Characterization of a Recently Purified Thermophilic DNase from a Novel Thermophilic Fungus

Abstract

A newly isolated thermophilic fungus was found to produce a partially inducible extracellular DNase. This manuscript focuses on the characterization of this novel thermophilic DNase in terms of optimal enzyme conditions, molecular weight, and certain kinetic properties. The DNase was found to be inactivated by the presence of EDTA demonstrating its dependence on metal cofactors for activity. Maximum activity occurred at pH 6.0 with no activity at pH 2.0 or 10.0. The optimal temperature for the purified DNase was 65 °C. The thermophilic DNase was found to be an exonuclease with an estimated molecular weight of 56 kDa.

E. coli can eat DNA as excellent nitrogen source to grow quickly

“…(E) Expression of comE and hofQ genes after 24 h of culture of in various media. 16S rRNA was used for normalization of gene expression; the relative level was determined using the 2 −ΔΔCt method (Landry et al , 2014).…”

“…(A) Gene expression of deoxyribonuclease EndA of E. coli in the presence or absence of DNA in the medium (G + N − ). 16S rRNA was used for normalization, and the relative level was determined using the 2 −ΔΔCt method (Landry et al , 2014). (B) The digestion of DNA (0.8 g/L) by DNase (0.01 ng/L) at 37°C for various time.…”

“…RT-qPCR was performed on a Piko real 96 Real-time PCR System (Thermo Scientific, USA). 16S rRNA was used for normalization of mRNA expression, the relative level of each mRNA was determined using the 2 −ΔΔCt method (Landry et al , 2014). The PCR conditions were comprised of pre-denaturation at 95°C for 10 min, 40 cycles of denaturation at 95°C for 15 s, annealing at 60°C for 30 s and extension at 72°C for 30 s. All RT-qPCR experiments were conducted with 3 duplicate wells, and each gene experiment was repeated 3 times.…”

“…(E) Expression of comE and hofQ genes after 24 h of culture of in various media. 16S rRNA was used for normalization of gene expression; the relative level was determined using the 2 −ΔΔCt method(Landry et al, 2014).Fig3Ashows the result of electrophoresis analysis of DNA in the culture media (G + N -, glucose as C source and DNA as N source) after removing E. coli cultured for a certain time. It can be seen that the amount of DNA (100-250 bp) decreased to some extent during culture, but the DNA length did not change.…”

Biofilms—Impacts on Human Health and Its Relevance to Space Travel

“…At a macro perspective, biofilm structures are comprised of various organic materials that, in theory, can be susceptible to some form of enzymatic degradation. Enzymes isolated from ubiquitous organisms to novel extremophiles possess properties that may make them effective against biofilms [ 111 , 112 ]. Many researchers have looked to enzymes for the removal of clinically relevant biofilms.…”