Judul: Aktivitas proteolitik ekstraseluler enteropathogenic escherichia coli pada media limbah cair tahu
Abstrak: Enteropathogenic Escherichia coli merupakan salah satu bakteri penyebab diare. Diketahui bahwa EPEC RB 1.2 yang diisolasi dari penderita diare mensintesis protease ekstraseluler pada media skim milk broth minimal. Penelitian ini bertujuan untuk mengetahui adanya aktivitas proteolitik ekstaseluler EPEC RB 1.2 pada media limbah cair tahu. Pada penelitian ini telah dilakukan uji aktivitas enzim proteolitik ekstraseluler EPEC RB 1.2 pada media limbah cair tahu. Dilihat dari kurva kekeruhan yang makin meningkat menunjukkan bahwa EPEC RB1.2 dapat tumbuh dalam media tersebut. Pada media limbah cair tahu yang ditambah susu skim 1% menampakkan adanya aktivitas proteolitik ekstraseluler EPEC RB 1.2 yang berbeda nyata dengan bakteri E.coli non patogen.
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Judul: Aktivitas Antibakteri Enterophatogenic Escherichia coli (EPEC) K11 dari Plantarisin F Rekombinan Hasil Purifikasi
Abstrak: Salah satu bakteri penyebab diare adalah enterophatogenic Escherichia coli (EPEC) K11. Pengobatan diare menggunakan antibotik secara terus menerus dapat menimbulkan resistensi. Plantarisin F rekombinan merupakan salah satu peptida antimikroba yang dihasilkan oleh Lactococcus lactis pNZ8148 rekombinan F dan berpotensi sebagai alternatif penggunaan antibiotik. Penelitian ini bertujuan menentukan aktivitas antibakteri EPEC K11 dari plantarisin F rekombinan hasil purifikasi. Proses purifikasi dilakukan dengan pengendapan garam amonium sulfat, kromatografi kolom filtrasi gel Sephadex G-50, dan kromatografi kolom penukar kation SP Sepharose. Sampel hasil purifikasi diuji aktivitas antibakterinya terhadap EPEC K11 dengan metode difusi agar. Pelet hasil pengendapan garam amonium sulfat, fraksi hasil kolom filtrasi gel, dan fraksi hasil kolom penukar kation memiliki aktivitas spesifik berturut-turut 235.107 AU/mg, 268.553 AU/mg, dan 6074.405 AU/mg. Aktivitas antibakteri tertinggi diperoleh pada sampel pelet hasil pengendapan garam amonium sulfat 60% dengan diameter zona bening sebesar 8 mm.
Keyword: antibacterial, enterophatogenic Escherichia coli (EPEC), plantaricin F recombinant, purification

Judul: The Construction of Greedy SVP LLL Algorithm
Abstrak: A lattice is a set of all integer linear combination of a set of linearly independent vectors in ℝ𝑛���. The independent vectors are called bases of lattice. Any lattice can be generated from many bases, and these bases have the same cardinality. In the lattice, the most fundamental and renowned problem is the Shortest Vector Problem (SVP). SVP is a tracking problem of the shortest nonzero vector in a lattice with equivalent bases. In two dimensions, SVP problem has resolved exactly by Gauss’ algorithm. When the lattice dimension is higher than two, A.K. Lenstra, H.W. Lenstra and L. Lovasz gave a LLL algorithm to compute approximation of nonzero shortest vector in the lattice. Reduced bases solution obtained from LLL algorithm still be an approximation and has polynomial running time of arbitrary dimension which large enough. In 1994, Schnoor and Euchner modified this LLL algorithm as a new variant which later was named deep insertion LLL algorithm. This algorithm is a modified version of the LLL algorithm to the terms of the exchange step to improve the accuracy of output of LLL reduced bases and applying it to the subset sum problem. The purpose of this research are: (1) Reconstruct the LLL algorithm and deep insertion LLL algorithm using a geometric approach. (2) Construct a greedy SVP LLL algorithm. (3) Implement the three algorithms in a symbolic programming language, and evaluate them experimentally. A bases ℬ=[𝐛���1,𝐛���2,…,𝐛���𝑛���] in ℝ𝑚��� is called reduced LLL with parameter 𝛿��� if satisfies: (a) |𝜇���𝑗���𝑖���|≤12, for every integer 𝑖���,𝑗��� with 1≤𝑖���<𝑗���<𝑛���. (b)𝛿���‖𝜋���𝑗���(𝐛���𝑗���)‖2≤‖𝜋���𝑗���(𝐛���𝑗���+1)‖2, for 𝑗���=1,2,…,𝑛���−1,where 𝛿��� is a reduced parameter of real numbers with 14<𝛿���<1. The first requirement is the reduced basis 𝛿��� must “nearly orthogonal” and in its computation case, this requirement can be reached out by using the Gram-Schmidt’s orthogonalization. While the second requirement is called exchange step, or used to called as Lovasz condition. By using both of these requirements, then they establish the LLL algorithm. Then, Schnoor and Euchner modify the LLL algorithm based on the requirements of the exchange step called the deep insertion LLL algorithm, where the exchange step is based on the comparison of the projected vector in orthogonal complement [𝐛���1,𝐛���2,…,𝐛���𝑘���−1]⊥ after j-th reduction. To construct greedy SVP LLL algorithm, the requirements of the exchange step is based on purely by comparing norm of lattice 𝐛���𝑗��� with norm lattice 𝐛���𝑖��� for 𝑖���=1,2,3…,𝑗���−1. The process of insertion reduced vector after the exchange step also has done greedily. Then, we calculate the number of arithmetic operation in greedy SVP LLL algorithm for further analysis. The result of our exprimentation for three algorithms on the certain matrix size shows that the running time of the three algorithms increases propotional to the size of the matrix. The result also shows that by using 𝛿���=34 for the LLL algorithm and the deep insertion LLL algorithm, and the greedy SVP LLL algorithm which is a new variant made by using no parameter of 𝛿���, outperform of the other of two previous algorithm in terms of speed with the same output.
Keyword: LLL algorithm, LLL deep insertion algorithm, greedy SVP LLL algorithm