Dual Role of Acidic Diacetate Sophorolipid as Biostabilizer for ZnO Nanoparticle Synthesis and Biofunctionalizing Agent Against Salmonella enterica and Candida albicans

Abstract

In the present study, a yeast species isolated from CETP, Vellore, Tamilnadu was identified as Cryptococcus sp. VITGBN2 based on molecular techniques and was found to be a potent producer of acidic diacetate sophorolipid in mineral salt media containing vegetable oil as additional carbon source. The chemical structure of the purified biosurfactant was identified as acidic diacetate sophorolipid through GC-MS analysis. This sophorolipid was used as a stabilizer for synthesis of zinc oxide nanoparticles (ZON). The formation of biofunctionalized ZON was characterized using UV-visible spectroscopy, XRD, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy. The antimicrobial activities of naked ZON and sophorolipid functionalized ZON were tested based on the diameter of inhibition zone in agar well diffusion assay, microbial growth rate determination, protein leakage analysis, and lactate dehydrogenase assay. Bacterial pathogen Salmonella enterica and fungal pathogen Candida albicans showed more sensitivity to sophorolipid biofunctionalized ZON compared with naked ZON. Among the two pathogens, S. enterica showed higher sensitivity towards sophorolipid biofunctionalized ZON. SEM analysis showed that cell damage occurred through cell elongation in the case of S. enterica, whereas cell rupture was found to occur predominantly in the case of C. albicans. This is the first report on the dual role of yeastmediated sophorolipid used as a biostabilizer for ZON synthesis as well as a novel functionalizing agent showing antimicrobial property.

Screening Antimicrobial Activity of Nickel Nanoparticles Synthesized Using Ocimum sanctum Leaf Extract

“…Microbicidal activity of NiGs is also due to the electrostatic interaction between positively charged nickel ions and negatively charged microbial cell membranes. These observations are in concurrence with earlier antimicrobial study [16] of zinc oxide nanoparticles against S. enterica and C. albicans.…”

“…After incubation, the contents were centrifuged at 5000 rpm for 5 min and supernatant was collected. 200 L of supernatant from each sample was mixed with 800 L of Bradford reagent and incubated for 10 min in dark at 37 ∘ C. The optical density was determined at 595 nm with bovine serum albumin as standard [16].…”

Microbial biosurfactants: current trends and applications in agricultural and biomedical industries

“…Furthermore, Basak et al . () reported that SL‐capped ZnO nanoparticle‐mediated C. albicans cell death occurs via membrane bursting followed by oozing out of proteins and intracellular materials. In addition to functioning as a cyclic lipopetide, the biosurfactant, SUR, has been found to exhibit versatile bioactive features including adjuvant for immunization and antitumour properties.…”

“…Nanoparticle-based therapeutics have been considered as some of the most promising platforms in drug delivery applications due to their ability to increase drug accumulation in solid tumours by enhanced permeability and retention (EPR) and MDR reversal through bypassing or inhibiting P-gp activity (Bao et al 2016). Furthermore, Basak et al (2014) reported that SL-capped ZnO nanoparticle-mediated C. albicans cell death occurs via membrane bursting followed by oozing out of proteins and intracellular materials. In addition to functioning as a cyclic lipopetide, the biosurfactant, SUR, has been found to exhibit versatile bioactive features including adjuvant for immunization and antitumour properties.…”

Synthesis, characterization and concentration dependant antibacterial potentials of nickel oxide nanoparticles against Staphylococcus aureus and Escherichia coli

“…In the present study, the smaller size of NiO nanoparticles was thought to be responsible for better antibacterial actions than its bulk form, as smaller size usually enhancedby the dispersibility and penetration into the intracellular matrix and interference with intracellular Ca 2+ absorption leading to cell damage [22]. Attachment of the nickel ions released from the NiO nanoparticles to the cell membrane of the microbes initiate electrostatic interactions, wherein it interferes with cellular physiology leading to their disruption [34]. Further, these damaged cell membranes are more susceptible to further interactions, which lead to more penetration of NiO nanoparticles and leakage of the intracellular organelles [22].…”