Total Plate Count Method Research Articles

Synthesis of Sulfonated Chitosan as An Active Agent of Antibacterial Packaging for Fish Fillets

Modifying chitosan by increasing its hydrophilic properties through sulfonation reactions will increase its solubility in water and antibacterial activity and expand the application of chitosan. This study aims to determine the antibacterial activity of sulfonated chitosan film applied as fish fillet packaging using the total plate count method. Sulfonated chitosan in this study was successfully synthesized by reacting chitosan with 1,3-propane sultone. Sulfonated chitosan products were characterized using FTIR and UV-Vis spectrophotometers, while antibacterial activity was measured using the disc diffusion method. The optimum temperature for sulfonated chitosan synthesis was 60°C (SCS60). The resulting SCS 60 was a yellowish-white solid soluble in water with a yield of 61.46% and a degree of substitution of 33%. The diameters of the SCS 60 inhibition zone against E. coli and S. aureus isolates were 7 and 10 mm, respectively. SCS60-gelatin film is elastic (elongation 272%) and more hydrophobic with a contact angle of 90.12° compared to chitosan-gelatin film (62.8°). SCC60-gelatin film was able to suppress bacterial growth in fish fillets by up to 0.3 × 104 cfu/g compared to unpackaged fish (30 × 104 cfu/g). Sulfonated chitosan has the potential to be an antibacterial food packaging material.

Potential Fermentation of Sweet Potato Pickle (Ipomoea batatas L.) with Lactobacillus plantarum B1765 in the Production of Short Chain Fatty Acids

Short-chain fatty acid (SCFA) is the final metabolic product of inulin that can provide various health benefits. In this study, the effect of fermentation duration of sweet potato pickle using Lactobacillus plantarum B1765 starter culture in the production of SCFA was studied, as well as its relationship with total Lactic Acid Bacteria (LAB), pH, and Total Titratable Acid (TTA). Fermentation was carried out with the addition of starter culture as much as 10% (v/v) at 37ºC for 4, 8, 12, 24, and 0 hours which was used as a control. The number of LAB was measured using the Total Plate Count (TPC) method, pH value was measured with a pH meter, TTA was measured using the acid-alkalimetric titration method, and SCFA was measured using an HPLC instrument with 0.1% H3PO4 eluent and 25% acetonitrile. Fermentation duration affects LAB growth, TTA, SCFA, and pH. The results showed that total LAB growth was optimal at 8 hours fermentation time at 2.81×108 CFU/mL, which increased by 2 log cycles from the initial fermentation time of 0 hours. Still, the pH decreased until it reached 3.23 ± 0.20, and TTA increased to 0,56 ± 0.02% until the end of fermentation at 24 hours. SCFA also increased until the end of fermentation at 24 hours, where acetic acid levels showed the highest levels (6.85 ± 0.30 mg/mL), followed by propionic acid (5.04 ± 0.20 mg/mL) and butyric acid (2.14 ± 0.10 mg/mL). Sweet potato pickles fermented with L. plantarum B1765 starter culture have met the SNI 01-3784-1995 standard and have the potential to be developed as a functional food source of SCFA, which has many health benefits.

Effect of Red Guava (Psidium guajava L.) Juice Concentration on Product Quality and Antioxidant Activity of Red Guava Synbiotic Yoghurt

Red guava juice has very strong antioxidant activity and has the potential to be processed into synbiotic functional beverage products that have health benefits. This study examined the effect of red guava juice concentration on product quality and antioxidant activity of red guava synbiotic yoghurt. Product quality tested included microbiological quality (total LAB) and chemical quality (pH value and Total Tritable Acid (TTA )value). The concentrations of red guava juice used were 0%, 10%, 20%, 30%, and 40%. Fermentation was carried out for 6 hours at 37⁰C by Lactic Acid Bacteria (LAB) from powdered mixed culture. Then organoleptic testing using the hedonic test, total LAB testing using the Total Plate Count (TPC) method, pH value testing using a pH meter, TTA value testing using the acid-base titration method, and antioxidant activity testing using the DPPH (2,2-diphenyl-1-picrylhydrazil) method. Test data were analyzed using SPSS software to determine the effect of red guava juice concentration on test results. The concentration of red guava juice in red guava synbiotic yoghurt affects the pH value, TTA value, and IC50 value as the result of antioxidant activity testing. Red guava juice concentration did not affect total LAB testing. Organoleptic assessment of red guava symbiotic yoghurt is in the range of like to like very much. The best formulation was red guava synbiotic yoghurt with 30% red guava juice concentration, which had strong antioxidant activity with an IC50 value of 59.637 ppm, pH value of 3.94, TTA value of 1.98%, and total LAB as much as 1.81x10⁸ colonies/g, so it has met the quality requirements of yoghurt according to Indonesian National Standard SNI 2981: 2009.

Study on Antioxidant Activity of Purple Sweet Potato (Ipomoea Batatas) Juice Fermented with Lactobacillus plantarum B1765

Purple sweet potatoes are a source of anthocyanins, which are antioxidants. However, the anthocyanin compounds in purple sweet potatoes are naturally bound in glycosidic form, so their potential as antioxidants is still limited. Fermentation is one method that can be used to degrade glycosidic bonds to liberate free phenolics so that it can increase the antioxidant potential of purple sweet potato. This research aims to study the growth of lactic acid bacteria (LAB), pH, total titratable acid (TAT), phenolic content, anthocyanin content, and antioxidant activity of sweet potato juice (Ipomoea batatas) fermented with Lactobacillus plantarum B1765 starter culture for 0.2, 4,6,8,10,12 and 14 hours. Total LAB was measured using the Total Plate Count (TPC) method, pH was measured using a pH meter, TAT was measured using acid-base titration, total phenolic content (TPC) was measured using the Folline-Ciocalteu method, anthocyanin content used the differential pH method and antioxidant activity was measured using the radical scavenging method 2, 2-diphenyl-1-picrylhydrazyl (DPPH) which is expressed in IC50 values. The results showed that fermentation time affected (p<0.05) total LAB, pH, TAT, phenols, anthocyanin levels, and antioxidant activity in purple sweet potato juice. Total BAL increased to reach an optimum of 2.6 x 108 CFU/mL within 6 hours. However, until the end of fermentation for 14 hours, there was still a decrease in pH to 3.73, an increase in TAT reaching 0.426%, an increase in total phenolics up to 324.21 mg GAE/g, a reduction in anthocyanin levels (13.68 mg/L) and an increase in antioxidant activity with an IC50 of 47 .05 ppm which is classified as very strong. This product meets the Indonesian National Standards for fermented drinks and can potentially be a source of antioxidants.

Effectiveness of Bamboo Stick Liquid Smoke (Bamboo sp.) With Methanol Extract of Sengon Twig Wood (Falcataria moluccana) as a Disinfectant

Pathogenic microorganisms that cause infectious diseases are widely spread in the environment, especially in public places that allow microorganisms to multiply. Disinfectants are used to prevent the spread of these microorganisms. The use of chemical-based disinfectants can cause side effects, so it is necessary to look for alternatives from natural materials, such as a mixture of bamboo stem liquid smoke and methanol extract from Sengon twig wood. The purpose of this study was to determine the effectiveness of a mixture of bamboo stem liquid smoke and methanol extract of Sengon twig on bacteria and fungi. This research method began with an inhibition test of the disc and well diffusion method with five comparison treatments (50:50, 40:60, 30:70, 20:80, 10:90) to obtain the most effective comparison of the volume of 100% bamboo stem liquid smoke mixture and 11% sengon twig wood methanol extract, then tested using the Total Plate Count (TPC) method with swab samples on wooden tables. The results showed that the most effective comparison of the volume of 100% bamboo stem liquid smoke mixture and 11% sengon twig wood methanol extract was the volume ratio of 50:50 from the results of the inhibition zone on Salmonella typhimurium with a diameter of 10.3 mm. The results of the mixed effectiveness test with a ratio of 50:50 with the swab test on the table showed a decrease in the number of bacteria (51%) and fungi (65%). This shows that the mixture of bamboo stem liquid smoke and methanol extract of Sengon twig wood is effective as a disinfectant.

Population and Characterization of Rhyzospheric Bacteria of Pineapple Plant (Ananas comosus L. Merr) on The Highland Land of Lumban Sihite Village, Regency Dairi

The rhizosphere is the part of the soil around the roots of plants which is known to have a greater number of rhizosphere bacteria compared to the soil far from the roots. This research aims to determine the population and characteristics of rhizosphere bacteria from pineapple plants (Ananas comosus L. Merr) on the highland land of Lumban Sihite village, Dairi district. The stages used in this research were taking samples at three different points, then carrying out multilevel dilutions, inoculating them into petri dishes filled with PCA (Plate Count Agar) media, then counting the growing colonies using the TPC (total plate count) method, purification, morphological characterization, gram staining and biochemical tests. The research results obtained at point 3 had the largest population of 463.96 x 10⁴ CFU/g, while point 1 had the lowest population, namely 20.07 x 10⁴ CFU/g. Based on the results of morphological, gram staining and biochemical characterization of bacterial isolates, the isolates were identified as belonging to the genus Azospirillum, Bacillus, Pseudomonas and Azotobacter.

Shelf-life and antioxidant activity of beef meatball containing api-api mangrove (Avicennia marina) leaf flour

Abstract Api-Api Mangrove (Avicennia marina) is one of the pioneers in the mangrove forest ecosystem. Avicennia marina belongs to the Verbenaceae family and is a cosmopolitan plant distributed along tropical and sub-tropical coastlines. Api-Api Mangrove (Avicennia marina) is a plant that is rich in bioactive substances such as antibacterial and antioxidant which are good for food preservation. Meatball is the one of the meat products which is easily damaged by bacteria and has a short shelf life. This study aimed to evaluate the microbiology quality and antioxidant activity of beef meatballs containing Api-Api Mangrove (Avicennia marina) leaf flour as a natural preservative. This research used a factorial completely randomized design. The treatments were meatballs containing Avicennia marina leaf flour 0%, 5%, 10%, 15%, and 20% that were refrigerated during 5 different storage times (at 0, 2, 4, 6, and 8 days). The shelf life of the meatballs was evaluated for microbial content, initially and at 2, 4, 6, and 8 days (S0, S2, S4, S6, and S8) using a standard total plate count method. Antioxidant activity was analyzed at S0 and S8. Analysis of Variance (ANOVA) was used to examine shelf life, and Duncan’s Multiple Range Test followed. Descriptive analysis was done on antioxidant activity. The results showed that the treatments did not significant on the shelf life of the meatballs. The shelf life of meatballs containing 20% of Avicennia marina leaf flour was longer (P<0,05) than other treatments. On the fourth day of storage, the meatballs were spoilage as indicated by the number of bacteria reaching 106 colonies per gram except the meatballs containing 20% of Avicennia marina leaf flour. These indicated that the Avicennia marina leaf flour can suppress the growth of bacteria. The antioxidant activity of meatballs containing Avicennia marina leaf flour was higher than those of the control. It can be concluded that the use of Avicennia marina leaf flour can be used as a natural preservative to support the resilience of the food sector.

Examination of Microbial Contamination of Fresh Cow Milk in the Limau Manis Area, Tanjung Morawa, Deli Serdang

Background: Milk serves as a crucial source of human nutrition, particularly for infants who rely on it before they can digest solid foods. The mammary glands of female mammals produce it and is typically characterized by its pure white appearance. Objective: This study aimed to assess the levels of mesophilic aerobic bacteria and yeast mould present in fresh cow's milk obtained from farms in Limau Manis Tanjung Morawa. Methods: The investigation into contamination levels employed the Total Plate Count (TPC) method for aerobic bacteria and the Yeast Mold Count (YMC) method, both of which are based on the guidelines outlined in the Indonesian National Standard (SNI) No. 3141.1 of 2011. Results: Findings revealed that the levels of aerobic mesophilic bacteria, as determined by the TPC method, met the stipulated requirements of SNI No. 3141.1 of 2011 across all five farms surveyed. However, the research utilizing the YMC method indicated that the yeast mould counts in the milk from all five farms did not meet the established criteria. Conclusion: The analysis of microbial contamination using the TPC and YMC methods demonstrated compliance and non-compliance, respectively, with the standards outlined in SNI No. 3141.1 of 2011.

The Effect of Fermented Jicama Extract with Lactobacillus plantarum B1765 as the Culture Starter on the Product Quality and Flavonoid Contents

Jicama (Pachyrhizus erosus) is a functional food containing phenolic compounds, with the main compounds being flavonoids. However, the presence of polyphenol oxidase and the structure of flavonoid compounds are still bound in the form of glycosides, so the bioactivity of jicama is not maximized. This study aims to determine the effects of jicama extract fermentation on product quality and increased flavonoid content in jicama. Fermentation was performed for 0, 12, 24, and 36 hours with 5% (v/v) of the starter culture, Lactobacillus plantarum B1765, at 37ºC. The result showed that fermentation times could increase Total Lactic Acid Bacteria (LAB), Total Tertitrable Acid (TTA), Total Phenolic Content (TPC), and Total Flavonoid Content (TFC). It also influenced a decrease in pH. The total LAB count was determined using the Total Plate Count method, the Total Tertitrable Acid was determined using acid-base titration, and the pH was determined using a pH meter. Total Phenolic Content was measured using the Folin-Ciocalteu method, and Total Flavonoid Content was measured using AlCl3 and potassium acetate. The analysis of the data revealed that jicama extract fermented optimum after 24 hours, with a total LAB count of 9.7x107±0.31 CFU/mL, a pH value of 4.21±0.22, a TTA of 0.376±0.025%, but TPC and TFC still increasing until 24 hours of fermentation to 16.22±0.312 mg GAE/g, and of 29.01±0.641 mg QE/g respectively. Fermentation of jicama extract with Lactobacillus plantarum B1765 increased total phenolic and total flavonoid contents and could be used as a functional food product.

Effectivity of Irrigation Solution from Stevia rebaudiana Bertoni Leaf Extract on the Growth of Enterococcus faecalis Bacteries

Disinfection of Enterococcus faecalis bacteria in dental root canal treatment using NaOCL 0.5-2.5% is still a challenge. There is still very little data on the effectvity of Stevia rebaudiana Bertoni leaf extract irrigation solution against the growth of Enterococcus faecalis. This study evaluated the effectiveness of Stevia rebaudiana Bertoni leaf extract irrigation solution against Enterococcus faecalis ATCC 29212 through MIC (Minimal Inhibitory Concentration) and MBC (Minimal Bactericide Concentration) values. A number of 100 µl of E. faecalis suspension was inoculated into 96 microtitration wells, each containing 100 µl of 100%, 50%, 25%, 12.5%, 6.25%, 3.125%, 1.56% of Stevia leaf extract irrigation solutions, positive (NaOCL 2.5%) and negative (distilled water) control. Incubation was carried out for 24 hours at 37°C then optical density was measured with a microplate reader at 600 nm. Five µl of 10-9 dilution of each group was dripped and spread onto nutrients agar plate. The number of Enterococcus faecalis colonies was counting manually. There was no significant difference in average colony count of Enterococcus faecalis between the 100% and 50% Stevia leaf extract irrigation solution groups and the positive control (p>0.05). However, the 25%, 12.5%, 6.25%, 3.125%, and 1.56% Stevia leaf extract irrigation solution groups showed significant differences (p<0.05). Stevia leaf extract irrigation solution suppressed growth at MIC 6.25% by turbidimetry and MIC 1.56% by total plate count method using nutrient agar and than killed Enterococcus faecalis at MBC 50%. The bactericidal ability of 100% and 50% Stevia leaf extract irrigation solution is equal to NaOCL 2.5%.

The effect of paraquat dichloride and carbosulfan on soil conditions and population dynamic of soil microbes in a cornfield: a case study in Sumedang, West Java

Paraquat dichloride (PC) is one of the herbicides active ingredients that is widely used by farmers to control various types of weeds, while carbosulfan (CS) is one of the insecticide’s active ingredients that is widely used to control various types of insect pests. The objective of this study is to analyze the impact of pesticides for PC and CS on the chemical and physical conditions of the soil and the dynamics of fungi and soil bacteria population in a corn field in Sumedang district, West Java. The experiment took place between August and October, during the dry season, concluding just as the rainy season began. The PC concentrations used were 0 mL/L, 3.33 mL/L, 4 mL/L, 4.66 mL/L and 5.33 mL/L, while the CS concentrations used were 0 mL/L, 0.5 mL/L, 1 mL/L, 1.5 mL/L and 2 mL/L. Soil sampling was conducted before and after the application of pesticides. The total abundance of fungi and bacteria was analyzed using the total plate count (TPC) method. The application of PC to the cornfield slightly decreased soil bulk density from 1.354 g/cm3 to 0.816 g/cm3, while the application of CS slightly increased soil bulk density. A decrease in bulk density is considered positive for the physical conditions of the soil for plant cultivation. In general, the result indicated that the application of PC and CS did not show a significant effect on the chemical characteristics of the soil, and also it did not affect the population of fungi and bacteria. Weather conditions, i.e. dry season (June-September) and rainy season (started from October) seem to affect more on soil conditions as well soil microbial population than the application of the pesticides.

Perbedaan Jumlah Koloni Bakteri Subgingiva Setelah Menyikat Gigi dengan Berbagai Pasta Gigi yang Mengandung Bahan Herbal Sirih (Peper betle Linn.), Siwak (Salvadaro persica) dan Cengkeh (Eugenia caryophyllus) pada Anak dengan Disabilitas Intelektual

Children with Intellectual Disabilities have a higher risk of oral diseases such as dental caries and periodontal diseases compared to other children. Therefore, efforts are needed to help maximize the prevention of these diseases. The abundance of herbal materials in the community, which have been proven to have antibacterial effects, has been increasingly formulated into toothpaste. This is expected not only to provide a mechanical cleaning effect on plaque but also to have antibacterial effects and inhibit plaque growth for a longer period in the oral cavity.This research aims to determine the difference in subgingival bacterial colonies after brushing teeth with various herbal-containing toothpaste in children with intellectual disabilities. The study was conducted using a quasi-experimental pre-post control group design. Subgingival fluid samples were taken from respondents aged 6-12 years before and after brushing their teeth with four groups: (K) without toothpaste, (A) toothpaste containing betel leaves (Piper betle Linn.), (B) toothpaste containing Miswak (Salvadora persica), and (C) toothpaste containing Clove (Eugenia caryophyllus). The samples were then cultured in Plate Count Agar media for 48 hours. Colony counting was performed using the Total Plate Count (TPC) method with a Colony Counter. Statistical analysis was conducted using Wilcoxon and Kruskal-Wallis tests.The results of the study showed a decrease in the number of CFUs (colony-forming units) after brushing teeth. Significant reductions were obtained in toothpaste B (p-value = 0.046) and toothpaste C (p-value = 0.028). In conclusion, toothpaste containing Miswak and Clove effectively reduces the number of bacterial colonies formed in subgingival fluid samples..

Evaluation of Pharmacological Activities of Piper Betle L. Extract on Bacterial Conjunctivitis Model of Wistar Rat caused by Streptococcus Pneumoniae

Abstract
 Introduction & Objectives : Conjunctivitis is an eye infection accounted as the third leading ophthalmology cases after cataract and glaucoma globally, with Streptococcus pneumoniae as the main causes in children. Several studies had indicated that Piper betle L. extract inhibited Streptococcus pneumoniae growth. To determine and evaluation of pharmacological activities of Piper Betle L. extract on bacterial conjunctivitis model of wistar rat caused by Streptococcus Pneumoniae
 Methods : This study was an analytical study with true experimental design and pre-test-post-test control group. Streptococcus pneumoniae colony growth media was analyzed using Mueller Hinton agar. Streptococcus pneumoniae colony was calculated using Total Plate Count methods.
 Results : Sample of this study involved 30 male wistar rat aged 4 – 9 minggu. Kruskal Wallis test reveald a significant differences of Streptococcus pneumoniae colony based on the treatment group (p=0,023). Subsequent test using Posthoc revealed that there was a significant differences in Streptococcus pneumoniae colony between placebo group and group using 25% (p = 0,039) and 30% (p=0,006) piper betle. Test results also revealed that no significant difference was found between placebo group and groups using 20% piper betle (p=0,159) and ofloxacin (p=1,000).
 Conclusion : There was a significant difference in Streptococcus pneumoniae colony among placebo group and piper betle eyedrops 25 % and 30 % group. However, significant result among placebo group and piper betle L. 20 % and ofloxacin group were absent.

EVALUATION OF PHARMACOLOGICAL ACTIVITIES OF PIPER BETLE L. EXTRACT ON BACTERIAL CONJUNCTIVITIS MODEL OF WISTAR RAT CAUSED BY STREPTOCOCCUS PNEUMONIAE

Introduction: Conjunctivitis is an eye infection accounted as the third leading ophthalmology cases after cataract and glaucoma globally, with Streptococcus pneumoniae as the main causes in children. Several studies had indicated that Piper betle L. extract inhibited Streptococcus pneumoniae growth. Methods: This study was an analytical study with true experimental design and pre-test-post-test control group. Streptococcus pneumoniae colony growth media was analyzed using Mueller Hinton agar. Streptococcus pneumoniae colony was calculated using Total Plate Count methods. Results: Sample of this study involved 30 male wistar rat aged 4 – 9 minggu. Kruskal Wallis test reveald a significant differences of Streptococcus pneumoniae colony based on the treatment group (p=0,023). Subsequent test using Posthoc revealed that there was a significant differences in Streptococcus pneumoniae colony between placebo group and group using 25% (p = 0,039) and 30% (p=0,006) piper betle. Test results also revealed that no significant difference was found between placebo group and groups using 20% piper betle (p=0,159) and ofloxacin (p=1,000). Conclusion: There was a significant difference in Streptococcus pneumoniae colony among placebo group and piper betle eyedrops 25 % and 30 % group. However, significant result among placebo group and piper betle L. 20 % and ofloxacin group were absent. Keywords: Bacterial conjungtivitis, Streptococcus pneumoniae, Piper betle L.

The Effect Of Burning Time On The Amount Of Bacteria Staphylococcus Aureus Contamination Of Grilled Meatballs Sold In Darusssalam, Banda Aceh

This study aims to determine the effect of heating time in the combustion process on Staphylococcus aureus contamination in grilled meatballs. A total of 9 samples of meatballs obtained from 3 sellers of grilled meatballs were divided into 3 treatments, namely burning at temperatures ranging from 56˚C-59˚C for 1 minute, 3 minutes, and 5 minutes, with 3 repetitions. Determination of the number of microbes was carried out using the Total Plate Count (TPC) method. The research data were analyzed using a two-way ANOVA analysis of variance followed by Duncan's test. The results showed that the duration of burning affected the amount of Staphylococcus aureus contamination in grilled meatballs. The best combustion was shown at 5 minutes, with a microbial count of 3.6 × 101 CUF/g. The results of the analysis of variance (ANOVA) showed that there was a significant difference (P0.05) in the average value of Staphylococcus aureus microbial contamination in grilled meatballs given treatment. Based on the calculation results, it can be concluded that 5 minutes of burning time is the most effective for decontaminating the amount of Staphylococcus aureus microbial contamination in grilled meatballs.

Diversity of bacteria isolated from raw milk of Senduro goats

Goat’s milk is widely consumed because of its good nutrition. However, goat’s milk is also a good habitat for several types of bacteria that may affect the milk quality. Therefore, information concerning the bacteria’s total number and diversity is crucial. This research aimed to reveal the total number and diversity of bacteria in Senduro goat’s milk from three farms. Samples of raw goat’s milk were collected from each farm in a sterile container. Then, the enumeration of the bacteria’s number was done using the Total Plate Count (TPC) method. The total number of bacteria obtained from goat’s milk on farms 1, 2, and 3 were 1.5 x 102 CFU/mL, 8.8 x 101 CFU/mL, and 1.3 x 102 CFU/mL, respectively. The morphological characteristics of the colonies showed the diversity of bacterial isolates in raw goat milk from the three farms. The three samples also shared several bacterial isolates with the same characteristics. It also can be concluded that the bacteria’s total number in goat’s milk from three farms is still acceptable and meets the standard. Identification of the group of each bacterial isolate is needed shortly to deepen our understanding of their role.

Influence of ZnO on Antibacterial Properties of Portland Cement

This research project focuses on evaluating the antimicrobial properties of a composite material composed of Portland Cement and Zinc Oxide (ZnO). The study assesses the antibacterial activity of this composite by using Escherichia coli (E. coli) as the test microorganism. Bacterial growth assessment is carried out through the Total Plate Count (TPC) method. The investigation involved varying the concentration of ZnO within the Portland Cement composite, specifically at levels of 0%, 1%, 3%, and 5%. The study primarily centers on generating reactive oxygen species (ROS) by ZnO, and this evaluation was conducted under both UV light exposure and without it. This dual approach allows for a comprehensive examination of ROS activity. Furthermore, the research project involves material characterization using X-ray Diffraction (XRD) to determine the nanoparticle size of ZnO and identify the crystal structures present within the composite material. Additionally, morphological analysis is performed using Scanning Electron Microscopy (SEM) to visualize the structural properties of ZnO embedded within the Portland Cement. SEM analysis is conducted at various magnifications, including 1000x, 2500x, 5000x, and 10,000x, to provide a detailed view of the ZnO's structural properties. In summary, this research project explores the antimicrobial potential of a composite material incorporating Portland Cement and ZnO, focusing on ROS generation and the composite material's structural properties. The findings will contribute to our understanding of the material's suitability for applications in antimicrobial environments.

Effect of fermented jicama extract with Lactobacillus plantarum B1765 as the starter culture on the product quality and total phenolic

This research studied the effect of fermented jicama extract with Lactobacillus plantarum B1765 as a starter culture on the product qualities and Total Phenolic (TP). Fermentation was carried out for 0, 12, 24, and 36 hours at 37oC with 5% (v/v) of starter culture then determine the Total Lactic Acid Bacteria (LAB) were measured using the Total Plate Count (TPC) method, pH, and TTA were measured using a pH meter and acid-base titration, and TP was measured using the Folin-Ciocalteu method. These results showed that the length of fermentation affected increasing total LAB, TTA, TP, and decreasing pH. The best fermentation time in jicama extract was fermented is 24 hours with a total LAB of (9.7±0.31)x107 CFU/mL, pH of 4.21±0.22, TTA of 0.220±0.069%, and TP of 16.22±0.31 mg GAE/g. This value is following the criteria for fermented beverage products. Fermented jicama extract with L. plantarum B1765 potentially increases the TP.

Influence of ZnO on Antibacterial Properties of Portland Cement

This research project focuses on evaluating the antimicrobial properties of a composite material composed of Portland Cement and Zinc Oxide (ZnO). The study assesses the antibacterial activity of this composite by using Escherichia coli (E. coli) as the test microorganism. Bacterial growth assessment is carried out through the Total Plate Count (TPC) method. The investigation involved varying the concentration of ZnO within the Portland Cement composite, specifically at levels of 0%, 1%, 3%, and 5%. The study primarily centers on generating reactive oxygen species (ROS) by ZnO, and this evaluation was conducted under both UV light exposure and without it. This dual approach allows for a comprehensive examination of ROS activity. Furthermore, the research project involves material characterization using X-ray Diffraction (XRD) to determine the nanoparticle size of ZnO and identify the crystal structures present within the composite material. Additionally, morphological analysis is performed using Scanning Electron Microscopy (SEM) to visualize the structural properties of ZnO embedded within the Portland Cement. SEM analysis is conducted at various magnifications, including 1000x, 2500x, 5000x, and 10,000x, to provide a detailed view of the ZnO's structural properties. In summary, this research project explores the antimicrobial potential of a composite material incorporating Portland Cement and ZnO, focusing on ROS generation and the composite material's structural properties. The findings will contribute to our understanding of the material's suitability for applications in antimicrobial environments.

Effect of nira (Arenga pinnata Merr) tapping tools on the abudance and identification of microorganisms

Arenga trees are known to have economic value, especially its water, called nira. Nira contains sucrose with a neutral pH at the start of tapping, but after 4 hours, the quality of nira will decrease. This is due to the influence of air (aerobic), so that the presence of microbes in nira becomes abundant and causes the fermentation process to take place more quickly. The fermented nira is known as ‘tuak’, the traditional drink of Bataknese people. Batak people believe the benefits of drinking tuak for health. In this study, nira was collected using a simple tapping device (APUS) with the aim of minimizing contact between surrounding air and bunches. APUS was applied to Arenga bunches in Samosir. Nira from tapping with and without APUS will be observed for microbial abundance (its density). Furthermore, the microbes contained in nira will be identified based on their morphological characters (physically). Identification aims to determine the types of microbes that are present from a natural habitat. Next, the microbes are isolated and studied for their shape and properties, before the microbes are utilized further. The results of microscopic observations showed that the nira sample tapped without using APUS (sample A) had a higher and more turbid microbial density and showed non-uniform microbial size (from large to small, like powder), while nira sample tapped with APUS (sample B) showed almost uniform microbial size with cleaner looking spots. Furthermore, the microbes in sample B were isolated on specific media. Acquisition of colonies in the form of acetic acid bacteria (BAA), lactic acid bacteria (BAL), and yeast. BAA isolates showed a group of gram-negative bacteria that could not retain the crystal violet stain when rinsed with alcohol, because the peptidoglycan in gram-negative bacteria was thinner than gram-positive ones, while BAL isolates were the opposite. The measurement of the number of colonies was carried out using the TPC (Total Plate Count) method at 6 dilutions and obtained for BAL and yeast were 147 and 30 colonies respectively.