Effects of Ascophyllum marine plant extract powder (AMPEP) on tissue growth, proximate, phenolic contents, and free radical scavenging activities in endemic red seaweed Gracilaria corticata var. cylindrica from India

Abstract

The red algal genus Gracilaria has considerable economic importance due to its agar content and rapid growth. This study was conducted on endemic Gracilaria corticata var. cylindrica to optimize different concentrations of AMPEP (0.01, 0.1, and 1.0 g L−1) and exposure time (15, 30, and 60 min) as a plant growth stimulant. Effect of 0.1 g L−1 and 30 min was found to be maximum in enhancing the daily growth rate and branch induction. The highest daily growth rate and number of branches were 7.62 ± 0.4% day−1 and 40.33 ± 8.6%, respectively. After 7 weeks, the plants were harvested and tested for carbohydrate, protein, lipid, and total phenolic content and free radical scavenging activity. Treatment with concentration of 0.1 g L−1 and exposure time 30 min showed the highest total carbohydrate (7.78 ± 0.08%), lipid (0.83 ± 0.11%), and total phenolic content (0.38 ± 0.01%) while treatment with 1 g L−1 and 60 min exposure time showed highest protein content (0.53 ± 0.01%). The antioxidant activity response was also observed and it showed less scavenging activity compare with the control. Application of AMPEP can have capacity for producing large numbers of plantlets within 4–5 weeks, making it highly attractive for implementation in sustainable seaweed farming. The present study also confirmed the commercial utility of indigenous resource G. corticata var. cylindrica for farming and catering domestic agar demand.