Judul: Degradasi Limbah Buah-buahan dan Sayur-sayuran pada Produksi Eko-enzim
Abstrak: Eco-enzyme is the product of the facultative anaerobic fermentation process of domestic agriculture waste which is carried out for several months and enriched by sugar and water addition. This research aims to study the degradation process during fermentation and to identify the characteristics of eco-enzyme. The ratio of the composition of the eco-enzyme solution consisting of organic kitchen waste (fruits or vegetables): sugar: water was 3:1:10, respectively. During the fermentation observation, characterization was tested by cellulase activity, pH, reducing sugar, total acid, alcohol, and microscopic surface morphology. The results showed that during week-0 to week-12th fermentation, there was the degradation of carbohydrates into reducing sugars, acids, and alcohol. Besides, cellulase activity also increased from 1.24U / mL to 2.2 U / mL in fruit waste in the range of week-3rd and week-6th. The increase in reducing sugars, total acid, and decrease in pH was very significant in the range of week-3rd and week-6th. From this research, it can be concluded that degradation of the substrate occurs during fermentation and the highest fermentation results occur in week-6 for fruit waste, which different results from vegetable waste., Eko-enzim adalah produk proses fermentasi anaerob dari limbah pertanian domestik yang dilakukan selama beberapa bulan dengan penambahan gula dan air. Tujuan dari penelitian ini adalah mengkaji proses degradasi selama fermentasi dan mengidentifikasi karakteristik eko-enzim. Perbandingan komposisi bahan untuk memproduksi eko-enzim terdiri dari limbah dapur organik (buah-buahan atau sayuran) : gula : air secara berturut-turut adalah 3:1: 10. Selama fermentasi dilakukan karakterisasi hasil terhadap aktivitas selulase, pH, gula pereduksi, total asam, alkohol, dan pengamatan morfologi permukaan. Hasil penelitian menunjukan bahwa selama fermentasi minggu ke-0 hingga ke-12 terjadi degradasi karbohidrat menjadi gula pereduksi, asam, dan alkohol. Disamping itu, aktivitas selulase juga meningkat yaitu dari 1,24U/mL menjadi 2,2 U/mL pada limbah buahbuahan di rentang minggu ke-3 dan ke-6. Peningkatan gula pereduksi, total asam, serta penurunan pH terjadi sangat nyata pada rentang minggu ke-3 dan ke-6. Dari penelitian ini dapat disimpulkan bahwa degradasi substrat terjadi selama fermentasi dan hasil fermentasi tertinggi terjadi pada minggu ke-6 untuk limbah buah-buahan, berbeda hasilnya dengan limbah dari sayur-sayuran.
Keyword: cellulase activity, eco-enzyme, fermentation, aktivitas selulase, fermentasi, eko-enzim

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: 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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