Judul: Profil Bakteri Asam Laktat dan Bakteri Pembentuk Asam pada Nira Kelapa (Cocos Nucifera L.)
Abstrak: Coconut sap has been widely used to produce coconut sugar in many countries. It is a liquid that coming out by tapping the unopened coconut flower. Coconut sap is rich in sugar (10~15%) and nearly at neutral pH condition. Those characteristics cause the coconut sap spontaneously fermented by certain microorganisms that present naturally in coconut flower due to unsanitary tapping process. This study aims to evaluate the profile of lactic acid bacteria and acidforming bacteria and to evaluate the effect of storage on coconut sap. Coconut sap was obtained from Sukabumi and Purbalingga. The initial amount of lactic acid bacteria and acid-forming bacteria in fresh coconut sap from Sukabumi and Purbalingga was already high. The average number of lactic acid bacteria in Sukabumi and Purbalingga fresh coconut sap respectively amounted to 7.38 log CFU/ml and 7.94 log CFU/ml, meanwhile the average number of acid-forming bacteria in Sukabumi and Purbalingga fresh coconut sap respectively amounted to 5.88 log CFU/ml and 7.95 log CFU/ml. The average pH value of fresh coconut sap from Sukabumi and Purbalingga were 5 dan 5.5 with total sugar 15 and 15.2o brix. Purbalingga coconut sap stored at room temperature for 4, 8, and 16 hours increased the number of lactic acid bacteria and acid-forming bacteria, as well as decreased its pH value. Those also happened in Sukabumi coconut sap stored for 18 hours at low temperature. Isolates from Sukabumi coconut sap was dominated by heterofermentative coccobacilli, 43 % isolated from MRSA medium and 62 % from GYC medium. Heterofermentative coccobacilli also dominated 81 % isolates in Purbalingga coconut sap obtained from MRSA medium, whereas isolates from GYC medium were dominated by heterofermentative bacilli (84%). Identification using API 50 CHL showed that coconut saps from both places were dominated by Weissella viridescens. Other lactic acid bacteria isolates were identified as Lactococcus lactis ssp lactis 1 and Leuconostoc mesenteroides ssp mesenteroides/dextranicum 1.
Keyword: lactic acid bacteria, coconut sap, acid-forming bacteria

Judul: Profil Fenotifik Bakteri Asam Laktat yang Berasal dari Daging Sapi
Abstrak: The aim of this research was to observe the fenotipic profile of twenty-eight lactid acid bacteria (LAB) isolated from fresh meat. Those characteristic is determined by growing the lactid acid bacteria tested on MRS media i) at different temperature conditions; that contained ii) 6.5% concentration of NaCl or iii) amoxilin and chloramphenicol antibiotic and incubated at 37oC for 24-48 hours. The data were analyzed using ANOVA with GLM procedure, which is provided by MINITAB. Dissimilarity of 28 LAB isolate and treatment as an interaction became the first major concern of this study. The result showed that depends on its growth temperature the LAB could be grouping as mesofilic bacteria (27 isolates LAB) and one of them categorized as thermofilic bacteria. Supplementation of 6,5% NaCl in MRS media was not influenced the growth of LAB, and all of the 28 isolates showed a normal growth in this media after incubated at 37 °C for 48 hours. Addition of antibiotic in the media influenced significantly the growth of LAB tested. Base on its capability to grow well at different temperatures and in MRS media contained NaCl 6,5%, also, especially base on its high tolerancy to growth at gastrointestinal tract condition(Wijayanto, unpublished), three isolates there were 1B1, 2B4 and 1A5, were selected and tested in MRS broth contained different antibiotics. The result found that isolat LAB 1A5 was the most sensitive to chloramphenicol. The growth of LAB 1B1 and 2B4 in MRS broth contained amoxicillin were better than others showed by the population reduction that not more than 2 log. Keywords : Lactic acid bacteria, growth, temperature, NaCl 6.5%, antibiotic
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Judul: Peluang Partikel Plasma Berada Pada Dimensi Debye Akibat Gangguan Gelombang Elektromagnetik dengan Menggunakan Persamaan Schrödinger
Abstrak: The solution of Schrodinger equations with plasma Coulomb potential in spherical coordinat results solution wave function and energy plasma particle. Electron probability density at Debye length with thermal effect same as ion, which indicates plasma in neutral state. Electromagnetic waves perturbation of an electric field given to result wave function perturbation system. The probability density of plasma particle due to electromagnetic waves perturbation is the largest when an electromagnetic waves frequency 1.41 times the plasma frequency .
Keyword: Schrödinger, plasma, electromagnetic wave