Structure and Stability Analysis of Antibacterial Substances Produced by Selenium Enriched Bacillus Cereus

Microorganisms can produce many antibiotics against bacteria and fungi, which have been used as potential choice of new antibiotics. In this paper, Bacillus cereus, was used to study the properties of antibacterial substance in its fermentation supernatant. The results showed that the source of antibacterial activity of Bacillus cereus was mainly the antibacterial substance produced by acid precipitation method, and further characterization speculates that the antibacterial substance may be lipopeptide substance. Then the antibacterial spectrum of the antibacterial substance was investigated, which showed that the antibacterial substance only had good inhibitory effect on Gram-positive bacteria and fungi, and selenium enrichment could significantly enhance the antibacterial activity of lipopeptide antibacterial substance produced by Bacillus cereus, and the inhibition mode of antibacterial substance to indicator bacteria was determined. The effects of different treatment methods on the stability of antibacterial substance were studied and the results showed that the antibacterial substance were stable to heat, ultrasonic and ultraviolet treatment, and their antibacterial activity would not be greatly affected. However, they were sensitive to pepsin. The optimum pH range of antibacterial activity was 3-5. This study may contribute to reuse the fermentation supernatant often discarded in the previous fermentation process. At the same time, the lipopeptide antibacterial substance extracted from the fermentation broth of selenium enriched Bacillus cereus can be used in the development of antibiotics and biopesticides, and open up a new way for the control of plant diseases.

Preliminary Study on Antibacterial Activity of Sawo Kecik (Manilkara kauki (L.) Dubard) Roots Extract

The roots of sawo kecik (Manilkara kauki (L.) Dubard) contain astringent that can be used to treat diarrhea for infants. However, the active antibacterial substance in sawo kecik roots has not been known. Therefore, the research to understand the antimicrobial activity of sawo kecik roots extract against Escherichia coli and Staphylococcus aureus was performed. Sawo kecik roots were macerated using methanol and chloroform. The result was then treated with E.coli and S.aureus with a concentration of 5 ppm and compared to negative control (solvent) and further observed and analyzed how reduced the bacterial growth with Two Ways ANOVA without interaction. The research results indicated that the sawo kecik roots methanol extract was effective to slow down the growth of S.aureus (0.160 ± 0.007) but ineffective against E.coli, whereas sawo kecik roots chloroform extract was not effective to reduce both bacteria. It can be concluded that further research is required to measure and verify the antibacterial activity of the extract using higher concentration samples and different research methodology.

Antimicrobial Activity and Antibiofilm Potential of Coenzyme Q0 against Salmonella Typhimurium

Coenzyme Q0 (CoQ0) has anti-inflammatory and anti-tumor effects; however, the antimicrobial and antibiofilm activities of CoQ0 against Salmonella enterica serovar Typhimurium are unknown. Thus, we investigated the bacteriostatic and antibiofilm activities, along with the underlying mechanism, of CoQ0 against S. Typhimurium. The minimum inhibitory concentration (MIC) of CoQ0 against S. enterica serovars Typhimurium was 0.1–0.2 mg/mL (549–1098 µM), and CoQ0 at MIC and 2MIC decreased viable S. Typhimurium counts below detectable limits within 6 and 4 h, respectively. CoQ0 at 20MIC (4 mg/mL) reduced S. Typhimurium on raw chicken by 1.5 log CFU/cm3 within 6 h. CoQ0 effectively disrupted cell membrane integrity and induced morphological changes in the cell, resulting in hyperpolarization, decreased intracellular ATP concentrations, and cellular constituents leakage. Biofilm-associated S. Typhimurium cells were killed by CoQ0 treatment. These findings suggest that CoQ0 could be applied as a natural antibacterial substance for use against S. Typhimurium by the food industry.

ANTIBACTERIAL SUBSTANCE PRODUCED BY A SOIL BACTERIA ISOLATED FROM RHIZOSPHERE OF ZINGIBER OFFICINALE

Objective: In our previous study, we have found many isolates of bacteria from Zingiber officinale rhizosphere in Magelang, Central Java, Indonesia. J4, one of the isolates, has been found to contain metabolites which have antibacterial activity. The active chemical compound was unidentified. This study aims to identify the molecular formula of the active compound which has potential antibacterial activity. Methods: Identification of selected bacteria (J4 isolate) was based on the 16S rRNA gene sequence. Extraction of J4 isolate culture broth was carried out using ethyl acetate and followed by fractionation with hexane, chloroform-methanol (7:3), and methanol. The fraction which has antibacterial activity analyzed using IR Spectroscopy and LC-TOF-MS. Results: BLAST analysis result of the 16S rRNA sequence showed that J4 isolate is Burkholderia sp with 99% similarity. According to the IR spectroscopy examination of the active fraction, there were OH, CH, and carbonyl stretching. LC-TOF-MS analysis showed 5 molecular formulas with m/z of 253, 274, 387 (two formulas), and 404 in the active fraction, but there was one formula with no OH groups. Conclusion: J4 isolate is a Burkholderia sp. The molecular formula for the antibacterial substance that might be produced by J4 isolate is C6H12N12, C21H29N3O5, C21H26N2O5, C17H22N8O3, and/or C15H35N3O.

Grapefruit Seed Extract as a Natural Derived Antibacterial Substance against Multidrug-Resistant Bacteria

Multidrug-resistant (MDR) bacteria are increasing due to the abuse and misuse of antibiotics, and nosocomial infections by MDR bacteria are also increasing. The aim of this study was to identify new substances that can target MDR bacteria among 12 plant extracts that are known to have antibacterial effects. The experiments were performed by the disk diffusion test and microdilution minimum inhibitory concentration (MIC) test, as described by the Clinical and Laboratory Standards Institute (CLSI). By screening against methicillin-sensitive Staphylococcus aureus (MSSA), grapefruit seed extract (GSE) was selected from 12 plant extracts for subsequent experiments. GSE showed antibacterial effects against methicillin-resistant S. aureus (MRSA) and vancomycin-resistant S. aureus (VRSA) in the disk diffusion test. Even at the lowest concentration, GSE showed antibacterial activity in the microdilution MIC test. As a result, we can conclude that GSE is a naturally derived antibacterial substance that exhibits a favorable antibacterial effect even at a very low concentration, so it is a good candidate for a natural substance that can be used to prevent or reduce nosocomial infections as coating for materials used in medical contexts or by mixing a small amount with other materials.

History of penicillin

The history of penicillin was shaped by the contributions of numerous scientists. The ultimate result was the discovery of the mould Penicillium's antibacterial activity and the subsequent development of penicillins, the most widely used antibiotics. Following an accidental discovery of the mould, later identified as Penicillium rubens, as the source of the antibacterial principle (1928) and the production of a pure compound (1942), penicillin became the first naturally derived antibiotic. There is anecdotal evidence of ancient societies using moulds to treat infections and of awareness that various moulds inhibited bacterial growth. However, it is not clear if Penicillium species were the species traditionally used or if the antimicrobial substances produced were penicillin. In 1928, Alexander Fleming was the first to discover the antibacterial substance secreted by the Penicillium mould and concentrate the active substance involved, giving it the name penicillin. His success in treating Harry Lambert's streptococcal meningitis, an infection until then fatal, proved to be a critical moment in the medical use of penicillin. Many later scientists were involved in the stabilisation and mass production of penicillin and in the search for more productive strains of Penicillium. Among the most important were Ernst Chain and Howard Florey, who shared with Fleming the 1945 Nobel Prize in Physiology or Medicine.

Study of the sensitivity of certain bacteria –pathogenic human health- to atlas cedar essential oils and antibiotics

The spread of microbial resistance around the world is one of the most serious threats to public health. Every year one to three antibiotics are released to the market, as each antibiotic has a limited effective lifespan after which microorganisms develop resistance. The need to identify new natural antimicrobial agents is an important research goal at the global level. The use of volatile plant extracts as antimicrobial agents represents a low risk for the development of resistance by microorganisms because these products are made up of several phytocompounds from different groups which work in synergy. The objective of this work is to test, in vitro, the antimicrobial activity of the essential oil of cedrus atlantica against six bacterial strains; Salmonella sp, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and streptococcus sp. And three strains of yeast; Candida Tropicalis, Candida Albicans, Saccharomyces Cerevisiae. With the aim of researching new effective antibacterial substance with a broad spectrum of action. The results of the quantitative analysis showed a richness in certain compounds identified by gas chromatography coupled with mass spectrometry; β-Himachalene, α-Himachalene, himachalene oxide and Limonene. The essential oil to show a significant antibacterial effect compared to the synthetic antibiotics tested Piperacillin 30 µg (PRL30) and Ampicillin 10 µg (AMP 10).

BRIGHT RED ANTIBIOTIC ABOMASUM OF KALMYK COWS

In cows of the Kalmyk breed, a chemical compound is released inside – hydrochloric acid. She, together with the gastric enzyme pepsin, breaks down the food received from the external environment into the stomach into the smallest elements that can be absorbed through the digestive glands of the stomach into the blood. Amino acids, sugars, fatty acids, fat and water-soluble vitamins, all of them, rush into the bloodstream, but the minerals, before leaving the bloodstream, it is in the stomach that they have time to bind together with gastric hydrochloric acid. The result of this chemical reaction will be, – chemical resistant chlorine compounds. In theory, this should be the end of it, but no, since chemical chloride salts are a nutrient medium for the growth of a special acid-resistant fungus inside the stomach. It is from its fungal structures that an antibacterial substance is released, a bright red color, similar to the color of the arterial blood of mammals. Having a bright red color, the antibiotic has been invisible to the human eye for many millennia. Red blood is a red antibiotic. The antibacterial substance suppresses all microflora entering the blood from the external environment, making it bactericidal resistant to microbes. Laboratory and practical research, carried out jointly with the 4th year students of the specialty "Veterinary Medicine", made it possible to understand the whole mechanism of the digestion process of the animal's body, evaluate its role in the life of Kalmyk cows and, based on this, try to outline a plan for the isolation of substance in pure crystalline form. Kalmyk cows have a strong endurance to destructive adverse environmental factors (cold, hunger) and a fairly strong immunity to pathogenic bacterial microflora, which allows us to conclude about the important properties of the antibacterial substance produced inside their stomachs. A lot of work remains to be done to prove the significance and importance of finding hydrochloric acid and an antibiotic, a bright red color, inside living mammalian bodies in the arid area of southern Russia.

The Improvement of Polymer Structure Related to Radical Treatment of Alveolar Abcesses

Painful periapical manifestations are inflammatory responses of periapical connective tissue to pulpal irritants, when the exudative forces become hyperactive. From the point of view of tooth preservation, apical resection is a valuable procedure in avoiding early edentation, as it is a factual surgical method that comes to aid the conservative endodontic therapy. Polymers are chemical compounds (in most cases organic) with large molecules (macromolecules) obtained from the union of a molecular chain (catena) of a large number of monomers usually with identical structural units. In our research we evaluated the resistance to traction 9 test specimens for which the structure was aimed at the improvement of the self-polymerizable acrylic structure by adding sodium maleate co-polymers, namely maleic anhydride, whose structure was linked to the anti-microbial substances, of the thymol type with controlled release, versions with greater resistance, they found clinical applicability on 244 cases. An increased resistance to fracture was registered for the test specimens II, which unites polymer powder together with the sodium maleate co-polymer, in a ratio of 3 to 1 (F = 1030 and max = 37.73), test specimen III, which unites polymer powder together with the co- anhydride maleic polymer, in a ratio of 3 to 1 (F = 950 and max = 37.88), followed by the same combinations to which it was added the care antibacterial substance, thymol. An important role in the long term in the success of the apical resection, in addition to the applied surgical technique, accrues to the retrograde obturation material, which insures an optimal healing at the peri-apical level insuring the bony apposition at this level.