S2) may influence the packing of active-site residues, probably changing the orientation of the lysine residue (Lys 46) and hence modifying the substrate specificities. Based
on the in vitro characterization and in silico predictions concerning DacD function, it can be speculated that three homologous proteins – PBP5, PBP6 and DacD – possibly exert different or partially overlapping cellular activity at different time points of the growth phases. This work is supported in parts by two different grants from the DBT and CSIR, Govt. of India to A.S.G. A.K. is supported by a fellowship from UGC, Govt. of India. There is no conflict of interest to declare. selleck screening library C.C. and D.K. contributed equally to this work. “
“Streptomyces netropsis SD-07, the producer of novel polyene macrolide antifungal antibiotics, was isolated from soil. For the investigation of the functions of its biosynthesis genes and regulation mechanisms, a genetic operating system is necessary. In this study, we successfully transferred the plasmid DNA of pSET152 from the methylation deficient donor, Escherichia coli ET12567/pSET152/pUZ8002, to S. netropsis SD-07 by conjugation and evaluated the crucial factors TGF-beta inhibitor influencing the conjugation frequency. Ca2+ ions in presence the conjugation media may increase the conjugation frequency by 1000–10 000 times than Ca2+ ions absence in the same conjugation media, and 10–100 time higher than
Mg2+ ions. Similar results (increasing the conjugation frequency by 10–100 times when media containing 60 mM CaCl2) were also obtained from the conjugation between E. coli ET12567 and Streptomyces
coelicolor, S. lavendulae, S. venezuelae, despite their conjugation media were different (MS, CM, GS). So, CaCl2 concentration is a crucial factor for increasing the conjugation frequency, and the suitable concentration may probably be 60 mM. In addition, synthetic medium containing a small amount of organic nitrogen source may benefit increasing the conjugation frequency. These findings could be valuable for the development of a practical Chlormezanone method for achieving conjugation in other Streptomyces spp. “
“Biodegradation of polycyclic aromatic hydrocarbons (PAHs) in soils has been linked to history of exposure to PAHs and prevailing environmental conditions. This work assessed the capacity of indigenous microorganisms in soils collected in Livingstone Island (South Shetlands Islands, Antarctica) with no history of pollution (∑PAHs: 0.14–1.47 ng g−1 dw) to degrade 14C-phenanhthrene at 4, 12 and 22 °C. The study provides evidence of the presence of phenanthrene-degrading microorganisms in all studied soils. Generally, the percentage of 14C-phenanhthrene mineralized increased with increasing temperature. The highest extent of 14C-phenanhthrene mineralization (47.93%) was observed in the slurried system at 22 °C.