Morphological and molecular characterization of Spirogyra species from water bodies in Chiang Rai Province, Thailand: insights into bioactivity and antioxidant potential

Abstract

This study aimed to identify Spirogyra species collected from lentic (sampling site code CR01) and lotic (sampling site code CR02) water areas in Chiang Rai Province, Thailand. The diagnosis was proceeded by studying the morphological characteristics combined with molecular techniques with the chloroplast rbcL gene (ribulose bisphosphate carboxylase). Additionally, the bioactive properties of Spirogyra extracts were evaluated through antimicrobial and antioxidant assays. The extraction was performed with water and ethanol extraction. The results indicated that the morphological characteristics of Spirogyra CR01 resembled Spirogyra neglecta, but the data of rbcL gene for this species were not available in the database. Therefore, the Spirogyra CR01 sequence was added to the GenBank database, representing the report of rbcL gene of Spirogyra neglecta sequencing data. Spirogyra CR02 was robustly identified as S. fluviatilis through molecular analysis. The extracts from both Spirogyra samples showed that the ethanolic extract has more activity than the water extract. The antimicrobial ability of the ethanolic extract from Spirogyra CR02 was observed to inhibit the growth of Bacillus cereus and Staphylococcus aureus, while the ethanolic extract from Spirogyra CR01 only inhibited B. cereus. Moreover, the ethanolic extract of Spirogyra CR01 had statistically significant (p<0.05) antioxidant activity, with the highest value recorded at 114.92±2.38 mg GAE/g extract. Overall, this study provides new sequencing information on the S. neglecta and their potential for use Spirogyra in functional food, functional ingredients and cosmeceutical products.