Genomic insight for algicidal activity in Rhizobium strain AQ_MP

Abstract

Occurrence of Harmful Algal Blooms (HABs) creates a threat to aquatic ecosystem affecting the existing ora and fauna. Hence, the mitigation of HABs through an eco-friendly approach remains a challenge for environmentalists. The present study provides the genomic insights of Rhizobium sp. (AQ_MP), an environmental isolate that showed the capability of degrading Microcystis aeruginosa (Cyanobacteria) at laboratory scale. Genome sequence analysis of Rhizobium sp. (AQ_MP) was performed to determine the algal lysis properties and toxin degradative pathway. It is envisaged that Rhizobium sp. (AQ_MP) secreted CAZymes like Glycosyltransferases (GT), Glycoside Hydrolases (GH), polysaccharide lyases (PL), which allowed algal polysaccharide degradation (lysis) and enabled nutrient release for the subsequent growth of Rhizobium sp. (AQ_MP) Genome analysis also showed the presence of the glutathione metabolic pathway, which is the biological detoxi cation pathway responsible for microcystin degradation. The conserved region mlrC, a microcystin toxin degrading responsible gene, was also annotated in Rhizobium sp. (AQ_MP). This study con rmed that Rhizobium sp. (AQ_MP) harbours a wide range of crucial enzymes released for lysis of Microcystis aeruginosa (M. aeruginosa) cells and also for degradation of microcystin toxin. This study thus nd promiscuity for scaling the lab based analysis to eld level in future.

Algicidal Bacteria: A Review of Current Knowledge and Applications to Control Harmful Algal Blooms

“…Algicidal compounds that have been fully characterized reveal a high diversity in both their structural characteristics and mechanisms of action (see review by Meyer et al, 2017 ). Identifying the genetic components responsible for algicidal activity among bacteria provides clues to the identity of potential algicidal compounds (e.g., Hotter et al, 2021 ; Hu et al, 2021 ; Li et al, 2021d ; Pal et al, 2021 ). This is exemplified by the genomic analysis of algicidal bacterium Brevibacillus laterosporus Bl-zj, which included a number of genes putatively involved in algicidal activity, including virulence factors, proteases and antibiotic resistance genes ( Zhang et al, 2021a ).…”

“…This may be a more critical factor for freshwater cyanobacteria, as the release of cyanotoxins may impact drinking water supplies. A few bacteria have been described with both algal-lytic activity against cyanobacteria, and the potential to also degrade microcystins (e.g., Li et al, 2021a ; Pal et al, 2021 ). Genome analysis of algicidal Rhizobium against M. aeruginosa , for example, revealed the genetic capacity for algal cell wall polysaccharide degradation responsible for algal-lytic properties, along with metabolic pathways for microcystin detoxification ( Pal et al, 2021 ).…”

Genomic Insights into Paucibacter aquatile DH15, a Cyanobactericidal Bacterium, and Comparative Genomics of the Genus Paucibacter

“…Although the mechanism may be even more intricate than previously thought, analyzing the genome of cyanobactericidal bacteria can provide valuable insights into their mechanisms of action against cyanobacteria. However, few studies have investigated the genomic features of cyanobactericidal bacteria [ 18 ].…”

The LuxS/AI-2 Quorum-Sensing System Regulates the Algicidal Activity of Shewanella xiamenensis Lzh-2

“…Algicidal bacteria that decrease the growth of cyanobacteria by producing algicides is a potential option (Yang et al, 2020). To date, many species with algicidal activity have been reported, such as Rhizobium strain AQ_MP (Pal et al, 2021), Shigella sp. H3, Alcaligenes sp.…”