Antifungal activity of zinc oxide nanoparticles (ZnO NPs) on phytopathogen isolated from tomato plant in Nepal.

Fungal diseases pose a major threat to global agriculture, leading to reduced crop yields, health issues and significant economic impact. Application of nanoparticles are being explored in agriculture because of its ecofriendly as well as enhanced antimicrobial properties. In this study, using an aqueous extract of air-dried tea leaves, zinc oxide nanoparticles (ZnO NPs) are synthesized and it was characterized using various techniques such as X-ray diffraction, UV-Vis, FTIR spectroscopy and microscopic analysis.

Scientific validation of medicinal plants used by Yakkha community of Chanuwa VDC, Dhankuta, Nepal.

Ethnobotanical knowledge is important among tribal people, but much of the information is empirical due to the lack of scientific validation. The purpose of this study was to document the medicinal plants used by an ethnic group (Yakkha) at Chanuwa VDC of Dhankuta district in Nepal and to validate scientifically in the use of plants based on results of phytochemical, antimicrobial and antioxidant property analyses and available literature reports. Data were collected through interviews of the Yakkha people with the help of a semi-structured questionnaire and the guided field walk method.

Functional characterization of kanB by complementing in engineered Streptomyces fradiae Deltaneo6::tsr.

A putative aminotransferase gene, kanB, lies in the biosynthetic gene cluster of Streptomyces kanamyceticus ATCC 12853 and has 66% identity with neo6 in neomycin biosynthesis. Streptomyces fradiae Deltaneo6::tsr was generated by disrupting neo6 in the neomycin producer Streptomyces fradiae. Neomycin production was completely abolished in the disruptant mutant but was restored through self-complementation of neo6.

Characterization of RbmD (glycosyltransferase in ribostamycin gene cluster) through neomycin production reconstituted from the engineered Streptomyces fradiae BS1.

Amino acid homology analysis predicted that rbmD, a putative glycosyltransferase from Streptomyces ribosidificus ATCC 21294, has the highest homology with neoD in neomycin biosynthesis. S. fradiae BS1, in which the production of neomycin was abolished, was generated by disruption of the neoD gene in the neomycin producer S.

Production of aminoglycosides in non-aminoglycoside producing Streptomyces lividans TK24.

The pRBM4 cosmid, which harbors a putative cluster of genes spanning a 31.8-kb chromosomal region of the ribostamycin producer Streptomyces ribosidificus ATCC 21294, was heterologously expressed in Streptomyces lividans TK24. ESI-MS/MS, HPLC, and LC-ESI MS analyses showed that the transformation gave rise to ribostamycin production in various culture broths.

The ribostamycin biosynthetic gene cluster in Streptomyces ribosidificus: comparison with butirosin biosynthesis.

A cluster of genes for ribostamycin (Rbm) biosynthesis was isolated from Streptomyces ribosidificus ATCC 21294. Sequencing of 31.892 kb of the genomic DNA of S.

Characterization of L-glutamine:2-deoxy-scyllo-inosose aminotransferase (tbmB) from Streptomyces tenebrarius.

2-Deoxystreptamine (DOS)-containing aminoglycoside-aminocyclitol (AmAc) antibiotics represent the majority of clinically important AmAcs. Biosynthetic investigations of formation of DOS in actinomycetes are limited to the characterization of 2-deoxy-scyllo-inosose synthase, the first step enzyme of the DOS biosynthetic pathway. A gene encoding L-glutamine:2-deoxy-scyllo-inosose aminotransferase (tbmB) from the tobramycin producer Streptomyces tenebrarius was expressed heterologously in Escherichia coli.

A gene cluster for biosynthesis of kanamycin from Streptomyces kanamyceticus: comparison with gentamicin biosynthetic gene cluster.

Gene clusters for the biosynthesis of kanamycin (Km) and gentamicin (Gm) were isolated from the genomic libraries of Streptomyces kanamyceticus and Micromonospora echinospora, respectively. The sequencing of the 47 kb-region of S. kanamyceticus genomic DNA revealed 40 putative open reading frames (ORFs) encoding Km biosynthetic proteins, regulatory proteins, and resistance and transport proteins.

An approach for cloning biosynthetic genes of 2-deoxystreptamine-containing aminocyclitol antibiotics: isolation of a biosynthetic gene cluster of tobramycin from Streptomyces tenebrarius.

Genes homologous to 2-deoxystreptamine (DOS) biosynthetic genes were isolated from aminoglycoside producers, Micromonospora and Streptomyces spp., using PCR primers based on the core sequences of 2-deoxy-scyllo-inosose (DOI) synthase and L-glutamine: scyllo-inosose aminotransferase (GIA). Identities of 40-45% were observed for DOI synthases, and 65-75% were observed for GIAs.