Original Research Article (Experimental): Targeting fungal menace through copper nanoparticles and Tamrajal

WHO reports, an escalation of antibiotic resistance in opportunistic pathogens like Candida. Tamrajal, i.e., water stored in copper vessels has been proclaimed as health elixir by ancient Ayurveda. Vis-a-Vis the use of copper contact surfaces and nanoparticles has gained significance for their antimicrobial effects. It thus seems imperative to examine copper nanoparticles and tamrajal as promising alternatives to existing antifungals.ObjectiveThis study not only assessed the influence of Tamrajal and copper nanoparticles on the morphological alterations of the Candida and its biofilm forming ability, but also on their ability to destroy preformed biofilms.Materials and methodsCopper oxide nanoparticles as well as Tamrajal were evaluated as complementary as well as stand-alone antimicrobial agents. ‘Time kill assay’ and ‘germ tube inhibition test’ were performed as end-point analysis for pathogenesis, while biofilm quantification, performed to assess the colonizing capability of Candida. Scanning Electron Microscope was used for visualizing the cells, whilst ICP-AES to determine the copper concentration.Results92–100% cytotoxicity to the fluconazole resistant Candida species was observed with copper oxide nanoparticles as well as tamrajal during 24hr time kill assay. The study also confirmed complete germ tube inhibition by copper in both its forms in addition to the reduction in the biofilm production.ConclusionCompared to the classes of antifungals like azoles, echinocandins etc, copper based anti-candidal agents highlight a potential way to combat resistant candidiasis. The possibility of accumulation of NP resulting in cytotoxicity puts tamrajal as the choice due to its efficacy as well as non-toxicity as per the EPA.

Study of the changes in the growth, protein, and bioactive profile of Chlorella emersonii KJ725233 in response to sodium and ammonium nitrate

India. The alterations in its chlorophyll, protein, and antioxidant content in response to cationic stress were studied.Chlorella emersonii KJ725233 (CEK) was subjected to NaNO3 and NH4 (NO3)2 at concentrations equivalent to0.9 g/l (1×) and 1.8 g/l (2×) in the cultivation media. Qualitative alterations in the bioactives of the microalgawere identified by gas chromatography–high-resolution mass spectrometry (GC-HRMS), while the protein,chlorophyll, and antioxidant manipulations were spectrophotometrically quantified. Doubling of the proteincontent was observed when CEK was grown in 1× NH4+, whereas in 2× NH4+, chlorosis was significant. 2× NH4+also induced oxidative stress on CEK as evident from the 85.72% ± 6.72%, 197.47% ± 7.01%, 22.24% ± 1.78%,and 187.37% ± 1.88% increase in antioxidant potential, ferric reducing capacity, radical scavenging potential, andtotal phenolic content, respectively, as compsared to CEK grown in 1× Na+. These alterations as indicated fromthe GC-HRMS data correlate to the bioactive inductions/variations of/in Vitamin E, phytol, and its isomer in CEKgrown in 2× NH4+. The study thus indicates that manipulations of nitrate salts in the media significantly induce, aswell as alter the concentrations of commercially significant compounds like Vitamin E, phytol, etc.

Studies on degradation efficiency of polycaprolactone by a naturally-occurring bacterium.

We report a strain of Bacillus, isolated from the rhizosphere of the mangrove Sesuvium portulacastrum, that degrades polycaprolactone (PCL) on timescales that are a factor of three shorter than hitherto reported, with complete degradation in only 20 days. The bacterium has been identified as Bacillus pumilus by means of 16S rRNA gene sequencing and FAME analysis; it secretes proteases and lipases and its ‘de-polymerase’ activity is evident by the zone of clearing in emulsified PCL. It is an aerobic chemoheterotroph capable of utilizing a variety of carbohydrates. Although not a true psychrophile, is a mesophile, growing optimally over a temperature range 30-45° C and pH range 5-12.5. It is a halophile tolerating NaCl concentrations up to 10% w/v, and is unique in degrading and utilizing PCL and its monomer, e-caprolactone (CL), as a sole carbon source. Degradation of PCL was monitored using Fourier Transform Infrared (FTIR) spectroscopy, light microscopy and scanning electron microscopy (SEM). This degradation was found to be enhanced by salts (NaCl, KCl, MgSO4, Na2HPO4) and at medium pH values in excess of 7. Under the same growth conditions, another standard Bacillus pumilus strain showed somewhat reduced PCL-degradation.