BIOSURFACTANT STABILIZED SILVER NANOPARTICLES ENHANCE BIOFILM DISSOLUTION

Abstract

Silver nanoparticles are chemically and physically unique as well as having a high surface volume ratio. This provides them with great antibacterial properties. However, pathogens can form biofilms, making metal nanoparticles ineffective. As a result, the disruption of biofilms by AgNPs with surface modification by a novel biosurfactant holds great promise as an antimicrobial therapy. This invention describes Nocardiopsis alba SM3, a new species of marine sponge with a biosurfactant production capacity. This biosurfactant can be effectively combined with silver nanoparticles to provide a powerful antimicrobial agent. The invention also describes ways of preparing culture media using rice straw as carbon source, obtaining surfactants, stabilizing AgNPs, and demonstrating superior antibiofilm activity. It is promising that this novel approach will lead to the -development of a new antimicrobial therapy that can be used to fight biofilm-related infections.

Specification

This invention involves producing natural biosurfactant that can be used to stabilize AgNPs
in antimicrobial therapy.
Biosurfactants produced by marine sponge actinomycete strains have low CMC values,
meaning they are effective even at relatively low concentrations. This property makes them
suitable for a wide range of applications, as they do not require high dosages to function
properly. The biosurfactants of marine sponge actinomycete are primarily composed of
natural compounds, making them biodegradable and environmentally friendly. Silver
nanoparticles exhibit remarkable resistance to pathogens. However, stabilization with
natural material prevents aggregation and exhibits potent antimicrobial properties. Natural
biosurfactants are excellent stabilizing agents for AgNPs in this context. In order to combat
the growing threat of antimicrobial resistance, the advancement in stabilizing AgNPs holds
great promise.
Some of the prior arts in this research are discussed as below.
Prior Art U.S. Pat. No. US20220372434Al reveals biosurfactant production using Bacillus
subtilis. Despite this, this strain cannot be easily manipulated in a laboratory to enhance
biosurfactant production. Higher biomass production and the availability of genetic
engineering approaches in actinomycete for higher production titers with low carbon source
material can contribute to environmental sustainability. In addition, the stabilization of
antibacterial agents using naturally derived surfactants will provide an advantage when it
comes to formulating nanomaterial drugs for the abating of antimicrobial resistance.
Prior Art EU. Pat. No. EP3502266Al reveals a bio-surfactant producing strain of Bacillus
subtilis using culture media containing red beans as a carbon source. When using
microorganisms, culture media should employ low cost materials to ensure environmental
sustain ability. The endosymbionts of new strain in this invention hold advantage producing
biosurfactants with distintict structure because of marine habitat. Due to serious public
health concerns about antimicrobial resistance, alternative drugs with higher stability are in
need. This invention provides a new source of renewable and sustainable biosurfactants
with antimicrobial activity. Furthermore, it is a promising alternative to conventional
antibiotics, as it is not associated with the risk of antimicrobial resistance .
Therefore, a better stabilizing agent for AgNPs is necessary to increase their antimicrobial
activity and prevent them from becoming drug resistant. The invention focuses on increased
production of biosurfactant derived from marine sponge actinomycetes and stabilizing the
AgNPs for enhanced antibiofilm disruption Silver nanoparticles have gained attention for their potential in disrupting biofilms. Biofilms
are complex microbial communities that adhere to surfaces and exhibit increased resistance to
antimicrobial agents. When silver nanoparticles come into contact with biofilms, they
penetrate through the biofilm matrix and disrupt the structural integrity of the microbial
community. One of the key mechanisms of silver nanoparticle biofilm disruption is the
inhibition of bacterial quorum sensing (QS) systems. Silver nanoparticles interfere with the
communication between bacteria, disrupting their collective action and inhibiting biofilm
formation. However the stability of AgNPs is concern.
Therefore, appropriate surface modification can make AgNPs more stable and exert potent
antibiofilm activity. Biosurfactants can interact with microbial proteins and can be
manipulated to modify enzyme conformation in a manner that alters enzyme activity, stability
and/or specificity. These unique properties of biosurfactants allow their use and possible
replacement of chemically synthesized surfactants in a great number of industrial operations.
Nanoparticles tend to aggregate or agglomerate due to various factors such as electrostatic
attractions, ·van der Waals forces, and steric repulsion. This aggregation can lead to a loss of
their desirable properties and reduced efficiency in applications. Therefore, stabilization is
necessary to prevent nanoparticle aggregation and maintain their properties. Biosurfactants
can play a significant role in stabilizing nanoparticles. They act as natural surfactants,
reducing the interfacial tension between nanoparticles and the surrounding medium. This
stabilization prevents nanoparticle aggregation and promotes their dispersion in the desired
formulation.
Biosurfactants have emerged as promising agents for stabilizing nanoparticles. Their natural
origin, biocompatibility, and tailored properties make them attractive candidates for various
nanoparticle applications. By reducing nanoparticle aggregation and enhancing dispersion,
biosurfactants· contribute to the stability and functionality of nanoparticles in various
industries. The present invention concerns the development of stable AgNPs using naturally
derived biosurfactants for improved antibiofilm activity. All technical and scientific terms used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which the invention pertains, unless defined
otherwise. The following definitions supplement those in the art and are directed to the
current application and are not to be imputed to any related or unrelated case, e.g., to any
commonly owned patent or application. Although any methods and materials similar or
equivalent to those described herein can be used in practice for testing, the preferred
materials and methods are described herein. Accordingly, the terminology used herein is for
the purpose of describing particular embodiments only, and is not intended to be limiting.
Biosurfactant produced by Nocardiopsis alba SM3 was thermostable and showed higher
stability at an alkaline pH 9.
The maximum amount of biosurfactant was found on day four of incubation. It reveals that
biosurfactant is secreted as a secondary metabolite during stationary phase of culture.
Zinc chloride was the strongest biosurfactant activator among the metals tested, whereas
magnesmm chloride, ferrous sulphate, magnesium sulphate and calcium chloride had the
least effect.
Phase-contrast microscopic observation of the cover slip assay revealed a disrupted biofilm.
With the addition of biosurfactant, silver nanoparticles can be stabilized. It yields colloidal
silver of a light yellowish - orange color. The reaction mixture undergoes black color
aggregations in four days when using the chemical reduction method. In biosurfactant-added
reaction mixtures, however, the stability was maintained for three months CLAIM 1: With its easy lab cultivation and genetic manipulation, the strain can be exploited
for enhanced production of natural biosurfactant derived from marine sponges.
CLAlM 2: Rice straw was used as a low-cost, environmentally friendly and sustainable
carbon source.
CLAIM 3: Metal nanoparticles can be stabilized using the isolated natural biosurfactant.
CLAIM 4: Stabilized nanoparticles exhibited enhanced antibiofilm properties.
CLAIM 5: A biosurfactant surface modified AgNP can be used to treat pathogens that are
multidrug resistant.

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