AbstrakBawang Batak (Allium chinense G. Don) adalah salah satu tanaman spesies Allium yang digunakan sebagai bahan penambah citarasa khas pada masakan suku Batak Sumatera Utara. Selain itu, bawang Batak dipercaya sebagai obat herbal kesehatan diantaranya sebagai agen antibakteri. Penelitian ini bertujuan untuk mengetahui aktivitas antibakteri ekstrak metanol daun bawang Batak (Allium chinense G. Don) terhadap Streptococcus mutans dan Bacillus cereus sebagai bakteri gram positif. Metode yang digunakan adalah metode difusi agar. Ekstrak metanol daun bawang Batak yang diperoleh kemudian diencerkan dengan menggunakan pelarut dimetil sulfoksida (DMSO) dengan variasi konsentrasi (0.88, 1.66 dan 2.5)%. Untuk blanko negatif digunakan pelarut DMSO. Model penelitian yang digunakan dalam penelitian ini adalah model penelitian eksperimental secara In Vitro. Hasil penelitian menunjukkan bahwa ekstrak metanol daun bawang Batak memiliki aktivitas antibakteri terhadap S. mutans dengan diameter zona hambat (5,10.5,12.7) mm dan B. cereus dengan diameter zona hambat (10,12.4,12.2) mm dan blanko negatif DMSO (0) mm tidak memiliki nilai untuk menghambat pertumbuhan bakteri. AbstractBatak Onion (Allium chinense G. Don) is one of the species of Allium plant which is used as a flavour enhancer typical for North Sumatran Batak cuisine. Also, the Batak onion is believed to be a herbal health remedy such as an antibacterial agent. This research aims to determine antibacterial activity of methanol extracts of Batak leeks (Allium chinense G. Don) on Streptococcus mutans and Bacillus cereus as Positive Gram Bacteria. The method was the agar diffusion method. Methanol extracts of Batak leeks were diluted using Dimethyl sulphoxide (DMSO) with concentration variations (0.88, 1.66 and 2.5)%. DMSO also was used as a negative blank. The research model was in Vitro experimental research model. The results showed that methanol extract of Batak leek had antibacterial activity against S. mutans with inhibition zone diameter (5,10.5,12.7)mm and B. cereus with inhibition zone diameter (10,12.4, 12.2)mm. The inhibition zone diameter (0) mm for the DMSO as negative blank.

Research on antimicrobial and toxicity tests of flavonoid total Dendrophthoe pentandra (L) Miq from false ashoke tree (Polyalthia longifolia) have been done. This study aims to determine the activity of toxicity of total flavonoid of Dendrophthoe pentandra (L) Miq as mistletoe of false ashoke tree (P. longifolia) based on Brine Shrimp Lethality Test (BSLT) method using Artemia salina Leach shrimp larvae obtained Lethal Concentration (LC 50) of 30.06 mg / L which means strong toxic activity. Antimicrobial test of flavonoid total has used the diffusion method in order to obtain the inhibit zone diameter on Streptococcus mutans at the total flavonoids concentration of 3%, 6% and 9% were 6; 9 and 17.25 mm, in Escherichia coli is 3.55; 4.25 and 9.15 mm and at Candida albicans is 8.30; 4 and 5.30 mm where S. mutans and E. coli are greater but C. albicans less affect but still have good inhibitory activity so effective to be developed as antimicrobial agents.

A study about the antimicrobial activity test of black tea ethanol extract (Camellia sinensis) against Pseudomonas aeruginosa has been carried out. The black tea leaves are sourced from Sidamanik Plantation, North Sumatra. The dried black tea leaf extract was obtained by maceration technique in which black tea leaves were macerated for 24 hours. Then, the macerate was concentrated to obtain a thick extract and make sure that the ethanol had evaporated. After that, the concentrated extract was made with a variation of 5%, 10% and 15%. The antimicrobial activity test used was the disc method, where distilled water was used as a negative blank. The results obtained for average SD for blank with diameter 6 mm, 5%, 10% and 15% extracts were 6 ± 0,00; 7,75 ± 0,35; 9,05 ± 0,07 and 9,95 ± 0,07 mm with the inhibition diameter 0 mm; 1,75 ± 0,35; 2,05 ±0,07 and 3,95 ± 0,07 mm. The conclusion of this study is that the concentration of the extract is straightly proportional to its inhibitory power, namely the higher the concentration of black tea ethanol extract, the higher its inhibitory activity against Pseudomonas aeruginosa, so it can be used as an antibacterial agent for Pseudomonas aeruginosa.

Penelitian mengenai uji aktivitas toksisitas dan antimikroba flavonoid total daun benalu (Dendrophthoe pentandra (L) Miq) dari pohon glodokan (Polyalthia longifolia) telah dilakukan. Penelitian ini bertujuan untuk mengetahui aktivitas toksisitas dari flavonoid total daun benalu pohon glodokan berdasarkan metode Brine Shrimp Lethality Test (BSLT)  menggunakan larva udang Artemia salina Leach diperoleh Lethal Concentration (LC50) sebesar 30.06 mg/L yang berarti memiliki aktivitas toksisitas yang toksik sementara untuk aktivitas antimikroba dari flavonoid total daun benalu pohon glodokan dengan Metode Difusi Agar diperoleh diameter zona hambat pada Streptococcus  mutans pada konsentrasi sampel flavonoid total pohon glodokan 3%, 6% dan 9 % adalah 6; 9 dan 17.25 mm, pada Escherichia coli adalah 3.55; 4.25 dan 9.15 mm dan pada Candida albicans adalah 8.30; 4 dan 5.30 mm dimana semakin besar konsentrasi maka daya hambat pada S. mutans dan E. coli semakin besar namun pada C. albicans kurang mempengaruhi tetapi memiliki aktivitas hambat yang baik sehingga efektif dikembangkan sebagai zat antimikroba.

This study aimed to determine the yield of activated carbon, iodine number, and surface area of palm activated carbon. Samples were produced by using sodium chloride (NaCl) as an activator. Palm shells that had been produced by the milling process were then sieved with a 12 mesh sieve and soaked in 20 % NaCl solution. The sample solution was heated over a water bath at 70 oC and continued with the drying process at a constant temperature of 105 oC. The activated shells continued the pyrolysis process at temperatures of 300, 400, and 500 oC for 3 hours. The activated carbon obtained from the pyrolysis process was weighed and then washed using hot distilled water. The samples were dried in an oven at a temperature of 105 oC for 24 hours. The results were analyzed for iodine number using iodometric titration method, surface area using Brunauer- Emmett-Teller (BET) method, and pore structure using the Scanning Electron Microscope (SEM) method. The results showed the best yield was 38.13 % obtained at 20% NaCl and a temperature of 400 oC. The best iodine number was 767.745 mg/g and surface area was 6.790 m2/g, pore volume 4.377 cc/g with pore size 9.781 A.