Isolation of Filamentous Fungi from the Caatinga Region and Production of Amylolytic Enzymes of Great Industrial Interest

The industrial importance and the high cost of the commercial amylase require the study of microorganisms that produce these enzymes. For this reason, the objective of this work was to isolate filamentous fungi from a region of the caatinga and evaluate their potential for the production of amylase. Four soil samples were collected from a deactivated dump located in the city of Diamantina, MG, in a region of the caatinga. The analysis of amylolytic production in a submerged medium at the ideal temperature of each microorganism was performed using the saccharification method, and the reducing sugars formed were quantified by DNS. Fourteen filamentous fungi were isolated, which had different morphological aspects. Regarding amylase production, a mean activity of 0.477 U·mL-1 was obtained with the isolates I 1.2.1 and I 4.4.1. These results bring important information regarding the biodiversity of the caatinga, in addition to the isolation of microorganisms that can be used as biological machinery to obtain metabolites with high biotechnological and industrial potential.

novel amylolytic enzyme from Palaeococcus ferrophilus with malto-oligosaccharide forming ability belonging to subfamily GH13_20

By heterologous expression of a gene from Palaeococcus ferrophilus,a novel recombinant enzyme designated AMPf was obtained and proved to be an amylolytic enzyme with unique catalytic characteristics.The optimal temperature and pH of AMPf were 50℃ and 7.0 respectively.Although sequence analysis and acarbose hydrolysis ability indicated that AMPf belongs to the subfamily GH13_20,interestingly,this enzyme hardly acts on cyclodextrins and pullulan distinguishing it from most enzymes in this subfamily.AMPf hydrolyzes starches to glucose,maltose,maltotriose,and maltotetrose as main products.AMPf mainly liberates glucose from starch with the concentration of 1%(w/v),while it shows malto-oligosaccharide forming ability with higher starch concentration of 4%(w/v).Also,the 4,6-ethylidene-4-nitrophenyl-maltoheptaose hydrolysis ability further indicates the unique combination endo-acting and glucose releasing exo-acting activtity of AMPf.AMPf could utilize maltose and maltotriose to produce malto-oligosaccharides by transglycosylation activity.It was proven AMPf has application protential in malto-oligosaccharides production.