Metagenomic analysis of bacterial diversity in pigeon pea after soaking in water

Abstract

This study investigated the diversity of bacterial community in the samples of pigeon pea (Cajanus cajan L. Millsp.) soaked in water for 12 h and 24 h. The detection of certain bacterial species in the samples that can be isolated and potentially be used as starter cultures in the development of pigeon pea‐based functional foods is the importance of this study. For bacterial identification, the V1–V9 regions on the 16S ribosomal RNA gene were amplified using 27F and 1492R primers under specific polymerase chain reaction conditions. Genomic DNA (130 ng) was sequenced on the R9.4 flow cell by Oxford Nanopore Technologies using a GridION sequencer. Library preparations were conducted using a Native Barcoding Kit 24 V14 (SQK‐NBD114.24). Primary data were acquired using MinKNOW version 22.05.7. A total of 13 bacterial families and 89 genera were identified in the pigeon pea sample soaked for 12 h, and 26 families and 90 genera were identified in the pigeon pea soaked for 24 h. The values of five diversity indices showed that the sample soaked in water for 24 h had richer bacterial abundance and diversity than for 12 h. Shannon and Simpson values revealed the higher bacterial diversity in the samples collected at 24 h than in those collected at 12 h. Species observation and abundance‐based coverage estimators (ACE) values demonstrated that the samples collected at 24 h harbored higher bac‐ terial richness than those collected at 12 h. Bacterial communities during soaking of the pigeon pea were dominated by the family Enterobacteriaceae and genus Enterobacter. The presence of bacterial genera like Lacticaseibacillus, Lentilactobacillus, and Secundilactobacillus is interesting because of their importance as starter cultures for fermented plant‐based milk products

Keywords

• bacterial diversity
• lactic acid bacteria
• metagenomic analysis
• pigeon pea
• soaking time