Judul: Eco-enzyme Fermentation Characters of Pineapple and Lemon Peels
Abstrak: Setiap tahun sampah di Indonesia semakin meningkat, seiring dengan bertambahnya jumlah penduduk, khususnya sampah organik berupa sisa makanan. Kesadaran masyarakat dalam melakukan pengolahan sampah cukup rendah, menyebabkan sampah akan menumpuk di tempat pembuangan akhir (TPA), dan menimbulkan masalah lingkungan. Sampah perlu didaur ulang untuk mengurangi penumpukan sampah. Salah satu contohnya dengan membuat eco-enzyme. Eco-Enzyme adalah larutan zat organik kompleks yang dihasilkan dari proses fermentasi, dibuat dari sisa bahan organik berupa kulit buah dicampurkan molase dan air di dalam botol kaca dengan perbandingan 3:1:10, disimpan dalam suhu ruang selama 3 bulan. Penelitian ini bertujuan untuk mengetahui perbandingan karakter fermentasi eco-enzyme menggunakan kulit nanas (Ananas comosus) dan kulit lemon (Citrus limon). Fermentasi diamati dengan mengukur penurunan pH, total gula, dan total plate count(TPC). Hasil penelitian menunjukkan nilai pH eco-enzyme mengalami penurunan selama proses fermentasi. Tingkat keasaman eco-enzyme rendah disebabkan banyak asam organik dihasilkan dari proses fermentasi. Gula reduksi mengalami peningkatan seiring fermentasi, menunjukkan karbohidrat kompleks pada telah dipecah dengan adanya enzim pada eco-enzyme. Jumlah mikroorganisme pada kedua produk eco-enzyme tidak berbeda nyata, terdapat sedikit koloni bakteri pada media CMC dan TSB. Peningkatan asam organik menyebabkan penurunan pertumbuhan mikroorganisme dan kadar gula reduksi dalam eco-enzyme., Every year, waste in Indonesia is increasing, in line with increasing population, especially organic waste in the form of food scraps. Public awareness in conducting waste management is low, causing waste to accumulate in landfills and environmental problems. Garbage needs to be recycled, by making eco-enzymes. Eco-Enzyme is a solution of complex organic substances, made from leftover organic matter mixed with molasses and water in a glass bottle with a ratio of 3:1:10, stored at room temperature for 3 months. This study aims to determine the comparison of eco-enzyme fermentation characters using pineapple peels (Ananas comosus) and lemon peels (Citrus limon). Fermentation was observed by measuring the decrease in pH, total sugar, and total plate count. The results showed that pH value of the eco-enzyme decreased during fermentation process. Eco-enzyme acidity level is low because a lot of organic acids are produced from fermentation process. Reducing sugar increases with fermentation, indicating that complex carbohydrates have been broken down in the presence of enzymes in eco-enzymes. The number of microorganisms was not significantly different, there were few bacterial colonies on the CMC and TSB media. The increase in organic acids causes a decrease in the growth of microorganisms and reduces sugar.
Keyword: Ecoenzyme, Fermentation, lemon peel, Pineapple peel

Judul: Pembuatan dan Analisis Karakteristik Eco-Enzyme Berbahan Dasar Kombinasi Kulit Buah: Nanas, Melon, Pepaya, dan Pisang
Abstrak: Eco-enzyme merupakan larutan multifungsi yang dihasilkan melalui proses fermentasi dari sampah organik (kulit buah), gula dan air dengan perbandingan 3:1:10 dalam wadah plastik kedap udara. Waktu fermentasi eco-enzyme umumnya selama tiga bulan kemudian larutan disaring. Eco-enzyme memiliki manfaat sebagai anti-jamur, anti-bakteri, insektisida, agen pembersih. bahkan penyubur tanaman. Perbedaan bahan baku yang digunakan dalam pembuatan eco-enzyme menghasilkan sifat fisik, kimia, dan biologi yang berbeda. Penelitian ini bertujuan mengetahui karakteristik organoleptik, kimia dan biologi eco-enzyme berbahan kombinasi kulit buah: nanas, melon, pepaya, dan pisang. Kombinasi bahan baku eco-enzyme menggunakan dua variasi gula yaitu gula pasir (G1) dan gula merah (G2), dan empat variasi kombinasi kulit buah di antaranya nanas–melon (K1), nanas–pepaya (K2), melon-pepaya (K3) dan pisang-nanas-melon (K4). Analisis yang dilakukan meliputi uji organoleptik, pH, N-tersedia, N-total, P, K, C-organik, total populasi mikrob dan fungi. Hasil penelitian uji organoleptik terdapat perbedaan warna dan aroma pada setiap kombinasi. Nilai pH yang dihasilkan di antara 3,05 – 3,41. Hasil pengukuran N-total tertinggi terdapat pada perlakuan G1K3 yaitu sebesar 0,56%, P-total tertinggi pada perlakuan G2K2 dan G2K3 sebesar 0,06% dan 0,07%, K-total tertinggi pada perlakuan G2K4 yaitu sebesar 0,99%, dan C-organik pada perlakuan G1K4 menunjukkan nilai yang tertinggi sebesar 1,44%. Nilai pH dan kandungan unsur hara pada eco-enzyme belum memenuhi standar mutu pupuk organik cair. Analisis populasi mikrob dan fungi menggunakan metode total plate count (TPC). Analisis populasi mikrob mengalami penurunan total populasi pada fermentasi bulan ketiga kecuali perlakuan G1K3 dan G2K3 yang mengalami kenaikan. Begitu juga pada total populasi fungi mengalami penurunan pada fermentasi bulan ketiga., Eco-enzyme is a multifunctional solution produced through a fermentation process from organic waste (fruit peel), sugar and water in a ratio of 3: 1: 10 in an airtight plastic container. The fermentation time of eco-enzymes is generally three months then the solution is filtered. Eco-enzymes have benefits such as anti-fungal, anti-bacterial, insecticide, cleaning agent, and even plant fertilizers. The difference in raw materials used to manufacture eco-enzymes results in different physical, chemical, and biological properties. This study aims to determine the physical, chemical, and biological characteristics of eco-enzymes made from a combination of pineapple, melon, papaya, and banana peels. The variety of eco-enzyme raw materials uses two variations of sugar, white sugar (G1) and brown sugar (G2), and four variations of fruit peel combinations consisted of pineapple-melon (K1), pineapple-papaya (K2), melon-papaya (K3) and banana-pineapple-melon (K4). The analysis included organoleptic tests, pH, available N, total N, total P, total K, C-organic, total population of microbe and fungal. The results of organoleptic test research have differences in color and scent in each combination. The resulting pH value is between 3.05 – 3.41. The highest total N measurement results were found in the G1K3 treatment at 0.56%, the highest total P in the G2K2 and G2K3 treatment at 0.06% and 0.07%, the highest total K in the G2K4 treatment at 0.99%, and the C-organic in the G1K4 treatment showing the highest value of 1.44%. The pH value and nutrient content in eco-enzymes have not met the quality standards of liquid organic fertilizers. Analysis of microbial and fungi populations using the total plate count (TPC)
Keyword: fermentation, microb, nutrient, organic fertilizer, organic waste

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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