Judul: Karakterisasi enzim hidrolase bakteri dari mata air soda Parbubu, Tapanuli Utara
Abstrak: North Tapanuli has a soda fountain as a source of potential biotic diversity of Indonesia, one of which is the hydrolytic bacteria. The purpose of this study was to isolate bacteria from the soda fountain and test Parbubu hidrolasenya enzyme activities, ie lipase, protease, and cellulase enzyme hidrolase and characterize the best in certain conditions of temperature and pH. Isolation of bacteria from the soda fountain Parbubu using pour plate method produced 23 isolates of bacteria. Test semikualitatif hidrolase enzyme using hydrolytic enzymes in media index showed that the bacterial isolates P9 has the highest lipase activity. Harvest time P9 bacterial lipase based on the growth curve and enzyme production curves, ie on the seventh hour of incubation. Lipase activity determined with titrimetric method shows that the fraction of the enzyme by precipitation (60-80)% of ammonium sulfate has the highest activity, that is equal to 3.5245 U / mL or 5992 times the activity of crude extract. Lipase enzyme has optimum activity at pH 7, at 5.9593 U / mL and at a temperature of 90 º C with the activity of 4.9019 U / mL.
Keyword: 

Judul: Karakterisasi Morfologi Sel dan Penapisan Aktivitas Hidrolisis dari Isolat Bakteri Tanah Pulau Muna, Sulawesi Tenggara
Abstrak: Bakteri penghasil enzim ekstraselular, khususnya enzim amilase, selulase, dan protease, dapat digunakan dalam berbagai industri. Lima belas isolat bakteri tanah yang diisolasi dari Pulau Muna, Sulawesi Tenggara, belum diketahui potensinya sebagai penghasil enzim-enzim tersebut. Penelitian ini bertujuan mengkarakterisasi morfologi sel dan menapis aktivitas amilolitik, proteolitik dan selulolitik dari bakteri tanah yang diisolasi dari Pulau Muna. Karakterisasi morfologi dilakukan dengan pewarnaan Gram. Penapisan bakteri dilakukan dengan metode kualitatif pada medium padat. Berdasarkan pengecatan Gram, 5 Isolat tergolong ke dalam bakteri Gram negatif dan 10 Isolat tergolong bakteri Gram positif, dengan bentuk sel yang bervariasi yaitu batang panjang dan bulat. Empat dari 15 isolat memiliki karakter hemolisis negatif atau gamma hemolisis sehingga diduga tidak bersifat patogen. Empat isolat tersebut selanjutnya digunakan untuk penapisan aktivitas hidrolisis terhadap amilum, selulosa, dan protein. Isolat M7 dan P7 mampu menghasilkan protease, selulase, dan amilase, sedangkan 2 isolat lainnya yaitu M4 dan P5 hanya mampu menghasilkan protease. Keempat bakteri tersebut dapat diteliti dan dikembangkan lebih lanjut sebagai penghasil enzim amilase, protease dan selulase., Bacteria producing extracellular enzymes, especially amylase, cellulase and protease enzymes, can be used in various industries. Fifteen isolates of soil bacteria isolated from Muna Island, Southeast Sulawesi, have no known potential as producers of these enzymes. This research aims to characterize cell morphology and screen the amylolytic, proteolytic and cellulolytic activities of soil bacteria isolated from Muna Island. Morphological characterization was carried out using Gram staining. Bacterial screening was carried out using qualitative methods on solid medium. Based on Gram staining, 5 isolates were classified as Gram negative bacteria and 10 isolates were classified as Gram positive bacteria, with varying cell shapes, namely long rods and round. Four of the 15 isolates had negative hemolysis or gamma hemolysis characteristics so they were suspected not to be pathogenic. The four isolates were then used to screen for hydrolysis activity on starch, cellulose and protein. Isolates M7 and P7 were able to produce protease, cellulase and amylase, while the other 2 isolates, namely M4 and P5, were only able to produce protease. These four bacteria can be researched and developed further as producers of amylase, protease and cellulase enzymes
Keyword: Amilase, hemolisis, indeks hidrolitik, Protease, Selulase

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