Eco-friendly bio-larvicidal and antimicrobial activity of isolated bioactive compound from Kurthia gibsonii (Bacillales).

The targeted organisms include mosquito vectors, bacterial pathogens and non-targeted organisms. Preliminary mosquito larvicidal activity was conducted using cell-free supernatants (CFSs) from 11 gut bacteria. Among them, the bacterium SS11 exhibited promising results and was identified as Kurthia gibsonii based on its 16S rRNA sequence (1350 bp). The diethyl ether extract (DEE) of K. gibsonii demonstrated significant larvicidal effects, with LC50 values of 5.59 µL/mL and 8.59 µL/mL for 3rd instar larvae of Aedes aegypti and 2nd instar larvae of Anopheles stephensi, respectively. Analysis of the DEE using FT-IR, and GC-MS revealed the presence of 16 functional groups, and 7 bioactive compounds, respectively. A molecular docking study identified GC-MS compounds against odorant receptors from A. aegypti and odorant-binding proteins from A. stephensi was performed to assess the interaction and binding affinity. Overall, these findings suggest that the bioactive compounds 2, 4, 6-tribromoaniline from the DEE of K. gibsonii hold potential as an environmentally compatible alternative for biocontrol purposes, and compounds 9-tricosene and didecyl phthalate can be used for mosquito traps.

Anti-Müllerian hormone as an endocrine biomarker of reproductive longevity and assessment of single nucleotide polymorphisms in AMH gene of Bos indicus breeds of cattle.

Anti-Müllerian hormone (AMH) is a member of the TGF-ß superfamily produced by follicular granulosa cells in women and cattle and is considered an endocrine biomarker of ovarian follicular reserve. The study examined how age and parity influence serum AMH concentration and investigated the presence of single nucleotide polymorphisms in AMH gene in Bos indicus breeds viz Malnad Gidda Amritmahal and Hallikar. All five exons of AMH gene amplified by polymerase chain reaction were subjected to sanger sequencing and identified important SNP and its effects. We observed a highly significant relationship between parity and AMH concentration in Amritmahal cattle, whereas Malnad Gidda and Hallikar breeds did not show a significant difference. We identified one SNP located in exon 5 (rs21402788) with base change A>G, a non-synonymous mutation resulting in a change in amino acid Q>R and the protein product. It is concluded that AMH level could be considered as an indicator of the ovarian reserve and productive herd life (longevity) irrespective of age/parity, especially in B. indicus breeds of cattle.

Molecular characterization and antioxidant assay of pigment producing bacteria, Sphingomonas paucimobilis and Microbacterium arborescens isolated from fresh water sediments.

This study focuses on isolation of pigment producing bacteria from fresh water sediment. The isolated bacteria were grown in nutrient broth and the maximum absorbance of 2.512 was obtained for the extracted pigment at 500 nm. The effective strains were optimized, pH 11 and temperature 30 °C was found to be more favorable for its maximum growth. The isolates were identified based on their molecular characterestics as Microbacterium arborescens and Sphingomonas paucimobilis, molecular size of the amplified 16S rRNA gene sequence was found to be approximately 1270 and 765 bp respectively. The antioxidant property of the pigment was analyzed using DPPH and ABTS assay. The IC50 value of Microbacterium arborescens was higher in all the three assays in comparison with Sphingomonas paucimobilis. The extracted pigment was characterized for the presence of compounds using GC-MS and FTIR analysis to determine the functional groups. As the pigment obtained from M. arborescens had shown better antioxidant activity it may be used as colorant in food industrial applications.

Target and non-target toxicity of fern extracts against mosquito vectors and beneficial aquatic organisms.

Dengue and malaria are significant mosquito-borne diseases that are rapidly spread worldwide, mainly in temperate countries. Pteridophytes were identified to be a significant source of novel mosquitocidal agents. The present research was to explore the eco-friendly larvicides from methanol extracts of ferns, viz., Actiniopteris radiata, Adiantum caudatum, Cheilanthes swartzii, Hemionitis arifolia and Lycopodium clavatum. The larvicidal potential of the extracts screened using larvae of dengue vector Aedes aegypti (III and IV instar) and malarial vector Anopheles stephensi (III and IV instar), showed 10-100% mortality rates. Biosafety assessment was made on embryos of Danio rerio and Artemia nauplii. The phyto-constituents of the methanol extract of A. radiata leaves were identified through gas chromatography-mass spectrometry (GC-MS). Methanolic leaf extracts of A. radiata, A. caudatum and C. swartzii exhibited larvicidal activity against III and IV instar larvae of Ae. aegypti (LC50: 37.47, 74.51 and 152.38 and 67.58, 95.89 and 271.46 ppm) and An. stephensi (LC50: 70.35, 112.12 and 301.05 and 113.83, 175.30 and 315.19 ppm), respectively. The GC-MS of the methanol extract of A. radiata leaves revealed the presence of 7 phyto-components among which, Carbamic acid, phenyl-, (2-Nitrophenyl) methyl ester (1), Benzoic acid, 3- methylbenzoate (2) and 4-(benzylimino)- 1,4-dihydro-1-(p-toluoylmethyl) pyridine (3) were dominant. Biosafety assessment of methanol extract of A. radiata leaves on embryos of Danio rerio (Zebra fish) and Artemia nauplii (micro crustacean) revealed that there were no destructive or teratogenic effects. To conclude, the larvicidal activity and insignificant toxicity to non-target aquatic organisms of A. radiata leaves makes it a potential and environment safe biocontrol agent against dengue and malarial vectors.

Antibacterial efficacy of silver nanoparticles and ethyl acetate's metabolites of the potent halophilic (marine) bacterium, Bacillus cereus A30 on multidrug resistant bacteria.

Bacteria are generally responsible for the prevalence of several diseases and pathogenic bacteria are showing increasing resistance to different antibacterials. During the present study an extremophilic bacterium-A30 isolated from the marine waters was characterized and evaluated against four multi-drug resistant (MDR) pathogens, viz; Methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The sensitivity pattern of the selected pathogens was tested with 31 antibiotics. Among the 47 marine microbial extracts tested on 4-MDR pathogens viz: Methicillin-resistant Staphylococcus aureus (MRSA), E. coli, K. pneumoniae and P. aeruginosa, only our strain A30 strain exhibited highest efficacy. This strain was subsequently subjected to 16S rDNA sequencing which confirmed its allocation as Bacillus cereus. Silver nanoparticle (AgNPs) synthesis and ethyl acetate extraction were performed using the supernatant of B. cereus. The synthesized AgNPs were characterized by UV-Visible, Fourier-transform infra-red (FT-IR), X-ray diffraction (XRD), Field emission-scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), and Zeta potential analyses. The presence of functional groups and 13 bioactive components in the ethyl acetate extract were analyzed using FT-IR and gas chromatography-mass spectrometry (GC-MS). The synthesized of AgNPs and the ethyl acetate extract showed preponderant activity against P. aeruginosa and MRSA, respectively. The effects of AgNPs were significant when compared to ethyl acetate extract. Therefore, the halophilic bacterium, B. cereus mediated AgNPs could provide antibacterial applications in the biomedical industries.

GC-MS analysis of bioactive components and synthesis of gold nanoparticle using Chloroxylon swietenia DC leaf extract and its larvicidal activity.

A rapid bio-reduction of chloroauric acid (HAuCl4) was achieved by Chloroxylon swietenia DC leaf extract (CSLE), which resulted in the formation of well dispersed C. swietenia gold nanoparticles (CSGNPs). The formation of GNPs was confirmed by color changes from yellowish green to purple and their characteristic peak at 545 nm. The characterization of synthesized CSGNPs was made through X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscopy (HRTEM) equipped with energy dispersive X-ray spectroscopy (EDX) followed by size and zeta potential analyses. The GC-MS profile of C. swietenia methanolic leaf extract (CSMLE) resulted 20 phytocomponents, among those heptacosanoic acid, 25-methyl-, methyl ester (C29H58O2) attributes highest peak area. The efficiency of the synthesized CSMLE, CSGNPs and CSLE were tested against fourth instar larvae of malarial and dengue vector, which resulted more substantial upshot than with leaf extract treated. The Lethal concentration (LC50) values of CSMLE, CSGNPs and CSLE were found to be 0.509, 0.340, 0.423 ppm and 0.602, 0.188, 0.646 ppm on Aedes aegypti and Anopheles stephensi, respectively. The findings form an important baseline information proceeding biologically innocuous biopesticide for controlling the malarial and dengue vectors.