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All Journal FLUIDA Jurnal Teknologi
Rinaldi, Kardian
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Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Electrical & Electronics Engineering Energy Engineering Environmental Science Materials Science & Nanotechnology Mechanical Engineering

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EM4 Effect on Macronutrients and Microbial Growth in Liquid Organic Fertilizer from Cibogo Market Waste Widyabudiningsih, Dewi; Rinaldi, Kardian; Firdaus, Fachrel Muhammad; Fauzi, Rafli Rizki; Hulupi, Mentik
Fluida Vol. 18 No. 1 (2025): FLUIDA
Publisher : Department of Chemical Engineering, Politeknik Negeri Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35313/fluida.v18i1.6050

Abstract

Waste represents a major environmental concern due to its contribution to pollution. According to the Ministry of Environment and Forestry, organic waste comprised 51.63% of total waste in Indonesia. This highlights the potential for converting organic waste into liquid organic fertilizer (LOF) through anaerobic fermentation. This study aimed to determine the relationship between macronutrient content and microbial growth in LOF and to determine the optimum fermentation time for producing LOF. LOF was made using organic waste from Cibogo market, including green vegetable waste and fruit peels banana, mango, and pineapple). The research was conducted using reactor which contained 5 kg of green vegetable waste and 5 kg of fruit peels, supplemented with EM4 bioactivator (200, 250, and 300 mL), water, and brown sugar. Samples were analyzed on days 0, 7, 14, 21, and 28. Chemical parameters measured included nitrogen, phosphorus, C-organic, and potassium content, and microbial analysis was conducted to determine the role of microorganisms in the fermentation process. Results showed that the optimal fermentation time for LOF production was seven days, corresponding to the peak concentrations of NPK and C-organic. However, further optimization of EM4 volume and the ratio between waste and bioactivator is required, since the nutrient levels remain below the recommended standard. Moreover, the correlation between microbial population and nutrient availability requires further research, particularly with respect to the quantity of EM4 applied.
Penentuan Kurva Pertumbuhan Lactococcus lactis dan Evaluasi Potensi Supernatan Bebas Sel sebagai Agen Antibakteri terhadap Escherichia coli Krista, Gustin Mustika; Rinaldi, Kardian; Rahma, Andien Tiara; Maswanti, Azzahra Junisa
Jurnal Teknologi Vol 25, No 2 (2025): Agustus 2025
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/teknologi.v25i2.7504

Abstract

The increasing resistance of pathogenic bacteria to synthetic antibiotics has driven the search for safer and more sustainable natural antimicrobial agents. Lactic acid bacteria, particularly Lactococcus lactis, are known to produce bioactive compounds such as bacteriocins that can inhibit the growth of pathogenic microorganisms. This study aimed to evaluate the growth profile of L. lactis, its antibacterial activity against Escherichia coli, and to identify functional groups of active compounds using Fourier Transform Infrared (FTIR) spectroscopy. Antibacterial activity was assessed using the disk diffusion method on MHA plates inoculated with standardized E. coli suspensions. The growth curve analysis showed that L. lactis entered the lag phase between 0–9 hours, the logarithmic phase from 10–17 hours, and the stationary phase from 18–40 hours. The highest antibacterial activity was observed at 23 hours of incubation, with an inhibition zone diameter of 20 mm against E. coli. FTIR analysis of the cell-free supernatant revealed the presence of O–H, C–H, amide I, COO⁻, and C–O functional groups, suggesting the presence of bioactive compounds such as bacteriocins (e.g., nisin), lactic acid, and carbohydrate residues from the fermentation medium. These findings highlight the potential of L. lactis as a natural antimicrobial agent and support its further application in functional food development and biopharmaceutical formulations.
Co-Authors Fauzi, Rafli Rizki Firdaus, Fachrel Muhammad Krista, Gustin Mustika Maswanti, Azzahra Junisa Mentik Hulupi Rahma, Andien Tiara Widyabudiningsih, Dewi