Biogenesis and characterization of proficient silver nanoparticles employing marine procured fungi Hamigera pallida and assessment of their antioxidative, antimicrobial and anticancer potency.

OBJECTIVE: To assess the anticancer potential of biosynthesized silver nanoparticles using marine derived fungi Hamigera pallida with their antibacterial and antioxidant activities. RESULTS: The biosynthesis of silver nanoparticles (AgNPs) was assessed by the change in color from bright yellow to dark brown. UV-Visible spectroscopy revealed its stability at 429 nm; ATR-FTIR spectroscopy revealed the functional group responsible for its production; X-Ray Diffraction revealed its crystalline FCC structure resembling the peaks in the XRD pattern, corresponding to (110), (111), (200), and (311) planes; TEM imaging revealed its spherical morphology with an average particle size of 5.85 ± 0.84 nm ranging from 3.69 to 16.11 nm and Tauc's plot analysis revealed a band gap energy of 2.22 eV, revealing aptitude of AgNPs as a semiconductors. The subsequent characterization results revealed the effective synthesis of silver nanoparticles. The biosynthesized AgNPs were found to have significant antimicrobial effect against three Gram-positive and three Gram-negative bacteria. They also demonstrated higher antioxidative potential by demonstrating strong radical scavenging activity against DPPH (2, 2-diphenyl-1-picrylhydrazyl). AgNPs showed highest anticancer activity (62.69 ± 1.73%) against human breast cancer (MCF-7) cell line at 100 µg/mL with the IC50 value of 66.07 ± 2.17 µg/mL. CONCLUSIONS: This study revealed the prospect for further utilization of AgNPs by Cell free filtrate of Hamigera pallida as an antibacterial, antioxidative and anticancer agents.

Biogenic synthesis of silver nanoparticles mediated by the consortium comprising the marine fungal filtrates of Penicillium oxalicum and Fusarium hainanense along with their antimicrobial, antioxidant, larvicidal and anticancer potency.

AIM: To biosynthesize silver nanoparticles (AgNPs) using fungal isolates [DS-2 (Penicillium oxalicum) and DW-8 (Fusarium hainanense)] as well as their mixed cell-free filtrate (CFF) acting as a consortium (DSW-28) and their bio-potentials. METHODS AND RESULTS: The fungi (DS-2 and DW-8) were harvested and CFF was prepared. CFF of each fungus and their mixture were reacted with silver nitrate solution under dark conditions for the synthesis of AgNPs. The UV-Visible spectra determined the surface plasmon resonance at 438, 441 and 437 nm for the AgNPs synthesized by DS-2, DW-8 and DSW-28, respectively. The band gap energy was found between 2.21 and 2.24 eV which depicted their ability to act as a semiconductor. The TEM imaging revealed the spherical shape and small size of AgNPs. The XRD pattern exhibited the crystalline structure corresponding to their peaks. The FTIR spectra indicate the presence of different functional groups present on the surface of AgNPs. The broad-spectrum antimicrobial activity was exhibited by AgNPs. The AgNPs also act as an effective antioxidant by depicting their radical scavenging activity against DPPH. Moreover, the AgNPs also inhibited the growth of fourth instar larvae of Aedes aegypti and Culex quinquefasciatus more efficiently in a dose-dependent method. The biosynthesized AgNPs from DSW-28 showed a significant anticancer activity against MCF-7 cells. CONCLUSION: The silver nanoparticles synthesized by the CFF of two different fungi act synergistically in a consortium leading towards the production of silver nanoparticles with smaller size and higher bioactivity. SIGNIFICANCE AND IMPACT OF THE STUDY: The impressive bioactivity of the silver nanoparticles synthesized by the mixture of CFF of various fungi acting as a consortium recommends their prospective use in agriculture as well as in biomedical as an antimicrobial, antioxidant, larvicidal and anticancer agents in future.

Efficient biodegradation of Congo red dye using fungal consortium incorporated with Penicillium oxalicum and Aspergillus tubingensis.

A novel approach had been carried out to develop fungal consortium, namely, RH-2, containing two marine procured fungal isolates in order to evaluate biodegradation of recalcitrant diazo dye Congo red. The fungi were isolated from the seacoast of Diu, India. According to the ITS sequencing, the strains were identified as Penicillium oxalicum (DS-2) and Aspergillus tubingensis (DS-4). Discs of 12 mm were cut out from the edge of both the fungal isolates (DS-2 and DS-4) and inoculated in flasks consisting of potato dextrose broth with 100 mg/L Congo red for the development of fungal consortium RH-2. The degradation by the fungal consortium RH-2 was more effective than the fungal monocultures DS-2 and DS-4 with the respective degradation reaching 97.15 ± 0.15%, 68.96 ± 0.09%, and 29.96 ± 0.21% in addition of yeast extract (1% w/v) within 12 h. The influence of dextrose (1% w/v), yeast extract (1% w/v), pH 5, and salt concentration (1% w/v) enhanced the degradation potential of fungal consortium RH-2. The maximal degradation was correlated with the production of laccase (12.498 ± 0.21 U/mL) and manganese peroxidase (10.314 ± 0.25 U/mL). The catabolism of Congo red was confirmed by UV-Visible spectroscopic analysis (Congo red λ-max = 499 nm) and ATR-FTIR spectroscopic analysis. The filtrates obtained after Congo red degradation were also evaluated for microbial toxicity against bacteria (Bacillus haynesii) and phytotoxicity analysis on plant seed (Trigonella foenum) which revealed that the filtrate acquired after the treatment of Congo red by fungal consortium RH-2 was less toxic than the original dye in nature. A novel aspect is determined by the evidence of mutualistic interaction between two different fungi for the rapid decolorization and degradation of dye providing a prospective of utilizing the developed consortium RH-2 as a cost-effective approach in textile wastewater treatment for cleaner environment.

Biogenically proficient synthesis and characterization of silver nanoparticles employing marine procured fungi Aspergillus brunneoviolaceus along with their antibacterial and antioxidative potency.

OBJECTIVES: To assess the extracellular synthesis of silver nanoparticles using marine derived fungi Aspergillus brunneoviolaceus with their antibacterial and antioxidant activities. RESULTS: The biosynthesis of silver nanoparticles was estimated by the change in color from light yellow to dark brown within 36 h as the reaction progressed. UV-Visible spectroscopy exhibited its stability at 411 nm; ATR-FTIR spectroscopy depicted the functional group responsible for its production; X-Ray Diffraction denoted its crystalline FCC structure resembling the peaks in XRD pattern, corresponding to [111], [200], [220], [311] and [222] planes; TEM imaging revealed its spherical morphology with the particle size ranging from 0.72 to 15.21 nm and Tauc's plot analysis that disclosed its band gap energy as 2.44 eV that manifested the potential of AgNPs to be semiconductors. The characterization data henceforth, confirmed the efficient production of silver nanoparticles. The biosynthesized AgNPs expressed strong antibacterial activity against two Gram-positive and three Gram-negative bacteria. They also proved to possess higher antioxidative potentials by showing their potent radical scavenging activity against DPPH (2, 2-diphenyl-1-picrylhydrazyl). CONCLUSIONS: The study unfolds the prospect for further utilization of this mycogenically synthesized AgNPs as antibacterial, antioxidative and anticancer agents.