Identification of culture-dependent microbes from mangroves reveals dominance of Bacillus including medically important species based on DNA signature

Abstract

Abstract. Dechavez R, Calub ML, Genobata DR, Balacuit R, Jose R, Tabugo SR. 2022. Identification of culture-dependent microbes from mangroves reveals dominance of Bacillus including medically important species based on DNA signature. Biodiversitas 23: 5342-5350. Mangroves are among the most crucial plant hosts in the marine environment because of their notable role in the ecosystem and their benefits. Identification of plant-associated and culture-dependent microbes is key to having a rich reservoir of bioactive substances. DNA barcoding was done based on 16S rRNA gene and ITS region. In this study, seven (7) mangrove species were identified as hosts. Results show that most bacterial isolates from plant leaves were gram-positive bacteria belonging to phylum: Firmicutes and genus Bacillus. Phylogenetic inference reveals a diverse non-monophyletic group with medically and economically necessary species. Among the host plants, Sonneratia alba harbored the most species of bacteria and fungi. These include two medically important strains of B. cereus and B. thuringiensis and host-specific bacteria like B. altitudinis in S. alba, B. velezensis in Rhizophora apiculata, B. clausii in Avicennia marina and B. firmus in A. marina were revealed. Meanwhile, some bacteria like B. subtilis and B. megaterium were found in three host species and B. cereus was the most abundant being recorded in four host plants. Diverse strains of fungi, Aspergillus sp., A. nomiae, A. tubingensis and A. niger were also present. This study served as baseline data for future research on diversity and host ecology for possible drug discovery.

Uncovering the secret weapons of an invasive plant: The endophytic microbes of Anthemis cotula

“…Proteobacteria was the second most abundant phylum, primarily represented by the class Gamma-proteobacteria. This finding is consistent with some previous studies [ [46] , [47] , [48] ] but differs from others that reported Proteobacteria as the dominant phylum in leaf endophytic bacteria [ 49 , 50 ]. Among the fungal isolates, the majority belonged to the phylum Ascomycota (90%), with classes Sordariomycetes (35%) and Dothideomycetes (30%) being the most represented.…”

High-throughput analysis using 16S rRNA sequencing of bacterial communities associated in selected mangrove species from Bayug Island, Iligan City, Philippines

“…When assessing the alpha diversity of the bacterial community using the Shannon index, it was observed that S. alba displayed the highest diversity, with a value of 2.75 among all the mangrove species examined (Figure 3). Results were consistent with previous studies where S. alba consistently exhibits the highest diversity in microbial communities (Muwawa et al 2021;Dechavez et al 2022). The genus Sonneratia is often found in river estuaries and can thrive in environments characterized by high environmental stress and poor conditions ).…”

“…These processes encompass methanogenesis, phosphate solubilization, sulfate reduction, and the synthesis of various compounds like antibiotics and enzymes (Wu and Lu 2015). Notably, genera like Serratia and Stenotrophomonas have been found to participate in the nitrogen cycle and carbon dioxide fixation (Dechavez et al 2022;Meng et al 2022). These nitrogen-fixing bacteria inhabit the rhizosphere and decompose leaves, pneumatophores, and mangrove sediments (Zhang et al 2017a), where the denitrification process occurs, converting nitrates into nitrogen.…”

Antibacterial test of Rhizophora apiculata extract originated from Mangrove Wonorejo Surabaya against Staphylococcus aureus and Escherichia coli

“…Mangrove habitat is a productive source of endophytic microorganisms. Mangroves' roots and leaves serve as a habitat for many bacteria, fungi, and algae [2]. The benefits of mangroves for human life are to cure muscle pain, back pain, rheumatic malaria, wounds, tuberculosis and spermicides and benefits for the environment [3].…”