Diameter Of Clear Zone Research Articles

Endophytics Bacteria from Pangi Fruit (Pangium edule REINW.) and Its Potential as Producer of Antibacterial Compound

Natural antibacterials can be derived from various types of plants, one of which is the Pangi plant (Pangium edule REINW.). Pangi fruit contains an antioxidant and antibacterial compound that can inhibit bacterial growth. This study aims to determine the isolates of endophytic bacteria contained in Pangi fruit and its potential as a producer of antibacterial compounds against Escherichia coli and Staphylococcus aureus bacteria. This study used exploratory description research method. Results Isolation research of endophytic bacteria from Pangi fruit obtained seven isolates. Each Isolate has a different morphology both from the shape, color, edges, and colony elevation. Based on the results of antibacterial activity testing, each isolate of endophytic bacteria showed different clear zone diameters. Endophytic bacteria showed different clear zone diameters against E. coli (0.75 mm – 4.5 mm) and S. aureus (1 mm – 5 mm). Endophytic bacterial isolates That have the potential as antibacterial with the largest clear zone diameter are Isolate PA 2.1 (4.5 mm) against E. c oli and isolate PA 3.2 (5 mm) against the bacteria S. aureus. Based on the results of morphological characterization of isolate PA 1.1 has similarities with the genus Basillus sp., isolates PA 1.2, PA 1.3 PA 2.2, PA 3.1 and PA 3.2 have similarity with the genus Basillus sp. PA 3.2 has similarities with the genus Paracoccus alcaliphilus and isolate PA 2.1 has similarities with the genus Alcaligenes sp.

Characterization of Pectinase Enzyme Produced from Indigenous Yeast Isolates During Fermentation of Robusta Coffee Beans

The following research aims to understand indigenous yeast isolates that are pectinolytic, the effect of incubation time on pectinase enzyme activity, and the pH and temperature properties of pectinase enzymes obtained from indigenous yeasts from spontaneous fermentation of robusta coffee beans. The following type of research is an experiment through RAL (Completely Randomized Design). The results showed that testing of seven indigenous yeast isolates was pectinolytic and that the highest pectinolytic ability was isolate K24I7 with a clear zone diameter of 3.13 mm. The characterization results of the pectinase enzyme produced from isolate K24I7 were optimum at pH 5.5 with an enzyme specific activity value of 10.09 U/mg and optimum temperature in the range of 40oC-60oC with an average enzyme specific activity of 10.08 U/mg. The pectinase enzyme produced from isolate K24I7 is thermophile because it is still active at 70°C

Cellulase gene expression in the thermophilic Thermomyces lanuginosus isolated from compost

Thermophilic fungi are superlative microorganisms for enzyme production, especially cellulase, and their using in biotechnological applications is due to their stability at utmost temperatures. In the current investigation, we isolated six genera encompassing six fungal species and one species variety from 30 samples of compost at 45 °C and 55 °C. Thermomyces lanuginosus was the most rampant species. The colony diameter of T. lanuginosus ranged from 2.8 to 4.3 cm at 45 °C on yeast-starch agar (YpSs) medium with white or greyish-brown mycelia. Fifteen isolates of T. lanuginosus were cellulase producers with variable competencies with a C/Z range of 1.09–1.38 cm. Fascinatingly, the clear zone diameter was much bigger when using Iodine than those obtained using Congo red. T. lanuginosus isolate no. 33 produced substantial amounts of cellulase on the four used media: Corncob (CC), Corncob treated with NaOH (C-NA), Yeast Peptone Dextrose (YPD), and CarboxyMethyl Cellulose (CMC) with the highest activity on CC; 143.9 μg/min, also cellulase gene expression levels of cel6Aq, cel7Aq, and bgl3Aq genes exhibited higher fold changes in the CC condition (7.26-fold, 11.51-fold, and 3.39-fold, respectively). X-ray fluorescence (XRF) analysis revealed the presence of 11 minerals with higher concentrations in CC than in C-NA. Supplementation of corncob medium with rosemary essential oil (CR) completely inhibited cellulase production. It adversely affected the growth, and changes in conidia, which were depicted using a scanning electron microscope (SEM). Interestingly, the conidia appeared much bigger than other media, and the large conidia diameter was 10.2–12.1 μm.

Capability lignin from Acacia crassicarpa black liquor as an environmentally benign antibacterial agent to produce antibacterial and hydrophobic textiles

Recently, the growing health awareness of society on the utilization of fabrics has led to an increasing demand for natural-based antibacterial textiles. Lignin, a generous polyphenol compound in nature, is capable of preventing bacterial growth; in particular, it dwells bacteria closely together on human skin, such as Staphylococcus epidermidis, Bacillus subtilis, Propionibacterium acnes, and Staphylococcus aureus. However, the antibacterial properties of lignin are limited by factors such as the lignin concentration, source, and type of bacteria. This study aimed to evaluate the potency of lignin as an antibacterial agent for textiles. Moreover, the thermal properties and wettability of the textile after lignin coating were also investigated. This study showed that lignin isolation methods significantly contributed to the inhibition of bacterial growth in the clear zone diameter. In addition, the lignin structure, lignin concentration, and type of bacteria had notably different antibacterial effects. SEM images showed that lignin was successfully coated on the fiber, and the antibacterial textile was successfully fabricated with clear zones in the range of 0.1–0.5 cm against four different bacteria. Lignin did not significantly improve the thermal stability of the textile, as proven by the TGA results. After the HDTMS coating by dispersion method, the wettability of the lignin-textile improved to that of the hydrophobic material, with a contact angle greater than 119.05° with excellent antibacterial properties (clear zone of 0.1–0.43 cm).

Termite gut microbiome being a rich source of potential lignocellulolytic bacterial strains

A study was carried out to identify prospective cellulose degrading bacteria isolated from termite gut collected from various agriculture sites. Eight of the bacterial isolates displayed a very distinct zone of clearing on CMC (Carboxylmethyl cellulose) agar media after staining with 1% Congo red, indicating that they may have cellulose degrading ability. On a CMC agar plate, CRDB6 had the largest colony diameter (3.08 cm) as well as clear zone diameter (0.96 cm), however CRDB 1 has maximum cellulolytic activity (1.45 cm) followed by CRDB5 and CRDB6 (1.33 cm and 1.28 cm) respectively. CRDB3, CRDB4 and CRDB9 showed Gram negative reaction among crop residue degrading bacterial isolates, while the remainder showed Gram positive reaction. The morphological characteristics of the bacteria isolates, such as colony shape, elevation, margin, colour and opacity, differed. Isolates CRDB6 produced highest β-glucosidase activity (12.66 m L-1) followed by CRDB1 (12.20 mg m L-1) and CRDB5 (10.21 m L-1) in Luria broth culture. Indole acetic acid production (with tryptophan) was greater in CRDB1 (389.33 mg/ml), CRDB6 (356.9 m L-1) and CRDB3 (315.96 m L-1) while as P-solubilization potential was peaked in CRDB6 (2.41 m L-1) followed by CRDB4 (1.76 m L-1) and CRDB3. Overall, isolate CRDB6 exhibited the highest cellulolytic activity as compared to rest of the bacterial isolates. These results will help in preparing bacterial consortia for the management of crop residues.

Green Synthesis and Characterization of 4'-Hydroxy-4-Nitro Chalcone using Grinding Techniques

<p>The challenge of developing environmentally friendly synthesis methods for biologically active compounds remains a significant focus in green chemistry. This study aimed to synthesize 4'-hydroxy-4-nitro chalcone from 4-hydroxyacetophenone and 4-nitrobenzaldehyde using a grinding technique and then characterize the synthesized compounds. The 4'-hydroxy-4-nitro chalcone was synthesized via the Claisen-Schmidt grinding method for 45 minutes at room temperature. The grinding results were extracted with chloroform. The formed crystals were tested for purity by thin-layer chromatography (TLC), and further purification was carried out by recrystallization. The synthesized chalcone was characterized using <strong>FTIR,<sup> 1H</sup>-NMR</strong>, and <strong><sup>13</sup>C-NMR</strong> spectroscopy. The chalcone was also tested for antibacterial activity using the disc diffusion method against <em>Staphylococcus aureus</em> and <em>Escherichia coli</em>. The results showed that 4'-hydroxy-4-nitro chalcone could be successfully synthesized from 4-hydroxyacetophenone and 4-nitrobenzaldehyde using the grinding technique, yielding orangish-white crystals with a 70.63% yield and a melting point of 173°C. Purity was confirmed by TLC, and structural characterization was achieved through <strong>FTIR, <sup>1</sup>H-NMR</strong> and <strong><sup>13</sup>C-NMR</strong> spectroscopy. Antibacterial testing revealed that the synthesized chalcone produced a clear zone diameter of 9.27 mm against <em>S. aureus</em> and 27.88 mm against <em>E. coli</em>. These results indicate that the compound has relatively strong antibacterial activity against <em>E. coli</em> and relatively weak activity against <em>S. aureus</em>. This study demonstrates the effectiveness of the green synthesis method and provides valuable insights into the antibacterial properties of 4'-hydroxy-4-nitro chalcone</p>

Characterization of endophytic bacteria isolated from wild rice plants in the Mekong Delta, Vietnam

Abstract. Thi QVC, Minh NLK, Thuy NP, Tat TQ, Tran T. 2024. Characterization of endophytic bacteria isolated from wild rice plants in the Mekong Delta, Vietnam. Biodiversitas 25: 2576-2585. Endophytic bacteria bring many benefits to plants, such as stimulating plant growth and inhibiting many microbial pathogens that cause plant diseases. Hence, this investigation aimed to evaluate the association of endophytic bacteria with wild rice (Oryza rufipogon) that can fix nitrogen, solubilize phosphorus and produce indole-3-acetic acid (IAA). Twelve-five bacterial strains were recovered from wild rice stems and roots collected from Vinh Long and Tien Giang provinces of the Mekong Delta. Among these strains, six had phosphorus solubilizing and seven had nitrogen-fixing activity. Strain BR3.5 fixed the highest nitrogen, i.e. ammonia (NH4+) content of 0.109 ± 0.002 mg/L after eight-day incubation. However, the highest phosphorus solubilization was recorded in two isolates, RR3.7 and RR1.1, with clear zone diameters of 0.800 ± 0.020 mm and 0.800 ± 0.030 mm, respectively. In addition, bacterial strains could synthesize IAA, and BR2.5 produced the highest, i.e., 0.067 ± 0.002 ?g/mL, IAA after eight-day incubation. Notably, strain BR3.5 exhibited multiple activities like nitrogen fixation (0.109 ± 0.002 mg/L), phosphorus solubilization (1.02 ± 0.002 mm), and IAA synthesis (0.056 ± 0.00 ?g/mL). Strain BR3.5 was identified as Pantoea sp. based on 16S rRNA gene sequencing (92.69% similarity) together with morpho-physiological and biochemical characteristics. The findings indicate that strain BR3.5 may be used for the production of biofertilizers for rice farming.

Bio-synthesis, purification and structural analysis of Cyclosporine-A produced by Tolypocladium inflatum with valorization of agro-industrial wastes

Cyclosporine A (CyA) holds significant importance as a strategic immunosuppressive drug for organ transplant patients. In this study, we aimed to produce pure and cost-effective Cyclosporine A (CyA) by fermenting a culture medium containing dairy sludge, using Tolypocladium inflatum PTCC 5253. Following the fermentation stage, ethyl acetate extraction and fast protein liquid chromatography were employed for sample purification. The initial evaluation of the effectiveness of CyA obtained from these processes was performed through bioassay, wherein the antimicrobial clear zone diameter was found to be larger compared to the sample obtained from the fermentation culture. The concentration of CyA was determined using high-performance liquid chromatography, yielding values of 334 mg/L, 456 mg/L, and 578 mg/L for the fermented, extracted, and purified samples, respectively. Further analysis utilizing liquid chromatography tandem mass spectrometry (LC/MS/MS) confirmed a purity of 91.9% and proper agreement with the standard sample based on the ion intensity of Z/m 1205. To validate the structure of CyA, nuclear magnetic resonance spectroscopy, Fourier-transform infrared (FT-IR), and Raman spectroscopy were employed. X-ray diffraction and differential scanning calorimetry analyses demonstrated that the purified CyA exhibited a crystal structure similar to the standard sample, characterized by two broad peaks at 2θ = 9° and 20°, and comparable glass transition temperatures (57–68 °C for the purified sample; 53–64 °C for the standard sample). Dynamic light scattering analysis confirmed a uniform particle size distribution in both the purified and standard samples. The zeta potentials of the purified and standard samples were determined to be − 25.8 ± 0.16 and − 23.63 ± 0.12 mV, respectively. Our results demonstrate that dairy sludge can serve as a suitable culture medium for the production of (CyA).

Pediatric Urinary Tract Infections at a Tertiary Care Center: Microbial Diversity and Antibiotic Resistance Patterns

Abstract Introduction: Urinary tract infection (UTI) remains a prevalent bacterial infection among the pediatric age group, ranking as the third-most common bacterial infection in children in developing countries, following gastrointestinal and respiratory tract infections. It continues to pose a significant health challenge. Materials and Methods: The urine samples underwent gross examination, wet mount, and Gram stain. Semiquantitative cultures were conducted on conventional media (MacConkey agar, blood agar, and CLED agar) and UTI chromogenic media. Uropathogen identification employed standard microbiological techniques. Antibiotic susceptibility was determined using the Kirby–Bauer disk diffusion method, with interpretation based on CLSI guidelines. Plates were incubated overnight, and clear zone diameters around antibiotic discs were measured for sensitivity or resistance determination. Results: The study comprised 64.75% male children and 35.25% female children. Analyzing the age distribution, the majority of participants fell within the age range of 1–5 years (35%), followed by those <1 year (33.75%), and the age group of 5–12 years, accounting for 31.25% of the total 400 participants. The findings from our investigation revealed a UTI prevalence of 17.25%, with Escherichia coli and Klebsiella emerging as the predominant uropathogens. Notably, these pathogens exhibited a significant susceptibility to carbapenems, nitrofurantoin, and amikacin. Conclusion: Our study identified a male predominance and various age distributions among UTI patients. Antibiotic susceptibility patterns revealed E. coli and Klebsiella pneumoniae’s high sensitivity to key antibiotics, whereas Enterococcus spp. exhibited significant high-level aminoglycoside resistance. This study underscores the importance of tailored antibiotic strategies based on local resistance profiles to combat UTIs effectively.

Synthesis of Schiff Base through the Condensation Reaction Between Cellulose Dialdehyde with Ethylenediamine and Aniline as Well as Antibacterial Activity Test

Schiff base was created using a condensation reaction involving Ethylene diamine or Aniline and dialdehyde cellulose (DAC), which was obtained by oxidizing α-cellulose with sodium periodate as the oxidizing agent. The cellulose dialdehyde was identified through qualitative analysis, which involved observing the formation of a brick red sediment during the Fehling test and a rise in solubility in water. Additionally, the presence of an aldehyde group was confirmed by analyzing the FT-IR spectrophotometer data, which showed a peak at a wave number of 1635.64 cm-1. The synthesized dialdehyde cellulose has an oxidation degree of 80.9% and a carbonyl level of 10.36%. The Schiff base was analyzed using an FT-IR spectrophotometer, which revealed peaks at wave numbers 1635.64 cm-1 and 1604.77 cm-1. These peaks suggest the creation of a Schiff base bond (C=N) resulting from the condensation of the amine group from Ethylene diamine and Aniline with the aldehyde group from DAC. The antibacterial activity of Schiff bases was evaluated using the disc plate diffusion method. The Schiff base resulting from the condensation of DAC with Ethylenediamine at concentrations of 0.15%, 0.30%, and 0.45% was tested against S.aureus and E.coli. Clear zones of inhibition were seen, indicating the antibacterial effect. The Schiff base resulting from the condensation of DAC with Aniline at concentrations of 0.15%, 0.30%, and 0.45% showed clear zone diameters of 6.9 mm, 9 mm, and 12.5 mm against S.aureus and 7 mm, 12.5 mm, and 13 mm against E.coli. The clear zone diameters in a row were 10 mm, 10.8 mm, and 20.1 mm against S.aureus and 10.5 mm, 14.6 mm, and 17.1 mm against E.coli. The condensation of dialdehyde cellulose with ethylene diamine and Aniline leads to Schiff base formation. This Schiff base has antibacterial characteristics that are effective against S.aureus and E.coli.

Antibacterial activity of ethanol extract of limpasu (Baccaurea lanceolata) pericarpium with the ultrasound assisted extraction method against Propionibacterium acne

Background: Acne, a prevalent skin condition, can arise from factors such as an unhealthy lifestyle, dietary habits, hormonal imbalances, and bacterial infections. Propionibacterium acnes is a notable bacterium responsible for acne. In South Borneo, the pericarpium of the limpasu plant (Baccaurea lanceolata) is traditionally used to treat acne. Objective: This study aims to scientifically validate the empirical antibacterial effects of limpasu pericarpium against Propionibacterium acnes, as reported by the communities in South Borneo. Methods: The ultrasound-assisted extraction (UAE) method was utilized to extract compounds from limpasu pericarpium. The antibacterial activity of the limpasu pericarpium extract was evaluated using the disc diffusion method at concentrations of 20%, 40%, 60%, 80%, and 100% w/v. Clindamycin served as the positive control, and 1% DMSO was the negative control. Results: The lowest concentration (20%) fell within the strong activity category, producing a clear zone diameter of 18.76 mm. Higher concentrations (40%, 60%, 80%, and 100%) demonstrated more potent antibacterial effects, with inhibition zones of 23.23 mm, 26.06 mm, 26.93 mm, and 27.33 mm, respectively. Notably, 60% to 100% concentrations exhibited greater inhibitory effects than the positive control, clindamycin, which had an inhibition zone of 25.23 mm. Conclusion: The study confirms the antibacterial properties of limpasu pericarpium against Propionibacterium acnes, supporting the traditional claims of its efficacy by the South Borneo communities.

Antibacterial activity of the black soldier fly (Hermetia illucens) larva protein hydrolysates against some pathogenic bacterial strains on freshwater fish

The study was carried out to determine the antibacterial activity of protein hydrolysates from black soldier fly (Hermetia illucens) larva (PHBSF) on some pathogenic bacteria including E. ictaluri, A. hydrophila, A. verroni, and S. agalactiae on freshwater fish. The results showed that the tested bacteria were highly sensitive with significant difference (P < 0.05) in diameter clear zone compared to the negative control at the tested concentrations of 20, 35, and 70 mg/100 µL. Particularlly, E. ictaluri was sensitive at all three test concentrations with the diameter of clear zones following 14.0 ± 1.0, 18.7 ± 0.7, and 20.7 ± 0.7 mm, respectively. A. veronii and S. agalactiae were sensitive at concentrations of 35 and 70 mg/100 µL, and A. hydrophila with a clear zone diameter of 14.3 ± 0.3 mm at the concentration of 70 mg/100 µL. The PHBSF was able to kill A. veronii and S. agalactiae with MIC (minimum inhibitory concentration) = MBC (minimum bactericidal concentration) = 44 mg/mL, while E. ictaluri and A. hydrophila were inhibited at MIC 44 mg/mL, and MBC was 88 mg/mL. These results indicated that PHBSF could be potentially used to prevent fish diseases caused by E. ictaluri, A. hydrophila, A. verroni, and S. agalactiae.

Antibacterial activity of Shallots (Allium xwakegi Araki.) cultivars in Palu Valley against Salmonella Typhi ATCC 27870 through in vitro and in silico evaluation

Background and Objectives: Shallots, recognized for their minimal toxicity, cost-effectiveness, and widespread avail- ability, are increasingly considered a viable source of biological activity. This study evaluates the antibacterial efficacy of a specific shallot cultivar from Palu Valley, Indonesia, against Salmonella typhi, the pathogen responsible for typhoid fever. Materials and Methods: Utilizing thin-layer chromatography (TLC-bioautography) and gas chromatography-mass spec- troscopy (GC-MS), the study identifies active compounds in shallot ethanol extract and employs molecular docking to assess interactions between receptors and ligands. Results: Findings indicate significant antibacterial activity, with a notable inhibition zone diameter of 31.5 mm at spot Rf 0.28 in TLC bioautography and an optimum concentration of 2% yielding an average clear zone diameter of 28.27 mm in the agar diffusion test. GC-MS analysis reveals 41 compounds, predominantly dodecanoic acid and 1,2,3-propanetriyl ester. Ad- ditionally, molecular docking reveals the lowest binding affinity (-7.3 kcal/mol) for Ergost-8-En-3-Ol, 14-Methyl-, (3.Beta,5. Alpha.) against DNA gyrase. Conclusion: This study confirms Palu Valley shallot extract's potent antibacterial effect against Salmonella typhi, highlight- ing its therapeutic potential.

Plackett–Burman screening of physico-chemical variables affecting Citrus peel-mediated synthesis of silver nanoparticles and their antimicrobial activity

With the growing resistance of pathogenic microbes to traditional drugs, biogenic silver nanoparticles (SNPs) have recently drawn attention as potent antimicrobial agents. In the present study, SNPs synthesized with the aid of orange (Citrus sinensis) peel were engineered by screening variables affecting their properties via Plackett–Burman design. Among the variables screened (temperature, pH, shaking speed, incubation time, peel extract concentration, AgNO3 concentration and extract/AgNO3 volume ratio), pH was the only variable with significant effect on SNPs synthesis. Therefore, SNPs properties could be enhanced to possess highly regular shape with zeta size of 11.44 nm and zeta potential of − 23.7 mV. SNPs purified, capped and stabilized by cloud point extraction technique were then checked for their antimicrobial activity against Bacillus cereus, Listeria innocua, Listeria monocytogenes, Staphylococcus aureus, Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhimurium and Candida albicans. The maximum antimicrobial activity of SNPs was recorded against E. coli, L. monocytogenes and C. albicans with clear zone diameter of 33.2, 31.8 and 31.7 mm, respectively. Based on minimum inhibition concentration and minimum bactericidal concentration of SNPs (300 mg/l) as well as their effect on respiratory chain dehydrogenases, cellular sugar leakage, protein leakage and lipid peroxidation of microbial cells, E. coli was the most affected. Scanning electron microscopy, protein banding and DNA fragmentation proved obvious ultrastructural and molecular alterations of E. coli treated with SNPs. Thus, biogenic SNPs with enhanced properties can be synthesized with the aid of Citrus peel; and such engineered nanoparticles can be used as potent antimicrobial drug against E. coli.

Determination of cellulolytic potentials of <i>Aspergillus</i> species isolated from central waste dump site of Nile University of Nigeria

A large number of microorganisms are capable of degrading cellulose but only a few of these microorganisms produce significant quantities of enzymes capable of completely hydrolyzing cellulose. Fungi are the main cellulase-producing microorganisms. This study was aimed to determine the cellulolytic potentials of Aspergillus species isolated from the central waste dump site of Nile University of Nigeria. In this study, fungal species were isolated from soil samples obtained from waste dump site using pour plate technique. The isolates were characterized using cultural and morphological features as well as microscopic examination. Aspergillus flavus, Aspergillus niger, and Aspergillus terreus, which were isolated were further screened on carboxymethylcellulose agar for their ability to degrade cellulose. Screening of fungal isolates was performed by plate method. Cellulolytic fungi were evaluated after 5 days for the production of cellulolytic enzymes by staining with 1% Congo red. The diameter of clear zone on fungal plates, gave an approximate indication of cellulase activities. Aspergillus niger had a zone of clearing of 25.50 mm while Aspergillus flavus had 18.50 mm. Aspergillus terreus did not show any cellulolytic activity. Aspergillus niger had the highest occurrence rate of 50%. Aspergillus flavus and Aspergillus terreus both had 25% occurrence rate.

Phytochemical analysis of Indonesian gadung mango leaf (Mangifera indica L. var. gadung) and their antibacterial activity

Abstract. Sulistyarsi A, Rahayu T, Primiani CN, Pujiati. 2023. Phytochemical analysis of Indonesian gadung mango leaf (Mangifera indica L. var. gadung) and their antibacterial activity. Biodiversitas 24: 6295-6304. The study was carried out to find out the secondary metabolite compounds in mango leaf extract (Mangifera indica L. var. gadung) using qualitative, quantitative, LC-MS and antibacterial activity with well diffusion method in inhibiting the growth of Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922. Research used a quantitative approach of randomized block design with variations of concentrations of 60, 80, and 100%, K- (aquadest), and K+ (chloramphenicol) in three times repeated groups. The results of qualitative and quantitative phytochemical tests show that mango leaf extract contains flavonoids (63408.464 mg/kg), saponins 3212.942 mg/kg), tannins (1050.191 mg/kg), alkaloids (605.123 mg/kg) and steroid (1050.191 mg/kg). Test of flavonoid derivat extract using LC-MS shows apigenin, kaempferol, fisetin, catechins, quercetin, ramnetin, astragalin, hirsutrin, isocercitrin, hyperin, rhamnetin 3-glucoside, rhamnetin 3-o-?galactopyranoside, isorhamnetin 3-galactoside, amentoflavone, routine, hyperin-6-gallate, epigallocycin (4??8) epigallocycin-3-ogalate ester. Antibacterial testing on S. aureus forms an average clear zone diameter of 30.46, 31.43, 32.81 mm furthermor in E.coli is 23.23, 23.84, 24.23 mm. Data of clear zone diameter was analyzed using ANOVA two-way and showed a value of sg. 0,001<0,05. It can be concluded that Indonesian gadung mango leaf extract contains secondary metabolites which have the potential to be an antibacterial agent.

Screening of protease-producing lactic acid bacteria from Indonesian fermented fish products and its application in chitin extraction from vannamei shrimp (Litopenaeus vannamei) shell

This study aimed to screen lactic acid bacteria (LAB) from traditional Indonesian fermented fish products, namely wadi and jambal, with high protease activity for chitin production from Litopenaeus vannamei shrimp shells. Twenty-eight colonies were successfully isolated and identified through biochemical tests such as catalase and Gram staining. Seven out of the twenty-eight colonies were identified as lactic acid bacteria based on their Gram-positive and catalase-negative results. These strains from wadi samples were named GWB 1.3, GWB 1.7, and GWB 2.5, while those from jambal samples were named GMJB 1.3, GMJB 1.6, GMJB 2.6, and GMJB 2.7. The protease activity of these strains was tested using the well-diffusion method on skim milk agar to assess their deproteinized activity. The diameter of the clear zone formed after 24, 48, and 72 hours of incubation was measured. GWB 1.7 and GMJB 2.6 showed the largest clear zone diameter with 21.3 mm and 22.5 mm, respectively, and were selected for the single step-fermentation of shrimp shells. The fermentation process was conducted in 6 days with different inoculum ranging from 0%, 5%, 10%, 15%, and 20% (v/v) as treatments. All treatments, including moisture, ash, and protein, were evaluated for proximate content in the final days. The results indicate that the 20% inoculum showed the highest deproteinization and demineralization for both bacterial strains. GWB 1.7 exhibited a demineralization of 43.7% and deproteinization of 25.2%, while GMJB 2.6 showed a demineralization of 39% and deproteinization of 16.1%. This study demonstrated that lactic acid bacteria from wadi and jambal samples could produce chitin from shrimp shells, a valuable biopolymer with various applications.

Pectinase Production by Rhizopus stolonifer A3 Isolated from Apple Peels

The application of pectinase in industries will continue to be developed. To broaden the applicability of enzyme manufacturing in new industries, more research to investigate pectinolytic microorganisms with high activity and stability is still required. Therefore, this study aimed to obtain pectinolytic fungi that have the potential as pectinase producers. Pectinolytic fungi were isolated from rotten apple peels and selected based on clear zone formation on pectic agar media after cetyl trimethyl ammonium bromide (CTAB) staining. Pectinolytic fungi were identified based on 18S rRNA partial gene sequences and morphological characteristics. Pectinase production used Mandels and Weber medium with citrus pectin 20 g l<sup>-1</sup> addition. Pectinase activity was determined based on the measurement of reducing sugars by a colorimetric method. A total of 5 fungal isolates were successfully isolated. All of the isolates had pectinolytic activities with clear zone diameters ranging between 0.99 to 7.32 mm. The isolate A3 showing the highest pectinolytic activity was identified as <em>Rhizopus stolonifer</em>. Microscopically, <em>R</em>. <em>stolonifer </em>A3 showed typical characteristics for <em>Rhizopus</em>, characterized by the presence of rhizoids, stolons and sporangiophores bearing a single spherical sporangium. The pectinase production of <em>R.</em> <em>stolonifer </em>A3 was optimum at initial pH 5.0, temperature 35 °C and incubation period of 3 days with pectinase activity of 14.75 U ml<sup>-1</sup>. <em>R. stolonifer </em>A3 produced acidic pectinase having optimum activity at pH 5.0 and temperature 50 °C. Thus <em>R.</em> <em>stolonifer </em>A3 has the potential to be used as a producer of acidic pectinase appropriate for use in the processing of fruit products.

Antibiotic-Producing Streptomyces sp. Isolated from the Soil of a Mangrove Ecosystem

Highlights: 1. The unexplored soil of mangrove ecosystems in Surabaya, Indonesia, has the potential to be home to biodiversity,including Streptomyces sp. that can produce antibiotics.2. Streptomyces sp. has antibacterial properties against Gram-positive and Gram-negative bacteria, and the duration ofincubation plays a critical role in regulating the antibacterial activity. Abstract A mangrove ecosystem in Surabaya, Indonesia, has a high salinity, pH, potassium, phosphorus, and nitrate contents. This ecosystem comprises a mixture of sand, dust, mud, and clay, which has the potential to be a conducive environment for the isolation of Streptomyces. The importance of Streptomyces in biotechnology lies in its ability to produce bioactive secondary metabolites, which represent a valuable reservoir of antibiotics. This research aimed to assess the antibiotic activity exhibited by Streptomyces sp. isolated from the soil of a mangrove ecosystem in Wonorejo, Surabaya, Indonesia. The analysis focused on the potential of Streptomyces sp. to produce antibiotics that work against Gram-positive bacteria (i.e., Staphylococcus aureus ATCC 25923 and Bacillus subtilis) as well as Gram-negative bacteria (i.e., Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Salmonella Typhimurium). The antibacterial activity test was conducted using the modified agar diffusion method. Observations were performed to identify any clear zone formation around the Streptomyces sp. agar colonies with a diameter of 0.8 cm and a height of 3 mm. The clear zone diameter was measured every 24 hours during the 10-day incubation period to assess the diversity of antibacterial activity. The antibacterial profile of Streptomyces sp. exhibited varying levels of activity against different bacterial strains in the tests conducted. The inhibition zone diameters demonstrated the highest levels of activity in Bacillus subtilis (15.9 mm) on day 7, Staphylococcus aureus (27.6 mm) on day 2, Pseudomonas aeruginosa (24.3 mm) on day 7, Escherichia coli (29.2 mm) on day 5, and Salmonella Typhimurium (27.5 mm) on day 7. The results indicated that Streptomyces sp. had inhibitory effects against Gram-positive bacteria as well as Gram-negative bacteria. In conclusion, Streptomyces sp. is a source of biodiversity found in the soil of mangrove ecosystems and has the ability to produce antibiotics.

Antimicrobial properties of lactic acid bacteria from fermented palm sap against E. coli and S. aureus growth

Palm sap produced from tapping can be a growing place for lactic acid bacteria (LAB). Palm sap has a lot of carbohydrate content, such as sucrose, fructose, and glucose, which can be a source of nutrition for the growth of microorganisms such as LAB). The result of LAB metabolism that is formed can be in the form of organic acid acids that can act as antimicrobial compounds. LAB have been isolated from fermented palm sap. This study aimed to determine the antibacterial properties of LAB from the fermentation of palm sap against E. coli and S. aureus using the well-agar diffusion method and the paper disc diffusion method. The study showed that LAB isolates (Lactobacillus A1, A6, B12, C1, and C4) and cell-free supernatants have antibacterial activity against E. coli and S. aureus. LAB antibacterial properties using cells with a clear zone diameter against E. coli ranges from 8.03 to 0.58 mm, and S. aureus inhibition zone diameter ranges from 9.13 to 11.16 mm. The antimicrobial activity of LAB using cell-free supernatants against E. coli ranges from 4.59 to 5.01 mm, and the diameter of the inhibitory zone against S. aureus ranges from 4.34 to 5.79 mm. From these results, LAB isolated from fermented palm sap can potentially be probiotics.