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All Journal AL KAUNIYAH Teknosains: Media Informasi Sains dan Teknologi BERITA BIOLOGI Bioma : Jurnal Ilmiah Biologi
Stella Magdalena
Atma Jaya Catholic University of Indonesia
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Education Immunology & microbiology Materials Science & Nanotechnology Physics

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DETECTION OF QUORUM QUENCHING -PRODUCING BACTERIA FROM RHIZOSPHERE SOIL AS A BIOCONTROL AGENTS Stella Magdalena; Inez Johanna; Yogiara Yogiara
Teknosains Vol 15 No 1 (2021): Januari-April
Publisher : Fakultas Sains dan Teknologi Universitas Islam Negeri Alauddin Makassar

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24252/teknosains.v15i1.16178

Abstract

Quorum sensing is known as a communication mechanism among bacteria to control gene expression such as bioluminescence, pigmentation, and pathogenicity. Quorum quenching is known as inhibition of quorum sensing activity. In order to block quorum sensing activity, some bacteria produced enzymes which could degrade AHL, such as AHL-acylase, AHL-lactonase, and AHL-oxidase and reductase. In this study, soil bacteria were isolated and screened for their quorum quenching activity. These isolates were divided into Streptomyces and non-Streptomyces isolates. Detection were done by using Chromobacterium violaceum as an indicator bacteria for pigment inhibition by quorum quenching activity. About 10 out of 695 isolates were shown to possess quorum quenching activity. These isolates were further identified by biochemical tests, Gram staining, and identified by 16S rRNA sequencing. Four positive isolates showed similarity with Streptomyces sp., and 6 positive isolates were non-Streptomyces which showed similarity with Pseudomonas putida, Bacillus pumilus, Bacillus sp., Enterobacter ludwigii, and Enterobacter sp.
The in Vitro Antibiofilm Activity of Bacteria Isolated From Waterfall and Marine Environment Against Human Bacterial Pathogens Stella Magdalena; Natassa Rustandi; Yogiara Yogiara
Al-Kauniyah: Jurnal Biologi Vol 13, No 2 (2020): AL-KAUNIYAH JURNAL BIOLOGI
Publisher : Department of Biology, Faculty of Science and Technology, Syarif Hidayatullah State Islami

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/kauniyah.v13i2.14926

Abstract

AbstrakKKeterlibatan biofilm pada infeksi kronis dan pada permukaan peralatan medis selalu menjadi wacana penting bagi kesehatan umum di dunia. Biofilm bakteri berkaitan dengan tingkat resistensi terhadap antibiotik yang menjadikan infeksi sulit untuk diobati. Untuk mengatasi masalah ini, pengendalian yang efektif perlu diimplementasikan, seperti penerapan senyawa antibiofilm. Beberapa tahun terakhir, lingkungan akuatik menjadi salah satu sumber potensi penghasil senyawa bioaktif, termasuk senyawa antibiofilm. Tujuan dari penelitian ini yaitu menapis dan mengkarakterisasi bakteri asal air terjun dan laut yang diperoleh dari beberapa lokasi di Indonesia, sebagai penghasil aktivitas antibiofilm. Isolat dievaluasi berdasarkan kemampuan aktivitas antimikroba terhadap enam bakteri patogen dan diikuti dengan penapisan senyawa antibiofilm. Sebanyak 11 dari 65 isolat menunjukkan aktivitas quorum sensing atau quorum quenching, dan hanya terdapat satu isolat yang memiliki aktivitas keduanya. Supernatan kesebelas isolat menunjukkan penghambatan pembentukan biofilm setidaknya terhadap satu patogen dengan metode uji biofilm statis. Karakterisasi senyawa bioaktif dari lima isolat yang terpilih menunjukkan aktivitas senyawa yang berbeda, seperti karbohidrat, protein, dan asam nukleat. Sekuensing gen penyandi 16S rRNA menetapkan kelima isolat tersebut berada dalam dua genus yang berbeda, Vibrio (WK2.4, WK2.6, and WK2.3) dan Pseudomonas (S1.2 dan S1.3). Penelitian ini memberikan wawasan baru terhadap pencarian kandidat bakteri akuatik sebagai agen antibiofilm yang potensial. Abstract Biofilm involvement in chronic infections and on the surface of medical equipment have been considered as public health concern worldwide. Bacterial biofilm is related to antibiotic resistance, making the diseases difficult to treat. An effective control strategy should be implemented, for example, by applying antibiofilm agents. The use of aquatic environment as potential sources of bioactive compounds, including the antibiofilm compounds, is recently of concern. This study aimed to screen and characterize bacteria with antibiofilm activity that were isolated from waterfall and marine environment and obtained from several locations in Indonesia. The isolates were firstly evaluated for their antimicrobial activity against six bacterial pathogens and followed by antibiofilm screening. Eleven out of 65 isolates showed quorum sensing or quorum quenching activity, and one of them showed both activities. Supernatants of 11 isolates inhibited biofilm formation of at least one pathogen by using static biofilm assay. Bioactive compounds characterization of the selected five isolates revealed the presence of different compounds, such as carbohydrates, proteins, and nucleic acids. The 16S rRNA gene sequencing analysis classified five isolates into two different genera, namely Vibrio (WK2.4, WK2.6, and WK2.3) and Pseudomonas (S1.2 and S1.3). The present study provides insights into the discovery of aquatic bacteria candidates as antibiofilm agents.
CHARACTERIZATION OF SUPERNATANT EXTRACT AND VIABILITY OF BACILLUS SUBTILIS KM16 AND PSEUDOMONAS SPP. IN FISH FEED AS BIOCONTROL AGENTS AGAINST AQUACULTURE PATHOGENS Stella Magdalena; Brenda Kristanti; Yogiara Yogiara
BERITA BIOLOGI Vol 20, No 1 (2021)
Publisher : Research Center for Biology-Indonesian Institute of Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/beritabiologi.v20i1.3973

Abstract

The use of biocontrol agent in aquaculture is being adapted as an effective alternative to antibiotics which can lead to the elaboration of antibiotic-resistant bacteria and confer unpleasant impacts to aquatic organisms. Aquatic bacteria have been discovered as biocontrol agents and potential probiotic candidates to improve the health of aquatic organisms, feed efficiency, and disease resistance to aquaculture pathogens. However, local isolate has not intensively been explored and used to increase aquaculture sector productivity. Therefore, this research aimed to determine minimum inhibitory concentrations of their antibacterial compounds against aquaculture pathogens and to characterize aquatic bacteria by their viability in the feed. Four isolates from several aquatic environments in Indonesia (Pseudomonas sp. S1.1, Pseudomonas sp. S1.2, Pseudomonas sp. SL1.1, and Bacillus subtilis KM16) were used to characterize of antibacterial compound and to determine the viability in feed. Ethyl acetate extracts from all isolates showed better antibacaterial activity against Aeromonas hydrophila and Vibrio vulnificus than chloroform and dichloromethane extracts, in which ethyl acetate extract from Bacillus subtilis KM16 showed the strongest antibacterial activity. Pseudomonas spp. were more effective against V. vulnificus (40 mg/mL) and Bacillus subtilis KM16 was more effective against A. hydrophila (20 mg/mL), as proved by the minimum inhibitory concentrations of their ethyl acetate extracts. In this research, Bacillus subtilis KM16 had stable viability in feed than Pseudomonas sp. isolates. 
INDUCTION ENDOSPORE FORMATION OF Bacillus subtilis KM16 AS A PROBIOTIC CANDIDATE BY OPTIMIZATION OF THE GROWTH CONDITIONS Stella Magdalena; Adelaide Geraldine; Yogiara
BIOMA : Jurnal Ilmiah Biologi Vol. 13 No. 1 (2024): April 2024
Publisher : LPPM Universitas PGRI Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26877/bioma.v13i1.418

Abstract

Probiotics are living microorganisms which have beneficial effects. One of the benefits is enhancing immunity. Therefore, probiotics are often supplemented into food, medical, and aquaculture products. B. subtilis KM16 as endospore-producing bacteria have been known to increase probiotic resistance to confront the unstable conditions of the digestive tract. Spore formation of Bacillus is supported by the optimal condition of growth medium and incubation periods. The sufficient availability of carbon, nitrogen, and mineral source in the growth medium, and environmental conditions can support the formation of optimal endospores. This research aimed to determine the suitable sugar composition of a medium and optimum incubation time suitable for endospores formation of B. subtilis KM16. Glucose and maltose were utilized as a carbon source in several concentration as a growth medium for B. subtilis KM 16. The incubation time was 48 and 72 hours. The viable number of vegetative cells was not significantly different for the type of sugar and incubation periods. Based on the glucose concentration, 0.2% glucose exhibited the uppermost number of cells, while 1% glucose concentration caused the decrease of vegetative cells. In this study, 0.2% glucose with 48 hours incubation period showed the highest percentage of sporulation frequencies, up to 48%, but it was not significantly different from the other glucose concentration. The medium that contains 0.2% glucose with 48 hours incubation period is the best medium for the utilization of B. subtilis KM16 cells and spores as probiotic candidates.
Co-Authors Adelaide Geraldine Brenda Kristanti Inez Johanna Natassa Rustandi Yogiara Yogiara Yogiara