Improvement of the nutritional value and growth of rotifer (Brachionus plicatilis) by different enrichment period with Bacillus sp.

Abstract

Brachionus plicatilis is a widely used as natural feed in hatchery. Characteristics of rotifers as biocapsule can improve the quality of rotifers in a practical way. Bacillus sp. is capable of improving the nutrition rotifers to produce vitamins, food detoxication or through enzymatic activity such as protease, lipase, and amylase. This research aimed at observing the influence of the enrichment length of Bacillus sp. on the quality of nutrition and growth of rotifers. The research container was a polyearbonate vessel of one ton volume which contained Nannochloropsis sp. with the density of 10⁵ cell/mL, it was then scattered with rotifer with the density of 1,000 ind./mL. The types of bacteria used were Bacillus subtilis, B. pumilus and B. licheformis with the density of 2x10¹⁰ cfu/g. The experiments tried with different enrichment length were A = 0 hour, B = 5 hours, C = 10 hours and D = 10 hours with triplicate. As the comparing data, rotifer culture experiment was carried out with Nannochlorophsis sp.as the control. The number of containers were 24 which consists of 12 for threatment and 12 pieces as control. Variables measured were proximate to each treatment and the growth of rotifers. The result of the research revealed the enrichment length of rotifers with Bacillus sp. has significantly (P<0,05) towards increased protein, crude fiber, ash, BETN, and growth. Optimum enrichment time was obtained at 5 hours.

Key words: rotifers, Bacillus, enrichment period, proximate

ABSTRAK

Brachionus plicatilis merupakan pakan alami yang banyak digunakan dalam pembenihan. Karakteristik rotifer sebagai biokapsul secara praktis dapat meningkatkan kualitas rotifer. Bacillus sp. mampu memperbaiki nutrisi rotifer dengan memproduksi vitamin, detoksikasi pangan maupun melalui aktivitas enzimatis seperti protease, lipase, dan amilase. Penelitian ini bertujuan untuk melihat pengaruh pengkayaan Bacillus sp. terhadap kualitas nutrisi dan pertumbuhan rotifer. Wadah penelitian menggunakan bak fiber volume 1 ton yang berisikan Nannochloropsis sp. dengan kepadatan 10⁵ cell/mL, kemudian ditebari rotifer dengan kepadatan 1.000 ind./mL. Jenis bakteri yang digunakan berupa Bacillus subtilis, B. Pumilus dan B. Licheformis dengan kepadatan 2x10¹⁰ cfu/g. Perlakuan yang diujikan adalah lama pengkayaan probiotik Bacillus sp. yang berbeda, yaitu perlakuan A (0 jam),  perlakuan B (5 Jam), perlakuan C (10 jam) dan perlakuan D (15 jam). Sebagai data pembanding dilakukan percobaan kultur rotifer dengan Nannochloropsis sp. sebagai kontrol. Jumlah wadah penelitian yang dipergunakan sebanyak 24 buah yang terdiri atas 12 buah untuk perlakuan dan 12 buah sebagai kontrol. Peubah yang diukur adalah proksimat pada masing-masing perlakuan dan pertumbuhan rotifer.  Hasil penelitian menunjukkan bahwa perlakuan lama pengkayaan rotifer dengan Bacillus sp. meningkatkan (P<0,05) terhadap kadar protein, serat kasar, abu, BETN, dan pertumbuhan rotifer. Lama pengkayaan optimum diperoleh pada 5 jam.

Kata kunci: rotifer, Bacillus, lama pengkayaan, proksimat