In this study, hydrolytic enzymes from sunn pest (Eurygaster integriceps) and cotton bollworm (Helicoverpa armigera) midguts were identified and characterized in terms of their optimum pH, Km and Vmax values. Hydrolytic activities were also tested for inhibition by several protease and alpha-amylase inhibitors which can be used for the development of insect resistant plants through transgenic technologies. For sunn pest midgut, a low proteolytic activity, belonging mostly to trypsin-like and leucine aminopeptidase-like proteases, and a very high alpha-amylase activity was found in sunn pest midgut, reflecting its high carbohydrate diet. Proteolytic activities could not be inhibited by natural protease inhibitors (SBTI and aprotinin) but inhibited significantly by a general serine protease inhibitor PMSF and metalloprotease inhibitors CdCl2 and CuCl2. alpha-Amylase activity of sunn pest midgut is resistant to inhibition by bean alpha-amylase inhibitor, but inhibited by chickpea, wheat and maize alpha-amylase inhibitors by 26 %, 37 % and 40 %, respectively. For cotton bollworm midgut, a very high proteolytic activity, belonging to serine and metalloprotease type, was detected. alpha-Amylase activity was lower compared to sunn pest midgut, but there were higher and diverse type of proteases, might be reflecting its wide range of host preference. Proteolytic activity was significantly inhibited by both natural protease inhibitors (SBTI and aprotinin). It was also inhibited by several synthetic protease inhibitors (PMSF, E-64, TPCK, CdCl2, CuCl2, Chymostatin). alpha-Amylase activity was inhibited by 60 % by wheat alpha-amylase inhibitor, while maize, chickpea and bean alpha-amylase inhibitors had no effect on cotton bollworm midgut alpha-amylase activity.

In this study, 11 bacterial isolates from Salt Lake,Turkey were identified by using fatty acid methyl ester (FAME) analysis. They were screened for production of industrially important enzymes xylanase, cellulase, &amp / #945 / -amylase and protease. These enzymes were characterized in terms of enzyme activity, stability, optimum temperature and optimum pH. One of the isolates was identified as Bacillus pumilus, and two of them were identified as Bacillus subtilis. Other isolates were determined to be Bacillus licheniformis. All the isolates were determined to produce xylanase. Optimum temperatures and optimum pH values of xylanases were 50-55 &deg / C and pH 7.0-8.0. Xylanases were quite stable up to pH 8.0 and 70 &deg / C. Isolates were not significant cellulase producers. Four of the isolates did not produce any cellulase enzyme and the rest produced negligible amounts of cellulase. Therefore, xylanases from the isolates were promising for pulp and paper industry, which requires cellulase free and stable xylanases. All the isolates produced appreciable quantities of &amp / #945 / -amylase. Optimum temperatures and optimum pH values of &amp / #945 / -amylases 60-80 &deg / C and pH 7.0-8.0. &amp / #945 / -Amylases were quite stable up to pH 9.0 and 80 &deg / C. &amp / #945 / -Amylases from the isolates were promising for starch processing industry, which requires &amp / #945 / -amylases stable at high temperatures and for detergent industry, which requires &amp / #945 / -amylases stable at alkaline pH values. Considerable protease productions were achieved by all the isolates. TTG 2 was the best protease producer with 271 U/ml. Optimum temperatures and optimum pH values of proteases were 50-60 &deg / C and pH 7.0-7.4. Proteases were quite stable up to pH 9.0 and 80 &deg / C. Proteases from the isolates were promising for detergent and leather industry, in which proteases must be stable at alkaline pH values.