A marine sponge associated strain of Bacillus subtilis and other marine bacteria can produce anticholinesterase compounds

Abstract

BackgroundAcetylcholinesterase (AChE) inhibitors or anticholinesterases reduce the activity of enzyme acetylcholinesterase that degrades the neurotransmitter acetylcholine in the brain. The inhibitors have a significant pharmacological role in neurodegenerative diseases like Alzheimer’s and Parkinson’s etc. Although plants have been a significant source of these compounds, there are very few sporadic reports of microorganisms producing such inhibitors. Anticholinesterase activity in bacterial associates of marine soft corals and sponges were not previously reported.ResultsWe screened 887 marine bacteria for the presence of acetylcholinesterase inhibitors, in a microplate based assay, and found that 140 (15.8%) of them inhibit the electric eel enzyme, acetylcholinesterase. Majority of the active isolates were bacterial associates of soft corals followed by sediment isolates while most of the potent inhibitors belonged to the bacterial associates of marine sponges. Maximum inhibition (54%) was exhibited by a bacterial strain M18SP4P (ii), isolated from the marine sponge Fasciospongia cavernosa. Based on phenotypic characterization and 16S rDNA sequencing, the strain was identified as Bacillus subtilis - revealing yet another activity in a strain of the model organism that is considered to be a cell factory. TLC bioautography of the methanol extract of this culture, showed the presence of two major components having this activity, when compared to Galanthamine, the positive control.ConclusionFrom the results of our study, we conclude that acetylcholinesterase inhibitors are quite prevalent in marine bacteria, particularly the bacterial associates of marine invertebrates. Several potential AChE inhibitors in marine bacteria are waiting to be discovered to provide easily manipulable natural sources for the mass production of these therapeutic compounds.

Production of Protease Showing Antibacterial Activity by Bacillus subtilis VCDA Associated with Tropical Marine Sponge Callyspongia diffusa

“…collected from Kanyakumari coast [17]. Two potential biosurfactants producing strains such as Bacillus subtilis and Bacillus amyloliquefaciens were reported as sponge associated bacteria from C. diffusa collected from Kanyakumari coast reported that B. subtilis associated with marine sponge can produce anticholinesterase compounds [18,19]. The Bacillus subtilis VCDA isolated from C. diffusa possessed inhibitory activity against E. coli (10 mm), S. aureus (16 mm), Proteus vulgaris (9 mm), Vibrio fluvialis (11 mm) which correlate with the reports of B. cereus SBSO 2 isolated from sponge Hyatella cribriformis that showed activity 12 mm for S. aureus, 11 mm for S. typhii, 7 mm against P. mirabilis and Vibrio cholerae (10 mm).…”

Natural Peptides in Drug Discovery Targeting Acetylcholinesterase

“…Based on its phenotypic properties and 16S rDNA sequencing, the strain was identified as Bacillus subtilis . This result showed that acetylcholinesterase inhibitors are quite common found in marine bacteria [ 102 ].…”

Research Advances and Detection Methodologies for Microbe-Derived Acetylcholinesterase Inhibitors: A Systemic Review

“…Additionally, from the metabolites of Actinobacillus N98-1021, Dong et al [ 56 ] isolated the compound N98-1021A, which exhibits the AchEI activity using the modified Ellman’s method and shows structural similarity to terferol. Moreover, Pandey et al [ 50 ] extracted a Bacillus subtilis strain-M18SP4P from Fasciospongia cavernosa and showed that this strain blocks 54% of acetylcholinesterase activity. Using galanthamine as a positive reference, TLC bioautography identified two components in the metabolites of M18SP4P with the AchEI activity.…”