Collision of millimetre droplets induces DNA and protein transfection into cells

Nonperturbing and simple transfection methods are important for modern techniques used in biotechnology. Recently, we reported that electrospraying can be applied to DNA transfection in cell lines, bacteria, and chicken embryos. However, the transfection efficiency was only about 2%. To improve the transfection rate, physical properties of the sprayed droplets were studied in different variations of the method. We describe a highly efficient technique (30–93%) for introduction of materials such as DNA and protein into living cells by electrospraying droplets of a high conductivity liquid onto cells incubated with the material for transfection. Electric conductivity has a sizable influence on the success of transfection. In contrast, molecular weight of the transfected material, types of ions in the electrospray solution, and the osmotic pressure do not influence transfection efficiency. The physical analysis revealed that collision of cells with millimetre-sized droplets activates intracellular uptake

Plant growth-promoting actinobacteria: a new strategy for enhancing sustainable production and protection of grain legumes

Grain legumes are a cost-effective alternative for the animal protein in improving the diets of the poor in South-East Asia and Africa. Legumes, through symbiotic nitrogen fixation, meet a major part of their own N demand and partially benefit the following crops of the system by enriching soil. In realization of this sustainability advantage and to promote pulse production, United Nations had declared 2016 as the “International Year of pulses”. Grain legumes are frequently subjected to both abiotic and biotic stresses resulting in severe yield losses. Global yields of legumes have been stagnant for the past five decades in spite of adopting various conventional and molecular breeding approaches. Furthermore, the increasing costs and negative effects of pesticides and fertilizers for crop production necessitate the use of biological options of crop production and protection. The use of plant growth-promoting (PGP) bacteria for improving soil and plant health has become one of the attractive strategies for developing sustainable agricultural systems due to their eco-friendliness, low production cost and minimizing consumption of non-renewable resources. This review emphasizes on how the PGP actinobacteria and their metabolites can be used effectively in enhancing the yield and controlling the pests and pathogens of grain legumes

The Family Frankiaceae

The family Frankiaceae, within the order Actinomycetales, contains bacteria isolated mainly from root nodules and occasionally from soil. Members of the genus Frankia have been found associated with the roots of 23 genera of dicots belonging to eight families. Historically, strains isolated in pure culture were grouped into two physiological categories, those that use carbohydrates and those that do not. Newer genomic information indicated that frankiae in general differ markedly in their complements of genes. Besides physiological grouping, these isolates were placed into four plant-compatibility groups (1-infective on Alnus and Myrica, 2-infective on Casuarina and Myrica, 3-infective on Elaeagnaceae and Myrica, 4-infective only on Elaeagnaceae). A 16S rRNA gene-based phylogenetic study, comprising non-isolated endophytes, yielded four clusters or clades, three of which are symbiotic (1-infective on Alnus and Casuarinaceae except Gymnostoma, 2-non-isolated strains in nodules of Rosaceae-Datisca-Coriaria-Rhamnaceae, 3-infective on Elaeagnaceae and Gymnostoma) and a fourth cluster that groups non-infective and non-effective strains. These groupings have been confirmed on the whole by analysis of other loci. DNA-DNA hybridization studies have yielded 12–15 genospecies, only one of which has been named, Frankia alni; one Candidatus Frankia datiscae was recently named to accommodate the genome of an endophyte in nodules of Datisca glomerata. The family Frankiaceae is close to Acidothermus, Cryptosporangium, Geodermatophilaceae (Geodermatophilus, Modestobacter, Blastococcus), Nakamurella, Sporichthya, and Fodinicola and was grouped into suborder Frankineae. A recent rearrangement has resulted in the elevation of suborder Frankineae to order Frankiales (Normand and Benson 2012b) containing families Acidothermaceae, Cryptosporangiaceae, Frankiaceae, Geodermatophilaceae, Nakamurellaceae, and Sporichthyaceae as well as the incertae sedis Fodinicola feengrottensis