scholarly journals ISOLASI BAKTERI DARI TANAH SEBAGAI PENGHASIL SENYAWA ANTIMIKROB

Biospecies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 46-51
Author(s):  
Sukmawati Sukmawati ◽  
FEBRIANTI ROSALINA

Antibiotik adalah bahan obat yang sangat memegang peranan penting dalam menanggulangi penyakit infeksi. Senyawa antimikroba dapat diperoleh dari tumbuh-tumbuhan, dan mikroba. Senyawa antimikrob yang dihasilkan oleh mikroba memiliki keunggulan dibandingkan dengan antibiotik sintetik karena memiliki sifat yang lebih efektif, sebab targetnya spesifik serta toksisitasnya rendah. Tujuan dari penelitian yang telah dilakukan ialah untuk mengisolasi bakteri dari tanah yang mampu menghasilkan senyawa antimikrob, serta untuk menguji aktivitas penghambtannya terhadap  pertumbuhan Escherichia coli dan Staphylococcus aureus. Metode yang telah digunakan dalam penelitian ini ialah isolasi, purifikasi, dan seleksi bakteri dari sampel tanah dengan metode uji penghambatan sedangkan bakteri Bacillus sp. Merupakan bakteri pembanding. Berdasarkan hasil penelitian yang diperoleh terdapat 2 isolat yang berpotensi memiliki aktivitas antimikroba yaitu isolat 1 dan isolate 4. Isolat 1 lebih berpotensi menghambat E. coli dengan indeks hambat 4.0 mm dibandingkan dengan penghambatan S. aureus dengan indeks hambat 3.1 mm. Sedangkan isolat 4 lebih berpotensi menghambat S. aureus dengan indeks hambat 2.8 mm dibandingkan dengan penghambatan terhadap E. coli dengan indeks hambat 1.4 mm.

2020 ◽  
Vol 5 (1) ◽  
pp. 1-10
Author(s):  
Risky Hadi Wibowo ◽  
Sipriyadi Sipriyadi ◽  
Welly Darwis ◽  
Santi Nurul Kamilah ◽  
Hizkia Puspa Pertiwi ◽  
...  

Pulau Enggano merupakan salah satu pulau terluar di Indonesia yang memiliki keragaman biota yang cukup tinggi, salah satunya adalah hewan spons. Spons adalah sekelompok hewan multiseluler, memiliki ciri tubuh berpori, dan organisme invertebrata berguna dalam memproduksi senyawa bioaktif. Bakteri yang terkait dengan spons dapat menjadi sumber alternatif senyawa bioaktif baru, terutama antimikrob. Penelitian ini bertujuan untuk mengetahui potensi bakteri yang terkait dengan Aplysina sp. asal Pulau Enggano sebagai penghasil senyawa antimikrob melawan mikrob patogen. Total 263 isolat berhasil diisolasi pada media agar-agar Sea water Complete (SWC). Isolat bakteri potensial selanjutnya diidentifikasi dengan pengamatan morfologi, pewarnaan Gram, serta dilanjutkan dengan uji biokimia. Hasil uji aktivitas antimikrob dari 16 isolat terpilih melalui uji antagonis, supernatan dan pelet terhadap mikrob patogen Escherichia coli, Staphylococcus aureus, Pseudomonas aeroginosa dan Candida albicans menunjukkan bahwa isolat ENG-4 memiliki kemampuanmenghambat pada dua mikrob pathogen yaitu E. coli, S. aureus. Isolat ENG-4 termasuk ke dalam bakteri gram positif dan merujuk pada genus Bacillus berdasarkan uji biokimia.POTENTIAL OF ISOLATE Bacillus sp. ENG-4 ASSOCIATED WITH MARINE SPONGE Aplysina sp. PRODUCING ANTIMICROBIAL COMPOUNDS FROM ENGGANO ISLAND. Enggano Island is one of the outer islands in Indonesia that has a high diversity of marine biota, one of them are sponges. Sponge is a group of multicellular animals, has a characteristic porous body, and invertebrate organisms are useful in producing bioactive compounds. Bacteria associated with sponges can be an alternative source of new bioactive compounds, especially antimicrobial. This study aims to determine the potential of bacteria associated with Aplysina sp. from Enggano island as a producer of antimicrobial compounds against pathogenic microbes. Total 263 isolates were successfully isolated in Sea water Complete (SWC) agar media. Potential isolates were further identified morphologically, Gram staining, and also biochemical tests. The results of the antimicrobial activity test of 16 selected isolates through antagonist, supernatant and pellet tests on pathogenic microbes of Escherichia coli, Staphylococcus aureus, Pseudomonas aeroginosa and Candida albicans showed that the ENG-4 isolate had the ability to inhibit two spesies of pathogens which are E. coli and S. aureus. ENG-4 isolate belong to gram-positive bacteria and refer to the genus Bacillus based on biochemical tests.


2021 ◽  
Vol 22 (2) ◽  
pp. 198-206
Author(s):  
Edelina Sinaga ◽  
Ni Wayan Kurniani Karja ◽  
Andriani Andriani ◽  
Amrozi Amrozi

Penelitian ini bertujuan untuk mengisolasi dan mengidentifikasi bakteri penyebab endometritis pada sapi Frisian Holstein (FH) serta menganalisis efektivitas nanokitosan secara in vitro terhadap bakteri penyebab endometritis. Sampel dikoleksi dari enam ekor sapi FH yang mengalami endometritis subklinis setelah dilakukan pemeriksaan dengan ultrasonografi/USG, kemudian dilakukan perhitungan jumlah koloni, isolasi dan identifikasi bakteri. Nanokitosan diukur kadar proteinnya dan dibuat menjadi pH netral dengan konsentrasi 0,5%, 1% dan 2% untuk digunakan pada tahap uji tantang dengan bakteri endometritis yang ditemukan. Hasil penelitian menunjukkan total plate count (TPC) pada cairan endometrium sapi FH paling tinggi terdapat pada sapi perah FH nomor 626 sebanyak 4,7 ± 0,6 Log sel/ mL dan terendah terdapat pada nomor 532 sebanyak 3,3 ± 0,8 Log sel/mL. Beberapa bakteri Gram negatif yang ditemukan pada penelitian ini yaitu Escherichia coli, Pseudomonas aeruginosa, dan Klebsiella sp. Bakteri Gram positif yang ditemukan adalah Staphylococcus aureus, Bacillus sp. dan S. pyogenes. Ujitantang nanokitosan pada bakteri E. coli dengan konsentrasi 1% dan 2% menunjukkan hasil yang tidak siginifikan jika dibandingkan dengan kontrol positif (P>0,05). Nanokitosan dengan semua konsentrasi mampu menurunkan jumlah bakteri Klebsiella sp. dan P. aeruginosa serta pada bakteri Bacillus sp. secara signifikan jika dibandingkan dengan kontrol negatif (P<0,05). Uji tantang nanokitosan 0,5% dan 2% mampu menurunkan jumlah koloni S. aureus tetapi tidak dapat menurunkan jumlah koloni S. pyogenes. Dapat disimpulkan bahwa pemberian nanokitosan sebagai antibakteri mampu menurunkan jumlah koloni bakteri Gram negatif (E. coli, Klebsiella sp. dan P. aeruginosa) dan Gram positif (Bacillus sp dan S. aureus).


2018 ◽  
Vol 41 (4) ◽  
pp. 353-363
Author(s):  
Alberto J. Valencia-Botin ◽  
Melesio Gutiérrez-Lomelí ◽  
Juan A. Morales-Del-Río ◽  
Pedro J. Guerrero-Medina ◽  
Miguel A. Robles-García ◽  
...  

Actualmente existe la necesidad de hacer frente al problema de la resistencia a los antibióticos y al uso indiscriminado de fungicidas químicos en la agricultura. El objetivo de este trabajo fue evaluar el efecto inhibitorio de extractos acuosos, metanólicos, acetónicos y hexánicos de hoja y tallo de Vitex mollis Kunth (Lamiaceae) contra diferentes bacterias (Escherichia coli, Micrococcus luteus, Salmonella enterica y Staphylococcus aureus) y especies del hongo Fusarium (F. verticillioides, F. oxysporum, F. tapsinum y F. oxysporum f.sp. lycopersici) de importancia en la salud y en la agricultura, así como determinar su composición química general. Se determinaron las concentraciones inhibitorias mínimas (CIM) de todos los extractos por la técnica de microdilución, excepto del hexánico, que no presentó inhibición en las bacterias estudiadas. S. enterica fue la bacteria que mostró mayor sensibilidad al extracto metanólico de tallo (CIM = 28 μg mL-1), le siguieron M. luteus (CIM = 32 μg mL-1), S. aureus (CIM = 75 μg mL-1) y E. coli (CIM = 80 μg mL- 1). Los extractos metanólicos y acuosos de tallo presentaron mayor porcentaje de inhibición contra los diferentes tipos de Fusarium evaluados por el método de dilución en agar. Los extractos de V. mollis inhibieron a F. verticillioides entre 62 y 91 % con 120 μg mL-1 de extracto. El orden de las especies de hongos inhibidas por los extractos fue: F. verticillioides > F. oxysporum > F. tapsinum > F. oxysporum f.sp. lycopersici. La composición química de las especies se determinó mediante pruebas para fenoles, taninos, flavonoides, triterpenos, alcaloides, cumarinas y saponinas. Ninguno de los extractos presentó alcaloides y saponinas. Los fenoles (37.1 mg EAG/g muestra seca) y flavonoides (26.8 mg EQ/g muestra seca) fueron los compuestos mayoritarios en los extractos metanólicos y acuosos. En conclusión, se requieren cantidades muy pequeñas de extracto para la inhibición de bacterias y de Fusarium; por lo tanto, V. mollis puede ser considerada una fuente de metabolitos para este fin y en la agricultura como control alternativo dentro de un manejo integrado de enfermedades.


2020 ◽  
Vol 24 (19) ◽  
pp. 2272-2282
Author(s):  
Vu Ngoc Toan ◽  
Nguyen Minh Tri ◽  
Nguyen Dinh Thanh

Several 6- and 7-alkoxy-2-oxo-2H-chromene-4-carbaldehydes were prepared from corresponding alkyl ethers of 6- and 7-hydroxy-4-methyl-2-oxo-2H-chromen-2-ones by oxidation using selenium dioxide. 6- and 7-Alkoxy-4-methyl-2H-chromenes were obtained with yields of 57-85%. Corresponding 4-carbaldehyde derivatives were prepared with yields of 41-67%. Thiosemicarbazones of these aldehydes with D-galactose moiety were synthesized by reaction of these aldehydes with N-(2,3,4,6-tetra-O-acetyl-β-Dgalactopyranosyl) thiosemicarbazide with yields of 62-74%. These thiosemicarbazones were screened for their antibacterial and antifungal activities in vitro against bacteria, such as Staphylococcus aureus, Escherichia coli, and fungi, such as Aspergillus niger, Candida albicans. Several compounds exhibited strong inhibitory activity with MIC values of 0.78- 1.56 μM, including 8a (against S. aureus, E. coli, and C. albicans), 8d (against E. coli and A. niger), 9a (against S. aureus), and 9c (against S. aureus and C. albicans).


2020 ◽  
Vol 15 (6) ◽  
pp. 665-679
Author(s):  
Alok K. Srivastava ◽  
Lokesh K. Pandey

Background: [1, 3, 4]oxadiazolenone core containing chalcones and nucleosides were synthesized by Claisen-Schmidt condensation of a variety of benzaldehyde derivatives, obtained from oxidation of substituted 5-(3/6 substituted-4-Methylphenyl)-1, 3, 4-oxadiazole-2(3H)-one and various substituted acetophenone. The resultant chalcones were coupled with penta-O-acetylglucopyranose followed by deacetylation to get [1, 3, 4] oxadiazolenone core containing chalcones and nucleosides. Various analytical techniques viz IR, NMR, LC-MS and elemental analysis were used to confirm the structure of the synthesised compounds.The compounds were targeted against Bacillus subtilis, Staphylococcus aureus and Escherichia coli for antibacterial activity and Aspergillus flavus, Aspergillus niger and Fusarium oxysporum for antifungal activity. Methods: A mixture of Acid hydrazides (3.0 mmol) and N, Nʹ- carbonyl diimidazole (3.3 mmol) in 15 mL of dioxane was refluxed to afford substituted [1, 3, 4]-oxadiazole-2(3H)-one. The resulted [1, 3, 4]- oxadiazole-2(3H)-one (1.42 mmol) was oxidized with Chromyl chloride (1.5 mL) in 20 mL of carbon tetra chloride and condensed with acetophenones (1.42 mmol) to get chalcones 4. The equimolar ratio of obtained chalcones 4 and β -D-1,2,3,4,6- penta-O-acetylglucopyranose in presence of iodine was refluxed to get nucleosides 5. The [1, 3, 4] oxadiazolenone core containing chalcones 4 and nucleosides 5 were tested to determined minimum inhibitory concentration (MIC) value with the experimental procedure of Benson using disc-diffusion method. All compounds were tested at concentration of 5 mg/mL, 2.5 mg/mL, 1.25 mg/mL, 0.62 mg/mL, 0.31 mg/mL and 0.15 mg/mL for antifungal activity against three strains of pathogenic fungi Aspergillus flavus (A. flavus), Aspergillus niger (A. niger) and Fusarium oxysporum (F. oxysporum) and for antibacterial activity against Gram-negative bacterium: Escherichia coli (E. coli), and two Gram-positive bacteria: Staphylococcus aureus (S. aureus) and Bacillus subtilis(B. subtilis). Result: The chalcones 4 and nucleosides 5 were screened for antibacterial activity against E. coli, S. aureus and B. subtilis whereas antifungal activity against A. flavus, A. niger and F. oxysporum. Compounds 4a-t showed good antibacterial activity whereas compounds 5a-t containing glucose moiety showed better activity against fungi. The glucose moiety of compounds 5 helps to enter into the cell wall of fungi and control the cell growth. Conclusion: Chalcones 4 and nucleosides 5 incorporating [1, 3, 4] oxadiazolenone core were synthesized and characterized by various spectral techniques and elemental analysis. These compounds were evaluated for their antifungal activity against three fungi; viz. A. flavus, A. niger and F. oxysporum. In addition to this, synthesized compounds were evaluated for their antibacterial activity against gram negative bacteria E. Coli and gram positive bacteria S. aureus, B. subtilis. Compounds 4a-t showed good antibacterial activity whereas 5a-t showed better activity against fungi.


2020 ◽  
Vol 10 (3) ◽  
pp. 316-329
Author(s):  
Fateme Mirzajani ◽  
Amin Hamidi

Introduction: In this project, the growth and volatile metabolites profiles of Escherichia coli (E. coli ) and Staphylococcus aureus were monitored under the influence of silver base chemical, nanoparticle and ultra-highly diluted compounds. Materials & Methods: The treatments were done for 12000 life cycles using silver nanoparticles (AgNPs) as well as ultra-highly diluted Argentum nitricum (Arg-n). Volatile organic metabolites analysis was performed using gas chromatography mass spectrometry (GC-MS). The results indicated that AgNPs treatment made the bacteria resistant and adapted to growth in the nanoparticle condition. The use of ultra-highly diluted Arg-n initially increased growth but it decreased later. Also, with the continuous usage of these materials, no more bacterial growth was observed. Results: The most important compounds produced by E. coli are Acetophenone, Octyl acetate, Styrene, 1,8-cineole, 4-t-butyl-2-(1-methyl-2-nitroethyl)cyclohexane, hexadecane and 2-Undecanol. The main compounds derived from S. aureus are Acetophenone,1,8-cineole, Benzaldehyde, 2-Hexan-1-ol, Tridecanol, Dimethyl Octenal and tetradecane. Acetophenone and 1,8-cineole were common and produced by both organisms. Conclusion: Based on the origin of the produced volatiles, main volatiles percentage of untreated sample is hydrocarbon (>50%), while bacteria treatments convert the ratio in to aldehydes, ketones and alcohols in the case of AgNPs, (>80%) and aldehydes, ketones and terpenes in the case of Arg-n (>70%).


2021 ◽  
pp. 096739112110111
Author(s):  
Hailiang Hu ◽  
Minmin Chen ◽  
Mengye Cao

The eco-friendly functionalized TiO2/polymer antifouling (AF) coating was successfully synthesized by dispersing TiO2 nanoparticles in waterborne epoxy-modified tung oil resin. The AF effectiveness of coating was evaluated toward Staphylococcus aureus ( S. aureus, ATCC6538), Escherichia coli ( E. coli, ATCC8739) and diatom ( Cyclotella sp., FACHB-1635). The nanoTiO2/polymer AF coating showed good antimicrobial activity both under the light and dark conditions by comparison with the pristine TiO2 nanoparticles and bulk polymer. Under light irradiation for 50 min, the AF coating showed only 8.4% and 8% survival rate for S. aureus and E. coli. In addition, The AF coatings exhibited favorable inhibition efficacy toward the growth and adhesion of Cyclotella sp., and the efficacy was enhanced with the increase of TiO2 content. It can be concluded that TiO2 nanoparticles endow the AF coatings with promoted fouling resistance properties.


Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1541
Author(s):  
Jie Zhang ◽  
Jia Wang ◽  
Qingjun Zhu ◽  
Binbin Zhang ◽  
Huihui Xu ◽  
...  

A novel AgBr/Ag2MoO4@InVO4 composite photocatalyst with different heterojunction structures was successfully constructed by compounding InVO4 with Ag2MoO4 and AgBr. According to the degradation, antibacterial and free radical trapping data, the photocatalytic antibacterial and antifouling activities of AgBr/Ag2MoO4@InVO4 composite were evaluated, and the corresponding photocatalytic reaction mechanism was proposed. Adding AgBr/Ag2MoO4@InVO4 composite, the degradation rate of ciprofloxacin (CIP) achieved 95.5% within 120 min. At the same time, the antibacterial rates of Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) achieved 99.99%. The AgBr/Ag2MoO4@InVO4 composite photocatalyst showed promising usage in photocatalytic antibacterial and purification areas.


2018 ◽  
Vol 19 (0) ◽  
Author(s):  
Priscila Alves Dias ◽  
Daiani Teixeira Silva ◽  
Cláudio Dias Timm

Resumo Kefir é o produto da fermentação do leite pelos grãos de kefir. Esses grãos contêm uma mistura simbiótica de bactérias e leveduras imersas em uma matriz composta de polissacarídeos e proteínas. Muitos benefícios à saúde humana têm sido atribuídos ao kefir, incluindo atividade antimicrobiana contra bactérias Gram positivas e Gram negativas. A atividade antimicrobiana de 60 microrganismos isolados de grãos de kefir, frente à Escherichia coli O157:H7, Salmonella enterica subsp. enterica sorotipos Typhimurium e Enteritidis, Staphylococcus aureus e Listeria monocytogenes, foi estudada através do teste do antagonismo. A ação antimicrobiana dos sobrenadantes das bactérias ácido-lácticas que apresentaram atividade no teste do antagonismo foi testada. O experimento foi repetido usando sobrenadantes com pH neutralizado. Salmonella Typhimurium e Enteritidis sobreviveram por 24 horas no kefir em fermentação. E. coli O157:H7, S. aureus e L. monocytogenes foram recuperados até 72 horas após o início da fermentação. Todos os isolados apresentaram atividade antimicrobiana contra pelo menos um dos patógenos usados no teste do antagonismo. Sobrenadantes de 25 isolados apresentaram atividade inibitória e três mantiveram essa atividade com pH neutralizado. As bactérias patogênicas estudadas sobreviveram por tempo superior àquele normalmente utilizado para a fermentação do kefir artesanal, o que caracteriza perigo em potencial para o consumidor quando a matéria-prima não apresentar segurança sanitária. Lactobacillus isolados de grãos de kefir apresentam atividade antimicrobiana contra cepas de E. coli O157:H7, Salmonella sorotipos Typhimurium e Enteritidis, S. aureus e L. monocytogenes além daquela exercida pela diminuição do pH.


Author(s):  
Alequis Tomás Pavón Oro

El cáncer es la segunda causa de muerte en el mundo, y específicamente en Chile el cáncer colorrectal es el único que presenta un aumento sostenido de la mortalidad en la última década. La búsqueda de nuevos agentes quimioterapeúticos anticancerígenos ha propuesto a los microorganismos extremófilos como una fuente potencial para obtener moléculas citotóxicas, que induzcan apoptosis en las células tumorales. Las condiciones extremas del continente antártico y las presiones selectivas por el espacio y los nutrientes que se producen entre los microorganismos del rizobioma de la planta Deschampsia antarctica Desv sugirieron como hipótesis que las bacterias rizosféricas aisladas en la Antártica secretan al sobrenadante de cultivo moléculas bioactivas que inhiben la invasión y proliferación de líneas tumorales humanas de origen colorrectal mediante un mecanismo apoptótico. En este sentido, el objetivo general del trabajo fue identificar y caracterizar a moléculas bioactivas con acción antinvasiva y antiproliferativa, además, determinar el mecanismo inhibitorio de la proliferación en líneas tumorales humanas de origen colorrectal. Los resultados del primer objetivo específico demostraron que los sobrenadantes de cultivo de los aislados rizosféricos antárticos K2 y MI disminuyeron la viabilidad de la línea celular de adenocarcinoma colorrectal LoVo en el ensayo de reducción metabólica del MTT. Además, como los sobrenadantes no tuvieron efecto en la viabilidad de las bacterias E. coli y Staphylococcus aureus, y tampoco en los hongos unicelulares Candida albicans y Saccharomyces cerevisiae, el resultado indicó que la actividad antiproliferativa fue selectiva hacia la línea celular LoVo.


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