrate utilisation for maintenance of cells. A statistical F-test has been performed for determining the validity of the model for a given set of experimental data with a level of significance alpha = 0.05 selected for this extractive batch recycle bioconversion process using ion-exchange resin.
The dissolving pulp industry, spread throughout the world, is the principal source of wood-hydrolysate effluent rich in hemicelluloses. This effluent is the major source of pollution in the industry. COD and BOD5 values of the effluent range from 60,000 to 103,000 and 42,000 to 78,000 mg/l respectively. Biomethanation of this effluent is the best possible treatment option for reducing the COD load and recovering the bioenergy embedded in the effluent. This paper deals with the study on the biphasic biomethanation of the wood-hydrolysate in upflow acidogenic reactor coupled with anaerobic filter methanogenic reactor. The two reactors were operated at organic loading rates of 69.6 and 30.1 g COD/l/d respectively. The overall COD, hemicelluloses and lignin reductions, and methane generation were observed to be 88%, 92%, 82% and 6.5 l/l reactor volume/d respectively. The relative size of the biphasic, anaerobic filter (mono-phasic) and upflow anaerobic sludge blanket (mono-phasic) reactors is found to be 1:1.6:2.03 respectively.