Xylitol, as an alternative low calorie sweetener is well accepted in formulations of various confectioneries and healthcare products. Worldwide it is industrially produced by catalytic hydrogenation of pure d-xylose solution under high temperature and pressure. Biotechnological xylitol production is a potentially attractive replacement for chemical process, as it occurs under much milder process conditions and can be based on sugar mixtures derived from low-cost industrial and agri-waste. However, microbial fermentation route of xylitol production is not so far practiced industrially. This review highlights the challenges and prospects of biotechnological xylitol production considering possible genetic modifications of fermenting microorganisms and various aspects of industrial bioprocessing and product downstreaming.
Several efforts have been made during
the last three decades to
develop successful lignocellulose-based technologies for the production
of fuels and chemicals. However, such technologies still seemed to
be emerging, because of the high technical risks involved and huge
capital investments. This paper describes a holistic approach toward
utilization of sugar cane bagasse as lignocellulosic feedstock into
fuel (ethanol), chemical (furfural), and energy (electricity), using
a biorefinery approach instead of co-generation. The proposed scheme
could be integrated with existing sugar or paper mills, where the
availability of biomass feedstock is in abundance. Fermentable sugar
components (xylose and glucose) from sugar cane bagasse have been
extracted employing acid hydrolysis and enzymatic saccharification.
Recovery and reuse of saccharifying enzyme was a major process advantage.
The pentose fraction was efficiently utilized for yeast biomass generation
and furfural production. High-temperature fermentation of a hexose
stream by thermophilic yeast Kluyveromyces sp. IIPE453 (MTCC 5314) with cell recycle produced ethanol with an overall
yield of 88% ± 0.05% and a productivity of 0.76 ± 0.02 g/L
h–1. A complete material balance on two consecutive
process cycles, each starting with 1 kg of feedstock, resulted in
an overall yield of 366 mL of ethanol, 149 g of furfural, and 0.30
kW of electricity.
Objectives: Adolescents remain largely neglected and especially girl from a deprived section in our society. The present study is an attempt to evaluate the nutritional status of early adolescent school girl from rural and urban areas. The study was, therefore, carried out to determine and compare the nutritional status of adolescent girl attending urban and rural secondary schools in Paschim Medinipur district of West Bengal, India. Methods: Cross-sectional data based on anthropometric measurements (height, weight) was collected from 2545 girls aged 10 to 14 years attending Govt. approved schools in Kharagpur town and Dantan-II block. The nutritional status has been assessed with the help of some anthropometric indices. The weight and height were recorded for each girl, and converted to nutritional indices (weightfor-age, height-for-height, BMI-for-age Z-scores of the National Center for Health Statistics reference standrads). Results: The mean nutritional indices (underweight, stunting and thinness) were found to be much lower among the rural girl than urban girl. The overall prevalent rates of underweight, stunting and thinness were 27.9%, 32.5% and 20.2% respectively. In the rural area these were 35.4%, 35.7% and 26.3%, while in the urban they were 19.6%, 29.0% and 13.6% respectively. Conclusions: The present study shows that undernutrition constituted major health problems among early adolescent school girls in rural areas of India. Hence, the special emphases are needed to formulate various developmental and healthcare programmes for rural communities to prevent undernutrition.
Ethanol production from sugarcane bagasse pith hydrolysate by thermotolerant yeast Kluyveromyces sp. IIPE453 was analyzed using response surface methodology. Variables such as Substrate Concentration, pH, fermentation time and Na2HPO4 concentration were found to influence ethanol production significantly. In a batch fermentation, optimization of key process variables resulted in maximum ethanol concentration of 17.44 g/L which was 88% of the theoretical with specific productivity of 0.36 g/L/h.
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