Abstract. Arifiyanto A, Afriani H, Putri MH, Damayanti B, Riyanto CL. 2021. The biological prospective of red-pigmented bacteria cultured from contaminated agar media. Biodiversitas 22: 1152-1159. Contaminated agar media was often depleted due to the growth of microbes, which is undesirable for culture. However, the contaminating microbes usually have a distinctive morphology. This research aimed to identify the potential of red-pigmented bacteria originated from the contamination of Drosophila melanogaster larvae. Fruit fly larvae that grow on contaminated tryptic soy agar were accompanied by the appearance of the red-pigmented bacteria colony. The bacterial colonies were purified by the re-streaking method on tryptic soybean agar. This strain was characterized morphologically, biochemically, and molecularly. Results showed that the MBC1 strain was identified as Serratia marcescens. The various metal susceptibility tests at 25 ppm did not affect the growth of the MBC1 strain. Meanwhile, it was also able to inhibit the growth of certain pathogens such as Aspergillus niger, Candida sp., Fusarium sp., and Rigidoporous sp. Strain MBC1 was able to produce antioxidant compounds. The lipolytic and amylolytic activity can be developed for bioremediate agriculture waste and biosurfactant production.

Hydrolase enzymes are a class of enzymes used to break down the organic substrates into simpler molecules. Hydrolase enzymes play a role in biocontrol, industry, and public health. One of the hydrolase enzyme producers is bacteria. Serratia marcescens strain MBC1 is a collection in the Microbiology Laboratory of the Department of Biology, Faculty of Mathematics and Natural Sciences, University of Lampung which enzymatic activities haven’t been known yet. This research aimed to determine the enzymatic activity of S. marcesescens strain MBC1 that can be used as a candidate for biocontrol agents, biosurfactant producers, industry, or in the health sector. The screening was carried out using a qualitative method plate assay using selective solid media for each test, with three replications for each test. The data obtained were analyzed statistically using analysis non-parametric kruskall-wallis test. The lipolytic activity of the S. marcescens strain MBC1 showed high efficacy with an enzymatic index of 5.52 and amylase, cellulases, protease, mannanase, and chitinase with enzymatic indexes, respectively, 4.17, 1.50, 0.69, 0.35, and 0.27. This enzyme activity of this isolate can be used as a candidate for biological control agents,biosurfactant producers, industry, or the health sector.

Campuran minyak dan bahan kimia pada surfaktan yang dibuang langsung ke lingkungan akan mengakibatkan penurunan kesuburan tanah sertamenghambat proses degradasi oleh mikroorganisme. Oleh karena itu dibutuhkan senyawa alami yang mampu mampu meningkatkan kelarutan minyak jelantah dalam air seperti biosurfaktan. Salah satu bakteri penghasil biosurfaktan yaitu Serratia marcescens. Penelitian ini bertujuan untuk mengetahui aktivitas biosurfaktan bakteri dari Serratia marcescens strain MBC 1 yang ditumbuhkan di media fermentasi tryptone water, limbah cair jagung dan limbah cair singkong dengan pH 6,7 dan 8. Uji yang dilakukan diantaranya uji emulsifikasi, oil displacement dan drop collapse. Hasil penelitian menunjukan biosurfaktan Serratia marcescens strain MBC 1 mampu meningkatkan kelarutan minyak jelantah dalam air. Hasil produksi pada media limbah jagung dengan pH 7 menunjukan aktivitas emulsifikasi paling optimum yaitu sebesar 49,26%.

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