Judul: Kajian Aktivitas Antibakteri Ekstrak Tempe Komak terhadap Bakteri Staphylococcus aureus dan Escherichia coli
Abstrak: Tempe is a modified product fermented by Rhizopus sp. which contains active substances, such as antibacterial substances. The objectives of the study are to compare the yield of hyacinth tempe and bench-scale soybean tempe and to determine the antibacterial activity from hyacinth tempe against bacteria: Staphylococcus aureus and Escherichia coli. The yield is determined by comparing the tempe’s mass and bean’s mass. The antibacterial activities of the extracts are analyzed using well diffusion method. The study shows that the yield of hyacinth tempe (154 %) is higher than the yield of bench-scale soybean (151 %). The study also shows that hyacinth tempe extract has no antibacterial activity against S. aureus 0.0 mm, while commercial-scale and bench-scale soybean tempe extract have antibacterial activity against S. aureus, respectively, 8.9 mm and 7.0 mm. However, all of the tempe extract have no antibacterial activity against E. coli. The raw material of tempe gives contribution to produce antibacterial substance against S. aureus during fermentation by R. oligosporus.
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Judul: Pengujian Aktivitas Antibakteri Ekstrak Tempe Koro Pedang (Canavalia ensiformis L.) terhadap Escherichia coli dan Staphylococcus aureus
Abstrak: Tempeh is a fermented food product usually made from soybean fermented by Rhizopus sp. The objectives of this study were to compare jack bean tempeh characteristics against soybean tempeh and to determine antibacterial activity of jack bean tempeh against Escherichia coli dan Staphylococcus aureus using well diffusion method. The tempeh extraction was conducted by methanol extraction following freezing to separate fatty compound. Characteristic of jack bean tempeh and soybean tempeh were different in moisture content, colour (L and a), and tenderness. The differences in moisture content and tenderness were caused by the difference of soaking time. The colour of jack bean tempeh and soybean tempeh were different because of the beans’s colour. The result showed that jack bean tempeh extracts did not have antibacterial activity against E. coli and S. aureus. Meanwhile, methanol extracts of soybean tempeh from laboratory and market were showed antibacterial activity against S. aureus (7.0 mm and 8.9 mm); but did not have antibacterial activity against E. coli.
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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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