Isolation, identification and characterization of Streptomyces metabolites as a potential bioherbicide.

Bioactive herbicidal compounds produced by soil microorganisms might be used to creating a bioherbicide for biological weed control. A total of 1,300 bacterial strains were isolated and screened for herbicidal activity against grass and broadleaf weeds. Among primarily selected 102 strains, the herbicidal activity of bacterial fermentation broths from the following three isolates strain-101, strain-128, and strain-329 reduced the growth of D. sanguinalis by 66.7%, 78.3%, and 100%, respectively as compared with control. Phylogenetic analysis of 16S rRNA gene sequencing determined that the strain-329 has 99% similarity to Streptomyces anulatus (HBUM 174206). The potential bioherbicidal efficacy of Streptomyces strain-329 was tested on grass and broadleaf weeds for phytotoxic activity through pre- and post-emergence applications. At pre-emergence application, the phytotoxic efficacy to D. sanguinalis and S. bicolor on seed germination were 90.4% and 81.3%, respectively at the 2x concentration, whereas in the case of Solanum nigrum, 85.2% phytotoxic efficacy was observed at the 4x concentration. The efficacy of Streptomyces strain-329 was substantially higher at post-emergence application, presenting 100% control of grass and broadleaf weeds at the 1x concentration. Two herbicidal compounds coded as 329-C1 and 329-C3 were extracted and purified by column chromatography and high-performance liquid chromatography methods. The active compound 329-C3 slightly increased leaf electrolytic leakage and MDA production as concentration-dependent manner. These results suggest that new Streptomyces sp. strain-329 produced bioherbicidal metabolites and may provide a new lead molecule for production an efficient bioherbicide to regulate grass and broadleaf weeds.

Butyrylcholinesterase K and apolipoprotein ε4 affect cortical thickness and neuropsychiatric symptoms in Alzheimer's disease.

Two major genotypes are known to affect the development and progression of Alzheimer's disease (AD) and its response to cholinesterase inhibitors: the apolipoprotein E (ApoE) and butyrylcholinesterase genes (BChE). This study analyzed the effects of the BChE and ApoE genotypes on the cortical thickness of patients with AD and examined how these genotypes affect the neuropsychiatric symptoms of AD. AD-drug-naïve patients who met the probable AD criteria proposed by the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association were recruited. Of 96 patients with AD, 65 were eligible for cortical thickness analysis. 3D T1-weighted images were acquired, and the cortical regions were segmented using the constrained Laplacian-based automated segmentation with proximities (CLASP) algorithm. Neuropsychiatric symptoms were measured by Neuropsychiatric Inventory (NPI) scores. BChE wild-type carriers (BChE-W) showed more thinning in the left dorsolateral prefrontal cortex, including the lateral premotor regions and anterior cingulate cortex, than did BChE-K variant carriers (BChE-K). ApoE-ε4 carriers had a thinner left medial prefrontal cortex, left superior frontal cortex, and left posterior cingulate cortex than did ApoE-ε4 non-carriers. Statistical analyses revealed that BChE-K carriers showed significantly less severe aberrant motor behavioral symptoms and that ε4 non-carriers showed less severe anxiety and indifference symptoms. The current findings show that, similar to ApoE-ε4 non-carriers, BChE-K carriers are protected from the pathological detriments of AD that affect frontal cortical thickness and neuropsychiatric symptoms. This study visually demonstrated the effects of the BChE-K and ApoE genotypes on the structural degeneration and complex aspects of the symptoms of AD.