No abstract

Background: Asam indol asetat (IAA) merupakan salah satu hormon pertumbuhan tanaman yang berperan penting dalam menstimulasi pertumbuhan tanaman. Peran IAA yang diproduksi eksogen dari bakteri mampu mempercepat pertumbuhan tanaman dalam memacu proses diferensiasi pada akar dalam membentuk rambut akar. Bakteri rizosfer kebanyakan sebagai penghasil IAA. Bacillus sp. merupakan salah satu bakteri rizosfer dari tanaman. Tujuan penelitian ini untuk mengetahui kandungan IAA dari Bacillus sp. dengan melakukan pengukuran kadar IAA menggunakan metode kolorimetri Metode: Tahapan penelitian meliputi peremajaan isolat uji, pembuatan kurva standar IAA dan mengukur kadar IAA dengan direaksikan menggunakan reagen Salkowsky. Hasil: Hasil dari penelitian ini diperoleh kandungan IAA dari kultur Bacillus sp. yang ditambahkan L-triptofan yaitu sebesar 39,92ppm. Kesimpulan: Kandungan IAA yang dihasilkan Bacillus sp. tergolong cukup tinggi untuk dapat diaplikasikan sebagai bakteri pemacu pertumbuhan tanaman (PGPR).

Submission ID: 1079439462File name: logous_Expression_of _Extracellular_Plantaricin_F_in_L.lactis.pdf (2.14M) Word count: 6759Character count: 35493

Lactobacillus plantarum produces bacteriocin called plantaricin that can kill or inhibit other bacteria. Plantaricin E (Pln E), a recombinant bacteriocin, has been successfully constructed and produced by a GRAS host, Lactococcus lactis. A polymerase chain reaction (PCR) overlapping technique has been used to construct a ligation of signal peptide gene, Pln A and bacteriocin encoding gene, Pln E. Furthermore, the fusion fragment were cloned into pNZ8148 vector and transformed into L. lactis NZ3900. Molecular expression study shows that recombinant L. lactis NZ3900 is able to express the mature pln E at transcription level with size of 168 bp. Plantaricin E is purified by ammonium sulphate precipitation followed by gel filtration chromatography. Purified fractions were proven to be active against Enteropathogenic Escherichia coli K.1.1. The other fractions of Pln E also have antibacterial activity against several Gram positive and Gram negative bacteria. Purified recombinant plantaricin E is 3.7 kDa in size. The cytotoxicity assay shows purified Pln E inhibits 46.949 ± 3.338% of HeLa cell lines on 10 ppm dose whilst the metabolite inhibits 53.487 ± 2.957% of HeLa cell line on 100 ppm dose. The IC calculation of Pln E metabolite is 107.453 ppm, while the purified protein is 11.613 ppm.

Sorghum is one of the five most important cereal crops  in the world, due to its multi-beneficial usages and wide adaptability, so it has the high potential to be developed. One of the current efforts to develop sorghum is through a modern technique, molecular-based. Thus, in vitro culture is an indispensable basic technique, especially in the callus formation process. In addition to commercial synthetic chemicals, various organic materials found in nature have the potential to be used as PGR in initiating callus formation, one of which is honey. This study aims to obtain the optimum concentration of honey as a substituent of sorghum callus induction medium. The research design used a completely randomized design with one factor (honey concentration), which consisted of 5 dffrent levels (0, 5, 15, 25 and 35 gL-1). Observation variables consisted of callus formed (hsi), percentage of callus formation (%) and callus morphology. Data were analyzed using the F variance test and DMRT test at the 5% level. The test results of this study indicate that the two variables are significantly different. The fastest callus formation was in the M0 medium (0 gL-1.), while in the percentage of callus formation. The best results were in the M4 honey treatment (35 gL-1) of 77.78%. Thus it can be seen that the administration of honey as a substituent of in vitro culture media can help increase the success of sorghum callus formation.