Judul: Efektivitas Penggunaan Probiotik Terhadap Produksi dan Kualitas serta Kadar Aflatoksin M1 pada Susu Sapi Perah
Abstrak: Aflatoxins are toxic compounds produced by Aspergillus flavus and A. parasiticus. The aflatoxins M1 in the milk are affected by the amount of aflatoxin B1. The utilization of lactic acid bacteria probiotic (LAB) in poultry was effectively to reduce the aflatoxin, but the use of probiotics for reducing the aflatoxin M1 levels have not been widely reprorted. The aims of this study was to determine the feeding effect of diets containing probiotics for aflatoxin M1 level, production and milk quality. The study comprised two phases, namely :1) The preparation of lactic acid bacteria probiotic (in vitro), 2) In vivo phase that using encapsulated and non-encapsulated probiotics in lactating dairy cows. The probiotic of lactic acid bacteria was consisted of encapsulation and non-encapsulated. That probiotics quality were determined by total colony and storability test at room temperature for 0, 2 and 4 weeks. The lactic acid bacteria used combination of Lactobaccillus achidophillus FNCC 0051, Bifidobacterium longum ATCC 15707 and Streptococcus thermophillus FNCC 1-9 03). The in vivo test used 9 dairy cows on 1 th, 2nd and 5th lactation phase. Each lactating phase used 3 cows and fed the diet without probiotic (R0), diet containing 109 cfu/g capsulation probiotic (R1) and diet containing 108 cfu/g encapsulation pribiotic (R3).The parameters measured were milk production, milk quality and aflatoxin M1 levels. ANCOVA test was used to analyze the milk production. Milk quality was analized by Analysis of Variance. Aflatoxin M1 level was presented in descriptive form. The results of non-encapsulation and encapsulation probiotic colonies were 1.3 x 109 (cfu / g) and 0.63 x 109 (cfu / g). The results of in vivo test showed that the addition non-encapsulation and encapsulation probiotic did not affect milk production, milk quality, protein content, fat content, lactose, and SNF. Dairy cows were given non-encapsulation and encapsulation probiotic reduced aflatoxin M1 levels in milk until the limit of detection (0.025 ppb). The conclusion of this study was the use non-encapsulation and encapsulation probiotic did not significantly effect milk production and quality but can reduced the concentration of aflatoxin M1 in milk of dairy cow.
Keyword: Aflatoxin M1, encapsulation, dairy cow, lactic acid bacteria, probiotics

Judul: Reduksi Aflatoxin M1 dalam Susu oleh Mikroorganisme yang Diisolasi dari Biji Kefir
Abstrak: One of the nutritious source that widely consumed including children and elderly is milk. However milk is not always free of contamination that can endanger people who consumed it, especially to children and elderly who are more prone to contamination. One of the most toxic mycotoxin is aflatoxin B1 (AFB1) which is mainly produced by Aspergillus flavus and Aspergillus parasticus. Those molds can grow on feed that is fed to the cow and converted inside the cow to aflatoxin M1 (AFM1). AFM1 considered as potential hazard because it almost has the same structure as AFB1 although only has 10% of AFB1 toxicity. AFM1 also is highly resistant to heat so it can survive on milk heating process. Mycotoxin can be reduced by several methods, such as chemical, physical and biological methods. Biological method with microorganism antagonism is one of the emerging methods because unlike chemical methods, microbial method use microorganism that belongs to GRAS (Generally Recognize as Safe). Decontamination method with microorganism usually done with lactic acid bacteria (LAB) or yeast. LAB and yeast can reduce AFM1 that contaminate milk. LAB and yeast can be found in kefir. Kefir is a fermented milk product which is made from cow or goat milk with kefir grains as starter. Kefir is known for its beneficial effect for health because of the metabolites that microorganism in kefir grains produce, such as lactic acid, kefiran, and bacteriocin. Kefir has complex bacterial composition that is varies according to the medium, origin of kefir grains, and storage condition. Hence microorganism from kefir grains has potential to reduce AFM1 in milk. This research was conducted to to compare the reduction ability of microorganism isolated from kefir grains with different incubation time and identify the strain of lactic acid bacteria and yeast that can effectively reduce AFM1 In general, this research was conducted through this following stages : (1) Preparation ; (2) Enumeration and isolation of microorganism from kefir grains (3) Column Preparation (4) Evaluation of reduction of AFM1 by microorganism isolated from kefir grains (5) Identification of LAB and yeast strains from kefir grains that can reduce AFM1. The result of the research showed that there were more aerobic lactic acid bacteria than anaerobic lactic acid bacteria in kefir grains. The means of colony count of anaerobic lactic acid bacteria, aerobic lactic acid bacteria, total yeast of kefir grains were 1.9 x 109 CFU/g, 2.1 x 109 CFU/g, 2.0 x 108 CFU/g respectively and in kefir milk were 1.0 x 108 CFU/g, 1.0 x 108 CFU/g, 7.6 x 107 CFU/g respectively. Evaluation of AFM1 reduction was done by microorganism isolated from kefir grains, namely anaerobic lactic acid bacteria (LAN), aerobic lactic acid bacteria (LAE) and yeast (YEA). This experient successfully isolated 10 isolates of LAE, 4 isolates of LAN and 9 isolates of YEA. This study used non-viable cell, for approximately 1.0 x 108 cfu/mL of microorganism to reduce 10 ng/mL AFM1 in Phosphate Buffer Saline (PBS). Non-viable cell was used for this experiment because past studies observed that non-viable cells showed higher percentages of AFM1 removal in a
Keyword: AFM1, decontamination, kefir grains, lactic acid bacteria, yeast

Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf