Amylase is part of an enzyme group that hydrolyzes starch, and many amylases are commercially used for starch hydrolysis in several industrial processes. For industrial applications of amylases, the reaction conditions for starch hydrolysis also differ depending on each industrial use. There are various microbial amylases that have been isolated and developed, which have suitable enzymatic properties for each application. Especially, some microbial amylases included in "extremozymes" have been widely applied to each industrial process. The purpose of this review is to summarize the classification of amylases and the diversity of microbial α-amylases and their current industrial applications, and we would like to indicate the direction of research in screening and applications for novel types of amylases included in "extremozymes".

Salinity and drought stress results in the production of ethylene. Rhizosphere bacterial activity suppresses the production of ethylene through the activity of 1-aminocycopropane-1-carboxylate (ACC) deaminase. In this study, a sampel of rhizosphere bacteria from coastal rice plant area was tested. The method used was acc deaminase activity test performed on Dworkin-Foster (DF) media and PCR acdS gene using specific primers of ACC and a quantitative analysis of the production of auxin (IAA). Of 47 isolates obtained, 8 were positively have acdS activity. The positive result was indicated by the presence of 1080 bp amplicon. Quantitative analysis showed the highest yield of 10.6 ppm of auxin. The results prove that there are some bacteria originated from coastal rice plant area which have acc deaminase activity.