Antibiofilm potential of a tropical marineBacillus licheniformisisolate: role in disruption of aquaculture associated biofilms

Abstract

Microbial biofilms are important in aquaculture industries as they resist antibiotic treatments. In this study, we have investigated the antibiofilm potential of a tropical marine culture Bacillus licheniformis D1 (containing an antimicrobial protein BLDZ1) against two aquaculture associated pathogens namely, Vibrio harveyi and Pseudomonas aeruginosa. Both the test cultures formed biofilms on polystyrene and glass surfaces. The cell free supernatant (CFS) of B. licheniformis inhibited V. harveyi and P. aeruginosa biofilms on polystyrene surfaces up to around 80% and 78% respectively. In addition, the CFS disrupted pre‐formed biofilms of test cultures by about 73%. Fluorescence and scanning electron microscope analysis confirmed the antibiofilm potential of the CFS. The cell free supernatant displayed antiadhesive activity that inhibited the initial attachment of the bacteria during the process of biofilm formation. In addition, the CFS exhibited antimicrobial activity and mediated cell death via cytoplasmic membrane disruption.

Advanced strategies for combating bacterial biofilms

“…BSs' role as anti-adhesive agents against several pathogens, suitable anti-adhesive coating agents are suitable for medical insertional materials that can reduce a large number of hospital infections without (Hassan & Mohammad, 2015) Acinetobacter indicus NS NS Treatment of biofilms for seven days at 500 μg/ml resulted in up to 82.5% biofilm disruption (Karlapudi et al, 2018) B. subtilis Lipopeptide surfactin, iturin and fengycin Biofilm formation on uropathogenic bacteria reduced (Moryl, Spętana et al, 2015) Corynebacterium xerosis Lipopeptide Coryxin Disrupted preformed biofilms of E. coli (66%), S. mutans (80%), S. aureus (82.5%), and P. aeruginosa (30%). (Dalili, Amini et al, 2015) Fasciospongia cavernosa Lipopeptide NS 125 mg/ml of lipopeptide was effective in reducing the biofilm formation activity of pathogenic MDR S. aureus (Kiran, Priyadharsini et al, 2017) Bacillus licheniformis NS NS Inhibited P. aeruginosa and Vibrio harveyi biofilms on polystyrene surfaces up to around 78% and 80% respectively (Hamza, Kumar, & Zinjarde, 2016) S. lentus Glycolipid NS At a concentration of 20 μg was able to disrupt mature biofilms of V. harveyi (78.7 ± 1.93%) and P. aeruginosa (81.7 ± 0.59%; (Hamza, Satpute, Banpurkar, Kumar, & Zinjarde, 2017) Lactobacillus casei Glycolipid NS Potentially disrupted biofilm formation under dynamic conditions (Kiran, Sabarathnam, & Selvin, 2010) Lactobacillus jensenii and Lactobacillus gasseri NS NS Disrupted biofilms of E. coli, Enterobacter aerogenes and Staphylococcus saprophyticus (Morais, Cordeiro et al, 2017) Note. NS: not specified.…”

Cell-Free Supernatants (CFSs) from the Culture of Bacillus subtilis Inhibit Pseudomonas sp. Biofilm Formation

“…These outcomes are consistent with earlier studies on the inhibition of pathogen biofilms by CFS bacterial cultures. Around 80% of Vibrio harveyi and 78% of Pseudomonas aeruginosa's biofilm development was suppressed by Bacillus licheniformis [52]. Additionally, Bacillus subtilis KATMIRA1933 and Bacillus amyloliquefaciens B-1895 demonstrated antibacterial and anti-biofilm efficacy against Acinetobacter sp., both individually and in combination with polymyxin E [15].…”

Evaluation of the Marine Bacterial Population in the Great Bitter Lake, Egypt, as a Source of Antimicrobial Secondary Metabolites

“…In addition to the antimicrobial activity of marine B. licheniformis' metabolites, other activities such as antiviral and immuneregulatory activities have also been reported [50]. The antimicrobial protein BLDZ1 from marine B. licheniformis inhibits the biofilm formation of microbial pathogens such as P. aeurginosa [51]. The genome mining of a marine B. pumilus strain showed at least twelve BGCs, including PKS-I, PKS-II, and NRPS which indicates a high bioactivity potential [52].…”