Determination of some biotechnologically important enzymes in endophytic bacteria isolated from cereal plants

Endophyte bacteria are the microorganisms that live the whole or part of their life cycle in the tissues of healthy plants without causing any obvious signs of disease. Although there is a lot of research on the plant growth promoting properties of endophytic bacteria, studies about bioactive compounds such as extracellular enzymes of biotechnological importance are relatively limited and new. In this study, the ability of 128 endophyte bacterial isolates, which were previously isolated from healthy root, stem and leaf samples using a surface sterilization technique from some culture and wild grain plants (Poaceae family), were investigated in terms of producing protease, lipase, amylase, pectinase, xylanase, and cellulase enzymes. Of the 128 strains tested, 84 were found to produce protease, 41 to cellulase, 28 to produce pectinase, 95 to lipase, 10 to xylanase and 71 to produce lipase. It was determined that there are 1 isolates that produce 6 enzymes, 8 isolates for 5 enzymes, 16 isolates for 4 enzymes, 37 isolates for 3 enzymes, 41 isolates for 2 enzymes and 19 isolates for 1 enzyme. 8 isolates produced none of these enzymes. In addition, molecular identification of a certain number of isolates selected according to enzyme indexes was performed by 16S rRNA sequencing. As a result of the sequence analysis, 16S rRNA gene region sequences of 17 isolates yielded certain strains belonging to 2 Pseudomonas sp., 1 Micrococcus sp., 5 Paenibacillus sp., 1 Streptococcus sp., 2 Curtobacterium sp., 1 Chryseobacterium sp., and 4 Bacillus sp. genera. Also, an isolate coinciding with Streptococcus thermophilus with a similarity rate of 90.93% was evaluated as a potential new species.