Gram-positive Bacteria Bacillus Subtilis Research Articles

Total phenolic content, antioxidant and antimicrobial activities of extracts from Pistacia lentiscus leaves

The purpose of the current study was to investigate total phenolic (TPC), total flavonoids (TF) and flavonols (FV) contents, as well as antioxidant and antimicrobial activities of different extracts of Pistacia lentiscus leaves. TP compounds were quantified by Folin-Ciocalteu, while antioxidant properties were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), radical scavenging assay (RSA), Ferric reducing activity power (FRAP) and β-carotene bleaching (βCB) assay. The antimicrobial activity was assessed against Gram-positive bacteria (Micrococcus luteus, Bacillus subtilis and Listeria innocua), Gram-negative bacteriaum (Escherichia coli) and fungi (Candida pelliculosa and Fusarium oxysporum albidinis). Overall, the ethanol fraction (EEPL) exhibited the highest TPC (70.4 ± 7.07 mg GAE g-1 powder), TF (32.06 ± 1.68 mg QE g-1 powder), FV (14.36 ± 1.68 mg QE g-1 powder) and RSA (IC50 = 5.34 ± 0.2 µg mL-1). Whereas, methanol extract (EMPL) displayed the highest FRAP (1.20 ± 0.02) and dichloromethane extract (EDPL) showed a high βCB (90.32 ± 2.98%). Furthermore, the antioxidant activities of extracts exhibited strong positive correlation with TP, TF and flavonols. The extracts obtained showed good inhibitory effect against most of the bacterial and fungal strains tested, suggesting their possible use as antimicrobial agents in medical or agro-industry sectors.

CHEMICAL COMPOSITION AND ANTIBACTERIAL ACTIVITY OF Codiaeum variegatum LEAVES

Natural substances of botanical origin have been important in African traditional medical practice. They have been used for various illnesses such as infections. Infectious diseases caused by pathogenic bacteria affect many communities and the treatment was made difficult partly because of antibiotic resistant strains. Phytochemicals isolated from medicinal plants are known to be effective in treating bacterial infections. The antibacterial activities of the ethanol and water leaf extracts of Codiaeum variegatumwere tested. Antibacterial effects of crude extracts were performed using modified Kirby-Bauer disc diffusion technique to determine the zone of inhibition. The extracts were tested for the antibacterial activities against Gram-positive bacteria (Bacillus subtilis) and Gram-negative bacteria (Serratia marcescens). The results demonstrated that both of ethanol and water leaf crude extracts of Codiaeum variegatumhave shown strong zone of inhibition against Serratia marcescens (20 mm) and Bacillus subtilis(12 mm) compared to control. This medicinal plant could be developed into affordable and safe standardized herbal products and may serve as a source of new molecules for broad-spectrum antimicrobial agents.

Quantification and isolation of Bacillus subtilis spores using cell sorting and automated gating.

The Gram-positive bacterium Bacillus subtilis is able to form endospores which have a variety of biotechnological applications. Due to this ability, B. subtilis is as well a model organism for cellular differentiation processes. Sporulating cultures of B. subtilis form sub-populations which include vegetative cells, sporulating cells and spores. In order to readily and rapidly quantify spore formation we employed flow cytometric and fluorescence activated cell sorting techniques in combination with nucleic acid fluorescent staining in order to investigate the distribution of sporulating cultures on a single cell level. Automated gating procedures using Gaussian mixture modeling (GMM) were employed to avoid subjective gating and allow for the simultaneous measurement of controls. We utilized the presented method for monitoring sporulation over time in germination deficient strains harboring different genome modifications. A decrease in the sporulation efficiency of strain Bs02018, utilized for the display of sfGFP on the spores surface was observed. On the contrary, a double knock-out mutant of the phosphatase gene encoding Spo0E and of the spore killing factor SkfA (Bs02025) exhibited the highest sporulation efficiency, as within 24 h of cultivation in sporulation medium, cultures of BS02025 already consisted of 80% spores as opposed to 18% for the control strain. We confirmed the identity of the different subpopulations formed during sporulation by employing sorting and microscopy.

Optogenetic control of Bacillus subtilis gene expression

The Gram-positive bacterium Bacillus subtilis exhibits complex spatial and temporal gene expression signals. Although optogenetic tools are ideal for studying such processes, none has been engineered for this organism. Here, we port a cyanobacterial light sensor pathway comprising the green/red photoreversible two-component system CcaSR, two metabolic enzymes for production of the chromophore phycocyanobilin (PCB), and an output promoter to control transcription of a gene of interest into B. subtilis. Following an initial non-functional design, we optimize expression of pathway genes, enhance PCB production via a translational fusion of the biosynthetic enzymes, engineer a strong chimeric output promoter, and increase dynamic range with a miniaturized photosensor kinase. Our final design exhibits over 70-fold activation and rapid response dynamics, making it well-suited to studying a wide range of gene regulatory processes. In addition, the synthetic biology methods we develop to port this pathway should make B. subtilis easier to engineer in the future.

A Surface Dielectric Barrier Discharge Plasma for Preparing Cotton-Fabric-Supported Silver Nanoparticles.

Cotton-fabric-supported silver nanoparticles (Ag NPs) have aroused great attention due to their remarkable physical and chemical properties and excellent broad-spectrum antibacterial performance.In this work, a surface dielectric barrier discharge (DBD) plasma method is developed and employed to prepare cotton fabric supported Ag NPs (Ag/cotton) for the first time. UV-Vis and X-ray photoelectron spectroscopy (XPS) results confirm the formation of Ag NPs. TEM images show that the size of Ag NPs is in the range 4.8–5.3 nm. Heat-sensitive cotton fabrics are not destroyed by surface DBD plasma according to FTIR and XRDresults. Wash fastness of the Ag/cotton samples is investigated using ultrasonic treatment for 30 min and it is shown that the Ag NPs possess good adhesion to the cotton fabric according to UV-Vis spectra. Antibacterial activity of the Ag/cotton samples shows that obvious bacteriostasis loops are observed around the samples with the appearance of both Gram-negative bacterium Escherichia coli (E. coli) and Gram-positive bacterium Bacillus subtilis (B. subtilis). The average diameter of the bacteriostasis loops against both E. coli and B. subtilis becomes larger with an increasing silver loading amount.This work provides a universal, fast, simple, and environmentally-friendly cold plasma method for synthesizing Ag NPs on heat-sensitive materials at atmospheric pressure.

Green Synthetic Approach and Antimicrobial Evaluation for Some Novel Pyridyl Benzoate Derivatives

Two series of substituted pyridyl 4-chlorobenzoates have been synthesized by microwave-assisted condensation of the corresponding 2-oxo-1,2-dihydropyridine-3-carbonitriles with 4-chlorobenzoyl chloride under solvent-free conditions. Alternatively, some compounds have also been prepared by conventional heating in methylene chloride in the presence of triethylamine. The structure of the synthesized compounds has been confirmed by spectral data (FTIR, 1D and 2D NMR). The new pyridyl benzoates were evaluated for antibacterial activity against gram-negative and gram-positive bacteria. The activity of 3-cyano-5-[(4-hydroxyphenyl)diazenyl]-4-methyl-6-phenylpyridin-2-yl 4-chlorobenzoate against gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) was comparable to that of amikacin used as standard antibiotic.

Synthesis of CdSe and CdSe:Ga nanostructures for antibacterial application

In this paper, the preparation of CdSe and CdSe:Ga nanoparticles using two methods: thermal evaporation and pulse laser ablation has been reported. Their structural properties were characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). As confirmed by the XRD curves, CdSe and CdSe:Ga nanoparticles exhibited polycrystalline and wurtzite hexagonal structures with orientation planes of (100), (101), (102), (110) and (112). Also, a homogeneous distribution of nano-rod, flower-like, cylindrical, hexagonal and both nano-rod and hexagonal shapes with different diameters was seen by FESEM images. The band gaps of CdSe and CdSe:Ga (without annealed and annealed at temperatures of 150 (6 h) and 500\(^{\circ }\)C (1 h)) were found to be 1.72, 1.7, 1.69 and 1.64 eV, respectively. The antibacterial activity could be increased by annealing CdSe:Ga nanoparticles at 150\(^{\circ }\)C for 6 h in Gram-positive bacteria (Bacillus subtilis), whereas it is decreased in Gram-negative bacteria (Enterobacter cloacae). Alternatively, annealing CdSe:Ga at 500\(^{\circ }\)C for 1 h led to an increase in the antibacterial activity in both Gram-positive and Gram-negative bacteria. It is concluded that the antibacterial activity is highly dependent on the type of bacteria, material, preparation conditions and the used methods.

ANTIMICROBIAL AND CHITINASE INHIBITORY ACTIVITIES OF 7-BENZAMIDOCOUMARINS

Objective: The aim of this study was to examine in vitro antimicrobial activity of a series of 7-benzamidocoumarin derivatives against three Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus, and Bacillus pumilus), three Gram-negative bacteria (Escherichia coli, Klebsiella pneumonia, and Salmonella typhi), and three fungi (Candida albicans, Candida tropicalis, and Aspergillus niger) by 2-fold serial dilution method.
 Materials and Methods: The compounds were synthesized by amide coupling of 7-amino-4-methyl coumarin 5 and 7-amino-4-chloromethyl coumarin 6 with different aromatic acids 7 (a-h) and heteroaromatic acids 8 (i-j) in the presence of phosphorous trichloride as an acid catalyst in acetonitrile. The synthesized compounds were evaluated for antimicrobial and chitinase inhibitory activity.
 Results: Compounds 9, 11, 12, 21, and 23 showed good antibacterial activity with minimum inhibitory concentration (MIC) ranging from 6.25 to 50 μg/mL. Among them, compound 21 was the most active molecule with MIC 6.25 μg/mL against S. aureus and 6.25 μg/mL against, B. pumilus and S. typhi. Compounds 11 and 21 were the most potent antifungal candidates with MIC 6.25–25 μg/mL against C. albicans and C. tropicalis. All the compounds were also evaluated for their chitinase inhibitory property and among them; compound 9 emerged as strong inhibitor of the enzyme.
 Conclusion: Some of the compounds showed very good antimicrobial activities. Among these, compound 21 showing potent antimicrobial activities against five of the nine microbial strains examined in this study, was the most active compound of the series. Some of the compounds also showed chitinase inhibitory properties. This study also provides a starting point for investigating the structure-activity relationships (SARs) of synthetic 7-benzamidocoumarins.

Green Synthesis of Ag Nanoparticles and Their Performance towards Antimicrobial Properties

Green synthesis is a forthcoming trend in the nanotechnology field where classical methods of synthesis are now replaced by inexpensive and eco-friendly methods. In this study, a green method has been developed for the synthesis of silver nanoparticles (AgNPs) where AgNPs were synthesised using water-based facile hydrothermal method. Silver nitrate (AgNO3) and polyvinylpyrrolidone (PVP) were used as precursor and reducing agents to produce AgNPs. The molar ratio effect of the precursor and stabiliser, its reaction temperature and reaction time were investigated. X-ray Powder Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and UV-Vis Spectrometry were used to characterise the AgNPs. The as-synthesized AgNPs with different molar ratios of the precursor to stabiliser were tested for antibacterial activities using Gram-positive bacteria (Bacillus subtilis) and Gram-negative bacteria (Escherichia coli). All the AgNPs samples exhibited antibacterial activities that were stronger against Gram-negative bacteria, as compared with Gram-positive bacteria. The diameter of the zone of inhibition (ZOI) increased with the increase of the AgNO3: PVP molar ratios. The results obtained proved that uniform AgNPs synthesized via green techniques have a high potential of influencing applications involving antimicrobial properties.

A mutant bacteriophage evolved to infect resistant bacteria gained a broader host range.

Bacteriophages (phages) are the most abundant entities in nature, yet little is known about their capacity to acquire new hosts and invade new niches. By exploiting the Gram-positive soil bacterium Bacillus subtilis (B. subtilis) and its lytic phage SPO1 as a model, we followed the coevolution of bacteria and phages. After infection, phage-resistant bacteria were readily isolated. These bacteria were defective in production of glycosylated wall teichoic acid (WTA) polymers that served as SPO1 receptor. Subsequently, a SPO1 mutant phage that could infect the resistant bacteria evolved. The emerging phage contained mutations in two genes, encoding the baseplate and fibers required for host attachment. Remarkably, the mutant phage gained the capacity to infect non-host Bacillus species that are not infected by the wild-type phage. We provide evidence that the evolved phage lost its dependency on the species-specific glycosylation pattern of WTA polymers. Instead, the mutant phage gained the capacity to directly adhere to the WTA backbone, conserved among different species, thereby crossing the species barrier.

Sol\u2013gel auto-combustion\xa0mediated cobalt ferrite nanoparticles: a potential material for antimicrobial applications

In the era of nanotechnology, nanoparticles (NPs) of metals and metal oxides/chalcogenides are widely been used in medical applications where antibiotic-resistant microorganisms become a serious threat to the human health. Cobalt ferrite (CoFe2O4) NPs, synthesized by a simple and cost-effective sol–gel auto-combustion method are envisaged for in vitro antimicrobial activities against Gram-positive bacteria (Bacillus subtilis; Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli; Pseudomonas aeruginosa). The structure, morphology, elemental analyses and surface area of CoFe2O4 NPs are initially screened. The antimicrobial efficiency of CoFe2O4 NPs is found to be optimum against the Gram-negative bacteria Escherichia coli (15 mm). In addition, membrane leakage assays performed to evaluate the intracellular cytoplasmic leakage with CoFe2O4 NPs demonstrate the ability to destroy the bacterial membrane integrity, confirming their antimicrobial potential.

Nitrosubstituted hydroxamate ligands in new triphenyltin(IV) complexes as prospective antimicrobial agents

New triphenyltin(IV) hydroxamate complexes, [Ph3Sn(4-NO2CnH)] and [Ph3Sn(4-NO2BzH)] have been synthesized by the reactions of Ph3SnCl with potassium 4-nitrocinnamo hydroxamate [4-NO2C6H4CHCHCONHOK] (KHL1) and potassium 4-nitro benzohydroxamate [4-NO2C6H4CONHOK] (KHL2). The complexes were synthesized in 1:1 molar ratio in MeOH + C6H6 and characterized by physicochemical and IR, 1H NMR, and mass spectrometry. The bidentate hydroxamate involving bonding through carbonyl and hydroxamic oxygen (O, O coordination) has been inferred from IR spectra. The electrochemical behavior of complexes has been analyzed. Quasi-irreversible two electron metal-centered cathodic process of type SnIV/SnII redox couple was indicated by cyclic voltammetric technique. The thermal behavior of 1 and 2 studied by TGA has shown continuous decomposition to yield Sn + 0.5SnO2 and SnO2 as final residues. The in vitro antimicrobial activity assays of 1 and 2 against pathogenic Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), Gram-negative bacteria (Salmonella typhi and Pseudomonas aeruginosa), and fungi (Aspergillus fumigatus and Alternaria alternata) were done by MIC method. The complexes have exhibited appreciable antimicrobial activity relative to the respective standard Gentamycin and Nystatin drugs.

Iron Homeostasis in Bacillus subtilis Requires Siderophore Production and Biofilm Formation.

Iron (Fe) is the most important metal in biology. Despite its abundance, Fe is mostly present as a ferric form in soils, strongly limiting its bioavailability. To overcome the challenge of Fe acquisition, many microorganisms produce siderophores to retrieve Fe from natural sources. Another ubiquitous feature of bacteria in natural environments is biofilm formation. Previous studies showed that external Fe strongly influenced biofilm formation in several bacteria, suggesting that this microenvironment plays a mechanistic role in micronutrient acquisition for bacteria. Here, we applied a complementary set of analytical methods and deletion mutants to evaluate the role of biofilm formation, siderophore production, and their interaction in Fe homeostasis in Bacillus subtilis We observed that Fe homeostasis, i.e., active growth at a constant intracellular Fe concentration, requires both siderophore production and biofilm formation. Also, we report that in B. subtilis, both biofilm formation and siderophore production are required to achieve active Fe acquisition from the medium and to sustain normal growth. Furthermore, we provide evidence that the formation of biofilm slightly enhances the kinetics of Fe complexation by catechol siderophores and markedly improves siderophore use efficiency. These results provide new perspectives on the mechanism underlying siderophore-based acquisition of Fe in biofilm-forming bacteria.IMPORTANCE Iron acquisition is of fundamental importance for microorganisms, since this metal is generally poorly bioavailable under natural conditions. In the environment, most bacteria are found tightly packed within multicellular communities named biofilms. Here, using the soil Gram-positive bacterium Bacillus subtilis, we show that biofilm formation and the production of siderophores, i.e., small molecules specifically binding metals, are both essential to ensure Fe uptake from the medium and maintain cellular Fe homeostasis. The biofilm matrix appears to play an important role favoring the efficient usage of siderophores. Taken together, our results demonstrate a close link between biofilm formation and iron acquisition in B. subtilis, allowing a better comprehension of how bacteria can cope with metal limitation under environmental conditions.

CopySwitch-in vivo Optimization of Gene Copy Numbers for Heterologous Gene Expression in Bacillus subtilis.

The Gram-positive bacterium Bacillus subtilis has long been used as a host for production and secretion of industrially relevant enzymes like amylases and proteases. It is imperative for optimal efficiency, to balance protein yield and correct folding. While there are numerous ways of doing so on protein or mRNA level, our approach aims for the underlying number of coding sequences. Gene copy numbers are an important tuning valve for the optimization of heterologous gene expression. While some genes are best expressed from many gene copies, for other genes, medium or even single copy numbers are the only way to avoid formation of inclusion bodies, toxic gene dosage effects or achieve desired levels for metabolic engineering. In order to provide a simple and robust method to address above-mentioned issues in the Gram-positive bacterium Bacillus subtilis, we have developed an automatable system for the tuning of heterologous gene expression based on the host's intrinsic natural competence and homologous recombination capabilities. Strains are transformed with a linearized, low copy number plasmid containing an antibiotic resistance marker and homology regions up- and downstream of the gene of interest. Said gene is copied onto the vector, rendering it circular and replicative and thus selectable. We could show an up to 3.6-fold higher gfp (green fluorescent protein) expression and up to 1.3-fold higher mPLC (mature phospholipase C) expression after successful transformation. Furthermore, the plasmid-borne gfp expression seems to be more stable, since over the whole cultivation period the share of fluorescent cells compared to all measured cells is consistently higher. A major benefit of this method is the ability to work with very large regions of interest, since all relevant steps are carried out in vivo and are thus far less prone to mechanical DNA damage.

PHYSICO-CHEMICAL AND TOXICOLOGICAL BEHAVIOUR OF Al2O3 NANOPARTICLES IN FINE PARTICULATE MATTER

The booming production and application of nanoparticles have raised great concern over its effect on environment, due to their increasing release in the environmental systems via intentional or unintentional activities, where their possible physicochemical and toxicological behavior remain unknown. The nanoparticles are released into the different environmental systems like air, soils and waters. However, their interaction with air matrices has been rarely investigated. For this reason, the changes of main physicochemical properties of Al2O3 nanoparticles in the presence of fine particulate matter were examined, as well as their toxicity towards gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) using colony counting method was assessed in the presence of fine particulate matter. E. coli and B. subtilis were the most strongly affected species by the Al2O3 nanoparticles under the influence of fine particulate media. Furthermore, the main physicochemical properties (particle size, zeta potential, and surface chemistry) were changed with the exposure of the fine particulate matter. Sulfone groups were detached and nitro groups were attached on nanoparticles surface according to FTIR analysis. Particle size of Al2O3 was decreased with the correlation of zeta potentials. This is one of the rare study to evaluate the effect of fine particulate media on Al2O3 nanoparticles with the respect of the physicochemical properties and toxicity of Al2O3.

Structural and Antibacterial Properties of WO3/ZnO Hybrid Particles against Pathogenic Bacteria

Abstract The antibacterial performance of hybrid ZnO particles coupled with a narrow bandgap semiconductor is a research field worthy to explore. WO3/ZnO hybrid particles were prepared by depositing WO3 on pre-synthesized ZnO particles via liquid impregnation method. The hybrid particles were mainly wurtzite ZnO. FESEM showed that the ZnO particles have rod-like structures. Tiny nanoparticles were formed on the surface of ZnO particles particularly after immersing in a high concentration of sodium tungstate. The presence of W in WO3/ZnO hybrid particles was verified by TEM/EDX mapping. WO3 appeared in the forms of porous layer on the surface of ZnO particles. The antibacterial susceptibility assay demonstrated that WO3/ZnO hybrid particles exhibited better inhibition effect against Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) than Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Interestingly, the Escherichia coli demonstrated inhibitory growth to WO3 (or W3+ ions).

Chemical composition and antimicrobial activity of essential oil from <i>Pyrethrum pulchrum</i> Ledeb.

The chemical composition and antimicrobial activity of the essential oil from the aerial parts of Pyrethrum pulchrum Ledeb. were investigated. Dried plant material was hydro-distillated yielding 0.1% of essential oil. The oil was analyzed by GC-MS techniques. Fifty-five compounds were identified representing 99.7% of the total oil composition. Camphor was the predominant compound (33.9%) followed by linalool (21.1%) and α-pinene (9.0%). The antimicrobial activity of the oil was determined using the disk diffusion method against Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus and Enterococcus faecalis), Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli), Mycobacterium vaccae and fungi (Candida albicans, Sporidiobolus salmonicolor and Penicillum notatum). The essential oil of P. pulchrum displays an intermediate activity against selected bacteria.

Fabrication of antibacterial electrospun cellulose acetate/ silver-sulfadiazine nanofibers composites for wound dressings applications

Metals and their nanoparticles, sodium alginate, honey and bacterial cellulose were widely used in the fabrication of scaffolds and wound dressings due to their biocompatibility, but silver sulfadiazine (SSD) is a leading topical antibacterial agent especially for the treatment of burn wound infections. In this novel research study, first time SSD was embedded with nanofibers. The objective of this study was to fabricate the wound dressings by blending of SSD with cellulose acetate (CA) for high profiled antibacterial properties. The resultant electrospun CA/SSD nanofibers revealed the appreciable morphology with uniform blending of SSD in the CA/SSD nanofibers. SEM images showed that the average diameter distribution of CA/SSD nanofibers was uniform with 292 ± 2, 287 ± 4, 293 ± 3 and 286 ± 6 nm. FT-IR spectra revealed that CA/SSD nanofibers having strong chemical interactions between SSD and CA. The XRD spectra and water contact angle test also showed that CA/SSD nanofibers revealed the suitable water absorbency as required for scaffoldings. The resultant CA/SSD nanofibers exhibited the appreciable antimicrobial activity against Gram-negative Escherichia Coli and Gram-positive Bacillus Subtilis bacteria with considerable sustainability for repetitive use. So, CA/SSD nanofibers can be used as a promising & distinguish product for wound dressings applications.

Less Is More: Toward a Genome-Reduced Bacillus Cell Factory for "Difficult Proteins".

The availability of complete genome sequences and the definition of essential gene sets were fundamental in the start of the genome engineering era. In a recent study, redundant and unnecessary genes were systematically deleted from the Gram-positive bacterium Bacillus subtilis, an industrial production host of high-value secreted proteins. This culminated in strain PG10, which lacks about 36% of the genome, thus representing the most minimal Bacillus chassis currently available. Here, we show that this “miniBacillus” strain has synthetic traits that are favorable for producing “difficult-to-produce proteins”. As exemplified with different staphylococcal antigens, PG10 overcomes several bottlenecks in protein production related to the secretion process and instability of the secreted product. These findings show for the first time that massive genome reduction can substantially improve secretory protein production by a bacterial expression host, and underpin the high potential of genome-engineered strains as future cell factories.

THE ANTIBACTERIAL AND ANTIOXIDATIVE STRESS ACTIVITIES AND CHARACTERISATION OF ASPARAGUS LARICINUS AQUEOUS EXTRACT

Background: Research indicates an increase in drug resistance to pathogenic human bacteria, despite the increase in synthetic antimicrobial drugs. As a result, medicinal plants are proving to be rich resources of constituents which can be used in drug development and synthesis of antimicrobial agents and/or their derivatives. Many of therapeutic drugs e.g. antimicrobial, anti-cancer and antioxidants have compounds extracted from plants as their primary active ingredients or molecules of plant origin serve as blue prints for synthetic or partially synthetic drugs. Methods: The antimicrobial activity of the Asparagus laricinus aqueous extract was evaluated by determination of minimum inhibitory concentration against laboratory strains of both gram-positive ( Bacillus subtilis , Streptococcus pneumonia and Staphylococcus aureus ) and gram-negative bacteria ( Pseudomonas aeruginosa , Escherichia coli and Proteus vulgaris ). The micro-plate assays based on iodo-nitrotetrazolium violet indicator was used to evaluate cell viability. Antioxidative stress activity of the extract was determined using Saccharomyces cerevisiae (BY4742) as the model eukaryotic system, while constitutes of the plant extract were profiled using LC/MS. Results: This study reports on the anti-bacterial and antioxidative stress activity of Asparagus laricinus . It was observed that 50µg/ml of the plant extract was the (MIC) for the gram-positive bacteria Bacillus subtilis , Streptococcus pneumonia and Staphylococcus aureus . While100µg/ml that was required for other gram-negative strains, Pseudomonas aeruginosa , Escherichia coli and Proteus vulgaris and Staphylococcus aureus was inhibited by 25µg/ml of the plant extract. The plant extract protected Saccharomycescerevisiae (BY4742) cells from oxidative stress when the cells were incubated with 10mM (H 2 O 2 ) for 1.5 hours. The phyto constituents of the plant extract were profiled using LC/MS and four major peaks were assigned chemical formulae. Conclusions: Asparagus laricinus water extract showed antimicrobial and antioxidative stress activities. LC/MS profile of major constituents of the plant extract revealed the presence of an alkaloid similar to 4-thiazolidinones, known to have important biological activities.