Abstract. Advisors : Dr. Dea Indriani Astuti. Degree : Science Bachelor (S.Si), Conferred July 2010

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2 Analysis of Nitrifying Bacteria Stability in Postlarva Freshwater Prawn Culture (Macrobrachium rosenbergii de Mann) in Laboratory Scale With and Without Addition of Substrate Student : Eleanor Louana Urfa Final Project (2010), Degree program In Microbiology, School of Life Sciences and Technology-ITB, eleanor.louana@gmail.com Advisors : Dr. Dea Indriani Astuti School of Life Sciences and Technology ITB, dea@sith.itb.ac.id Degree : Science Bachelor (S.Si), Conferred July 2010 Abstract The freshwater prawn (Macrobrachium rosenbergii de Mann) is one of the freshwater aquaculture commodities which had the potential to fulfill the food demand because of its high economic value. One of the factors which affect the success in its culture is the stability of water quality which include ph, temperature, dissolved oxygen (DO) and the chemical compound composition such as ammonium, nitrite, nitrate. Accumulation of chemical compound which comes from the freshwater prawn excretion and the food left-over had the potency of causing death and increasing stress for the freshwater prawn. One way to encounter this problem is the utilization of nitrification bacteria to stabilize the water quality during the culture process. This research has the purpose in knowing the effect of utilization of nitrification bacteria with CaCO3 as a substrate to water quality on post larval stadium of freshwater prawn, and to measure the stability of nitrification bacteria abundance during the process of culturization of fresh water prawn. Experiment is conducted on laboratory scale in 45 days period, in a 5 L aquarium designed with aeration system. Each aquarium filled with 5 freshwater prawn with length (3.214±0.102) cm and the starting weight (0.219±0.030) gr. Research conducted in four variation, (1) Control aquarium, (2) Aquarium with utilization of nitrification bacteria (3) Control with CaCO 3 substrate, (4) Aquarium with both nitrification bacteria culture suspension and CaCO 3 substrate. The utilization of nitrification bacteria conducted 24 hour before freshwater prawn culture introduced into the aquarium with inoculums density is 10 5 cfu/ml in 10% from total volume of water. Research is

3 conducted with 3 replication for each treatment. In the research, the measurement is conducted on: water physical quality such as DO, temperature, and ph daily; chemical factor such as ammonium, nitrite, and nitrate composition; number of bacterial population with TPC with 3 day interval. According to result of the research, the water physical factor shows a stability but the chemical factor shows a varied number. In first treatment (1) The ammonium content is in the range of ppm, nitrite at ppm, and nitrate at ppm. In second treatment (2) ammonium content is in the range of ppm, nitrite at ppm, and nitrate at ppm. In third treatment (3) ammonium content is in the range of ppm, nitrite at ppm, and nitrate at ppm. In fourth treatment (4) ammonium content is in the range of ppm, nitrite at ppm, and nitrate at ppm. The result of TPC count shows that the treatment in utilization of solid CaCO 3 substrate could keep the stability of bacterial number. According to those result, could be concluded, the utilization of both nitrifying bacteria and solid CaCO 3 as substrate could maintain the stability of water quality and during 21 day of culture the number of nitrifying bacteria is still maintained. Keywords : Nitrifying Bacteria, Postlarvae, Macrobrachium rosenbergii de Mann, Laboratorium Scale, Substrate

4 Analisis Stabilitas Nitrifying Bacteria pada Kultur Postlarva Udang Galah (Macrobrachium rosenbergii de Mann) Skala Laboratorium Dengan dan Tanpa Penambahan Substrat Mahasiswa : Eleanor Louana Urfa Skripsi (2010), Program Studi Sarjana Mikrobiologi SITH, eleanor.louana@gmail.com Pembimbing : Dr. Dea Indriani Astuti SITH-ITB, dea@sith.itb.ac.id Gelar : Sarjana Sains (S.Si), Wisuda Juli 2010 Abstrak Udang galah (Macrobrachium rosenbergii de Mann) merupakan salah satu komoditas akuakultur air tawar yang berpotensi untuk memenuhi kebutuhan pangan karena memiliki nilai ekonomis yang cukup tinggi. Salah satu faktor yang mempengaruhi keberhasilan budidaya udang galah adalah kestabilan kualitas air yang meliputi ph, suhu, disolved oxygen (DO) dan kandungan senyawa kimia seperti amonium, nitrit dan nitrat. Akumulasi senyawa kimia yang berasal dari ekskresi udang galah dan sisa pakan berpotensi menyebabkan kematian dan penurunan nafsu makan udang. Salah satu upaya penanggulangan yang dapat dilakukan adalah penambahan bakteri nitrifikasi untuk menstabilkan kualitas air selama proses kultur. Penelitian ini bertujuan untuk mengetahui pengaruh pemberian bakteri nitrifikasi dengan substrat padatan CaCO 3 terhadap kualitas air pada kultur udang galah stadium postlarva (PL40) dan untuk mengetahui stabilitas kelimpahan bakteri nitrifikasi selama proses budidaya udang galah. Eksperimen dilakukan pada skala laboratorium selama 45 hari, pada akuarium 5 L yang dilengkapi dengan sistem aerasi. Setiap akuarium kultur, dirisi 5 ekor udang galah dengan panjang awal (3,214±0,102) cm dan berat awal (0,219±0,030) gr. Penelitian dilakukan dalam empat variasi perlakuan, yaitu (1) kontrol, (2) penambahan suspensi kultur bakteri nitrifikasi, (3) kontrol dengan penambahan padatan CaCO 3, serta (4) penambahan suspensi bakteri nitrifikasi dan padatan CaCO 3. Penambahan suspensi kultur bakteri nitrifikasi dilakukan 24 jam sebelum kultur udang dimasukkan dengan kepadatan inokulum 10 5 cfu/ml sebanyak 10% dari volume total air kultur. Keseluruhan variasi perlakuan dilakukan sebanyak tiga replikat. Dalam proses penelitian, dilakukan pengukuran faktor fisika air seperti DO, suhu dan ph setiap hari;

5 serta faktor kimia yaitu kandungan amonium, nitrit dan nitrat; dan penghitungan jumlah bakteri yang dilakukan dengan metode TPC dengan interval pengukuran per 3 hari. Berdasarkan hasil penelitian, faktor fisika air menunjukkan nilai yang stabil sedangkan faktor kimia memperlihatkan nilai yang bervariasi. Pada perlakuan (1) kandungan amonium berada pada kisaran 0,052 0,123 ppm, nitrit 0,0239 0,0735 ppm, dan nitrat 17, ,417 ppm. Pada perlakuan (2) kandungan amonium menunjukkan nilai 0,040-0,079 ppm, nitrit 0,010-0,067 ppm dan nitrat 23, ,701 ppm. Pada perlakuan (3) kandungan amonium berada pada kisaran 0,048-0,099 ppm, nitrit 0,021-0,077 ppm dan nitrat 4, ,091 ppm. Pada perlakuan (4) kandungan amonium menunjukkan nilai 0,043-0,074 ppm, nitrit 0,013-0,060 ppm dan nitrat 279, ,455 ppm. Hasil penghitungan TPC memperlihatkan bahwa perlakuan dengan penambahan substrat padatan CaCO 3 dapat menjaga kestabilan jumlah bakteri. Berdasarkan hasil tersebut, dapat disimpulkan bahwa penambahan bakteri nitrifikasi dan penggunaan substrat padatan CaCO 3 dapat menjaga kualitas air dan stabilitas jumlah bakteri pada kultur udang galah. Kata kunci: Nitrifying Bacteria, Postlarva, Macrobrachium rosenbergii de Mann, Skala Laboratorium, Substrat