Bacteria Bacillus Cereus Research Articles

Green Synthesis of Silver Nanoparticles Using the Plant Extract of Acer oblongifolium and Study of Its Antibacterial and Antiproliferative Activity via Mathematical Approaches.

In this study, the antibacterial and antifungal properties of silver nanoparticles synthesized with the aqueous plant extract of Acer oblongifolium leaves were defined using a simplistic, environmentally friendly, reliable, and cost-effective method. The aqueous plant extract of Acer oblongifolium, which served as a capping and reducing agent, was used to biosynthesize silver nanoparticles. UV visible spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and scanning electron microscopy were used to analyze the biosynthesized Acer oblongifolium silver nanoparticles (AgNPs). Gram-positive bacteria (Bacillus paramycoides and Bacillus cereus) and Gram-negative bacteria (E. coli) were used to test the AgNPs’ antibacterial activity. The presence of different functional groups was determined by FTIR. The AgNPs were rod-like in shape. The nanoparticles were more toxic against Escherichia coli than both Bacillus cereus and Bacillus paramycoides. The AgNPs had IC50 values of 6.22 and 9.43 and mg/mL on HeLa and MCF-7, respectively, proving their comparatively strong potency against MCF-7. This confirmed that silver nanoparticles had strong antibacterial activity and antiproliferative ability against MCF-7 and HeLa cell lines. The mathematical modeling revealed that the pure nanoparticle had a high heat-absorbing capacity compared to the mixed nanoparticle. This research demonstrated that the biosynthesized Acer oblongifolium AgNPs could be used as an antioxidant, antibacterial, and anticancer agent in the future.

Antibacterial properties of alcohol and water extracts of Waltheria indica (L.) plants collected from Binh Thuan province, Vietnam

This study aimed to investigate the antibacterial ability of Waltheria indica species collected from two communes of Phan Thiet city, Binh Thuan province. Research methods included making ethanol extracts and decoction and investigating their ability to inhibit bacteria through agar well diffusion method and determining the minimum inhibitory concentration (MIC). The results showed that the ethanol extract was resistant to 5 tested strains of bacteria (Bacillus cereus, Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, Escherichia coli) with diameters of bacterial inhibition zones ranging from 6.76 to 14.50 mm, in which the resistance to Gram-positive strains was better than Gram-negative strains. The decoction inhibited only 3/5 of the tested bacterial strains (S. aureus, E. faecium, E. coli) with MICs from 125 to 750 mg/mL (dry weight of plant per volume of decoction). The antibacterial activities of extracts from the stems, leaves, and roots of the plants were different. Samples obtained from the 2 sites also showed different antibacterial capacities.

Bioactivity-guided identification and isolation of a major antimicrobial compound in Cistus creticus subsp. creticus leaves and resin “ladano”

Cistus creticus subsp. creticus is a shrubby Mediterranean plant used since ancient times in folk medicine for the treatment of different diseases. C. creticus extracts and resin contain different types of secondary metabolites, such as terpenoids (predominantly labdane type diterpenoids), and phenylpropanoids. Growth conditions seem to influence the content of labdane-type diterpenes and flavan-3-ols in leaves of C. creticus subsp. creticus. Histochemical staining of leaves’ trichomes and comprehensive phytochemical characterization of resin, leaves and their exudates, indicated that long-stalked capitate trichomes of C. creticus subsp. creticus, grown both in vitro (IV) and in greenhouse (GH), are capable of producing bioactive oleoresin-related terpenoids and phenylpropanoids compounds. Bioactivity-guided approach was implemented in search for the major antibacterial compound in C. creticus resin against two Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and two Gram-positive bacteria (Bacillus cereus and Micrococcus flavus). Bioautographic assay on TLC plates with separated components of Cistus resin extract, revealed a pronounced zone of microbial growth inhibition, corresponded to a highly active compound with Rf values of 0.45, structurally characterized and identified as ent-3β-acetoxy-13-epi-manoyl oxide. This finding opens the route for focusing on isolation and functional characterization of genes involved in the biosynthesis of ent-3β-acetoxy-13-epi-manoyl oxide and its precursor ent-3β-hydroxy-13-epi-manoyl oxide, with the aim to establish sustainable in vitro biotechnological protocols for its large-scale production in homologous and heterologous plant and microbial hosts.

OPTIMIZATION OF THE GROWTH MEDIA OF Bacillus cereus BACTERIA WITH THE ADDITION OF SKIM MILK AND DIFFERENT CARBON SOURCES

The goal of this research was to find the optimal media for growing B. cereus bacteria with various carbon sources. This study used an experimental method with two Bacillus cereus bacterium isolates, namely B. cereus strain SN7 (isolate N) and a consortium of bacteria isolates (a combination of several B. cereus isolates with different strains). The two isolates were grown in sago liquid waste media, tofu liquid waste media, and molasses liquid waste media supplemented with a protein source, skim milk, with three replications in each treatment. Bacterial culture growth was measured every 6 hours for 24 hours using two methods: the TPC method and bacterial cell biomass measurement. According to the results of this study's measurements, molasses waste media was the best modified medium for B.cereus growth. The difference in growth between the B. cereus strain SN7 bacterial isolates and the consortium cultured on molasses media was not significant. The isolates with the largest number of cell growth were B. cereus consortium isolates, with 2,023 x108 CFU/mL in the TPC method and 1,011 g/mL in the biomass measurement method at 24 hours

Anti‐inflammatory and bactericidal effect of keratin/harmaline/ginkgo biloba electrospun nano fibres as band aid

This study represents the extraction of keratin from hedgehogs spines doped with Harmaline and Ginkgo Biloba, and electrospun on the surface of cotton fabric (animal rights laws were performed). The field emission scanning electron microscopy (FESEM) was used to investigate the morphology of produced keratin Harmaline Ginkgo Biloba (KHG). The thermogravimetric analysis (TGA) shows the weight loss of samples in different temperatures. The aim and goal of producing KHG on the cotton fabric surface was to use as band aid; therefore, the bactericidal and anti-inflammatory of samples were investigated. The results show that the KHG band aid has about 95% bactericidal properties against both gram-positive and gram-negative bacteria (Bacillus cereus and Escherichia coli). On the other hand, the results of oedema reduction on rats indicate that KHG band aid has good anti-inflammatory property, which is near to the indomethacin. Furthermore, the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) analyses of KHG band aid and its cell viability demonstrate that the KHG band aid has very low cytotoxicity.

Physiochemical properties, antibacterial, antifungal, and antioxidant activities of essential oils from orange (Citrus nobilis) peel

The continuous fresh consumption or juice production of orange fruits (citrus nobilis) has discarded a vast number of orange peels, which has caused significant impacts on environmental issues. This study attempted to utilize discarded orange peels to extract essential oils (EOs) and evaluated their physiochemical properties, antibacterial, antifungal, and antioxidant activities. EOs were extracted via a distillation system using a Clevenger apparatus and gas chromatography - mass spectrometry analysis was employed to characterize their chemical components. The antibacterial and antifungal test were evaluated using a well diffusion method, and antioxidant activity was determined based on DPPH radicals scavenging effect and ferric reducing antioxidant power (FRAP). The obtained EOs with the yield of 3.29 ± 0.24% in which limonene was found to be the most abundant compound in the EOs (90.42%) followed by β-myrcene (4.7%) and α-pinene (1.22%). The result showed that Gram-positive bacterium (Bacillus cereus) was susceptible to the 50% EOs than Gram-negative bacterium (Escherichia coli) with respect to inhibitory zone diameter of 15.00 ± 0.58 mm and 11.33 ± 0.58 mm. The 50% EOs also inhibited nearly 70% of the mycelial growth of Aspergillus flavus as well as exhibiting antioxidant activity with IC50 values of 0.15 ± 0.01 mg/mL and 18.29 ± 0.13 mg/mL for DPPH and FRAP assay, respectively. The orange peel EOs could be a promising alternative to synthetic preservatives in food industry due to their antimicrobial and antifungal activity as well as their antioxidant activity.

Excellent photocatalytic activity of Ag2O loaded ZnO/NiO nanocomposites in sun-light and their biological applications

In this paper, Ag2O decorated ZnO and NiO-based nanocomposites have been successfully synthesized through a simple chemical method. The prepared samples are characterized using different techniques to approve the chemical structure, elemental composition, morphology, and optical properties. In addition, the photocatalytic activity towards the degradation of methylene blue (MB) in an aqueous solution under sunlight irradiation has been investigated. The observed results indicated the heterostructures of ZnO/Ag2O have significantly higher activity than the bare ZnO and Ag2O nanoparticles under visible light irradiation. The photocatalytic degradation of MB by the ZnO/Ag2O sample has occurred within 50 min compared to other higher-cost methods in the literature. ZnO/NiO nanocomposite has also been shown to be an effective antibacterial agent against Gram-positive bacteria Bacillus cereus and Gram-negative bacteria Salmonella typhi and Klebsiella sp.

Synthesis of Imidazolium Hydrogen Sulphate and Morpholinium Tetrafluoroborate Ionic Liquids: Its Antimicrobial Activity

Recent years have seen renewed interest in the application of ionic liquids (ILs) on extraction. Along with this grow of ionic liquids, there are significant concern over the effect of ILs on the biomass extraction. Therefore the aim of this present work was to study the inhibitory effect of synthesized ILs particularly imidazolium hydrogen sulphate [IM][HSO4] and morpholinium tetrafluoroborate [MOR][BF4]. Antibaterial and antifungal activities were carried out againts Bacillus cereus, Bacillus thuringiensis and Pseudallescheria boydii which are the main producer of ferulic acid (FA). Results showed that the inhibitory effects of [IM][HSO4] againts bacteria (Bacillus cereus andBacillus thuringiensis) and fungus (Pseudallescheria boydii) were more extensive with inhibition zone of 20.3 and 52.3 mm respectively compared to [MOR][BF4] with 8.3 and 34.0 mm. This result represented the inhibitory effect of ILs especially on fungus as compared to bacteria tested in this present study.

Microbiota Analysis and Microbiological Hazard Assessment in Chinese Chive (Allium tuberosum Rottler) Depending on Retail Types.

Chinese chive (Allium tuberosum Rottler) has potential risks associated with pathogenic bacterial contamination as it is usually consumed raw. In this study, we investigated the microbiota of Chinese chives purchased from traditional markets and grocery stores in March (Spring) and June (Summer) 2017. Differences in bacterial diversity were observed, and the microbial composition varied across sampling times and sites. In June, potential pathogenic genera, such as Escherichia, Enterobacter, and Pantoea, accounted for a high proportion of the microbiota in samples purchased from the traditional market. A large number of pathogenic bacteria (Acinetobacter lwoffii, Bacillus cereus, Klebsiella pneumoniae, and Serratia marcescens) were detected in the June samples at a relatively high rate. In addition, the influence of the washing treatment on Chinese chive microbiota was analyzed. After storage at 26°C, the washing treatment accelerated the growth of enterohemorrhagic Escherichia coli (EHEC) because it caused dynamic shifts in Chinese chive indigenous microbiota. These results expand our knowledge of the microbiota in Chinese chives and provide data for the prediction and prevention of food-borne illnesses.

Novel Antiviral and Antibacterial Durable Polyester Fabrics Printed with Selenium Nanoparticles (SeNPs).

The COVID-19 pandemic has clearly shown the importance of developing advanced protective equipment, and new antiviral fabrics for the protection and prevention of life-threatening viral diseases are needed. In this study, selenium nanoparticles (SeNPs) were combined with polyester fabrics using printing technique to obtain multifunctional properties, including combined antiviral and antibacterial activities as well as coloring. The properties of the printed polyester fabrics with SeNPs were estimated, including tensile strength and color fastness. Characterization of the SeNPs was carried out using TEM and SEM. The results of the analysis showed good uniformity and stability of the particles with sizes range from 40–60 nm and 40–80 nm for SeNPs 25 mM and 50 mM, respectively, as well as uniform coating of the SeNPs on the fabric. In addition, the SeNPs—printed polyester fabric exhibited high disinfection activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with an inhibition percentage of 87.5%. Moreover, a toxicity test of the resulting printed fabric revealed low cytotoxicity against the HFB4 cell line. In contrast, the treated fabric under study showed excellent killing potentiality against Gram-positive bacteria (Bacillus cereus) and Gram-negative bacteria (Pseudomonas aeruginosa, Salmonella typhi, and Escherichia coli). This multifunctional fabric has high potential for use in protective clothing applications by providing passive and active protection pathways.

Effect of Cuminum Cyminum and Caraway Essential Oil on Bacillus Cereus Inoculated in Sterilized Milk

Background: In recent years, particular attention has been paid to the use of natural preservatives in foods instead of chemical ones. Methods: In this study, the antimicrobial activity of Cuminum cyminum and Caraway essential oil on Bacillus cereus at 10°C in sterilized milk was investigated. The Bacillus cereus Bacterium was recovered in a nutritious Meal culture medium. Subsequently, 103 bacteria per cc in milk were selected and into utensil milk those were added to autoclaved before that time. Then, Concentrations of 0, 0.03, 0.06, 0.1, 0.2, 1 and 2 percent of essential oil of Cuminum cyminum plant and of 0, 0.03, 0.06, 0.1, 0.2, 1, 1.5 and 2 percent of the essential oil of the caraway plant was added to the sterilized milk container. Then the study of bacterial condition was done on days 0, 1, 3, 6, 9, 12, 15, 18 and 21 by spread plate count. Then, according to the logarithm of the obtained data, repeated measures of ANOVA. Results: Based on the results, it was found that essential oils of cumin and caraway had an inhibitory effect on growth of Bacillus cereus compared to control group (p value < 0.05). Conclusion: In this research, essential oils of Cumin and caraway showed suitable antibacterial effects against growth of Bacillus cereus in milk. The results showed that Cumin is more effective than caraway.

High-throughput discovery of novel lanthipeptides and producers by metagenomic mining of isolates population (MMIP) from Chinese spicy cabbage

Lanthipeptides are known antimicrobial agents having great potential for application in food preservation. Many lanthipeptide biosynthetic gene clusters (BGCs) were mined in fermented food microbiota, however, it is difficult to obtain the bioactive lanthipeptides and their producing strains. Here, we established a high-throughput strategy designated Metagenomic Mining of Isolates Population (MMIP) to efficiently excavate and obtain novel lanthipeptides, especially their potential producing strains. MMIP procedure involves gathering bacteria isolates using culturable strategy, metagenomic mining for lanthipeptides and screening their producers, and characterization of specific lanthipeptides. 928 biosynthetic gene clusters including 139 ribosomally synthesized and post-translationally modified peptides (RiPPs) gene clusters were discovered in the metagenomic data of the isolates by antiSMASH. Entianin, lactocin S, lichenicidin, and 17 novel lanthipeptides gene clusters corresponding to 29 possible producers were further found from the harvested isolates population. Entianin and a novel two-component lanthipeptide paralicin were purified from Bacillus subtilis C5B1 and Bacillus paralicheniformis BaC1-8, respectively. They showed strong inhibitory activity to food spoilage bacteria Bacillus cereus and Listeria monocytogenes, and have great potential for application in food preservation. A novel lanthipeptide polysacin was also obtained using semi-in vitro biosynthesis. MMIP affords a novel strategy for effectively excavating lanthipeptides, especially their producers from diverse environmental niches.

Seaweed (Hypnea SP.) Supplementation in Feed Play Role in Boosting Immunity of Nile Tilapia (Oreochromis Niloticus)

Hypneasp. is the most common economically potential seaweed species inBangladesh. In this experiment, an initiative was taken to formulate fish feedusing seaweed (Hypneasp.) that can improve the immunity of Nile Tilapia,Oreochromisniloticus. Seaweed was supplemented in different percentages withcommercial feed to evaluate their effects on their serum bactericidal activities. A90-days experiment was conducted under five treatments – T1 (5% seaweed), T2(10% seaweed), T3 (15% seaweed), T4 (20% seaweed) and C (only commercialfeed) with a replica for each. Fish blood was collected, serum was separated fromblood and serum bactericidal activity was tested. Blood serum of 10% seaweedtreated fish showed the highest sensitivity against three bacteria (Bacillus cereus,Salmonella typhimurium, Shigellaflexneri) followed by 5% seaweed which showedsensitivity against Bacillus cereus and slightly against Salmonella typhimuriumandShigellaflexneriand 15% seaweed showed slight bactericidal activity againstBacillus cereus only, whereas, no bactericidal activity was observed for controland 20% seaweed treated fishes. The result indicates that the use of an optimumamount of seaweed supplements can improve the immunity system of Niletilapia which can prevent the growth of bacteria and likely make fishes safe forhuman consumption. Dhaka Univ. J. Biol. Sci. 31(1): 177-181, 2022 (January)

A NIR‐light‐driven Black Phosphorus Based Nanocomposite for Combating Bacteria

AbstractNanocomposites of semiconducting two‐dimensional (2D) materials provide advantageous for combating bacterial infections to overcome antibiotic resistance. In this study, the nanocomposites of 2D black phoshorus (BP) and silver nanoparticles (NPs) were prepared by anchoring as‐synthesized Ag NPs on few‐layer BP nanosheets via liquid self‐assembly method and used as a NIR‐light‐driven antibacterial agent against Gram‐negative bacteria (Escherichia coli and Pseudomonas aeruginosa), and Gram‐positive bacteria (Enterococcus faecalis and Bacillus cereus). The BP/Ag nanocomposites showed excellent photothermal effect and oxidative stress ability to inhibit the initial logarithmic growth phase of E. faecalis and B. cereus. According to the bacterial growth curve, agar plate assay and live/dead viability test, as‐synthesized BP/Ag nanocomposites were found to be more effective antibacterial agent for Gram‐positive bacteria than Gram‐negative bacteria. The presented NIR‐light‐driven BP‐based nanoplatform can open a new avenue for avoiding bacterial resistance and combating pathogenic bacteria and also broad‐spectrum disinfection applications.

EVALUATION OF SOME TRADITIONAL THERAPEUTIC PROPERTIES OF USNEA LONGISSIMA (ASCOMYCOTA, LICHENIZED FUNGI): ANTIMICROBIAL, ANTIQUORUM AND ANTIOXIDANT

Usnea longissima, fruticose lichen growing in the temperate region, is well known traditional medicinal herb and a reservoir of some unique secondary metabolites. Traditionally it has been commonly used as an antimicrobial agent for the treatment of ailments like tuberculosis, ulcers and skin diseases, etc. In our study, we evaluate antimicrobial, antiquorum sensing (QS) and antioxidant activity of Usnea longissima secondary metabolites extracted in acetone, methanol, and 70% hydroalcoholic solvents. Antimicrobial activity of extracts was evaluated against fungus (Aspergillus niger, Candida albicans) and six bacterial (Agrobacterium tumefaciens, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aerogenosa, Staphylococcus aureus, Streptococcus mutans) strains. Whereas anti-QS activity was tested against biosensor strain Chromobacterium violaceum (CV) MCC 2290 and antibiofilm activity was checked in two gram-negative bacteria (P. aeruginosa and E. coli), two gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) and fungus (Candida albicans). Results of experimental data indicated that methanolic extract exhibited maximum activity against A. tumefaciens (24±0.2 mm) and C. albicans (30±0.3 mm) with the minimum inhibitory concentration of 300µg/mL and 200µg/mL respectively. Interestingly, we also observed that all extracts effectively inhibited quorum sensing in C. violaceum and biofilm formation in Bacillus cereus, Escherichia coli, Pseudomonas aerogenosa, Staphylococcus aureus, at the concentration (100-300 µg/mL), for Candida albicans (50-150 µg/mL). Usnea longissima extract showed strong reducing power and hydroxyl radical activity and low DPPH scavenging activity. The present study suggested that U. longissima possesses potential antimicrobial and antiquorum sensing activity. These biological properties could be attributed to its significant antioxidant potential which validates its traditional use as an antimicrobial herbal source.

Microbial Degradation Pathways of Acrylic Paint Thinner Gas in Biotrickling Filter and Comparison of Kinetic Models Under Different Gas Concentrations

In this study, the effect of inlet concentration of pollutants, empty bed residence time (EBRT) and liquid recycling velocity on the performance of the BTF was explored. The results showed the best operating characteristics of the biotrickling filter for this study were at an inlet concentration of 500 mg/m3�Cthe EBRT of 300s and liquid recycling velocity of 25.46 m h-1. At this condition, the total removal efficiency of pollutants can reach more than 90%. Among them, the removal efficiency of toluene and ethylbenzene was above 95%, and the xylene (m-xylene, o-xylene) could reach more than 70%, corresponding to elimination capacities (ECs) of 3.02 �} 0.33 g m-3 h-1, 1.81 �} 0.2 g m-3 h-1, 0.60 �} 0.07 g m-3 h-1. Through the fatty acid identification system and 16S rDNA identification, it could be found that the four dominant bacteria (Bacillus cereus, Bacillus subtilis, Acinetobacter calcoaceticus, Belem Bacillus) had a significant effect on the removal of acrylic paint thinner. According to the detection of organic compounds by gas chromatography and the corresponding enzymes produced by four dominant bacteria, the pathways for microorganisms to degrade pollutants could be inferred. The absorption-biofilm theory and the adsorption-biofilm theory were used to simulate and verify the degradation process of exhaust gas at different concentrations respectively.

Sustainable phyto-fabrication of silver nanoparticles using Gmelina arborea exhibit antimicrobial and biofilm inhibition activity

Increase in bacterial resistance to commonly used antibiotics is a major public health concern generating interest in novel antibacterial treatments. Aim of this scientific endeavor was to find an alternative efficient antibacterial agent from non-conventional plant source for human health applications. We used an eco-friendly approach for phyto-fabrication of silver nanoparticles (AgNPs) by utilizing logging residue from timber trees Gmelina arborea (GA). GC–MS analysis of leaves, barks, flowers, fruits, and roots was conducted to determine the bioactive compounds. Biosynthesis, morphological and structural characterization of GA-AgNPs were undertaken by UV–Vis spectroscopy, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDX), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometer (XRD). GA-AgNPs were evaluated for antibacterial, antibiofilm, antioxidant, wound healing properties and their toxicity studies were carried out. Results identified the presence of terpenoids, sterols, aliphatic alcohols, aldehydes, and flavonoids in leaves, making leaf extract the ideal choice for phyto-fabrication of silver nanoparticles. The synthesis of GA-AgNPs was confirmed by dark brown colored colloidal solution and spectral absorption peak at 420 nm. Spherical, uniformly dispersed, crystalline GA-AgNPs were 34–40 nm in diameter and stable in solutions at room temperature. Functional groups attributed to the presence of flavonoids, terpenoids, and phenols that acted as reducing and capping agents. Antibacterial potency was confirmed against pathogenic bacteria Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus by disc diffusion assay, MIC and MBC assay, biofilm inhibition assay, electron-microscopy, cell staining and colony counting techniques. The results from zone of inhibition, number of ruptured cells and dead-cell-count analysis confirmed that GA-AgNPs were more effective than GA-extract and their bacteria inhibition activity level increased further when loaded on hydrogel as GA-AgNPs-PF127, making it a novel distinguishing feature. Antioxidant activity was confirmed by the free radical scavenging assays (DPPH and ABTS). Wound healing potential was confirmed by cell scratch assay in human dermal fibroblast cell lines. Cell-proliferation study in human chang liver cell lines and optical microscopic observations confirmed non-toxicity of GA-AgNPs at low doses. Our study concluded that biosynthesized GA-AgNPs had enhanced antibacterial, antibiofilm, antioxidant, and wound healing properties.

Perbandingan Aktivitas Antimikroba Ekstrak Etanol dari Tiga Spesies Ganoderma Asal Pulau Lombok

The use of antibiotics is one of the most important ways to deal with the spread and treatment of pathogenic microbial infections. The search for new antibiotic sources continues to be carried out to anticipate the emergence of microbial resistance. One of the natural resources that has the potential as an antimicrobial source is a member of the macrofungi of the Genus Ganoderma. The purpose of this study was to evaluate the antimicrobial performance of the ethanol extracts of Ganoderma lucidum, G. applanatum dan Ganorderma sp. against fungi (Candida albicans dan Cryptococcus neoformans), gram positive bacteria (Bacillus cereus dan Staphylococcus aureus) and gram negative bacteria (Escherichia coli dan Shigella sp.). Macrofungi samples were taken from the forest area of Nature Tourism Park (TWA) Gunung Tunak, TWA Kerandangan, TWA Suranadi, TWA Nuraksa Sesaot, TWA Lemor and Pusuk forest. The stages of the method performed are sample collection, sample preparation, extraction, and testing of antimicrobial activity using the well difusion method. The ethanol extract concentrations for testing were 20%, 40%, 60% and 80%. The results showed that the three Ganoderma species had anti-fungal and antibacterial activity and that different levels of concentration had an effect on inhibition. The size of the inhibition zone is directly proportional to the higher the extract concentration. The antimicrobial activity of the ethanol extract of G. lucidum was higher when compared to G. applanatum and Ganoderma sp. both against fungi (Candida albicans and Cryptococcus neoformans) as well as against gram-positive and gram-negative test bacteria. In addition, G. applanatum showed very weak inhibition against both groups of tested bacteria. Key words: candidiasis; cryptococcosis; comorbid infections; macerations; pathogens

Establishing a MALDI-TOF-TOF-MS method for rapid identification of three common Gram-positive bacteria (Bacillus cereus, Listeria monocytogenes, and Micrococcus luteus) associated with foodborne diseases

We aimed to establish a method for the rapid identification of three common Gram-positive bacteria (Bacillus cereus, Listeria monocytogenes, and Micrococcus luteus) associated with foodborne diseases. MALDI-TOF-MS was used to determine the effects of sample pretreatment, culture medium, and culture time on the identification results. Then, MALDI-TOF-TOF-MS was used to establish an optimized method and further explore the effects of culture time on secondary proteins. Among the three sample pretreatment methods, formic acid extraction outperformed direct transfer and extended direct transfer, resulting in more protein peaks and higher peak intensity in B. cereus culture samples. However, with different culture times (1–7 d), ion peaks of all bacterial proteins were relatively stable according to MALDI-TOF-TOF-MS data. The protein peaks of B. cereus (1430 m/z), L. monocytogenes (2100 m/z), and M. luteus (2140 m/z) were split into small ion peaks at 1162, 1465, and 1625 m/z, respectively. After 7 d of culture, the secondary spectra, peak intensities, and peak values of formic acid-treated samples were relatively stable, indicating that secondary protein peaks were less affected by culture time. It provides a new approach for the routine identification and market supervision of food safety in China.

Detection of antibacterial activity of lactic acid bacteria, isolated from Sumba mare's milk, against Bacillus cereus, Staphylococcus aureus, and Escherichia coli.

Objective:The purpose of this research is to detect the antibacterial properties of lactic acid bacteria (LAB) against pathogenic bacteria.Materials and Methods:Isolation and determination of Lactobacillus spp. Testing of the antibacterial activity of LAB was conducted using filtrate and nonfiltrate forms. The lactic acid bacterial isolates were confirmed to be identified through Gram staining, cell shape, catalase testing, and motility testing.Results:The results of the analysis of the LAB inhibition zone using filtrate and nonfiltrate forms against the bacteria Bacillus cereus were included in the very strong category. The results of the analysis of the LAB inhibitory zone using filtrate and nonfiltrate forms and the agar well method against Staphylococcus aureus bacteria were classified into the very strong category. The results of the LAB inhibitory zone analysis using filtrate and nonfiltrate forms with the well method against Escherichia coli bacteria are included in the very strong category, whereas the results from the LAB inhibitory zone analysis using the filtrate and nonfiltrate forms with the agar diffusion method (disks) are included in the strong category.Conclusion:Based on the results, LAB isolated from Sumba mare’s milk displayed antibacterial activity in the strong and very strong categories against pathogenic bacteria such as B. cereus, S. aureus, and E. coli.