Hasrul Satria Nur

Program Studi Biologi, FMIPA, Universitas Lambung Mangkurat, Banjarbaru 70714, Indonesia

Email : satrianch@yahoo.com

Abstrak

Mandai adalah makanan fermentasi yang dibuat secara tradisional dari kulit buah cempedak (Arthocarphus champeden Spreg.). Pada umumnya mandai dibuat dengan konsentrasi garam tinggi. Tujuan penelitian adalah mempelajari suksesi mikroba dan aspek biokimiawi selama fermentasi dengan kadar garam rendah. Jumlah sel mikroba dan aspek biokimia selama fermentasi diamati pada hari ke-3, 5, 7, dan 14. Total sel bakteri dan khamir diukur dengan metode cawan tuang. Pengukuran juga dilakukan terhadap substrat sebelum inkubasi. Pengamatan terhadap aspek biokimia meliputi kadar gula pereduksi, N-total, garam, dan pH. Hasil penelitian menunjukkan pola suksesi mikroba selama fermentasi. Pertumbuhan sel khamir dominan di hari ke-5 (2,8 x 10⁹ CFU/g), tetapi sel bakteri dominan di hari ke-14 (1,1 x 10⁷ CFU/g). Penurunan kadar gula reduksi dan N-total terjadi di hari ke-14 (0,240%) dan hari ke-5 (0,159%). Kadar garam substrat relatif stabil dan nilai pH bervariasi pada kisaran 3,71-6,12 selama fermentasi.

Abstract

Microbial succession and biochemical aspects of mandai fermentation at low salt concentration. Mandai is fermented food that traditionally made from the flesh of jack fruit (Arthocarphus champeden Spreg.). Usually mandai is made as high salt concentration. However, the objective of this research is to study the succession and biochemical aspects of microbials during fermentation at low salt concentration (10% w/v) for 14 days. During the period of fermentation microbial cell numbers and biochemical aspects were observed at the 3^rd, 5^th, 7^th and 14^th day. Total cell number of bacteria and yeast were measured by pour plate method. The measurement was also conducted on flesh before incubation. The biochemical aspect observation included the contents of reducing sugar, N-total, salt, and pH. The research results indicated that the pattern of microbial succession occurred the fermentation. Yeast cells grew dominantly (2.8 x 10⁹ CFU/g) on the 5^th day fermentation but bacteria were dominant at the end (1.1 x 10⁷ CFU/g). The highest decrease of reducing sugar and N-total contents were 0.240% at the 14^th day and 0.159% at the 5^th day, respectively. However, salt concentration was relatively stable and pH was varied within the range of 3.71-6.12 for the whole period fermentation.

Keywords: Fermentation, low salt, mandai, succession

]]> http://nursatrianch.wordpress.com/2008/12/18/9/feed/ 1 nursatrianch http://nursatrianch.wordpress.com/2008/12/18/6/ http://nursatrianch.wordpress.com/2008/12/18/6/#comments Thu, 18 Dec 2008 15:38:26 +0000 nursatrianch http://nursatrianch.wordpress.com/?p=6 ]]> Pemanfaatan Bakteri Selulolitik Dan Xilanolitik Yang Potensial Untuk Dekomposisi Jerami Padi

Hasrul Satria Nur ¹, Anja Meryandini ^2,3, Hamim ³

ABSTRACT

Utilization of Potential Cellulolytic and Xilanolytic Bacteria for Decomposition of Rice Straw (Hasrul Satria Nur, Anja Meryandini, and Hamim). There were 3 prospective isolates of cellulolytic bacteria resulted from the total of 31 isolates we found, i.e. C4-4, C5-1, and C11-1. Four combinations of bacteria including C4-4 + Xilanolytic (A), C5-1 + Xilanolytic (B), C11-1 + Xilanolytic (C), 45I-3 + 234P-16 (D), and control (E, without bacteria) were applied as inoculant of rice straw decomposition. In the incubation period the pH-H₂O value of C4-4 + Xilanolytic (A) and C5-1 + Xilanolytic (B) was relatively stable. The C/N ratio of all treatments decreased after 3 weeks of incubation. The C/N ratio value of A, B, C, D and E treatments were 22.48, 23.43, 27.49, 26.82, and 29.53 respectively. Decomposition rate all of combination treatments were faster than the control. The content of macro-micro nutrient of A, B, C, and D treatments increased in the end of measurement, while the control didn’t. The physical characteristic of substrate after incubation was better in A and B treatments that others. The result indicated that the combination of C4-4 + Xilanolytic (A) and C5-1 + Xilanolytic (B) bacteria were the best combination for decomposition of rice straw.

Key words: Cellulolytic, Decomposition, Rice straw, Xilanolytic¹

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