Enhancing ethanol production from cellulosic sugars using Scheffersomyces (Pichia) stipitis.

Studies were performed on the effect of CaCO3 and CaCl2 supplementation to fermentation medium for ethanol production from xylose, glucose, or their mixtures using Scheffersomyces (Pichia) stipitis. Both of these chemicals were found to improve maximum ethanol concentration and ethanol productivity. Use of xylose alone resulted in the production of 20.68 ± 0.44 g L(-1) ethanol with a productivity of 0.17 ± 0.00 g L(-1) h(-1), while xylose plus 3 g L(-1) CaCO3 resulted in the production of 24.68 ± 0.75 g L(-1) ethanol with a productivity of 0.21 ± 0.01 g L(-1) h(-1). Use of xylose plus glucose in combination with 3 g L(-1) CaCO3 resulted in the production of 47.37 ± 0.55 g L(-1) ethanol (aerobic culture), thus resulting in an ethanol productivity of 0.39 ± 0.00 g L(-1) h(-1). These values are 229 % of that achieved in xylose medium. Supplementation of xylose and glucose medium with 0.40 g L(-1) CaCl2 resulted in the production of 44.84 ± 0.28 g L(-1) ethanol with a productivity of 0.37 ± 0.02 g L(-1) h(-1). Use of glucose plus 3 g L(-1) CaCO3 resulted in the production of 57.39 ± 1.41 g L(-1) ethanol under micro-aerophilic conditions. These results indicate that supplementation of cellulosic sugars in the fermentation medium with CaCO3 and CaCl2 would improve economics of ethanol production from agricultural residues.

Physico-chemical evaluation of bitter and non-bitter Aloe and their raw juice for human consumption.

In addition to Aloe vera which is bitter in taste, a non-bitter Aloe is also found in arid part of Rajasthan. This non-bitter Aloe (NBA) is sporadically cultivated as vegetable and for health drink. In spite of its cultivation and various uses, very little information is available about its detailed botanical parameters and chemical characters. This study aims to evaluate the physico-chemical characters of NBA through employing floral morphology, leaf characters and leaf gel and to compare them with those of A. vera. Of eleven floral characters studied, eight characters of NBA were significantly different from that of A. vera. Most visible difference was observed in their reproductive shoots which are highly branched in NBA (5.21 inflorescence/shoot) as compared to A. vera (1.5 inflorescence/shoot). NBA produces less leaf-biomass (-29.32 %) with less leaf-thickness (-31.44 %) but higher leaf length, width, and no. of spine/side by 17.56 %, 21.34 % and 16.11 %, respectively, with significant difference as compared to A. vera. But its polysaccharide content (0.259 %) is at par with that of A. vera. The raw juice from the leaf of NBA has very low aloin content (4.1 ppm) compared to that from A. vera (427.3 ppm) making it a safer health drink compared to the one obtained from A. vera. Thus, NBA raw juice emerged as suitable alternative to A. vera juice for human consumption.