S1, which is a locally isolated and improved strain showed viability at 40, 45 and 50C and produced ethanol at 40, 43 and 45C. (50gL?1) at 40C, 46% viability was retained by S1 at 48h and it was improved to 80% by soy flour supplementation. S1 (2) up to 45C for its application in local distilleries. MATERIALS AND METHODS Materials Soy bean from local market was powdered and dried at 80C. All the other materials were GW-786034 cell signaling purchased from standard suppliers: culture media Oxoid limited USA, and other chemicals are from Sigma-Aldrich, USA. Saccharomyces cerevisiae S1 S1 is a locally isolated GW-786034 cell signaling and improved thermotolerant strain (2); maintained in peptone, yeast extract and nutrient (PYN) C agar (2.5gL?1) slants. Analytical methods Glucose (23), trehalose (TCA soluble anthrone positive carbohydrate) (36), ethanol (39) and viable cell count (30) were determined by standard methods. Peptone, yeast extract and nutrient (PYN) medium The medium contained (gL?1) peptone, 3.5, yeast extract, 3.0, MgSO4.7H2O, 1.0, KH2PO4, 2.0; and (NH4)2SO4, 1.0 at pH 5.0. Under different experimental conditions, different amounts of glucose were added to the medium and represented as glucose (amount in gL?1) C PYN medium (2). Inoculum of S1 Glucose (50gL?1) C PYN medium (100mL) was inoculated with 2 loops full of S1 and incubated at 36C for 18h with shaking at 150rpm. Thermo- tolerance and ethanol production S1 grown at 36C in glucose (50gL?1) CPYN medium for 18h was incubated at 40, 45, 50 and GW-786034 cell signaling 55C separately in triplicates and viability was monitored. All the following treatments were done in triplicates. For the ethanol production studies, inocua (10%, v/v, 18h) were added to the glucose (100gL?1) C PYN medium and incubated at 40, 43 and 45C separately with shaking (150rpm). Temperature shift cultivation on ethanol Ctolerance Culture of S1 prepared at IRAK2 36C in glucose (50gL?1) C PYN medium was given different treatments as shown in Table 1 and the viable cell count was monitored. Table 1 S1 culture grown at 36C in glucose (50gL-1) C PYN medium were given different treatments. After the different treatment the cultures were incubated at the indicated temperature. S1 grown at 36C in glucose (50gL?1) C PYN medium, heat shock was given by incubating at 45C for 30min. Control did not have heat treatment. Then 1mL aliquots of the test and control cultures were mixed with 1mL normal saline (pre-equilibrated at 58C) and incubated at 58C for 5min. The viability was determined. Trehalose was extracted (37) and estimated (36). Yeast cells without heat shock were used as control. Weight of the dry cells was measured. Ethanol shock on trehalose content Ethanol content in the S1 culture grown for 18h at 36C in glucose (50gL?1) C PYN medium was measured and ethanol was added to make up the total concentration to 200gL?1. After 30min, cells subjected to ethanol shock were harvested by centrifugation (7 x 103 rpm) and trehalose content and dry cell weight were measured. To the control, no ethanol shock was given. Growth temperature on thermo-tolerance S1 inocula prepared at 28, 32 and 36C were incubated at 58C and viability was monitored. In another setup 18 old culture grown at 28C was incubated at 36C for 90 min and then incubated at 58C and the viability was monitored. Soy flour supplementation on thermo-tolerance Viability of S1 grown at 40C in glucose (100gL?1) C PYN medium supplemented with 20gL?1 soy flour was monitored while the control medium did not have soy flour. Soy flour supplementation on osmo-tolerance Sorbitol (0C400gL?1) was added to glucose (100gL?1) C PYN. Soy flour (40 gL?1) was added to the test while the control did not have soy flour. Glucose (200gL?1) C PYN medium and glucose (300gL?1) C PYN medium with and without soy flour supplementation were also taken. Viable cell count and ethanol were determined at 48h of incubation. Soy flour supplementation on ethanol tolerance To glucose (100gL?1) C PYN medium with and without soy flour (40gL?1), ethanol (0C200g L?1) was added and incubated at 40C. Viable cell count and ethanol were measured at 48h. Combined effects of osmo- and ethanol C stresses Sorbitol (200gL?1) was added separately into different.