Application of Biosynthesized Silver Nanoparticles Against a Cancer Promoter Cyanobacterium, Microcystis aeruginosa

Surface-enhanced Raman Scattering (SERS) fiber probe provides abundant interaction area between light and materials, permits detection within limited space and is especially useful for remote or in situ detection. A silver decorated SERS fiber optic probe was prepared by hydrothermal method. This method manages to accomplish the growth of silver nanoparticles and its adherence on fiber optic tip within one step, simplifying the synthetic procedure. The effects of reaction time on phase composition, surface plasmon resonance property and morphology were investigated by X-ray diffraction analysis (XRD), ultraviolet-visible absorption spectrum (UV-VIS absorption spectrum) and scanning electron microscope (SEM). The results showed that when reaction time is prolonged from 4–8 hours at 180 °C, crystals size and size distribution of silver nanoparticles increase. Furthermore, the morphology, crystal size and distribution density of silver nanoparticles evolve along with reaction time. A growth mechanism based on two factors, equilibrium between nucleation and growth, and the existence of PVP, is hypothesized. The SERS fiber probe can detect rhodamin 6G (R6G) at the concentration of 10−6 M. This SERS fiber probe exhibits promising potential in organic dye and pesticide residue detection.

Download Full-text

Assessment of the bactericidal effect of green synthesized silver nanoparticles against a panel of infectious microorganisms

Planta Medica ◽

10.1055/s-0036-1596752 ◽

2016 ◽

Vol 81 (S 01) ◽

pp. S1-S381

Author(s):

E Antunes ◽

M Mmola ◽

M Meyer ◽

DR Beukes

Keyword(s):

Silver Nanoparticles ◽

Bactericidal Effect ◽

Green Synthesized Silver Nanoparticles

Download Full-text

Influence of increased nutrient supply on Microcystis aeruginosa at cellular and proteomic levels

Aquatic Microbial Ecology ◽

10.3354/ame01939 ◽

2020 ◽

Vol 85 ◽

pp. 47-58

Author(s):

Y Jiang ◽

Y Liu

Keyword(s):

Microcystis Aeruginosa ◽

Regulatory Protein ◽

Acid Synthesis ◽

Nutrient Supply ◽

Nitrogen Supply ◽

Nitrogen And Phosphorus ◽

Comprehensive Description ◽

Amino Acid Synthesis ◽

High Nutrient ◽

Proteomic Responses

Various studies have observed that increased nutrient supply promotes the growth of bloom-forming cyanobacteria, but only a limited number of studies have investigated the influence of increased nutrient supply on bloom-forming cyanobacteria at the proteomic level. We investigated the cellular and proteomic responses of Microcystis aeruginosa to elevated nitrogen and phosphorus supply. Increased supply of both nutrients significantly promoted the growth of M. aeruginosa and the synthesis of chlorophyll a, protein, and microcystins. The release of microcystins and the synthesis of polysaccharides negatively correlated with the growth of M. aeruginosa under high nutrient levels. Overexpressed proteins related to photosynthesis, and amino acid synthesis, were responsible for the stimulatory effects of increased nutrient supply in M. aeruginosa. Increased nitrogen supply directly promoted cyanobacterial growth by inducing the overexpression of the cell division regulatory protein FtsZ. NtcA, that regulates gene transcription related to both nitrogen assimilation and microcystin synthesis, was overexpressed under the high nitrogen condition, which consequently induced overexpression of 2 microcystin synthetases (McyC and McyF) and promoted microcystin synthesis. Elevated nitrogen supply induced the overexpression of proteins involved in gas vesicle organization (GvpC and GvpW), which may increase the buoyancy of M. aeruginosa. Increased phosphorus level indirectly affected growth and the synthesis of cellular substances in M. aeruginosa through the mediation of differentially expressed proteins related to carbon and phosphorus metabolism. This study provides a comprehensive description of changes in the proteome of M. aeruginosa in response to an increased supply of 2 key nutrients.

Download Full-text