Cost effective production of pullulan from agri-industrial residues using response surface methodology.

Response surface methodology was used to develop an economically feasible process for the fermentative production of pullulan using agri-industrial residues, jaggery, de-oiled jatropha seed cake (DOJSC) and corn steep liquor (CSL), as sole media components. A second order polynomial model was obtained using central composite design to understand the effects of interactions among these substrates on pullulan biosynthesis. Results indicated that, lower concentrations of CSL and DOJSC and higher concentrations of jaggery favoured pullulan production. The optimal nutrient composition (18% jaggery, 3% DOJSC and 0.97% CSL) as suggested by the model resulted in production of 66.25 g/L pullulan with a productivity of 0.92 g/Lh. Analysis of raw material cost component for pullulan production suggested that sole utilization of agri-residues may lead to development of cost effective process for pullulan production.

Utilization of corn steep liquor for biosynthesis of pullulan, an important exopolysaccharide.

Five different agricultural wastes viz. rice bran oil cake, soya bean oil cake, cotton seed oil cake, mustard seed oil cake and corn steep liquor (CSL) were evaluated for their use as nutrient along with 15% (w/v) glucose as carbon source for biosynthesis of pullulan using Aureobasidium pullulans RBF 4A3. Among the selected agricultural wastes, CSL was found to be the best and supported production of 77.92gL(-1) pullulan under un-optimized conditions. Single point optimization technique resulted in increase in 18% pullulan (88.59gL(-1)) production. The process was successfully validated in a 7-L fermenter and a process economic analysis has suggested that use of CSL as nutrient may result in 3-fold reduction of cost of raw materials for pullulan production as compared to a process where conventional nitrogen sources were used. These observations may be helpful in development of a cost effective process for pullulan production.

Multi-centre experience on the use of perhexiline in chronic heart failure and refractory angina: old drug, new hope.

AIMS: The objective of this study is to report on our 5-year collective experience on the use of perhexiline in the UK, in patients with chronic heart failure (CHF) and/or refractory angina with respect to 'real-life' drug side effects and toxicity, therapeutic drug level monitoring, 5 year mortality outcomes and predictors of response to perhexiline therapy. METHODS AND RESULTS: Data on clinical history, perhexiline monitoring, follow-up, and mortality were retrospectively collated from centralized perhexiline databases from two tertiary referral centres. A total of 151 patients were on perhexiline therapy at two UK tertiary referral centres. At 3-4 months, 68.8% of patients had drug level within the therapeutic range and 20.8% were above the therapeutic range. A total of 58.9% of patients reported to have felt better on the perhexiline (responders). The presence of refractory angina was an independent predictor of response to perhexiline therapy (odds ratio 2.84, 95% confidence interval 1.28-6.32, P = 0.01). Five-year mortality was non-significantly different between patients with refractory angina, CHF, or both (20.5, 31.0, and 38.4%, P = 0.20, respectively). CONCLUSION: Perhexiline therapy provides symptomatic relief in the majority of patients with minimal side effects or toxicity. Careful therapeutic level monitoring for dose titration is important to prevent acute and chronic toxicity. Patients with refractory angina were more likely to be responders.