Extracellular Enzymatic Activities of Endophytic Bacteria Isolates Obtained from Dioclea reflexa Hook Seeds

Abstract

Seeds endophytes play crucial roles in enhancing plants’ health and productivity by conferring protection, improving fitness and  resilience, and enhancing nutrient uptake. These endophytes are also used for environmental management and production of bioactive compounds for various biomedical applications. In recent years, endophytes are of interest as potential sources of biocatalysts because  of their unique properties. In this study, endophytic microbes were isolated from the seeds of an underutilized tree climber, Dioclea reflexa Hook, the isolates were biochemically characterized using standard protocols and screened to produce some hydrolytic enzymes  of biotechnological importance. Seven distinct Isolates were biochemically characterized. High enzymatic activities were observed from amylolytic enzymes screened in this study. Cellulolytic activities or enzymes were undetected in the isolates at Day 0, which slightly  increased in some of the isolates at 24- and 48-hour fermentation period. The highest activities were observed from isolate DRFH102 as  4.64 U/ml at 24-hour for amylase, 0.45 U/ml at 48-hour for cellulase, 1.7 U/ml at 48-hour for Lipase, 2.82 U/ml at 48-hours for β-Amylase,  4.5 U/ml for 24-hours for protease, 3.6-3.8 U/ml between 0-48 hours at glucoamylase and 5.7 U/ml at 24-hour for β1, 3-glucanase. The  isolate (DRFHIS02) with the highest range of enzyme secretion was molecularly identified as Bacillus subtilis. This study reveals that  endophytic bacteria from Dioclea reflexa Hook seeds can be another alternative source of hydrolytic enzyme production for various  industrial and biotechnological applications. These enzymes can further be studied to understand their biochemical properties.