Exploring the synthetic potential of cell bound β-glycosidase of Pichia etchellsii

Consumer Behavior and Fascinating Challenges on Household Laundry and Dishwashing

Intense research in household cleaning offers more innovative cleaning solutions. Over the half of consumers worldwide favor functionality over “natural” and “multipurpose” claims in household care products. Due to rapid urbanization, emergence of small pack size, current environmental pressures and price escalation of petrochemical feedstock, the demand for sustainable laundry and dishwashing products is developing rapidly. The user-centered researches revealed that the increase in per capita income and wide range of choices, greatly influence consumers interactions with products as expenditure for household laundry and increase the number of sophisticated consumers. Dishwashing accounts for barely more than 0.5% of total per capita expenditure. Low energy as well as water consumption, high performance values are very important for the consumers when purchasing automatic washing appliances. Multi-usability and efficiency capture continuously the attention of the consumers in large scale in the sense of economic viability, environmental feasibility and reverted interest to use traditional liquid and powder detergents. Brand value and integrity proves to be also surprisingly important. Researches revealed that many consumers prefer household appliances with low water and energy consumption. As per the statistics, since half of the total surfactant consumption belongs to household applications particularly dishwashing and laundry washing, the natural product based surfactants produced from biomass are expected to continue to drive cleaning market.

Response surface methodology based optimization of β-glucosidase production from Pichia pastoris

The thermotolerant yeast Pichia etchellsii produces multiple cell bound β-glucosidases that can be used for synthesis of important alkyl- and aryl-glucosides. Present work focuses on enhancement of β-glucosidase I (BGLI) production in Pichia pastoris. In the first step, one-factor-at-a-time experimentation was used to investigate the effect of aeration, antifoam addition, casamino acid addition, medium pH, methanol concentration, and mixed feed components on BGLI production. Among these, initial medium pH, methanol concentration, and mixed feed in the induction phase were found to affect BGLI production. A 3.3-fold improvement in β-glucosidase expression was obtained at pH 7.5 as compared to pH 6.0 on induction with 1 % methanol. Addition of sorbitol, a non-repressing substrate, led to further enhancement in β-glucosidase production by 1.4-fold at pH 7.5. These factors were optimized with response surface methodology using Box-Behnken design. Empirical model obtained was used to define the optimum "operating space" for fermentation which was a pH of 7.5, methanol concentration of 1.29 %, and sorbitol concentration of 1.28 %. Interaction of pH and sorbitol had maximum effect leading to the production of 4,400 IU/L. The conditions were validated in a 3-L bioreactor with accumulation of 88 g/L biomass and 2,560 IU/L β-glucosidase activity.