Biosurfactant from a marine bacterium disrupts biofilms of pathogenic bacteria in a tropical aquaculture system

Abstract

Bacterial infections are major constraints in aquaculture farming. These pathogens often adapt to the biofilm mode of growth and resist antibiotic treatments. We have used a non-toxic glycolipid biosurfactant (BS-SLSZ2) derived from a marine epizootic bacterium Staphylococcus lentus to treat aquaculture associated infections in an eco-friendly manner. We found that BS-SLSZ2 contained threose, a four-carbon sugar as the glycone component, and hexadecanoic and octadecanoic acids as the aglycone components. The critical micelle concentration of the purified glycolipid was 18 mg mL-1. This biosurfactant displayed anti-adhesive activity and inhibited biofilm formation by preventing initial attachment of cells onto surfaces. The biosurfactant (at a concentration of 20 μg) was able to inhibit Vibrio harveyi and Pseudomonas aeruginosa biofilms by 80.33 ± 2.16 and 82 ± 2.03%, respectively. At this concentration, it was also able to disrupt mature biofilms of V. harveyi (78.7 ± 1.93%) and P. aeruginosa (81.7 ± 0.59%). The biosurfactant was non-toxic towards Artemia salina. In vivo challenge experiments showed that the glycolipid was effective in protecting A. salina nauplii against V. harveyi and P. aeruginosa infections. This study highlights the significance of marine natural products in providing alternative biofilm controlling agents and decreasing the usage of antibiotics in aquaculture settings.

Lactobacillus acidophilus Derived Biosurfactant as a Biofilm Inhibitor: A Promising Investigation Using Microfluidic Approach

“…Physical properties including SFT, IFT, CA, CMC, emulsification, stability at different pH, temperature and ionic character (IC) were explored for L. acidophilus NCIM 2903 derived CFBS. SFT, IFT, CMC measurements were carried out by pendant drop technique, while CA using sessile drop technique with the help of optical contact angle (OCA) Goniometer (DataPhysics, Stuttgart, Germany) [28]. In addition, IC and emulsification activity (%) was also determined.…”

Pseudomonas aeruginosa RTE4: A Tea Rhizobacterium With Potential for Plant Growth Promotion and Biosurfactant Production

“…Four different surfaces were used for determining the Contact Angle (CA) of purified BS viz. glass slide (highly hydrophilic), overhead projector (OHP) sheet (intermediate hydrophilic-hydrophobic), Teflon (polytetrafluoroethylene-PTFE) tape and parafilm (highly hydrophobic) and measured by sessile drop method ( Hamza et al, 2017 ). A 7 μl drop was placed on those different surfaces and CA was analyzed by Optical Contact Angle Goniometer (OCA 15+, DataPhysics Instruments, GmbH, Germany) using SCA 20 software.…”

“…Thus, from literature it appears that Pseudomonas strains are one of the promising microbial systems which can be exploited for production of surface active agents. Studies have been conducted on BS produced by marine bacteria (Dhasayan et al, 2015;Hamza et al, 2017;Tripathi et al, 2018), bacteria from oil contaminated soil (Ebadi et al, 2018;Soltanighias et al, 2019), heavy metal contaminated soil (Sheng et al, 2008), rhizospheric bacteria of black pepper (Tran et al, 2008) and from variety of crop plants (Goswami and Deka, 2019). After an in-depth literature survey, we came to a conclusion that there is no single report on BS producing-PGP tea rhizobacteria.…”

Marine-Derived Surface Active Agents: Health-Promoting Properties and Blue Biotechnology-Based Applications

“…Additionally, it managed to dislodge bacteria from pre-formed P. aeruginosa BHKH-19 and S. liquefaciens BHKH-23 single-strain biofilms [27]. Lastly, BS-SLSZ2 (a biosurfactant glycolipid isolated from the marine epizootic bacterium Staphylococcus lentum) prevented the adhesion of V. harveyi and P. aeruginosa (two common agricultural pathogens that infect Altemia salina), thereby limiting their ability to form biofilms, but without exerting biocidal and/or bacteriostatic activities [28].…”