Isolation, diversity, and biotechnological potential of rhizo- and endophytic bacteria associated with mangrove plants from Saudi Arabia

Abstract

ABSTRACT. Marine bacteria have been exceptional sources of halotolerant enzymes since decades. The aim of the present study was to isolate bacteria producing hydrolytic enzymes from seven different mangroves collected from the coastal area of Thuwal, Jeddah, Saudi Arabia, and to further screen them for other enzymatic and antifungal activities. We have isolated 46 different rhizo-and endophytic bacteria from the soil, roots, and leaves of the mangroves using different enzymatic media. These bacterial strains were capable of producing industrially important enzymes (cellulase, protease, lipase, and amylase). The bacteria were screened further for antagonistic activity against fungal pathogens. Finally, these bacterial strains were identified on the basis of the16S rDNA sequence. Taxonomic and phylogenetic analysis revealed 95.9-100% sequence identity to type strains of related species. The dominant phylum was Gammaproteobacteria (γ-Proteobacteria), which comprised 10 different genera -Erwinia, Vibrio, Psychrobacter, Aidingimonas, Marinobacter, Chromohalobacter, Halomonas, Microbulbifer, and Alteromonas. Firmicutes was the second dominant phylum, which contained only the genus Bacillus. Similarly, only Isoptericola belonged to Actinobacteria. Further these enzymeproducing bacteria were tested for the production of other enzymes. Most of the active strains showed cellulytic and lipolytic activities. Several were also active against fungal pathogens. Our results demonstrated that the mangroves represent an important source of potentially active bacteria producing enzymes and antifungal metabolites (bioactive products). These bacteria are a source of novel halophilic enzymes and antibiotics that can find industrial and medicinal use.

Enzymatic Activity of Endophytic Bacterial Isolates from Selected Mangrove Plants in Kenya

“…The study also revealed that members of Bacillus species were the most dominant in both the leaves and roots. This is in line with previous studies conducted on endophytes in mangrove plants found in Saudi Arabia that revealed the most dominant species being Bacillus [13]. Bacillus and related species have also shown presence of proteases, pectinases and cellulases in endophytic bacteria of Paenibacillus polymyxa [22].…”

“…Freshly prepared isolates were inoculated by streaking using a sterile wire loop and incubated at 30ºC for 18-24 hours to allow bacterial growth. The hydrolytic activity of the isolate was then confirmed by addition of iodine according to the method described by Bibi et al [13]. A clear zone around the colonies confirmed the presence of amylases.…”

Research Article Isolation, diversity, and biotechnological potential of maize (<i>Zea</i> <i>mays</i>) grains bacteria

“…With respect to the genera Burkholderia, Staphylococcus, and Ochrobactrum, the proteases of the species Burkholderia pseudomallei, Staphylococcus aureus, Staphylococcus epidermidis, and Ochrobactrum anthropi were also characterized (Bompard-Gilles et al, 2000;Shaw et al, 2004;Chin et al, 2007;Martínez-García et al, 2018). Despite the production of proteases by the genera Isoptericola, Massilia, and Sphingomonas being also described in the literature (Lindquist et al, 2003;Willsey & Wargo, 2015, Bibi et al, 2017, none has been studied so far, and this is the first report about the species Staphylococcus hominis and Massilia timonae as protease producers (Table 1).…”

“…has been described in rice roots (Hernández et al, 2015) as well as the occurrence of Isoptericola sp. in the rhizosphere of cucumber and mangrove plants (Kämpfer et al, 2016;Bibi et al, 2017). As our maize samples were in soil contact when collected, it may have been contaminated by these soil-related bacteria.…”

Invited Review: Biodiversity of Plant Polysaccharide-Degrading Bacteria in Mangrove Ecosystem

“…In two mangrove systems in Bertioga and Cananéia, Brazil, 25 isolates showed endo-1,4-D-glucanase activity, and 12 out of the isolates belong to the genus Bacillus (Castro et al 2014). On the other hand, Bibi and co-researchers reported that several bacterial strains belonging to genera, Aidingimonas, Altermonas, Bacillus, Chromohalobacter, Erwinia, Halomonas, Marinobacter, Microbulbifer and Vibrio were isolated as cellulose-degrading bacteria from six different plant specimens collected from coastal area of Thuwal, Jeddah, Saudi Arabia (Bibi et al 2017). A novel Vibrio species, Vibrio xiamenensis, was isolated from mangrove soil in Xiamen, Fujian, China and was identified as a cellulase producing bacterium (Gao et al 2012).…”