16 research outputs found
Plant growth-promoting activities of Streptomyces spp. in sorghum and rice
Five strains of Streptomyces (CAI-24, CAI-121, CAI-127, KAI-32 and KAI-90) were earlier reported by us as biological control agents against Fusarium wilt of chickpea caused by Fusarium oxysporum f. sp. ciceri (FOC). In the present study, the Streptomyces were characterized for enzymatic activities, physiological traits and further evaluated in greenhouse and field for their plant growth promotion (PGP) of sorghum and rice. All the Streptomyces produced lipase, β-1-3-glucanase and chitinase (except CAI-121 and CAI-127), grew in NaCl concentrations of up to 6%, at pH values between 5 and 13 and temperatures between 20 and 40°C and were highly sensitive to Thiram, Benlate, Captan, Benomyl and Radonil at field application level. When the Streptomyces were evaluated in the greenhouse on sorghum all the isolates significantly enhanced all the agronomic traits over the control. In the field, on rice, the Streptomyces significantly enhanced stover yield (up to 25%; except CAI-24), grain yield (up to 10%), total dry matter (up to 18%; except CAI-24) and root length, volume and dry weight (up to 15%, 36% and 55%, respectively, except CAI-24) over the control. In the rhizosphere soil, the Streptomyces significantly enhanced microbial biomass carbon (except CAI-24), nitrogen, dehydrogenase (except CAI-24), total N, available P and organic carbon (up to 41%, 52%, 75%, 122%, 53% and 13%, respectively) over the control. This study demonstrates that the selected Streptomyces which were antagonistic to FOC also have PGP properties
Formulation and evaluation of atenolol oro dispersable tablets by co-processed super-disintegration process
Oral disintegrating tablet (ODT) is defined as A solid dosage form containing medical substances or active ingredient which disintegrates rapidly usually within a matter of seconds when placed upon the tongue. The aim of the present research is to formulate Atenolol oral disintegrating tablets.Atenolol is ?1- cardio selective adrenergic receptor blocker, widely used in the treatment of hypertension, angina pectoris, arrhythmias and myocardial infarction. It works by slowing down the heart and reducing the work load of the heart.Atenolol was specifically developed so as to pass the blood brain barrier and overcome theside effects such as depression and nightmares.It has been reported that atenolol undergo extensive hepatic first pass metabolism following oral administration and has shorter biological half-life of 6 7 hours with oral bioavailability of 50%. The conventional tablets of atenolol are reported to exhibit fluctuations in the plasma drug levels after administration. Atenolol ODTs are prepared by novel co-processed super-disintegration process using Cross Povidone and Cross carmellose sodium, as the super disintegrants. The prepared tablets were characterized for their hardness, weight variation, disintegration time, wetting time, water absorption ratio friability, and in vitro dissolution studies.he ability of the tablet to release the drug faster depends on the concentration and type of super disintegrant. In this study the oral disintegrating tablets containing Cross carmellose sodium and Cross Povidone as the super disintegrant in the ratio of 1:1 shows better release of drug. About 99.5% of the drug was released from the tablets in 6 mins. Therefore, based on the physico chemical properties, in vitro drug release profile and mouth feel formulation F 1 containing 1:1 of Cross carmellose sodium and crospovidone is optimised as the best formulation
Methionine-functionalized graphene oxide/sodium alginate bio-polymer nanocomposite hydrogel beads: Synthesis, isotherm and kinetic studies for an adsorptive removal of fluoroquinolone antibiotics
This work was supported by Pt. Ravishankar Research Fellowship Scheme, Raipur, Chhattisgarh, India (grant number V.R. No. 3114/4/Fin./Sch.//2018). This work was also supported by national funds through FCT-Fundacao para a Ciencia e a Tecnologia, I.P., under the Scientific Employment Stimulus-Institutional Call (CEECINST/00102/2018) and by the Associate Laboratory for Green Chemistry-LAQV, financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020).In spite of the growing demand for new antibiotics, in the recent years, the occurrence of fluoroquinolone antibiotics (as a curative agent for urinary tract disorders and respiratory problems) in wastewater have drawn immense attention. Traces of antibiotic left-overs are present in the water system, causing noxious impact on human health and ecological environments, being a global concern. Our present work aims at tackling the major challenge of toxicity caused by antibiotics. This study deals with the efficient adsorption of two commonly used fluoroquinolone (FQ) antibiotics, i.e., Ofloxacin (OFX) and Moxifloxacin (MOX) on spherical hydrogel beads generated from methionine‒functionalized graphene oxide/ sodium alginate polymer (abbreviated Met-GO/SA) from aqueous solutions. The composition, morphology and crystal phase of prepared adsorbents were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HR-TEM) and thermogravimetric analysis/differential thermogravimetry (TGA/DTG). Batch adsorption tests are followed to optimize the conditions required for adsorption process. Both functionalized and non-functionalized adsorbents were compared to understand the influence of several experimental parameters, such as, the solution pH, contact time, adsorbent dosage, temperature and initial concentration of OFX and MOX on adsorption. The obtained results indicated that the functionalized adsorbent (Met-GO/SA) showed a better adsorption efficiency when compared to non-functionalized (GO/SA) adsorbent. Further, the Langmuir isotherm was validated as the best fitting model to describe adsorption equilibrium and pseudo second-order-kinetic model fitted well for both types of adsorbate. The maximum adsorption capacities of Met-GO/SA were 4.11 mg/g for MOX and 3.43 mg/g for OFX. Thermodynamic parameters, i.e., ∆G°, ∆H° and ∆S° were also calculated. It was shown that the overall adsorption process was thermodynamically favorable, spontaneous and exothermic in nature. The adsorbents were successfully regenerated up to four cycles with 0.005 M NaCl solutions. Overall, our work showed that the novel Met-GO/SA nanocomposite could better contribute to the removal of MOX and OFX from the liquid media. The gel beads prepared have adequate features, such as simple handling, eco-friendliness and easy recovery. Hence, polymer gel beads are promising candidates as adsorbents for large-scale water remediation.publishersversionpublishe
Efficacy of Jatropha, Annona and Parthenium biowash on Sclerotium rolfsii, Fusarium oxysporum f. sp. ciceri and Macrophomina phaseolina, pathogens of chickpea and sorghum
The demand for products and technologies based on plants to control plant pathogens has increased in
recent years due to concern about the use of hazardous pesticides. In the present investigation,
washings of vermicompost (called biowash) prepared from foliage of Jatropha (Jatropha curcas),
Annona (Annona squamosa) and Parthenium (Parthenium hysterophorus) were evaluated against
fungal pathogens viz. Fusarium oxysporum f. sp. ciceri (FOC; causes wilt in chickpea), Sclerotium
rolfsii (causes collar rot in chickpea) and Macrophomina phaseolina (causes charcoal rot in sorghum).
Crude biowash of the botanicals were partitioned against ethyl acetate and the resultant organic and
aqueous fractions were tested against the fungi. Similarly, crude biowash was also passed through C18
solid phase extraction cartridges and the resultant adsorbed and non-adsorbed fractions were tested
against the fungi. Organic fractions of all the three biowash at 0.5% inhibited the growth of S. rolfsii
between 78 and 87%, M. phaseolina between 62 and 65%, whereas only Parthenium was able to
effectively inhibit FOC (91%), compared to control. Adsorbed fractions of all the three biowash at 0.5%
inhibited the growth of S. rolfsii between 81 and 92%, M. phaseolina between 76 and 77% and FOC
between 26 and 49%, compared to control. Both aqueous and non-adsorbed fractions of all the three
biowash did not inhibit any of the fungi. Since Jatropha biowash showed consistently higher levels of
inhibition (>80%) in both fractionation methods on S. rolfsii, this was selected for further purification of
their secondary metabolites. When the organic fraction of Jatropha biowash was further fractionated by
C18 open column chromatography with eluent 5, 10, 20, 40, 60, 80 and 100% MeOH fractions, only 80%
methanol (MeOH) fraction was found to inhibit S. rolfsii. The active 80% MeOH fraction showed three
clear bands when chromatographed on Silica Gel 60 F254 thin layer chromatography (TLC) plates with Rf
values 0.95, 0.90 and 0.70. Hence, it was concluded that one of these three bands could be the active
ingredients that inhibited S. rolfsii and can be further exploited as a bio-fungicide
Evaluation of bacteria isolated from rice rhizosphere for biological control of charcoal rot of sorghum caused by Macrophomina phaseolina (Tassi) Goid.
A total of 360 bacteria, isolated from the rhizospheres of a system of rice
intensification (SRI) fields, were characterized for the production of siderophore,
fluorescence, indole acetic acid (IAA), hydrocyanic acid (HCN) and solubilization of
phosphorus. Of them, seven most promising isolates (SRI-156, -158, -178, -211, -229, -305
and -360) were screened for their antagonistic potential against Macrophomina phaseolina
(causes charcoal rot in sorghum) by dual culture assay, blotter paper assay and in greenhouse.
All the seven isolates inhibited M. phaseolina in dual culture assay, whereas six isolates
solubilized phosphorous (except SRI-360), all seven produced siderophore, four produced
fluorescence (except SRI-178, -229 and -305), six produced IAA (except SRI-305) and five
produced HCN (except SRI-158 and -305). In the blotter paper assay, no charcoal rot
infection was observed in SRI-156-treated sorghum roots, indicating complete inhibition of
the pathogen, while the roots treated with the other isolates showed 49−76% lesser charcoal
rot infection compared to the control. In the antifungal activity test (in green house on
sorghum), all the isolates increased shoot dry mass by 15−23% and root dry mass by
15−20% (except SRI-158 and -360), over the control. In order to confirm the plant growthpromoting
(PGP) traits of the isolates, the green house experiment was repeated but, in the
absence of M. phaseolina. The results further confirmed the PGP traits of the isolates as
evidenced by increases in shoot and root dry mass, 22−100% and 5−20%, respectively, over
the control. The sequences of 16S rDNA gene of the isolates SRI-156, -158, -178, -211, -229,
-305 and -360 were matched with Pseudomonas plecoglossicida, Brevibacterium antiquum,
Bacillus altitudinis, Enterobacter ludwigii, E. ludwigii, Acinetobacter tandoii and P.
monteilii, respectively in BLAST analysis. This study indicates that the selected bacterial
isolates have the potential for PGP and control of charcoal rot disease in sorghum
Evaluation of actinomycete isolates obtained from herbal vermicompost for the biological control of Fusarium wilt of chickpea
A total of 137 actinomycetes cultures, isolated from 25 different herbal vermicomposts, were characterized for their antagonistic potential against Fusarium oxysporum f. sp. ciceri (FOC) by dual-culture assay. Of the isolates, five most promising FOC antagonistic isolates (CAI-24, CAI-121, CAI-127, KAI-32 and KAI-90) were characterized for the production of siderophore, cellulase, protease, hydrocyanic acid (HCN), indole acetic acid (IAA) and antagonistic potential against Rhizoctonia bataticola, which causes dry root rot in chickpea (three strains viz. RB-6, RB-24 and RB-115) and sorghum (one strain). All of the five FOC antagonistic isolates produced siderophore and HCN, four of them (except KAI-90) produced IAA, KAI-32 and KAI-90 produced cellulase and CAI-24 and CAI-127 produced protease. In the dual-culture assay, three of the isolates, CAI-24, KAI-32 and KAI-90, also inhibited all three strains of R. bataticola in chickpea, while two of them (KAI-32 and KAI-90) inhibited the tested strain in sorghum. When the FOC antagonistic isolates were evaluated further for their antagonistic potential in the greenhouse and wilt-sick field conditions on chickpea, 45–76% and 4–19% reduction of disease incidence were observed, respectively compared to the control. The sequences of 16S rDNA gene of the isolates CAI-24, CAI-121, CAI-127, KAI-32 and KAI-90 were matched with Streptomyces tsusimaensis, Streptomyces caviscabies, Streptomyces setonii, Streptomyces africanus and an identified species of Streptomyces, respectively using the BLAST searching. This study indicated that the selected actinomycete isolates have the potential for biological control of Fusarium wilt disease in chickpea
A Novel Staphylococcus Podophage Encodes a Unique Lysin with Unusual Modular Design
ABSTRACT Drug-resistant staphylococci, particularly Staphylococcus aureus and Staphylococcus epidermidis, are leading causes of hospital-acquired infections. Bacteriophages and their peptidoglycan hydrolytic enzymes (lysins) are currently being explored as alternatives to conventional antibiotics; however, only a limited diversity of staphylococcal phages and their lysins has yet been characterized. Here, we describe a novel staphylococcal phage and its lysins. Bacteriophage Andhra is the first reported S. epidermidis phage belonging to the family Podoviridae. Andhra possesses an 18,546-nucleotide genome with 20 open reading frames. BLASTp searches revealed that gene product 10 (gp10) and gp14 harbor putative catalytic domains with predicted peptidase and amidase activities, characteristic functions of phage lysins. We purified these proteins and show that both Andhra_gp10 and Andhra_gp14 inhibit growth and degrade cell walls of diverse staphylococci, with Andhra_gp10 exhibiting more robust activity against the panel of cell wall substrates tested. Site-directed mutagenesis of its predicted catalytic residues abrogated the activity of Andhra_gp10, consistent with the presence of a catalytic CHAP domain on its C terminus. The active site location combined with the absence of an SH3b cell wall binding domain distinguishes Andhra_gp10 from the majority of staphylococcal lysins characterized to date. Importantly, close homologs of Andhra_gp10 are present in related staphylococcal podophages, and we propose that these constitute a new class of phage-encoded lysins. Altogether, our results reveal insights into the biology of a rare family of staphylococcal phages while adding to the arsenal of antimicrobials with potential for therapeutic use. IMPORTANCE The spread of antibiotic resistance among bacterial pathogens is inciting a global public health crisis. Drug-resistant Staphylococcus species, especially S. aureus and S. epidermidis, have emerged in both hospital and community settings, underscoring the urgent need for new strategies to combat staphylococcal infections. Bacterial viruses (phages) and the enzymes that they use to degrade bacterial cell walls (lysins) show promise as alternative antimicrobials; however, only a limited variety of staphylococcal phages and their lysins have yet been identified. Here, we report the discovery and characterization of a novel staphylococcal phage, Andhra. We show that Andhra encodes two lysins (Andhra_gp10 and Andhra_gp14) that inhibit growth and degrade the cell walls of diverse staphylococci, including S. aureus and S. epidermidis strains. Andhra and its unique lysins add to the arsenal of antimicrobials with potential for therapeutic use
Efficacy of botanical extracts and entomopathogens on control of Helicoverpa armigera and Spodoptera litura
Interest in biological control of insect-pests of economically important plants has been stimulated in recent years by trends in agriculture towards greater sustainability and public concern about the use of hazardous pesticides. Botanicals and microorganisms have the capability to synthesize biologically active secondary metabolites such as antibiotics, herbicides and pesticides. In this investigation, washings of herbal vermicompost (called biowash; viz. Annona, Chrysanthemum, Datura, Jatropha, Neem, Parthenium, Pongamia, Tridax and Vitax) and plant growth promoting (PGP) bacteria [viz. Bacillus subtilis (BCB-19), Bacillus megaterium (SB-9), Serratia mercescens (HIB-28) and Pseudomonas spp. (SB-21)] and fungus (Metarhizium anisopliae) were evaluated for their efficacy against Helicoverpa armigera and Spodoptera litura. When the feed was treated with crude biowash for healthy larvae (4-day old), 42 and 86% mortality and 32 and 71% weight reduction over control was reported for H. armigera, while in the case of S. litura, it was between 46 and 74% larval mortality and 47 and 77% weight reduction over control. When healthy larvae were treated with PGP bacteria and fungus, the mortality rate varied between 59 and 73%, with 55 and 92% weight reduction over control on H. armigera, while for S. litura, 54 and 72% larval mortality and 44 and 79% weight reduction over control was reported. The results of the compatibility studies (entomopathogenic potential biowash of the botanicals with PGP bacteria and fungus) indicate that there was no definite sign of suppression of any of the botanicals on the PGP bacteria and fungus, except Datura with B. subtilis BCB-19, whereas, there was definite sign of enhanced growth of B. megaterium SB-9 with all the botanicals. Compatibility studies between PGP bacteria and fungus showed that all bacteria are compatible with each other except M. anisopliae. Crude biowash of the promising botanicals (Annona, Datura, Jatropha, Neem, Parthenium and Pongamia) were further fractionated on C18 solid phase extraction cartridge (SPE) and the resultant adsorbed and non-adsorbed fractions were tested against H. armigera. Results indicate that both adsorbed as well as non-adsorbed fractions showed significant mortality on H. armigera. Adsorbed fractions of all the six biowash showed mortality between 81 and 93% (64 and 73% for non-adsorbed fraction) over control and the weight reduction of the larvae was found between 73 and 91% (80 and 97% for non-adsorbed fraction) over control. It was therefore concluded that the aforementioned six botanicals and five entomopathogens has great potential in the management of H. armigera and S. litur
Agrobacterium-mediated transformation of tomato (Lycopersicon esculentum var. Pusa Ruby) with coat-protein gene of physalis mottle tymovirus
Transgenic tomato plants harboring the coat protein (CP) gene of Physalis mottle tymovirus (PhMV) were obtained through Agrobacterium-medidited genetic transformation. The cotyledonary leaves were transformed by cocultivation with Agrobacterium strain LBA4404 carrying the binary vector pBI 121. The CP gene of PhMV was cloned into the binary vector by deleting the GUS gene. Cotyledonary explants were cultured on the regeneration medium supplemented with 50 mg/L kanamycin and 400 mg/L cefotaxime (MSI). Shoots regenerated via callus. Putative transformants were transferred to a rooting medium containing 25 mg/L kanamycin (MS 2), where successful rooting was obtained. Transgenic nature of the transformants was checked by PCR and Western analyses. The Tt progenies segregate into a 3:1 ratio. Southern analysis confirmed the integration of CP gene into the tomato genome of T<sub>1</sub> progenies. The transgenic tomato plants were further challenged with PhMV and exhibited delay in symptom development, thus confirming the establishment of transgenic plants with partial resistance to the virus