Advances in Pathway Engineering for Natural Product Biosynthesis

Biocatalysts provide an efficient, inexpensive and environmentally friendly alternative to traditional organic synthesis, especially for compounds with complex stereochemistries. The past decade has seen a significant rise in the use of biocatalysts for the synthesis of compounds in an industrial setting; however, the incorporation of single enzymatically catalysed steps into organic synthesis schemes can be problematic. The emerging field of synthetic biology has sparked interest in the development of whole-cell factories that can convert simple, common metabolites into complex, high-value molecules with a range of applications such as pharmaceuticals and biofuels. This Review summarises conventional methods and recent advances in metabolic engineering of pathways in microorganisms for the synthesis of natural products

Trueperella pyogenes and Escherichia coli as an etiological factor of endometritis in cows and the susceptibility of these bacteria to selected antibiotics

The aim of this study was to determine the percentage of participation of particular species of microorganisms, isolated from the uterus of cows with endometritis and from cows without inflammatory lesions of the uterus, in the same postpartum period. The aim of the study was also to examine how long after parturition non-treated endometritis persists. Moreover, antibiotic susceptibility tests were carried out of the bacterial isolates dominating in the uterus. Forty cows were included in the study: 20 cows with endometritis (experimental group) and 20 cows without any inflammatory condition of the uterus (control group). The material for cytological and bacteriological tests was collected on the 5th , 26th , 40th and 60th day after parturition, using an intrauterine brush adapted for cows. The total number of collected isolates was 149, including 120 isolates from the uterus of cows with endometritis and 29 isolates from the uterus of cows without endometritis. The following species of microorganisms were isolated from the material collected from cows with endometritis: T. pyogenes (49.2%), E.coli (22.5%), F. necrophorum (11.7%), Staphylococcus sp. (6.7%), B. melaninogenicus (5.8%), and Streptococcus sp. (4.1%). The participation percentage of particular species of bacteria in the material collected from the uterus of cows without endometritis was as follows: T. pyogenes (27.6%), E.coli (24.2%), Staphylococcus sp. (20.7%), Streptococcus sp. (20.7%), B. melaninogenicus (3.4%) and F. necrophorum (3.4%). The highest percentage of T. pyogenes isolates was susceptible to ceftiofur (89.6%); cefoperazone (85.1%) and amoxicillin combined with clavulanic acid (79.1%). E. coli isolates were most susceptible to amoxicillin combined with clavulanic acid (100%), cefoperazone (94.1%) and oxytetracycline (82.3%)