Isolation of Potential Root Bacterial Endophytes from Abaca (Musa textilis Nee) var. Inosa and Surface Sterilization of Abaca Explants with Varying Time Exposure

Surface sterilization eliminates external contaminants from biological samples, such as plant tissues. Optimal sterilization protocols must balance the effective elimination of contaminants without compromising the viability or integrity of the sample for plant tissue-culture applications such as callus induction. This study aimed to determine the optimum exposure time with varying durations of 5, 15, and 25 minutes for surface sterilization of Abaca explants using 100% commercial bleach solution. The results revealed that longer exposure time (25 minutes) to 100% commercial bleach solution resulted in no occurrence of contamination. This finding emphasize the importance of optimizing exposure time in surface sterilization, to support their potential applications in agriculture for promoting plant growth and reducing stress in plant tissue culture systems. Additionally, bacterial root endophytes reside within the root tissues of plants known to be essential for helping plants grow and tolerate stress. This study further aimed to isolate and characterize putative root bacterial endophytes from Abaca var. Inosa collected from Philippine Fiber Industry Development Authority (PhilFIDA) in Polomolok, South Cotabato. Five (5) putative bacterial endophytes were successfully isolated and identified using Vitek-2 Compact system: Staphylococcus aureus, Staphylococcus haemolyticus, Staphylococcus pseudintermedius, Sphingomonas paucimobilis, and Serratia marcescens. The successful isolation of putative root bacterial endophytes expands our understanding of the plant's microbiome and its potential contributions to plant growth and stress tolerance. Overall, these results provide valuable insights for developing improved surface sterilization protocols of Abaca explants and enhancing plant productivity and resilience in agricultural settings through the use of bacterial endophytes with plant-growth promoting potentials.