Assessment of combination of pretreatment of Sorghum durra stalk and production of chimeric enzyme (ß-glucosidase and endo ß-1,4 glucanase, CtGH1-L1-CtGH5-F194A) and cellobiohydrolase (CtCBH5A) for saccharification to produce bioethanol.

Optimization of pretreatment and saccharification of Sorghum durra stalk (Sds) was carried out. The chimeric enzyme (CtGH1-L1-CtGH5-F194A) having ß-glucosidase (CtGH1) and endo ß-1,4 glucanase activity (CtGH5-F194A) and cellobiohydrolase (CtCBH5A) from Clostridium thermocellum were used for saccharification. Chimeric enzyme will save production cost of two enzymes, individually. Stage 2 pretreatment by 1% (w/v) NaOH assisted autoclaving + 1.5% (v/v) dilute H2SO4 assisted oven heating gave lower total sugar yield (366.6 mg/g of pretreated Sds) and total glucose yield (195 mg/g of pretreated Sds) in pretreated hydrolysate with highest crystallinity index 55.6% than the other stage 2 pretreatments. Optimized parameters for saccharification of above stage 2 pretreated biomass were 3% (w/v) biomass concentration, enzyme (chimera: cellobiohydrolase) ratio, 2:3 (U/g) of biomass, total enzyme loading (350 U/g of pretreated biomass), 24 h and 30 °C. Best stage 2 pretreated Sds under optimized enzyme saccharification conditions gave maximum total reducing sugar yield 417 mg/g and glucose yield 285 mg/g pretreated biomass in hydrolysate. Best stage 2 pretreated Sds showed significantly higher cellulose, 71.3% and lower lignin, 2.0% and hemicellulose, 12.2% (w/w) content suggesting the effectiveness of method. This hydrolysate upon SHF using Saccharomyces cerevisiae under unoptimized conditions produced ethanol yield, 0.12 g/g of glucose. Abbreviation: Ct-Clostridium thermocellum, Sds-Sorghum durra stalk, TRS-Total reducing sugar, HPLC-High performance liquid chromatography, RI-Refractive index, ADL-acid insoluble lignin, GYE-Glucose yeast extract, MGYP-Malt glucose yeast extract peptone, SHF-separate hydrolysis and fermentation, OD-Optical density, PVDF-Poly vinylidene fluoride, TS-total sugar, FESEM-Field emission scanning electron microscopy, XRD-X-ray diffraction, FTIR-Fourier transform infra-red spectroscopy and CrI-Crystallinity index.

Assessment of olfaction using the "i-smell" test in an Indian population: a pilot study.

The objective of our study was to assess the olfactory function in patients having sinonasal disease and in normal healthy individuals and to establish a clinical test for olfaction in Indian population. Odor threshold and odor identification testing in patients of sinonasal disease and in subjects with no sinonasal disease was done in an academic tertiary medical center. Fifty patients with sinonasal disease (Group A) and 100 normal subjects with no complaints of olfactory dysfunction (Group B) were prospectively recruited. Group A was evaluated using visual analogue scales for subjective grading of olfactory function, nasal endoscopy and odor threshold and identification abilities. Group B was evaluated using nasal endoscopy and combined olfactory score. The combined olfactory score (COS) in group A ranged from 0 to 15 (mean 7.85, SD 2.26). The score in group B ranged from 7 to 19 (mean 14.57, SD 4.78). Statistically significant correlation was observed between VAS and COS (r = 0.764, p < 0.001) and nasal endoscopy score and COS (r = 0.55, p < 0.001) in group A. The "I-Smell" test could effectively discriminate between subjects with olfactory dysfunction and the normosmic subjects and is feasible to be used in Indian population.